diff options
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 5993 |
1 files changed, 5993 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c new file mode 100644 index 000000000..6c492fca6 --- /dev/null +++ b/fs/ext4/extents.c @@ -0,0 +1,5993 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com + * Written by Alex Tomas <alex@clusterfs.com> + * + * Architecture independence: + * Copyright (c) 2005, Bull S.A. + * Written by Pierre Peiffer <pierre.peiffer@bull.net> + */ + +/* + * Extents support for EXT4 + * + * TODO: + * - ext4*_error() should be used in some situations + * - analyze all BUG()/BUG_ON(), use -EIO where appropriate + * - smart tree reduction + */ + +#include <linux/fs.h> +#include <linux/time.h> +#include <linux/jbd2.h> +#include <linux/highuid.h> +#include <linux/pagemap.h> +#include <linux/quotaops.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/fiemap.h> +#include <linux/backing-dev.h> +#include "ext4_jbd2.h" +#include "ext4_extents.h" +#include "xattr.h" + +#include <trace/events/ext4.h> + +/* + * used by extent splitting. + */ +#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ + due to ENOSPC */ +#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */ +#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */ + +#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */ +#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */ + +static __le32 ext4_extent_block_csum(struct inode *inode, + struct ext4_extent_header *eh) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + __u32 csum; + + csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh, + EXT4_EXTENT_TAIL_OFFSET(eh)); + return cpu_to_le32(csum); +} + +static int ext4_extent_block_csum_verify(struct inode *inode, + struct ext4_extent_header *eh) +{ + struct ext4_extent_tail *et; + + if (!ext4_has_metadata_csum(inode->i_sb)) + return 1; + + et = find_ext4_extent_tail(eh); + if (et->et_checksum != ext4_extent_block_csum(inode, eh)) + return 0; + return 1; +} + +static void ext4_extent_block_csum_set(struct inode *inode, + struct ext4_extent_header *eh) +{ + struct ext4_extent_tail *et; + + if (!ext4_has_metadata_csum(inode->i_sb)) + return; + + et = find_ext4_extent_tail(eh); + et->et_checksum = ext4_extent_block_csum(inode, eh); +} + +static int ext4_split_extent(handle_t *handle, + struct inode *inode, + struct ext4_ext_path **ppath, + struct ext4_map_blocks *map, + int split_flag, + int flags); + +static int ext4_split_extent_at(handle_t *handle, + struct inode *inode, + struct ext4_ext_path **ppath, + ext4_lblk_t split, + int split_flag, + int flags); + +static int ext4_find_delayed_extent(struct inode *inode, + struct extent_status *newes); + +static int ext4_ext_truncate_extend_restart(handle_t *handle, + struct inode *inode, + int needed) +{ + int err; + + if (!ext4_handle_valid(handle)) + return 0; + if (handle->h_buffer_credits >= needed) + return 0; + /* + * If we need to extend the journal get a few extra blocks + * while we're at it for efficiency's sake. + */ + needed += 3; + err = ext4_journal_extend(handle, needed - handle->h_buffer_credits); + if (err <= 0) + return err; + err = ext4_truncate_restart_trans(handle, inode, needed); + if (err == 0) + err = -EAGAIN; + + return err; +} + +/* + * could return: + * - EROFS + * - ENOMEM + */ +static int ext4_ext_get_access(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + if (path->p_bh) { + /* path points to block */ + BUFFER_TRACE(path->p_bh, "get_write_access"); + return ext4_journal_get_write_access(handle, path->p_bh); + } + /* path points to leaf/index in inode body */ + /* we use in-core data, no need to protect them */ + return 0; +} + +/* + * could return: + * - EROFS + * - ENOMEM + * - EIO + */ +int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, + struct inode *inode, struct ext4_ext_path *path) +{ + int err; + + WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); + if (path->p_bh) { + ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); + /* path points to block */ + err = __ext4_handle_dirty_metadata(where, line, handle, + inode, path->p_bh); + } else { + /* path points to leaf/index in inode body */ + err = ext4_mark_inode_dirty(handle, inode); + } + return err; +} + +static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t block) +{ + if (path) { + int depth = path->p_depth; + struct ext4_extent *ex; + + /* + * Try to predict block placement assuming that we are + * filling in a file which will eventually be + * non-sparse --- i.e., in the case of libbfd writing + * an ELF object sections out-of-order but in a way + * the eventually results in a contiguous object or + * executable file, or some database extending a table + * space file. However, this is actually somewhat + * non-ideal if we are writing a sparse file such as + * qemu or KVM writing a raw image file that is going + * to stay fairly sparse, since it will end up + * fragmenting the file system's free space. Maybe we + * should have some hueristics or some way to allow + * userspace to pass a hint to file system, + * especially if the latter case turns out to be + * common. + */ + ex = path[depth].p_ext; + if (ex) { + ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); + ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); + + if (block > ext_block) + return ext_pblk + (block - ext_block); + else + return ext_pblk - (ext_block - block); + } + + /* it looks like index is empty; + * try to find starting block from index itself */ + if (path[depth].p_bh) + return path[depth].p_bh->b_blocknr; + } + + /* OK. use inode's group */ + return ext4_inode_to_goal_block(inode); +} + +/* + * Allocation for a meta data block + */ +static ext4_fsblk_t +ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex, int *err, unsigned int flags) +{ + ext4_fsblk_t goal, newblock; + + goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); + newblock = ext4_new_meta_blocks(handle, inode, goal, flags, + NULL, err); + return newblock; +} + +static inline int ext4_ext_space_block(struct inode *inode, int check) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent); +#ifdef AGGRESSIVE_TEST + if (!check && size > 6) + size = 6; +#endif + return size; +} + +static inline int ext4_ext_space_block_idx(struct inode *inode, int check) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent_idx); +#ifdef AGGRESSIVE_TEST + if (!check && size > 5) + size = 5; +#endif + return size; +} + +static inline int ext4_ext_space_root(struct inode *inode, int check) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent); +#ifdef AGGRESSIVE_TEST + if (!check && size > 3) + size = 3; +#endif + return size; +} + +static inline int ext4_ext_space_root_idx(struct inode *inode, int check) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent_idx); +#ifdef AGGRESSIVE_TEST + if (!check && size > 4) + size = 4; +#endif + return size; +} + +static inline int +ext4_force_split_extent_at(handle_t *handle, struct inode *inode, + struct ext4_ext_path **ppath, ext4_lblk_t lblk, + int nofail) +{ + struct ext4_ext_path *path = *ppath; + int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext); + + return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ? + EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0, + EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO | + (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0)); +} + +/* + * Calculate the number of metadata blocks needed + * to allocate @blocks + * Worse case is one block per extent + */ +int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + int idxs; + + idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent_idx)); + + /* + * If the new delayed allocation block is contiguous with the + * previous da block, it can share index blocks with the + * previous block, so we only need to allocate a new index + * block every idxs leaf blocks. At ldxs**2 blocks, we need + * an additional index block, and at ldxs**3 blocks, yet + * another index blocks. + */ + if (ei->i_da_metadata_calc_len && + ei->i_da_metadata_calc_last_lblock+1 == lblock) { + int num = 0; + + if ((ei->i_da_metadata_calc_len % idxs) == 0) + num++; + if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) + num++; + if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { + num++; + ei->i_da_metadata_calc_len = 0; + } else + ei->i_da_metadata_calc_len++; + ei->i_da_metadata_calc_last_lblock++; + return num; + } + + /* + * In the worst case we need a new set of index blocks at + * every level of the inode's extent tree. + */ + ei->i_da_metadata_calc_len = 1; + ei->i_da_metadata_calc_last_lblock = lblock; + return ext_depth(inode) + 1; +} + +static int +ext4_ext_max_entries(struct inode *inode, int depth) +{ + int max; + + if (depth == ext_depth(inode)) { + if (depth == 0) + max = ext4_ext_space_root(inode, 1); + else + max = ext4_ext_space_root_idx(inode, 1); + } else { + if (depth == 0) + max = ext4_ext_space_block(inode, 1); + else + max = ext4_ext_space_block_idx(inode, 1); + } + + return max; +} + +static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) +{ + ext4_fsblk_t block = ext4_ext_pblock(ext); + int len = ext4_ext_get_actual_len(ext); + ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); + + /* + * We allow neither: + * - zero length + * - overflow/wrap-around + */ + if (lblock + len <= lblock) + return 0; + return ext4_inode_block_valid(inode, block, len); +} + +static int ext4_valid_extent_idx(struct inode *inode, + struct ext4_extent_idx *ext_idx) +{ + ext4_fsblk_t block = ext4_idx_pblock(ext_idx); + + return ext4_inode_block_valid(inode, block, 1); +} + +static int ext4_valid_extent_entries(struct inode *inode, + struct ext4_extent_header *eh, + ext4_fsblk_t *pblk, int depth) +{ + unsigned short entries; + ext4_lblk_t lblock = 0; + ext4_lblk_t prev = 0; + + if (eh->eh_entries == 0) + return 1; + + entries = le16_to_cpu(eh->eh_entries); + + if (depth == 0) { + /* leaf entries */ + struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); + struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; + ext4_fsblk_t pblock = 0; + while (entries) { + if (!ext4_valid_extent(inode, ext)) + return 0; + + /* Check for overlapping extents */ + lblock = le32_to_cpu(ext->ee_block); + if ((lblock <= prev) && prev) { + pblock = ext4_ext_pblock(ext); + es->s_last_error_block = cpu_to_le64(pblock); + return 0; + } + prev = lblock + ext4_ext_get_actual_len(ext) - 1; + ext++; + entries--; + } + } else { + struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); + while (entries) { + if (!ext4_valid_extent_idx(inode, ext_idx)) + return 0; + + /* Check for overlapping index extents */ + lblock = le32_to_cpu(ext_idx->ei_block); + if ((lblock <= prev) && prev) { + *pblk = ext4_idx_pblock(ext_idx); + return 0; + } + ext_idx++; + entries--; + prev = lblock; + } + } + return 1; +} + +static int __ext4_ext_check(const char *function, unsigned int line, + struct inode *inode, struct ext4_extent_header *eh, + int depth, ext4_fsblk_t pblk) +{ + const char *error_msg; + int max = 0, err = -EFSCORRUPTED; + + if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { + error_msg = "invalid magic"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { + error_msg = "unexpected eh_depth"; + goto corrupted; + } + if (unlikely(eh->eh_max == 0)) { + error_msg = "invalid eh_max"; + goto corrupted; + } + max = ext4_ext_max_entries(inode, depth); + if (unlikely(le16_to_cpu(eh->eh_max) > max)) { + error_msg = "too large eh_max"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { + error_msg = "invalid eh_entries"; + goto corrupted; + } + if (!ext4_valid_extent_entries(inode, eh, &pblk, depth)) { + error_msg = "invalid extent entries"; + goto corrupted; + } + if (unlikely(depth > 32)) { + error_msg = "too large eh_depth"; + goto corrupted; + } + /* Verify checksum on non-root extent tree nodes */ + if (ext_depth(inode) != depth && + !ext4_extent_block_csum_verify(inode, eh)) { + error_msg = "extent tree corrupted"; + err = -EFSBADCRC; + goto corrupted; + } + return 0; + +corrupted: + ext4_error_inode(inode, function, line, 0, + "pblk %llu bad header/extent: %s - magic %x, " + "entries %u, max %u(%u), depth %u(%u)", + (unsigned long long) pblk, error_msg, + le16_to_cpu(eh->eh_magic), + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), + max, le16_to_cpu(eh->eh_depth), depth); + return err; +} + +#define ext4_ext_check(inode, eh, depth, pblk) \ + __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk)) + +int ext4_ext_check_inode(struct inode *inode) +{ + return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0); +} + +static void ext4_cache_extents(struct inode *inode, + struct ext4_extent_header *eh) +{ + struct ext4_extent *ex = EXT_FIRST_EXTENT(eh); + ext4_lblk_t prev = 0; + int i; + + for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) { + unsigned int status = EXTENT_STATUS_WRITTEN; + ext4_lblk_t lblk = le32_to_cpu(ex->ee_block); + int len = ext4_ext_get_actual_len(ex); + + if (prev && (prev != lblk)) + ext4_es_cache_extent(inode, prev, lblk - prev, ~0, + EXTENT_STATUS_HOLE); + + if (ext4_ext_is_unwritten(ex)) + status = EXTENT_STATUS_UNWRITTEN; + ext4_es_cache_extent(inode, lblk, len, + ext4_ext_pblock(ex), status); + prev = lblk + len; + } +} + +static struct buffer_head * +__read_extent_tree_block(const char *function, unsigned int line, + struct inode *inode, ext4_fsblk_t pblk, int depth, + int flags) +{ + struct buffer_head *bh; + int err; + + bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS); + if (unlikely(!bh)) + return ERR_PTR(-ENOMEM); + + if (!bh_uptodate_or_lock(bh)) { + trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); + err = bh_submit_read(bh); + if (err < 0) + goto errout; + } + if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) + return bh; + err = __ext4_ext_check(function, line, inode, + ext_block_hdr(bh), depth, pblk); + if (err) + goto errout; + set_buffer_verified(bh); + /* + * If this is a leaf block, cache all of its entries + */ + if (!(flags & EXT4_EX_NOCACHE) && depth == 0) { + struct ext4_extent_header *eh = ext_block_hdr(bh); + ext4_cache_extents(inode, eh); + } + return bh; +errout: + put_bh(bh); + return ERR_PTR(err); + +} + +#define read_extent_tree_block(inode, pblk, depth, flags) \ + __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \ + (depth), (flags)) + +/* + * This function is called to cache a file's extent information in the + * extent status tree + */ +int ext4_ext_precache(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_ext_path *path = NULL; + struct buffer_head *bh; + int i = 0, depth, ret = 0; + + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + return 0; /* not an extent-mapped inode */ + + down_read(&ei->i_data_sem); + depth = ext_depth(inode); + + path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), + GFP_NOFS); + if (path == NULL) { + up_read(&ei->i_data_sem); + return -ENOMEM; + } + + /* Don't cache anything if there are no external extent blocks */ + if (depth == 0) + goto out; + path[0].p_hdr = ext_inode_hdr(inode); + ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0); + if (ret) + goto out; + path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr); + while (i >= 0) { + /* + * If this is a leaf block or we've reached the end of + * the index block, go up + */ + if ((i == depth) || + path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) { + brelse(path[i].p_bh); + path[i].p_bh = NULL; + i--; + continue; + } + bh = read_extent_tree_block(inode, + ext4_idx_pblock(path[i].p_idx++), + depth - i - 1, + EXT4_EX_FORCE_CACHE); + if (IS_ERR(bh)) { + ret = PTR_ERR(bh); + break; + } + i++; + path[i].p_bh = bh; + path[i].p_hdr = ext_block_hdr(bh); + path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr); + } + ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED); +out: + up_read(&ei->i_data_sem); + ext4_ext_drop_refs(path); + kfree(path); + return ret; +} + +#ifdef EXT_DEBUG +static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) +{ + int k, l = path->p_depth; + + ext_debug("path:"); + for (k = 0; k <= l; k++, path++) { + if (path->p_idx) { + ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), + ext4_idx_pblock(path->p_idx)); + } else if (path->p_ext) { + ext_debug(" %d:[%d]%d:%llu ", + le32_to_cpu(path->p_ext->ee_block), + ext4_ext_is_unwritten(path->p_ext), + ext4_ext_get_actual_len(path->p_ext), + ext4_ext_pblock(path->p_ext)); + } else + ext_debug(" []"); + } + ext_debug("\n"); +} + +static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) +{ + int depth = ext_depth(inode); + struct ext4_extent_header *eh; + struct ext4_extent *ex; + int i; + + if (!path) + return; + + eh = path[depth].p_hdr; + ex = EXT_FIRST_EXTENT(eh); + + ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); + + for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { + ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), + ext4_ext_is_unwritten(ex), + ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); + } + ext_debug("\n"); +} + +static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, + ext4_fsblk_t newblock, int level) +{ + int depth = ext_depth(inode); + struct ext4_extent *ex; + + if (depth != level) { + struct ext4_extent_idx *idx; + idx = path[level].p_idx; + while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { + ext_debug("%d: move %d:%llu in new index %llu\n", level, + le32_to_cpu(idx->ei_block), + ext4_idx_pblock(idx), + newblock); + idx++; + } + + return; + } + + ex = path[depth].p_ext; + while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { + ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", + le32_to_cpu(ex->ee_block), + ext4_ext_pblock(ex), + ext4_ext_is_unwritten(ex), + ext4_ext_get_actual_len(ex), + newblock); + ex++; + } +} + +#else +#define ext4_ext_show_path(inode, path) +#define ext4_ext_show_leaf(inode, path) +#define ext4_ext_show_move(inode, path, newblock, level) +#endif + +void ext4_ext_drop_refs(struct ext4_ext_path *path) +{ + int depth, i; + + if (!path) + return; + depth = path->p_depth; + for (i = 0; i <= depth; i++, path++) + if (path->p_bh) { + brelse(path->p_bh); + path->p_bh = NULL; + } +} + +/* + * ext4_ext_binsearch_idx: + * binary search for the closest index of the given block + * the header must be checked before calling this + */ +static void +ext4_ext_binsearch_idx(struct inode *inode, + struct ext4_ext_path *path, ext4_lblk_t block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent_idx *r, *l, *m; + + + ext_debug("binsearch for %u(idx): ", block); + + l = EXT_FIRST_INDEX(eh) + 1; + r = EXT_LAST_INDEX(eh); + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ei_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), + m, le32_to_cpu(m->ei_block), + r, le32_to_cpu(r->ei_block)); + } + + path->p_idx = l - 1; + ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block), + ext4_idx_pblock(path->p_idx)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent_idx *chix, *ix; + int k; + + chix = ix = EXT_FIRST_INDEX(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { + if (k != 0 && + le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { + printk(KERN_DEBUG "k=%d, ix=0x%p, " + "first=0x%p\n", k, + ix, EXT_FIRST_INDEX(eh)); + printk(KERN_DEBUG "%u <= %u\n", + le32_to_cpu(ix->ei_block), + le32_to_cpu(ix[-1].ei_block)); + } + BUG_ON(k && le32_to_cpu(ix->ei_block) + <= le32_to_cpu(ix[-1].ei_block)); + if (block < le32_to_cpu(ix->ei_block)) + break; + chix = ix; + } + BUG_ON(chix != path->p_idx); + } +#endif + +} + +/* + * ext4_ext_binsearch: + * binary search for closest extent of the given block + * the header must be checked before calling this + */ +static void +ext4_ext_binsearch(struct inode *inode, + struct ext4_ext_path *path, ext4_lblk_t block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent *r, *l, *m; + + if (eh->eh_entries == 0) { + /* + * this leaf is empty: + * we get such a leaf in split/add case + */ + return; + } + + ext_debug("binsearch for %u: ", block); + + l = EXT_FIRST_EXTENT(eh) + 1; + r = EXT_LAST_EXTENT(eh); + + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ee_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), + m, le32_to_cpu(m->ee_block), + r, le32_to_cpu(r->ee_block)); + } + + path->p_ext = l - 1; + ext_debug(" -> %d:%llu:[%d]%d ", + le32_to_cpu(path->p_ext->ee_block), + ext4_ext_pblock(path->p_ext), + ext4_ext_is_unwritten(path->p_ext), + ext4_ext_get_actual_len(path->p_ext)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent *chex, *ex; + int k; + + chex = ex = EXT_FIRST_EXTENT(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { + BUG_ON(k && le32_to_cpu(ex->ee_block) + <= le32_to_cpu(ex[-1].ee_block)); + if (block < le32_to_cpu(ex->ee_block)) + break; + chex = ex; + } + BUG_ON(chex != path->p_ext); + } +#endif + +} + +int ext4_ext_tree_init(handle_t *handle, struct inode *inode) +{ + struct ext4_extent_header *eh; + + eh = ext_inode_hdr(inode); + eh->eh_depth = 0; + eh->eh_entries = 0; + eh->eh_magic = EXT4_EXT_MAGIC; + eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); + eh->eh_generation = 0; + ext4_mark_inode_dirty(handle, inode); + return 0; +} + +struct ext4_ext_path * +ext4_find_extent(struct inode *inode, ext4_lblk_t block, + struct ext4_ext_path **orig_path, int flags) +{ + struct ext4_extent_header *eh; + struct buffer_head *bh; + struct ext4_ext_path *path = orig_path ? *orig_path : NULL; + short int depth, i, ppos = 0; + int ret; + + eh = ext_inode_hdr(inode); + depth = ext_depth(inode); + if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { + EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", + depth); + ret = -EFSCORRUPTED; + goto err; + } + + if (path) { + ext4_ext_drop_refs(path); + if (depth > path[0].p_maxdepth) { + kfree(path); + *orig_path = path = NULL; + } + } + if (!path) { + /* account possible depth increase */ + path = kcalloc(depth + 2, sizeof(struct ext4_ext_path), + GFP_NOFS); + if (unlikely(!path)) + return ERR_PTR(-ENOMEM); + path[0].p_maxdepth = depth + 1; + } + path[0].p_hdr = eh; + path[0].p_bh = NULL; + + i = depth; + if (!(flags & EXT4_EX_NOCACHE) && depth == 0) + ext4_cache_extents(inode, eh); + /* walk through the tree */ + while (i) { + ext_debug("depth %d: num %d, max %d\n", + ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + + ext4_ext_binsearch_idx(inode, path + ppos, block); + path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); + path[ppos].p_depth = i; + path[ppos].p_ext = NULL; + + bh = read_extent_tree_block(inode, path[ppos].p_block, --i, + flags); + if (IS_ERR(bh)) { + ret = PTR_ERR(bh); + goto err; + } + + eh = ext_block_hdr(bh); + ppos++; + path[ppos].p_bh = bh; + path[ppos].p_hdr = eh; + } + + path[ppos].p_depth = i; + path[ppos].p_ext = NULL; + path[ppos].p_idx = NULL; + + /* find extent */ + ext4_ext_binsearch(inode, path + ppos, block); + /* if not an empty leaf */ + if (path[ppos].p_ext) + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); + + ext4_ext_show_path(inode, path); + + return path; + +err: + ext4_ext_drop_refs(path); + kfree(path); + if (orig_path) + *orig_path = NULL; + return ERR_PTR(ret); +} + +/* + * ext4_ext_insert_index: + * insert new index [@logical;@ptr] into the block at @curp; + * check where to insert: before @curp or after @curp + */ +static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, + struct ext4_ext_path *curp, + int logical, ext4_fsblk_t ptr) +{ + struct ext4_extent_idx *ix; + int len, err; + + err = ext4_ext_get_access(handle, inode, curp); + if (err) + return err; + + if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { + EXT4_ERROR_INODE(inode, + "logical %d == ei_block %d!", + logical, le32_to_cpu(curp->p_idx->ei_block)); + return -EFSCORRUPTED; + } + + if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) + >= le16_to_cpu(curp->p_hdr->eh_max))) { + EXT4_ERROR_INODE(inode, + "eh_entries %d >= eh_max %d!", + le16_to_cpu(curp->p_hdr->eh_entries), + le16_to_cpu(curp->p_hdr->eh_max)); + return -EFSCORRUPTED; + } + + if (logical > le32_to_cpu(curp->p_idx->ei_block)) { + /* insert after */ + ext_debug("insert new index %d after: %llu\n", logical, ptr); + ix = curp->p_idx + 1; + } else { + /* insert before */ + ext_debug("insert new index %d before: %llu\n", logical, ptr); + ix = curp->p_idx; + } + + len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; + BUG_ON(len < 0); + if (len > 0) { + ext_debug("insert new index %d: " + "move %d indices from 0x%p to 0x%p\n", + logical, len, ix, ix + 1); + memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); + } + + if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { + EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); + return -EFSCORRUPTED; + } + + ix->ei_block = cpu_to_le32(logical); + ext4_idx_store_pblock(ix, ptr); + le16_add_cpu(&curp->p_hdr->eh_entries, 1); + + if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { + EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); + return -EFSCORRUPTED; + } + + err = ext4_ext_dirty(handle, inode, curp); + ext4_std_error(inode->i_sb, err); + + return err; +} + +/* + * ext4_ext_split: + * inserts new subtree into the path, using free index entry + * at depth @at: + * - allocates all needed blocks (new leaf and all intermediate index blocks) + * - makes decision where to split + * - moves remaining extents and index entries (right to the split point) + * into the newly allocated blocks + * - initializes subtree + */ +static int ext4_ext_split(handle_t *handle, struct inode *inode, + unsigned int flags, + struct ext4_ext_path *path, + struct ext4_extent *newext, int at) +{ + struct buffer_head *bh = NULL; + int depth = ext_depth(inode); + struct ext4_extent_header *neh; + struct ext4_extent_idx *fidx; + int i = at, k, m, a; + ext4_fsblk_t newblock, oldblock; + __le32 border; + ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ + int err = 0; + size_t ext_size = 0; + + /* make decision: where to split? */ + /* FIXME: now decision is simplest: at current extent */ + + /* if current leaf will be split, then we should use + * border from split point */ + if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); + return -EFSCORRUPTED; + } + if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { + border = path[depth].p_ext[1].ee_block; + ext_debug("leaf will be split." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } else { + border = newext->ee_block; + ext_debug("leaf will be added." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } + + /* + * If error occurs, then we break processing + * and mark filesystem read-only. index won't + * be inserted and tree will be in consistent + * state. Next mount will repair buffers too. + */ + + /* + * Get array to track all allocated blocks. + * We need this to handle errors and free blocks + * upon them. + */ + ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), GFP_NOFS); + if (!ablocks) + return -ENOMEM; + + /* allocate all needed blocks */ + ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); + for (a = 0; a < depth - at; a++) { + newblock = ext4_ext_new_meta_block(handle, inode, path, + newext, &err, flags); + if (newblock == 0) + goto cleanup; + ablocks[a] = newblock; + } + + /* initialize new leaf */ + newblock = ablocks[--a]; + if (unlikely(newblock == 0)) { + EXT4_ERROR_INODE(inode, "newblock == 0!"); + err = -EFSCORRUPTED; + goto cleanup; + } + bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); + if (unlikely(!bh)) { + err = -ENOMEM; + goto cleanup; + } + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = 0; + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_depth = 0; + neh->eh_generation = 0; + + /* move remainder of path[depth] to the new leaf */ + if (unlikely(path[depth].p_hdr->eh_entries != + path[depth].p_hdr->eh_max)) { + EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", + path[depth].p_hdr->eh_entries, + path[depth].p_hdr->eh_max); + err = -EFSCORRUPTED; + goto cleanup; + } + /* start copy from next extent */ + m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; + ext4_ext_show_move(inode, path, newblock, depth); + if (m) { + struct ext4_extent *ex; + ex = EXT_FIRST_EXTENT(neh); + memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); + le16_add_cpu(&neh->eh_entries, m); + } + + /* zero out unused area in the extent block */ + ext_size = sizeof(struct ext4_extent_header) + + sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries); + memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); + ext4_extent_block_csum_set(inode, neh); + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old leaf */ + if (m) { + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto cleanup; + le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto cleanup; + + } + + /* create intermediate indexes */ + k = depth - at - 1; + if (unlikely(k < 0)) { + EXT4_ERROR_INODE(inode, "k %d < 0!", k); + err = -EFSCORRUPTED; + goto cleanup; + } + if (k) + ext_debug("create %d intermediate indices\n", k); + /* insert new index into current index block */ + /* current depth stored in i var */ + i = depth - 1; + while (k--) { + oldblock = newblock; + newblock = ablocks[--a]; + bh = sb_getblk(inode->i_sb, newblock); + if (unlikely(!bh)) { + err = -ENOMEM; + goto cleanup; + } + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = cpu_to_le16(1); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); + neh->eh_depth = cpu_to_le16(depth - i); + neh->eh_generation = 0; + fidx = EXT_FIRST_INDEX(neh); + fidx->ei_block = border; + ext4_idx_store_pblock(fidx, oldblock); + + ext_debug("int.index at %d (block %llu): %u -> %llu\n", + i, newblock, le32_to_cpu(border), oldblock); + + /* move remainder of path[i] to the new index block */ + if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != + EXT_LAST_INDEX(path[i].p_hdr))) { + EXT4_ERROR_INODE(inode, + "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", + le32_to_cpu(path[i].p_ext->ee_block)); + err = -EFSCORRUPTED; + goto cleanup; + } + /* start copy indexes */ + m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; + ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, + EXT_MAX_INDEX(path[i].p_hdr)); + ext4_ext_show_move(inode, path, newblock, i); + if (m) { + memmove(++fidx, path[i].p_idx, + sizeof(struct ext4_extent_idx) * m); + le16_add_cpu(&neh->eh_entries, m); + } + /* zero out unused area in the extent block */ + ext_size = sizeof(struct ext4_extent_header) + + (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries)); + memset(bh->b_data + ext_size, 0, + inode->i_sb->s_blocksize - ext_size); + ext4_extent_block_csum_set(inode, neh); + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old index */ + if (m) { + err = ext4_ext_get_access(handle, inode, path + i); + if (err) + goto cleanup; + le16_add_cpu(&path[i].p_hdr->eh_entries, -m); + err = ext4_ext_dirty(handle, inode, path + i); + if (err) + goto cleanup; + } + + i--; + } + + /* insert new index */ + err = ext4_ext_insert_index(handle, inode, path + at, + le32_to_cpu(border), newblock); + +cleanup: + if (bh) { + if (buffer_locked(bh)) + unlock_buffer(bh); + brelse(bh); + } + + if (err) { + /* free all allocated blocks in error case */ + for (i = 0; i < depth; i++) { + if (!ablocks[i]) + continue; + ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, + EXT4_FREE_BLOCKS_METADATA); + } + } + kfree(ablocks); + + return err; +} + +/* + * ext4_ext_grow_indepth: + * implements tree growing procedure: + * - allocates new block + * - moves top-level data (index block or leaf) into the new block + * - initializes new top-level, creating index that points to the + * just created block + */ +static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, + unsigned int flags) +{ + struct ext4_extent_header *neh; + struct buffer_head *bh; + ext4_fsblk_t newblock, goal = 0; + struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; + int err = 0; + size_t ext_size = 0; + + /* Try to prepend new index to old one */ + if (ext_depth(inode)) + goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode))); + if (goal > le32_to_cpu(es->s_first_data_block)) { + flags |= EXT4_MB_HINT_TRY_GOAL; + goal--; + } else + goal = ext4_inode_to_goal_block(inode); + newblock = ext4_new_meta_blocks(handle, inode, goal, flags, + NULL, &err); + if (newblock == 0) + return err; + + bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); + if (unlikely(!bh)) + return -ENOMEM; + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) { + unlock_buffer(bh); + goto out; + } + + ext_size = sizeof(EXT4_I(inode)->i_data); + /* move top-level index/leaf into new block */ + memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size); + /* zero out unused area in the extent block */ + memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); + + /* set size of new block */ + neh = ext_block_hdr(bh); + /* old root could have indexes or leaves + * so calculate e_max right way */ + if (ext_depth(inode)) + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); + else + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); + neh->eh_magic = EXT4_EXT_MAGIC; + ext4_extent_block_csum_set(inode, neh); + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto out; + + /* Update top-level index: num,max,pointer */ + neh = ext_inode_hdr(inode); + neh->eh_entries = cpu_to_le16(1); + ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); + if (neh->eh_depth == 0) { + /* Root extent block becomes index block */ + neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); + EXT_FIRST_INDEX(neh)->ei_block = + EXT_FIRST_EXTENT(neh)->ee_block; + } + ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", + le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), + le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), + ext4_idx_pblock(EXT_FIRST_INDEX(neh))); + + le16_add_cpu(&neh->eh_depth, 1); + ext4_mark_inode_dirty(handle, inode); +out: + brelse(bh); + + return err; +} + +/* + * ext4_ext_create_new_leaf: + * finds empty index and adds new leaf. + * if no free index is found, then it requests in-depth growing. + */ +static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, + unsigned int mb_flags, + unsigned int gb_flags, + struct ext4_ext_path **ppath, + struct ext4_extent *newext) +{ + struct ext4_ext_path *path = *ppath; + struct ext4_ext_path *curp; + int depth, i, err = 0; + +repeat: + i = depth = ext_depth(inode); + + /* walk up to the tree and look for free index entry */ + curp = path + depth; + while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { + i--; + curp--; + } + + /* we use already allocated block for index block, + * so subsequent data blocks should be contiguous */ + if (EXT_HAS_FREE_INDEX(curp)) { + /* if we found index with free entry, then use that + * entry: create all needed subtree and add new leaf */ + err = ext4_ext_split(handle, inode, mb_flags, path, newext, i); + if (err) + goto out; + + /* refill path */ + path = ext4_find_extent(inode, + (ext4_lblk_t)le32_to_cpu(newext->ee_block), + ppath, gb_flags); + if (IS_ERR(path)) + err = PTR_ERR(path); + } else { + /* tree is full, time to grow in depth */ + err = ext4_ext_grow_indepth(handle, inode, mb_flags); + if (err) + goto out; + + /* refill path */ + path = ext4_find_extent(inode, + (ext4_lblk_t)le32_to_cpu(newext->ee_block), + ppath, gb_flags); + if (IS_ERR(path)) { + err = PTR_ERR(path); + goto out; + } + + /* + * only first (depth 0 -> 1) produces free space; + * in all other cases we have to split the grown tree + */ + depth = ext_depth(inode); + if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { + /* now we need to split */ + goto repeat; + } + } + +out: + return err; +} + +/* + * search the closest allocated block to the left for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the smallest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +static int ext4_ext_search_left(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys) +{ + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + int depth, ee_len; + + if (unlikely(path == NULL)) { + EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); + return -EFSCORRUPTED; + } + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); + if (*logical < le32_to_cpu(ex->ee_block)) { + if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { + EXT4_ERROR_INODE(inode, + "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", + *logical, le32_to_cpu(ex->ee_block)); + return -EFSCORRUPTED; + } + while (--depth >= 0) { + ix = path[depth].p_idx; + if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, + "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", + ix != NULL ? le32_to_cpu(ix->ei_block) : 0, + EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? + le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0, + depth); + return -EFSCORRUPTED; + } + } + return 0; + } + + if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { + EXT4_ERROR_INODE(inode, + "logical %d < ee_block %d + ee_len %d!", + *logical, le32_to_cpu(ex->ee_block), ee_len); + return -EFSCORRUPTED; + } + + *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; + *phys = ext4_ext_pblock(ex) + ee_len - 1; + return 0; +} + +/* + * search the closest allocated block to the right for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the largest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +static int ext4_ext_search_right(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys, + struct ext4_extent **ret_ex) +{ + struct buffer_head *bh = NULL; + struct ext4_extent_header *eh; + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + ext4_fsblk_t block; + int depth; /* Note, NOT eh_depth; depth from top of tree */ + int ee_len; + + if (unlikely(path == NULL)) { + EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); + return -EFSCORRUPTED; + } + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); + if (*logical < le32_to_cpu(ex->ee_block)) { + if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { + EXT4_ERROR_INODE(inode, + "first_extent(path[%d].p_hdr) != ex", + depth); + return -EFSCORRUPTED; + } + while (--depth >= 0) { + ix = path[depth].p_idx; + if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, + "ix != EXT_FIRST_INDEX *logical %d!", + *logical); + return -EFSCORRUPTED; + } + } + goto found_extent; + } + + if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { + EXT4_ERROR_INODE(inode, + "logical %d < ee_block %d + ee_len %d!", + *logical, le32_to_cpu(ex->ee_block), ee_len); + return -EFSCORRUPTED; + } + + if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { + /* next allocated block in this leaf */ + ex++; + goto found_extent; + } + + /* go up and search for index to the right */ + while (--depth >= 0) { + ix = path[depth].p_idx; + if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) + goto got_index; + } + + /* we've gone up to the root and found no index to the right */ + return 0; + +got_index: + /* we've found index to the right, let's + * follow it and find the closest allocated + * block to the right */ + ix++; + block = ext4_idx_pblock(ix); + while (++depth < path->p_depth) { + /* subtract from p_depth to get proper eh_depth */ + bh = read_extent_tree_block(inode, block, + path->p_depth - depth, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + eh = ext_block_hdr(bh); + ix = EXT_FIRST_INDEX(eh); + block = ext4_idx_pblock(ix); + put_bh(bh); + } + + bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + eh = ext_block_hdr(bh); + ex = EXT_FIRST_EXTENT(eh); +found_extent: + *logical = le32_to_cpu(ex->ee_block); + *phys = ext4_ext_pblock(ex); + *ret_ex = ex; + if (bh) + put_bh(bh); + return 0; +} + +/* + * ext4_ext_next_allocated_block: + * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. + * NOTE: it considers block number from index entry as + * allocated block. Thus, index entries have to be consistent + * with leaves. + */ +ext4_lblk_t +ext4_ext_next_allocated_block(struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + if (depth == 0 && path->p_ext == NULL) + return EXT_MAX_BLOCKS; + + while (depth >= 0) { + if (depth == path->p_depth) { + /* leaf */ + if (path[depth].p_ext && + path[depth].p_ext != + EXT_LAST_EXTENT(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_ext[1].ee_block); + } else { + /* index */ + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_idx[1].ei_block); + } + depth--; + } + + return EXT_MAX_BLOCKS; +} + +/* + * ext4_ext_next_leaf_block: + * returns first allocated block from next leaf or EXT_MAX_BLOCKS + */ +static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + /* zero-tree has no leaf blocks at all */ + if (depth == 0) + return EXT_MAX_BLOCKS; + + /* go to index block */ + depth--; + + while (depth >= 0) { + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return (ext4_lblk_t) + le32_to_cpu(path[depth].p_idx[1].ei_block); + depth--; + } + + return EXT_MAX_BLOCKS; +} + +/* + * ext4_ext_correct_indexes: + * if leaf gets modified and modified extent is first in the leaf, + * then we have to correct all indexes above. + * TODO: do we need to correct tree in all cases? + */ +static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + int depth = ext_depth(inode); + struct ext4_extent *ex; + __le32 border; + int k, err = 0; + + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + + if (unlikely(ex == NULL || eh == NULL)) { + EXT4_ERROR_INODE(inode, + "ex %p == NULL or eh %p == NULL", ex, eh); + return -EFSCORRUPTED; + } + + if (depth == 0) { + /* there is no tree at all */ + return 0; + } + + if (ex != EXT_FIRST_EXTENT(eh)) { + /* we correct tree if first leaf got modified only */ + return 0; + } + + /* + * TODO: we need correction if border is smaller than current one + */ + k = depth - 1; + border = path[depth].p_ext->ee_block; + err = ext4_ext_get_access(handle, inode, path + k); + if (err) + return err; + path[k].p_idx->ei_block = border; + err = ext4_ext_dirty(handle, inode, path + k); + if (err) + return err; + + while (k--) { + /* change all left-side indexes */ + if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) + break; + err = ext4_ext_get_access(handle, inode, path + k); + if (err) + break; + path[k].p_idx->ei_block = border; + err = ext4_ext_dirty(handle, inode, path + k); + if (err) + break; + } + + return err; +} + +int +ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, + struct ext4_extent *ex2) +{ + unsigned short ext1_ee_len, ext2_ee_len; + + if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2)) + return 0; + + ext1_ee_len = ext4_ext_get_actual_len(ex1); + ext2_ee_len = ext4_ext_get_actual_len(ex2); + + if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != + le32_to_cpu(ex2->ee_block)) + return 0; + + /* + * To allow future support for preallocated extents to be added + * as an RO_COMPAT feature, refuse to merge to extents if + * this can result in the top bit of ee_len being set. + */ + if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) + return 0; + /* + * The check for IO to unwritten extent is somewhat racy as we + * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after + * dropping i_data_sem. But reserved blocks should save us in that + * case. + */ + if (ext4_ext_is_unwritten(ex1) && + (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) || + atomic_read(&EXT4_I(inode)->i_unwritten) || + (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN))) + return 0; +#ifdef AGGRESSIVE_TEST + if (ext1_ee_len >= 4) + return 0; +#endif + + if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) + return 1; + return 0; +} + +/* + * This function tries to merge the "ex" extent to the next extent in the tree. + * It always tries to merge towards right. If you want to merge towards + * left, pass "ex - 1" as argument instead of "ex". + * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns + * 1 if they got merged. + */ +static int ext4_ext_try_to_merge_right(struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex) +{ + struct ext4_extent_header *eh; + unsigned int depth, len; + int merge_done = 0, unwritten; + + depth = ext_depth(inode); + BUG_ON(path[depth].p_hdr == NULL); + eh = path[depth].p_hdr; + + while (ex < EXT_LAST_EXTENT(eh)) { + if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) + break; + /* merge with next extent! */ + unwritten = ext4_ext_is_unwritten(ex); + ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + + ext4_ext_get_actual_len(ex + 1)); + if (unwritten) + ext4_ext_mark_unwritten(ex); + + if (ex + 1 < EXT_LAST_EXTENT(eh)) { + len = (EXT_LAST_EXTENT(eh) - ex - 1) + * sizeof(struct ext4_extent); + memmove(ex + 1, ex + 2, len); + } + le16_add_cpu(&eh->eh_entries, -1); + merge_done = 1; + WARN_ON(eh->eh_entries == 0); + if (!eh->eh_entries) + EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); + } + + return merge_done; +} + +/* + * This function does a very simple check to see if we can collapse + * an extent tree with a single extent tree leaf block into the inode. + */ +static void ext4_ext_try_to_merge_up(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path) +{ + size_t s; + unsigned max_root = ext4_ext_space_root(inode, 0); + ext4_fsblk_t blk; + + if ((path[0].p_depth != 1) || + (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || + (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) + return; + + /* + * We need to modify the block allocation bitmap and the block + * group descriptor to release the extent tree block. If we + * can't get the journal credits, give up. + */ + if (ext4_journal_extend(handle, 2)) + return; + + /* + * Copy the extent data up to the inode + */ + blk = ext4_idx_pblock(path[0].p_idx); + s = le16_to_cpu(path[1].p_hdr->eh_entries) * + sizeof(struct ext4_extent_idx); + s += sizeof(struct ext4_extent_header); + + path[1].p_maxdepth = path[0].p_maxdepth; + memcpy(path[0].p_hdr, path[1].p_hdr, s); + path[0].p_depth = 0; + path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + + (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); + path[0].p_hdr->eh_max = cpu_to_le16(max_root); + + brelse(path[1].p_bh); + ext4_free_blocks(handle, inode, NULL, blk, 1, + EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); +} + +/* + * This function tries to merge the @ex extent to neighbours in the tree. + * return 1 if merge left else 0. + */ +static void ext4_ext_try_to_merge(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex) { + struct ext4_extent_header *eh; + unsigned int depth; + int merge_done = 0; + + depth = ext_depth(inode); + BUG_ON(path[depth].p_hdr == NULL); + eh = path[depth].p_hdr; + + if (ex > EXT_FIRST_EXTENT(eh)) + merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); + + if (!merge_done) + (void) ext4_ext_try_to_merge_right(inode, path, ex); + + ext4_ext_try_to_merge_up(handle, inode, path); +} + +/* + * check if a portion of the "newext" extent overlaps with an + * existing extent. + * + * If there is an overlap discovered, it updates the length of the newext + * such that there will be no overlap, and then returns 1. + * If there is no overlap found, it returns 0. + */ +static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, + struct inode *inode, + struct ext4_extent *newext, + struct ext4_ext_path *path) +{ + ext4_lblk_t b1, b2; + unsigned int depth, len1; + unsigned int ret = 0; + + b1 = le32_to_cpu(newext->ee_block); + len1 = ext4_ext_get_actual_len(newext); + depth = ext_depth(inode); + if (!path[depth].p_ext) + goto out; + b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block)); + + /* + * get the next allocated block if the extent in the path + * is before the requested block(s) + */ + if (b2 < b1) { + b2 = ext4_ext_next_allocated_block(path); + if (b2 == EXT_MAX_BLOCKS) + goto out; + b2 = EXT4_LBLK_CMASK(sbi, b2); + } + + /* check for wrap through zero on extent logical start block*/ + if (b1 + len1 < b1) { + len1 = EXT_MAX_BLOCKS - b1; + newext->ee_len = cpu_to_le16(len1); + ret = 1; + } + + /* check for overlap */ + if (b1 + len1 > b2) { + newext->ee_len = cpu_to_le16(b2 - b1); + ret = 1; + } +out: + return ret; +} + +/* + * ext4_ext_insert_extent: + * tries to merge requsted extent into the existing extent or + * inserts requested extent as new one into the tree, + * creating new leaf in the no-space case. + */ +int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, + struct ext4_ext_path **ppath, + struct ext4_extent *newext, int gb_flags) +{ + struct ext4_ext_path *path = *ppath; + struct ext4_extent_header *eh; + struct ext4_extent *ex, *fex; + struct ext4_extent *nearex; /* nearest extent */ + struct ext4_ext_path *npath = NULL; + int depth, len, err; + ext4_lblk_t next; + int mb_flags = 0, unwritten; + + if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) + mb_flags |= EXT4_MB_DELALLOC_RESERVED; + if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { + EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); + return -EFSCORRUPTED; + } + depth = ext_depth(inode); + ex = path[depth].p_ext; + eh = path[depth].p_hdr; + if (unlikely(path[depth].p_hdr == NULL)) { + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + return -EFSCORRUPTED; + } + + /* try to insert block into found extent and return */ + if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) { + + /* + * Try to see whether we should rather test the extent on + * right from ex, or from the left of ex. This is because + * ext4_find_extent() can return either extent on the + * left, or on the right from the searched position. This + * will make merging more effective. + */ + if (ex < EXT_LAST_EXTENT(eh) && + (le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex) < + le32_to_cpu(newext->ee_block))) { + ex += 1; + goto prepend; + } else if ((ex > EXT_FIRST_EXTENT(eh)) && + (le32_to_cpu(newext->ee_block) + + ext4_ext_get_actual_len(newext) < + le32_to_cpu(ex->ee_block))) + ex -= 1; + + /* Try to append newex to the ex */ + if (ext4_can_extents_be_merged(inode, ex, newext)) { + ext_debug("append [%d]%d block to %u:[%d]%d" + "(from %llu)\n", + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext), + le32_to_cpu(ex->ee_block), + ext4_ext_is_unwritten(ex), + ext4_ext_get_actual_len(ex), + ext4_ext_pblock(ex)); + err = ext4_ext_get_access(handle, inode, + path + depth); + if (err) + return err; + unwritten = ext4_ext_is_unwritten(ex); + ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + + ext4_ext_get_actual_len(newext)); + if (unwritten) + ext4_ext_mark_unwritten(ex); + eh = path[depth].p_hdr; + nearex = ex; + goto merge; + } + +prepend: + /* Try to prepend newex to the ex */ + if (ext4_can_extents_be_merged(inode, newext, ex)) { + ext_debug("prepend %u[%d]%d block to %u:[%d]%d" + "(from %llu)\n", + le32_to_cpu(newext->ee_block), + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext), + le32_to_cpu(ex->ee_block), + ext4_ext_is_unwritten(ex), + ext4_ext_get_actual_len(ex), + ext4_ext_pblock(ex)); + err = ext4_ext_get_access(handle, inode, + path + depth); + if (err) + return err; + + unwritten = ext4_ext_is_unwritten(ex); + ex->ee_block = newext->ee_block; + ext4_ext_store_pblock(ex, ext4_ext_pblock(newext)); + ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + + ext4_ext_get_actual_len(newext)); + if (unwritten) + ext4_ext_mark_unwritten(ex); + eh = path[depth].p_hdr; + nearex = ex; + goto merge; + } + } + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) + goto has_space; + + /* probably next leaf has space for us? */ + fex = EXT_LAST_EXTENT(eh); + next = EXT_MAX_BLOCKS; + if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) + next = ext4_ext_next_leaf_block(path); + if (next != EXT_MAX_BLOCKS) { + ext_debug("next leaf block - %u\n", next); + BUG_ON(npath != NULL); + npath = ext4_find_extent(inode, next, NULL, 0); + if (IS_ERR(npath)) + return PTR_ERR(npath); + BUG_ON(npath->p_depth != path->p_depth); + eh = npath[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { + ext_debug("next leaf isn't full(%d)\n", + le16_to_cpu(eh->eh_entries)); + path = npath; + goto has_space; + } + ext_debug("next leaf has no free space(%d,%d)\n", + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + } + + /* + * There is no free space in the found leaf. + * We're gonna add a new leaf in the tree. + */ + if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) + mb_flags |= EXT4_MB_USE_RESERVED; + err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags, + ppath, newext); + if (err) + goto cleanup; + depth = ext_depth(inode); + eh = path[depth].p_hdr; + +has_space: + nearex = path[depth].p_ext; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto cleanup; + + if (!nearex) { + /* there is no extent in this leaf, create first one */ + ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext)); + nearex = EXT_FIRST_EXTENT(eh); + } else { + if (le32_to_cpu(newext->ee_block) + > le32_to_cpu(nearex->ee_block)) { + /* Insert after */ + ext_debug("insert %u:%llu:[%d]%d before: " + "nearest %p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext), + nearex); + nearex++; + } else { + /* Insert before */ + BUG_ON(newext->ee_block == nearex->ee_block); + ext_debug("insert %u:%llu:[%d]%d after: " + "nearest %p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext), + nearex); + } + len = EXT_LAST_EXTENT(eh) - nearex + 1; + if (len > 0) { + ext_debug("insert %u:%llu:[%d]%d: " + "move %d extents from 0x%p to 0x%p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_unwritten(newext), + ext4_ext_get_actual_len(newext), + len, nearex, nearex + 1); + memmove(nearex + 1, nearex, + len * sizeof(struct ext4_extent)); + } + } + + le16_add_cpu(&eh->eh_entries, 1); + path[depth].p_ext = nearex; + nearex->ee_block = newext->ee_block; + ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); + nearex->ee_len = newext->ee_len; + +merge: + /* try to merge extents */ + if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) + ext4_ext_try_to_merge(handle, inode, path, nearex); + + + /* time to correct all indexes above */ + err = ext4_ext_correct_indexes(handle, inode, path); + if (err) + goto cleanup; + + err = ext4_ext_dirty(handle, inode, path + path->p_depth); + +cleanup: + ext4_ext_drop_refs(npath); + kfree(npath); + return err; +} + +static int ext4_fill_fiemap_extents(struct inode *inode, + ext4_lblk_t block, ext4_lblk_t num, + struct fiemap_extent_info *fieinfo) +{ + struct ext4_ext_path *path = NULL; + struct ext4_extent *ex; + struct extent_status es; + ext4_lblk_t next, next_del, start = 0, end = 0; + ext4_lblk_t last = block + num; + int exists, depth = 0, err = 0; + unsigned int flags = 0; + unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; + + while (block < last && block != EXT_MAX_BLOCKS) { + num = last - block; + /* find extent for this block */ + down_read(&EXT4_I(inode)->i_data_sem); + + path = ext4_find_extent(inode, block, &path, 0); + if (IS_ERR(path)) { + up_read(&EXT4_I(inode)->i_data_sem); + err = PTR_ERR(path); + path = NULL; + break; + } + + depth = ext_depth(inode); + if (unlikely(path[depth].p_hdr == NULL)) { + up_read(&EXT4_I(inode)->i_data_sem); + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + err = -EFSCORRUPTED; + break; + } + ex = path[depth].p_ext; + next = ext4_ext_next_allocated_block(path); + + flags = 0; + exists = 0; + if (!ex) { + /* there is no extent yet, so try to allocate + * all requested space */ + start = block; + end = block + num; + } else if (le32_to_cpu(ex->ee_block) > block) { + /* need to allocate space before found extent */ + start = block; + end = le32_to_cpu(ex->ee_block); + if (block + num < end) + end = block + num; + } else if (block >= le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex)) { + /* need to allocate space after found extent */ + start = block; + end = block + num; + if (end >= next) + end = next; + } else if (block >= le32_to_cpu(ex->ee_block)) { + /* + * some part of requested space is covered + * by found extent + */ + start = block; + end = le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex); + if (block + num < end) + end = block + num; + exists = 1; + } else { + BUG(); + } + BUG_ON(end <= start); + + if (!exists) { + es.es_lblk = start; + es.es_len = end - start; + es.es_pblk = 0; + } else { + es.es_lblk = le32_to_cpu(ex->ee_block); + es.es_len = ext4_ext_get_actual_len(ex); + es.es_pblk = ext4_ext_pblock(ex); + if (ext4_ext_is_unwritten(ex)) + flags |= FIEMAP_EXTENT_UNWRITTEN; + } + + /* + * Find delayed extent and update es accordingly. We call + * it even in !exists case to find out whether es is the + * last existing extent or not. + */ + next_del = ext4_find_delayed_extent(inode, &es); + if (!exists && next_del) { + exists = 1; + flags |= (FIEMAP_EXTENT_DELALLOC | + FIEMAP_EXTENT_UNKNOWN); + } + up_read(&EXT4_I(inode)->i_data_sem); + + if (unlikely(es.es_len == 0)) { + EXT4_ERROR_INODE(inode, "es.es_len == 0"); + err = -EFSCORRUPTED; + break; + } + + /* + * This is possible iff next == next_del == EXT_MAX_BLOCKS. + * we need to check next == EXT_MAX_BLOCKS because it is + * possible that an extent is with unwritten and delayed + * status due to when an extent is delayed allocated and + * is allocated by fallocate status tree will track both of + * them in a extent. + * + * So we could return a unwritten and delayed extent, and + * its block is equal to 'next'. + */ + if (next == next_del && next == EXT_MAX_BLOCKS) { + flags |= FIEMAP_EXTENT_LAST; + if (unlikely(next_del != EXT_MAX_BLOCKS || + next != EXT_MAX_BLOCKS)) { + EXT4_ERROR_INODE(inode, + "next extent == %u, next " + "delalloc extent = %u", + next, next_del); + err = -EFSCORRUPTED; + break; + } + } + + if (exists) { + err = fiemap_fill_next_extent(fieinfo, + (__u64)es.es_lblk << blksize_bits, + (__u64)es.es_pblk << blksize_bits, + (__u64)es.es_len << blksize_bits, + flags); + if (err < 0) + break; + if (err == 1) { + err = 0; + break; + } + } + + block = es.es_lblk + es.es_len; + } + + ext4_ext_drop_refs(path); + kfree(path); + return err; +} + +/* + * ext4_ext_determine_hole - determine hole around given block + * @inode: inode we lookup in + * @path: path in extent tree to @lblk + * @lblk: pointer to logical block around which we want to determine hole + * + * Determine hole length (and start if easily possible) around given logical + * block. We don't try too hard to find the beginning of the hole but @path + * actually points to extent before @lblk, we provide it. + * + * The function returns the length of a hole starting at @lblk. We update @lblk + * to the beginning of the hole if we managed to find it. + */ +static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *lblk) +{ + int depth = ext_depth(inode); + struct ext4_extent *ex; + ext4_lblk_t len; + + ex = path[depth].p_ext; + if (ex == NULL) { + /* there is no extent yet, so gap is [0;-] */ + *lblk = 0; + len = EXT_MAX_BLOCKS; + } else if (*lblk < le32_to_cpu(ex->ee_block)) { + len = le32_to_cpu(ex->ee_block) - *lblk; + } else if (*lblk >= le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex)) { + ext4_lblk_t next; + + *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); + next = ext4_ext_next_allocated_block(path); + BUG_ON(next == *lblk); + len = next - *lblk; + } else { + BUG(); + } + return len; +} + +/* + * ext4_ext_put_gap_in_cache: + * calculate boundaries of the gap that the requested block fits into + * and cache this gap + */ +static void +ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start, + ext4_lblk_t hole_len) +{ + struct extent_status es; + + ext4_es_find_delayed_extent_range(inode, hole_start, + hole_start + hole_len - 1, &es); + if (es.es_len) { + /* There's delayed extent containing lblock? */ + if (es.es_lblk <= hole_start) + return; + hole_len = min(es.es_lblk - hole_start, hole_len); + } + ext_debug(" -> %u:%u\n", hole_start, hole_len); + ext4_es_insert_extent(inode, hole_start, hole_len, ~0, + EXTENT_STATUS_HOLE); +} + +/* + * ext4_ext_rm_idx: + * removes index from the index block. + */ +static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, int depth) +{ + int err; + ext4_fsblk_t leaf; + + /* free index block */ + depth--; + path = path + depth; + leaf = ext4_idx_pblock(path->p_idx); + if (unlikely(path->p_hdr->eh_entries == 0)) { + EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); + return -EFSCORRUPTED; + } + err = ext4_ext_get_access(handle, inode, path); + if (err) + return err; + + if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { + int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; + len *= sizeof(struct ext4_extent_idx); + memmove(path->p_idx, path->p_idx + 1, len); + } + + le16_add_cpu(&path->p_hdr->eh_entries, -1); + err = ext4_ext_dirty(handle, inode, path); + if (err) + return err; + ext_debug("index is empty, remove it, free block %llu\n", leaf); + trace_ext4_ext_rm_idx(inode, leaf); + + ext4_free_blocks(handle, inode, NULL, leaf, 1, + EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); + + while (--depth >= 0) { + if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr)) + break; + path--; + err = ext4_ext_get_access(handle, inode, path); + if (err) + break; + path->p_idx->ei_block = (path+1)->p_idx->ei_block; + err = ext4_ext_dirty(handle, inode, path); + if (err) + break; + } + return err; +} + +/* + * ext4_ext_calc_credits_for_single_extent: + * This routine returns max. credits that needed to insert an extent + * to the extent tree. + * When pass the actual path, the caller should calculate credits + * under i_data_sem. + */ +int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, + struct ext4_ext_path *path) +{ + if (path) { + int depth = ext_depth(inode); + int ret = 0; + + /* probably there is space in leaf? */ + if (le16_to_cpu(path[depth].p_hdr->eh_entries) + < le16_to_cpu(path[depth].p_hdr->eh_max)) { + + /* + * There are some space in the leaf tree, no + * need to account for leaf block credit + * + * bitmaps and block group descriptor blocks + * and other metadata blocks still need to be + * accounted. + */ + /* 1 bitmap, 1 block group descriptor */ + ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); + return ret; + } + } + + return ext4_chunk_trans_blocks(inode, nrblocks); +} + +/* + * How many index/leaf blocks need to change/allocate to add @extents extents? + * + * If we add a single extent, then in the worse case, each tree level + * index/leaf need to be changed in case of the tree split. + * + * If more extents are inserted, they could cause the whole tree split more + * than once, but this is really rare. + */ +int ext4_ext_index_trans_blocks(struct inode *inode, int extents) +{ + int index; + int depth; + + /* If we are converting the inline data, only one is needed here. */ + if (ext4_has_inline_data(inode)) + return 1; + + depth = ext_depth(inode); + + if (extents <= 1) + index = depth * 2; + else + index = depth * 3; + + return index; +} + +static inline int get_default_free_blocks_flags(struct inode *inode) +{ + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) || + ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) + return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET; + else if (ext4_should_journal_data(inode)) + return EXT4_FREE_BLOCKS_FORGET; + return 0; +} + +static int ext4_remove_blocks(handle_t *handle, struct inode *inode, + struct ext4_extent *ex, + long long *partial_cluster, + ext4_lblk_t from, ext4_lblk_t to) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned short ee_len = ext4_ext_get_actual_len(ex); + ext4_fsblk_t pblk; + int flags = get_default_free_blocks_flags(inode); + + /* + * For bigalloc file systems, we never free a partial cluster + * at the beginning of the extent. Instead, we make a note + * that we tried freeing the cluster, and check to see if we + * need to free it on a subsequent call to ext4_remove_blocks, + * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space. + */ + flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; + + trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster); + /* + * If we have a partial cluster, and it's different from the + * cluster of the last block, we need to explicitly free the + * partial cluster here. + */ + pblk = ext4_ext_pblock(ex) + ee_len - 1; + if (*partial_cluster > 0 && + *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) { + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(sbi, *partial_cluster), + sbi->s_cluster_ratio, flags); + *partial_cluster = 0; + } + +#ifdef EXTENTS_STATS + { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + spin_lock(&sbi->s_ext_stats_lock); + sbi->s_ext_blocks += ee_len; + sbi->s_ext_extents++; + if (ee_len < sbi->s_ext_min) + sbi->s_ext_min = ee_len; + if (ee_len > sbi->s_ext_max) + sbi->s_ext_max = ee_len; + if (ext_depth(inode) > sbi->s_depth_max) + sbi->s_depth_max = ext_depth(inode); + spin_unlock(&sbi->s_ext_stats_lock); + } +#endif + if (from >= le32_to_cpu(ex->ee_block) + && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { + /* tail removal */ + ext4_lblk_t num; + long long first_cluster; + + num = le32_to_cpu(ex->ee_block) + ee_len - from; + pblk = ext4_ext_pblock(ex) + ee_len - num; + /* + * Usually we want to free partial cluster at the end of the + * extent, except for the situation when the cluster is still + * used by any other extent (partial_cluster is negative). + */ + if (*partial_cluster < 0 && + *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1)) + flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; + + ext_debug("free last %u blocks starting %llu partial %lld\n", + num, pblk, *partial_cluster); + ext4_free_blocks(handle, inode, NULL, pblk, num, flags); + /* + * If the block range to be freed didn't start at the + * beginning of a cluster, and we removed the entire + * extent and the cluster is not used by any other extent, + * save the partial cluster here, since we might need to + * delete if we determine that the truncate or punch hole + * operation has removed all of the blocks in the cluster. + * If that cluster is used by another extent, preserve its + * negative value so it isn't freed later on. + * + * If the whole extent wasn't freed, we've reached the + * start of the truncated/punched region and have finished + * removing blocks. If there's a partial cluster here it's + * shared with the remainder of the extent and is no longer + * a candidate for removal. + */ + if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) { + first_cluster = (long long) EXT4_B2C(sbi, pblk); + if (first_cluster != -*partial_cluster) + *partial_cluster = first_cluster; + } else { + *partial_cluster = 0; + } + } else + ext4_error(sbi->s_sb, "strange request: removal(2) " + "%u-%u from %u:%u", + from, to, le32_to_cpu(ex->ee_block), ee_len); + return 0; +} + + +/* + * ext4_ext_rm_leaf() Removes the extents associated with the + * blocks appearing between "start" and "end". Both "start" + * and "end" must appear in the same extent or EIO is returned. + * + * @handle: The journal handle + * @inode: The files inode + * @path: The path to the leaf + * @partial_cluster: The cluster which we'll have to free if all extents + * has been released from it. However, if this value is + * negative, it's a cluster just to the right of the + * punched region and it must not be freed. + * @start: The first block to remove + * @end: The last block to remove + */ +static int +ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + long long *partial_cluster, + ext4_lblk_t start, ext4_lblk_t end) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + int err = 0, correct_index = 0; + int depth = ext_depth(inode), credits; + struct ext4_extent_header *eh; + ext4_lblk_t a, b; + unsigned num; + ext4_lblk_t ex_ee_block; + unsigned short ex_ee_len; + unsigned unwritten = 0; + struct ext4_extent *ex; + ext4_fsblk_t pblk; + + /* the header must be checked already in ext4_ext_remove_space() */ + ext_debug("truncate since %u in leaf to %u\n", start, end); + if (!path[depth].p_hdr) + path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); + eh = path[depth].p_hdr; + if (unlikely(path[depth].p_hdr == NULL)) { + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + return -EFSCORRUPTED; + } + /* find where to start removing */ + ex = path[depth].p_ext; + if (!ex) + ex = EXT_LAST_EXTENT(eh); + + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + + trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster); + + while (ex >= EXT_FIRST_EXTENT(eh) && + ex_ee_block + ex_ee_len > start) { + + if (ext4_ext_is_unwritten(ex)) + unwritten = 1; + else + unwritten = 0; + + ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, + unwritten, ex_ee_len); + path[depth].p_ext = ex; + + a = ex_ee_block > start ? ex_ee_block : start; + b = ex_ee_block+ex_ee_len - 1 < end ? + ex_ee_block+ex_ee_len - 1 : end; + + ext_debug(" border %u:%u\n", a, b); + + /* If this extent is beyond the end of the hole, skip it */ + if (end < ex_ee_block) { + /* + * We're going to skip this extent and move to another, + * so note that its first cluster is in use to avoid + * freeing it when removing blocks. Eventually, the + * right edge of the truncated/punched region will + * be just to the left. + */ + if (sbi->s_cluster_ratio > 1) { + pblk = ext4_ext_pblock(ex); + *partial_cluster = + -(long long) EXT4_B2C(sbi, pblk); + } + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + continue; + } else if (b != ex_ee_block + ex_ee_len - 1) { + EXT4_ERROR_INODE(inode, + "can not handle truncate %u:%u " + "on extent %u:%u", + start, end, ex_ee_block, + ex_ee_block + ex_ee_len - 1); + err = -EFSCORRUPTED; + goto out; + } else if (a != ex_ee_block) { + /* remove tail of the extent */ + num = a - ex_ee_block; + } else { + /* remove whole extent: excellent! */ + num = 0; + } + /* + * 3 for leaf, sb, and inode plus 2 (bmap and group + * descriptor) for each block group; assume two block + * groups plus ex_ee_len/blocks_per_block_group for + * the worst case + */ + credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); + if (ex == EXT_FIRST_EXTENT(eh)) { + correct_index = 1; + credits += (ext_depth(inode)) + 1; + } + credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); + + err = ext4_ext_truncate_extend_restart(handle, inode, credits); + if (err) + goto out; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + err = ext4_remove_blocks(handle, inode, ex, partial_cluster, + a, b); + if (err) + goto out; + + if (num == 0) + /* this extent is removed; mark slot entirely unused */ + ext4_ext_store_pblock(ex, 0); + + ex->ee_len = cpu_to_le16(num); + /* + * Do not mark unwritten if all the blocks in the + * extent have been removed. + */ + if (unwritten && num) + ext4_ext_mark_unwritten(ex); + /* + * If the extent was completely released, + * we need to remove it from the leaf + */ + if (num == 0) { + if (end != EXT_MAX_BLOCKS - 1) { + /* + * For hole punching, we need to scoot all the + * extents up when an extent is removed so that + * we dont have blank extents in the middle + */ + memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * + sizeof(struct ext4_extent)); + + /* Now get rid of the one at the end */ + memset(EXT_LAST_EXTENT(eh), 0, + sizeof(struct ext4_extent)); + } + le16_add_cpu(&eh->eh_entries, -1); + } + + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num, + ext4_ext_pblock(ex)); + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + } + + if (correct_index && eh->eh_entries) + err = ext4_ext_correct_indexes(handle, inode, path); + + /* + * If there's a partial cluster and at least one extent remains in + * the leaf, free the partial cluster if it isn't shared with the + * current extent. If it is shared with the current extent + * we zero partial_cluster because we've reached the start of the + * truncated/punched region and we're done removing blocks. + */ + if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) { + pblk = ext4_ext_pblock(ex) + ex_ee_len - 1; + if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) { + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(sbi, *partial_cluster), + sbi->s_cluster_ratio, + get_default_free_blocks_flags(inode)); + } + *partial_cluster = 0; + } + + /* if this leaf is free, then we should + * remove it from index block above */ + if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) + err = ext4_ext_rm_idx(handle, inode, path, depth); + +out: + return err; +} + +/* + * ext4_ext_more_to_rm: + * returns 1 if current index has to be freed (even partial) + */ +static int +ext4_ext_more_to_rm(struct ext4_ext_path *path) +{ + BUG_ON(path->p_idx == NULL); + + if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) + return 0; + + /* + * if truncate on deeper level happened, it wasn't partial, + * so we have to consider current index for truncation + */ + if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) + return 0; + return 1; +} + +int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, + ext4_lblk_t end) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + int depth = ext_depth(inode); + struct ext4_ext_path *path = NULL; + long long partial_cluster = 0; + handle_t *handle; + int i = 0, err = 0; + + ext_debug("truncate since %u to %u\n", start, end); + + /* probably first extent we're gonna free will be last in block */ + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + +again: + trace_ext4_ext_remove_space(inode, start, end, depth); + + /* + * Check if we are removing extents inside the extent tree. If that + * is the case, we are going to punch a hole inside the extent tree + * so we have to check whether we need to split the extent covering + * the last block to remove so we can easily remove the part of it + * in ext4_ext_rm_leaf(). + */ + if (end < EXT_MAX_BLOCKS - 1) { + struct ext4_extent *ex; + ext4_lblk_t ee_block, ex_end, lblk; + ext4_fsblk_t pblk; + + /* find extent for or closest extent to this block */ + path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE); + if (IS_ERR(path)) { + ext4_journal_stop(handle); + return PTR_ERR(path); + } + depth = ext_depth(inode); + /* Leaf not may not exist only if inode has no blocks at all */ + ex = path[depth].p_ext; + if (!ex) { + if (depth) { + EXT4_ERROR_INODE(inode, + "path[%d].p_hdr == NULL", + depth); + err = -EFSCORRUPTED; + } + goto out; + } + + ee_block = le32_to_cpu(ex->ee_block); + ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1; + + /* + * See if the last block is inside the extent, if so split + * the extent at 'end' block so we can easily remove the + * tail of the first part of the split extent in + * ext4_ext_rm_leaf(). + */ + if (end >= ee_block && end < ex_end) { + + /* + * If we're going to split the extent, note that + * the cluster containing the block after 'end' is + * in use to avoid freeing it when removing blocks. + */ + if (sbi->s_cluster_ratio > 1) { + pblk = ext4_ext_pblock(ex) + end - ee_block + 1; + partial_cluster = + -(long long) EXT4_B2C(sbi, pblk); + } + + /* + * Split the extent in two so that 'end' is the last + * block in the first new extent. Also we should not + * fail removing space due to ENOSPC so try to use + * reserved block if that happens. + */ + err = ext4_force_split_extent_at(handle, inode, &path, + end + 1, 1); + if (err < 0) + goto out; + + } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) { + /* + * If there's an extent to the right its first cluster + * contains the immediate right boundary of the + * truncated/punched region. Set partial_cluster to + * its negative value so it won't be freed if shared + * with the current extent. The end < ee_block case + * is handled in ext4_ext_rm_leaf(). + */ + lblk = ex_end + 1; + err = ext4_ext_search_right(inode, path, &lblk, &pblk, + &ex); + if (err) + goto out; + if (pblk) + partial_cluster = + -(long long) EXT4_B2C(sbi, pblk); + } + } + /* + * We start scanning from right side, freeing all the blocks + * after i_size and walking into the tree depth-wise. + */ + depth = ext_depth(inode); + if (path) { + int k = i = depth; + while (--k > 0) + path[k].p_block = + le16_to_cpu(path[k].p_hdr->eh_entries)+1; + } else { + path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), + GFP_NOFS); + if (path == NULL) { + ext4_journal_stop(handle); + return -ENOMEM; + } + path[0].p_maxdepth = path[0].p_depth = depth; + path[0].p_hdr = ext_inode_hdr(inode); + i = 0; + + if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) { + err = -EFSCORRUPTED; + goto out; + } + } + err = 0; + + while (i >= 0 && err == 0) { + if (i == depth) { + /* this is leaf block */ + err = ext4_ext_rm_leaf(handle, inode, path, + &partial_cluster, start, + end); + /* root level has p_bh == NULL, brelse() eats this */ + brelse(path[i].p_bh); + path[i].p_bh = NULL; + i--; + continue; + } + + /* this is index block */ + if (!path[i].p_hdr) { + ext_debug("initialize header\n"); + path[i].p_hdr = ext_block_hdr(path[i].p_bh); + } + + if (!path[i].p_idx) { + /* this level hasn't been touched yet */ + path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); + path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; + ext_debug("init index ptr: hdr 0x%p, num %d\n", + path[i].p_hdr, + le16_to_cpu(path[i].p_hdr->eh_entries)); + } else { + /* we were already here, see at next index */ + path[i].p_idx--; + } + + ext_debug("level %d - index, first 0x%p, cur 0x%p\n", + i, EXT_FIRST_INDEX(path[i].p_hdr), + path[i].p_idx); + if (ext4_ext_more_to_rm(path + i)) { + struct buffer_head *bh; + /* go to the next level */ + ext_debug("move to level %d (block %llu)\n", + i + 1, ext4_idx_pblock(path[i].p_idx)); + memset(path + i + 1, 0, sizeof(*path)); + bh = read_extent_tree_block(inode, + ext4_idx_pblock(path[i].p_idx), depth - i - 1, + EXT4_EX_NOCACHE); + if (IS_ERR(bh)) { + /* should we reset i_size? */ + err = PTR_ERR(bh); + break; + } + /* Yield here to deal with large extent trees. + * Should be a no-op if we did IO above. */ + cond_resched(); + if (WARN_ON(i + 1 > depth)) { + err = -EFSCORRUPTED; + break; + } + path[i + 1].p_bh = bh; + + /* save actual number of indexes since this + * number is changed at the next iteration */ + path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); + i++; + } else { + /* we finished processing this index, go up */ + if (path[i].p_hdr->eh_entries == 0 && i > 0) { + /* index is empty, remove it; + * handle must be already prepared by the + * truncatei_leaf() */ + err = ext4_ext_rm_idx(handle, inode, path, i); + } + /* root level has p_bh == NULL, brelse() eats this */ + brelse(path[i].p_bh); + path[i].p_bh = NULL; + i--; + ext_debug("return to level %d\n", i); + } + } + + trace_ext4_ext_remove_space_done(inode, start, end, depth, + partial_cluster, path->p_hdr->eh_entries); + + /* + * If we still have something in the partial cluster and we have removed + * even the first extent, then we should free the blocks in the partial + * cluster as well. (This code will only run when there are no leaves + * to the immediate left of the truncated/punched region.) + */ + if (partial_cluster > 0 && err == 0) { + /* don't zero partial_cluster since it's not used afterwards */ + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(sbi, partial_cluster), + sbi->s_cluster_ratio, + get_default_free_blocks_flags(inode)); + } + + /* TODO: flexible tree reduction should be here */ + if (path->p_hdr->eh_entries == 0) { + /* + * truncate to zero freed all the tree, + * so we need to correct eh_depth + */ + err = ext4_ext_get_access(handle, inode, path); + if (err == 0) { + ext_inode_hdr(inode)->eh_depth = 0; + ext_inode_hdr(inode)->eh_max = + cpu_to_le16(ext4_ext_space_root(inode, 0)); + err = ext4_ext_dirty(handle, inode, path); + } + } +out: + ext4_ext_drop_refs(path); + kfree(path); + path = NULL; + if (err == -EAGAIN) + goto again; + ext4_journal_stop(handle); + + return err; +} + +/* + * called at mount time + */ +void ext4_ext_init(struct super_block *sb) +{ + /* + * possible initialization would be here + */ + + if (ext4_has_feature_extents(sb)) { +#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) + printk(KERN_INFO "EXT4-fs: file extents enabled" +#ifdef AGGRESSIVE_TEST + ", aggressive tests" +#endif +#ifdef CHECK_BINSEARCH + ", check binsearch" +#endif +#ifdef EXTENTS_STATS + ", stats" +#endif + "\n"); +#endif +#ifdef EXTENTS_STATS + spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); + EXT4_SB(sb)->s_ext_min = 1 << 30; + EXT4_SB(sb)->s_ext_max = 0; +#endif + } +} + +/* + * called at umount time + */ +void ext4_ext_release(struct super_block *sb) +{ + if (!ext4_has_feature_extents(sb)) + return; + +#ifdef EXTENTS_STATS + if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { + struct ext4_sb_info *sbi = EXT4_SB(sb); + printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", + sbi->s_ext_blocks, sbi->s_ext_extents, + sbi->s_ext_blocks / sbi->s_ext_extents); + printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", + sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); + } +#endif +} + +static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) +{ + ext4_lblk_t ee_block; + ext4_fsblk_t ee_pblock; + unsigned int ee_len; + + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + ee_pblock = ext4_ext_pblock(ex); + + if (ee_len == 0) + return 0; + + return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock, + EXTENT_STATUS_WRITTEN); +} + +/* FIXME!! we need to try to merge to left or right after zero-out */ +static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) +{ + ext4_fsblk_t ee_pblock; + unsigned int ee_len; + + ee_len = ext4_ext_get_actual_len(ex); + ee_pblock = ext4_ext_pblock(ex); + return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock, + ee_len); +} + +/* + * ext4_split_extent_at() splits an extent at given block. + * + * @handle: the journal handle + * @inode: the file inode + * @path: the path to the extent + * @split: the logical block where the extent is splitted. + * @split_flags: indicates if the extent could be zeroout if split fails, and + * the states(init or unwritten) of new extents. + * @flags: flags used to insert new extent to extent tree. + * + * + * Splits extent [a, b] into two extents [a, @split) and [@split, b], states + * of which are deterimined by split_flag. + * + * There are two cases: + * a> the extent are splitted into two extent. + * b> split is not needed, and just mark the extent. + * + * return 0 on success. + */ +static int ext4_split_extent_at(handle_t *handle, + struct inode *inode, + struct ext4_ext_path **ppath, + ext4_lblk_t split, + int split_flag, + int flags) +{ + struct ext4_ext_path *path = *ppath; + ext4_fsblk_t newblock; + ext4_lblk_t ee_block; + struct ext4_extent *ex, newex, orig_ex, zero_ex; + struct ext4_extent *ex2 = NULL; + unsigned int ee_len, depth; + int err = 0; + + BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) == + (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)); + + ext_debug("ext4_split_extents_at: inode %lu, logical" + "block %llu\n", inode->i_ino, (unsigned long long)split); + + ext4_ext_show_leaf(inode, path); + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + newblock = split - ee_block + ext4_ext_pblock(ex); + + BUG_ON(split < ee_block || split >= (ee_block + ee_len)); + BUG_ON(!ext4_ext_is_unwritten(ex) && + split_flag & (EXT4_EXT_MAY_ZEROOUT | + EXT4_EXT_MARK_UNWRIT1 | + EXT4_EXT_MARK_UNWRIT2)); + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + if (split == ee_block) { + /* + * case b: block @split is the block that the extent begins with + * then we just change the state of the extent, and splitting + * is not needed. + */ + if (split_flag & EXT4_EXT_MARK_UNWRIT2) + ext4_ext_mark_unwritten(ex); + else + ext4_ext_mark_initialized(ex); + + if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) + ext4_ext_try_to_merge(handle, inode, path, ex); + + err = ext4_ext_dirty(handle, inode, path + path->p_depth); + goto out; + } + + /* case a */ + memcpy(&orig_ex, ex, sizeof(orig_ex)); + ex->ee_len = cpu_to_le16(split - ee_block); + if (split_flag & EXT4_EXT_MARK_UNWRIT1) + ext4_ext_mark_unwritten(ex); + + /* + * path may lead to new leaf, not to original leaf any more + * after ext4_ext_insert_extent() returns, + */ + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto fix_extent_len; + + ex2 = &newex; + ex2->ee_block = cpu_to_le32(split); + ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); + ext4_ext_store_pblock(ex2, newblock); + if (split_flag & EXT4_EXT_MARK_UNWRIT2) + ext4_ext_mark_unwritten(ex2); + + err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); + if (err != -ENOSPC && err != -EDQUOT) + goto out; + + if (EXT4_EXT_MAY_ZEROOUT & split_flag) { + if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { + if (split_flag & EXT4_EXT_DATA_VALID1) { + err = ext4_ext_zeroout(inode, ex2); + zero_ex.ee_block = ex2->ee_block; + zero_ex.ee_len = cpu_to_le16( + ext4_ext_get_actual_len(ex2)); + ext4_ext_store_pblock(&zero_ex, + ext4_ext_pblock(ex2)); + } else { + err = ext4_ext_zeroout(inode, ex); + zero_ex.ee_block = ex->ee_block; + zero_ex.ee_len = cpu_to_le16( + ext4_ext_get_actual_len(ex)); + ext4_ext_store_pblock(&zero_ex, + ext4_ext_pblock(ex)); + } + } else { + err = ext4_ext_zeroout(inode, &orig_ex); + zero_ex.ee_block = orig_ex.ee_block; + zero_ex.ee_len = cpu_to_le16( + ext4_ext_get_actual_len(&orig_ex)); + ext4_ext_store_pblock(&zero_ex, + ext4_ext_pblock(&orig_ex)); + } + + if (!err) { + /* update the extent length and mark as initialized */ + ex->ee_len = cpu_to_le16(ee_len); + ext4_ext_try_to_merge(handle, inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); + if (!err) + /* update extent status tree */ + err = ext4_zeroout_es(inode, &zero_ex); + /* If we failed at this point, we don't know in which + * state the extent tree exactly is so don't try to fix + * length of the original extent as it may do even more + * damage. + */ + goto out; + } + } + +fix_extent_len: + ex->ee_len = orig_ex.ee_len; + ext4_ext_dirty(handle, inode, path + path->p_depth); + return err; +out: + ext4_ext_show_leaf(inode, path); + return err; +} + +/* + * ext4_split_extents() splits an extent and mark extent which is covered + * by @map as split_flags indicates + * + * It may result in splitting the extent into multiple extents (up to three) + * There are three possibilities: + * a> There is no split required + * b> Splits in two extents: Split is happening at either end of the extent + * c> Splits in three extents: Somone is splitting in middle of the extent + * + */ +static int ext4_split_extent(handle_t *handle, + struct inode *inode, + struct ext4_ext_path **ppath, + struct ext4_map_blocks *map, + int split_flag, + int flags) +{ + struct ext4_ext_path *path = *ppath; + ext4_lblk_t ee_block; + struct ext4_extent *ex; + unsigned int ee_len, depth; + int err = 0; + int unwritten; + int split_flag1, flags1; + int allocated = map->m_len; + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + unwritten = ext4_ext_is_unwritten(ex); + + if (map->m_lblk + map->m_len < ee_block + ee_len) { + split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT; + flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; + if (unwritten) + split_flag1 |= EXT4_EXT_MARK_UNWRIT1 | + EXT4_EXT_MARK_UNWRIT2; + if (split_flag & EXT4_EXT_DATA_VALID2) + split_flag1 |= EXT4_EXT_DATA_VALID1; + err = ext4_split_extent_at(handle, inode, ppath, + map->m_lblk + map->m_len, split_flag1, flags1); + if (err) + goto out; + } else { + allocated = ee_len - (map->m_lblk - ee_block); + } + /* + * Update path is required because previous ext4_split_extent_at() may + * result in split of original leaf or extent zeroout. + */ + path = ext4_find_extent(inode, map->m_lblk, ppath, 0); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = ext_depth(inode); + ex = path[depth].p_ext; + if (!ex) { + EXT4_ERROR_INODE(inode, "unexpected hole at %lu", + (unsigned long) map->m_lblk); + return -EFSCORRUPTED; + } + unwritten = ext4_ext_is_unwritten(ex); + split_flag1 = 0; + + if (map->m_lblk >= ee_block) { + split_flag1 = split_flag & EXT4_EXT_DATA_VALID2; + if (unwritten) { + split_flag1 |= EXT4_EXT_MARK_UNWRIT1; + split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT | + EXT4_EXT_MARK_UNWRIT2); + } + err = ext4_split_extent_at(handle, inode, ppath, + map->m_lblk, split_flag1, flags); + if (err) + goto out; + } + + ext4_ext_show_leaf(inode, path); +out: + return err ? err : allocated; +} + +/* + * This function is called by ext4_ext_map_blocks() if someone tries to write + * to an unwritten extent. It may result in splitting the unwritten + * extent into multiple extents (up to three - one initialized and two + * unwritten). + * There are three possibilities: + * a> There is no split required: Entire extent should be initialized + * b> Splits in two extents: Write is happening at either end of the extent + * c> Splits in three extents: Somone is writing in middle of the extent + * + * Pre-conditions: + * - The extent pointed to by 'path' is unwritten. + * - The extent pointed to by 'path' contains a superset + * of the logical span [map->m_lblk, map->m_lblk + map->m_len). + * + * Post-conditions on success: + * - the returned value is the number of blocks beyond map->l_lblk + * that are allocated and initialized. + * It is guaranteed to be >= map->m_len. + */ +static int ext4_ext_convert_to_initialized(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path **ppath, + int flags) +{ + struct ext4_ext_path *path = *ppath; + struct ext4_sb_info *sbi; + struct ext4_extent_header *eh; + struct ext4_map_blocks split_map; + struct ext4_extent zero_ex1, zero_ex2; + struct ext4_extent *ex, *abut_ex; + ext4_lblk_t ee_block, eof_block; + unsigned int ee_len, depth, map_len = map->m_len; + int allocated = 0, max_zeroout = 0; + int err = 0; + int split_flag = EXT4_EXT_DATA_VALID2; + + ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" + "block %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)map->m_lblk, map_len); + + sbi = EXT4_SB(inode->i_sb); + eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) + >> inode->i_sb->s_blocksize_bits; + if (eof_block < map->m_lblk + map_len) + eof_block = map->m_lblk + map_len; + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + zero_ex1.ee_len = 0; + zero_ex2.ee_len = 0; + + trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); + + /* Pre-conditions */ + BUG_ON(!ext4_ext_is_unwritten(ex)); + BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); + + /* + * Attempt to transfer newly initialized blocks from the currently + * unwritten extent to its neighbor. This is much cheaper + * than an insertion followed by a merge as those involve costly + * memmove() calls. Transferring to the left is the common case in + * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE) + * followed by append writes. + * + * Limitations of the current logic: + * - L1: we do not deal with writes covering the whole extent. + * This would require removing the extent if the transfer + * is possible. + * - L2: we only attempt to merge with an extent stored in the + * same extent tree node. + */ + if ((map->m_lblk == ee_block) && + /* See if we can merge left */ + (map_len < ee_len) && /*L1*/ + (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/ + ext4_lblk_t prev_lblk; + ext4_fsblk_t prev_pblk, ee_pblk; + unsigned int prev_len; + + abut_ex = ex - 1; + prev_lblk = le32_to_cpu(abut_ex->ee_block); + prev_len = ext4_ext_get_actual_len(abut_ex); + prev_pblk = ext4_ext_pblock(abut_ex); + ee_pblk = ext4_ext_pblock(ex); + + /* + * A transfer of blocks from 'ex' to 'abut_ex' is allowed + * upon those conditions: + * - C1: abut_ex is initialized, + * - C2: abut_ex is logically abutting ex, + * - C3: abut_ex is physically abutting ex, + * - C4: abut_ex can receive the additional blocks without + * overflowing the (initialized) length limit. + */ + if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ + ((prev_lblk + prev_len) == ee_block) && /*C2*/ + ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ + (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + trace_ext4_ext_convert_to_initialized_fastpath(inode, + map, ex, abut_ex); + + /* Shift the start of ex by 'map_len' blocks */ + ex->ee_block = cpu_to_le32(ee_block + map_len); + ext4_ext_store_pblock(ex, ee_pblk + map_len); + ex->ee_len = cpu_to_le16(ee_len - map_len); + ext4_ext_mark_unwritten(ex); /* Restore the flag */ + + /* Extend abut_ex by 'map_len' blocks */ + abut_ex->ee_len = cpu_to_le16(prev_len + map_len); + + /* Result: number of initialized blocks past m_lblk */ + allocated = map_len; + } + } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) && + (map_len < ee_len) && /*L1*/ + ex < EXT_LAST_EXTENT(eh)) { /*L2*/ + /* See if we can merge right */ + ext4_lblk_t next_lblk; + ext4_fsblk_t next_pblk, ee_pblk; + unsigned int next_len; + + abut_ex = ex + 1; + next_lblk = le32_to_cpu(abut_ex->ee_block); + next_len = ext4_ext_get_actual_len(abut_ex); + next_pblk = ext4_ext_pblock(abut_ex); + ee_pblk = ext4_ext_pblock(ex); + + /* + * A transfer of blocks from 'ex' to 'abut_ex' is allowed + * upon those conditions: + * - C1: abut_ex is initialized, + * - C2: abut_ex is logically abutting ex, + * - C3: abut_ex is physically abutting ex, + * - C4: abut_ex can receive the additional blocks without + * overflowing the (initialized) length limit. + */ + if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ + ((map->m_lblk + map_len) == next_lblk) && /*C2*/ + ((ee_pblk + ee_len) == next_pblk) && /*C3*/ + (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + trace_ext4_ext_convert_to_initialized_fastpath(inode, + map, ex, abut_ex); + + /* Shift the start of abut_ex by 'map_len' blocks */ + abut_ex->ee_block = cpu_to_le32(next_lblk - map_len); + ext4_ext_store_pblock(abut_ex, next_pblk - map_len); + ex->ee_len = cpu_to_le16(ee_len - map_len); + ext4_ext_mark_unwritten(ex); /* Restore the flag */ + + /* Extend abut_ex by 'map_len' blocks */ + abut_ex->ee_len = cpu_to_le16(next_len + map_len); + + /* Result: number of initialized blocks past m_lblk */ + allocated = map_len; + } + } + if (allocated) { + /* Mark the block containing both extents as dirty */ + ext4_ext_dirty(handle, inode, path + depth); + + /* Update path to point to the right extent */ + path[depth].p_ext = abut_ex; + goto out; + } else + allocated = ee_len - (map->m_lblk - ee_block); + + WARN_ON(map->m_lblk < ee_block); + /* + * It is safe to convert extent to initialized via explicit + * zeroout only if extent is fully inside i_size or new_size. + */ + split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; + + if (EXT4_EXT_MAY_ZEROOUT & split_flag) + max_zeroout = sbi->s_extent_max_zeroout_kb >> + (inode->i_sb->s_blocksize_bits - 10); + + if (ext4_encrypted_inode(inode)) + max_zeroout = 0; + + /* + * five cases: + * 1. split the extent into three extents. + * 2. split the extent into two extents, zeroout the head of the first + * extent. + * 3. split the extent into two extents, zeroout the tail of the second + * extent. + * 4. split the extent into two extents with out zeroout. + * 5. no splitting needed, just possibly zeroout the head and / or the + * tail of the extent. + */ + split_map.m_lblk = map->m_lblk; + split_map.m_len = map->m_len; + + if (max_zeroout && (allocated > split_map.m_len)) { + if (allocated <= max_zeroout) { + /* case 3 or 5 */ + zero_ex1.ee_block = + cpu_to_le32(split_map.m_lblk + + split_map.m_len); + zero_ex1.ee_len = + cpu_to_le16(allocated - split_map.m_len); + ext4_ext_store_pblock(&zero_ex1, + ext4_ext_pblock(ex) + split_map.m_lblk + + split_map.m_len - ee_block); + err = ext4_ext_zeroout(inode, &zero_ex1); + if (err) + goto out; + split_map.m_len = allocated; + } + if (split_map.m_lblk - ee_block + split_map.m_len < + max_zeroout) { + /* case 2 or 5 */ + if (split_map.m_lblk != ee_block) { + zero_ex2.ee_block = ex->ee_block; + zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk - + ee_block); + ext4_ext_store_pblock(&zero_ex2, + ext4_ext_pblock(ex)); + err = ext4_ext_zeroout(inode, &zero_ex2); + if (err) + goto out; + } + + split_map.m_len += split_map.m_lblk - ee_block; + split_map.m_lblk = ee_block; + allocated = map->m_len; + } + } + + err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, + flags); + if (err > 0) + err = 0; +out: + /* If we have gotten a failure, don't zero out status tree */ + if (!err) { + err = ext4_zeroout_es(inode, &zero_ex1); + if (!err) + err = ext4_zeroout_es(inode, &zero_ex2); + } + return err ? err : allocated; +} + +/* + * This function is called by ext4_ext_map_blocks() from + * ext4_get_blocks_dio_write() when DIO to write + * to an unwritten extent. + * + * Writing to an unwritten extent may result in splitting the unwritten + * extent into multiple initialized/unwritten extents (up to three) + * There are three possibilities: + * a> There is no split required: Entire extent should be unwritten + * b> Splits in two extents: Write is happening at either end of the extent + * c> Splits in three extents: Somone is writing in middle of the extent + * + * This works the same way in the case of initialized -> unwritten conversion. + * + * One of more index blocks maybe needed if the extent tree grow after + * the unwritten extent split. To prevent ENOSPC occur at the IO + * complete, we need to split the unwritten extent before DIO submit + * the IO. The unwritten extent called at this time will be split + * into three unwritten extent(at most). After IO complete, the part + * being filled will be convert to initialized by the end_io callback function + * via ext4_convert_unwritten_extents(). + * + * Returns the size of unwritten extent to be written on success. + */ +static int ext4_split_convert_extents(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path **ppath, + int flags) +{ + struct ext4_ext_path *path = *ppath; + ext4_lblk_t eof_block; + ext4_lblk_t ee_block; + struct ext4_extent *ex; + unsigned int ee_len; + int split_flag = 0, depth; + + ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n", + __func__, inode->i_ino, + (unsigned long long)map->m_lblk, map->m_len); + + eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) + >> inode->i_sb->s_blocksize_bits; + if (eof_block < map->m_lblk + map->m_len) + eof_block = map->m_lblk + map->m_len; + /* + * It is safe to convert extent to initialized via explicit + * zeroout only if extent is fully insde i_size or new_size. + */ + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + + /* Convert to unwritten */ + if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { + split_flag |= EXT4_EXT_DATA_VALID1; + /* Convert to initialized */ + } else if (flags & EXT4_GET_BLOCKS_CONVERT) { + split_flag |= ee_block + ee_len <= eof_block ? + EXT4_EXT_MAY_ZEROOUT : 0; + split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); + } + flags |= EXT4_GET_BLOCKS_PRE_IO; + return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); +} + +static int ext4_convert_unwritten_extents_endio(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path **ppath) +{ + struct ext4_ext_path *path = *ppath; + struct ext4_extent *ex; + ext4_lblk_t ee_block; + unsigned int ee_len; + int depth; + int err = 0; + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + + ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical" + "block %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)ee_block, ee_len); + + /* If extent is larger than requested it is a clear sign that we still + * have some extent state machine issues left. So extent_split is still + * required. + * TODO: Once all related issues will be fixed this situation should be + * illegal. + */ + if (ee_block != map->m_lblk || ee_len > map->m_len) { +#ifdef CONFIG_EXT4_DEBUG + ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu," + " len %u; IO logical block %llu, len %u", + inode->i_ino, (unsigned long long)ee_block, ee_len, + (unsigned long long)map->m_lblk, map->m_len); +#endif + err = ext4_split_convert_extents(handle, inode, map, ppath, + EXT4_GET_BLOCKS_CONVERT); + if (err < 0) + return err; + path = ext4_find_extent(inode, map->m_lblk, ppath, 0); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = ext_depth(inode); + ex = path[depth].p_ext; + } + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + /* first mark the extent as initialized */ + ext4_ext_mark_initialized(ex); + + /* note: ext4_ext_correct_indexes() isn't needed here because + * borders are not changed + */ + ext4_ext_try_to_merge(handle, inode, path, ex); + + /* Mark modified extent as dirty */ + err = ext4_ext_dirty(handle, inode, path + path->p_depth); +out: + ext4_ext_show_leaf(inode, path); + return err; +} + +/* + * Handle EOFBLOCKS_FL flag, clearing it if necessary + */ +static int check_eofblocks_fl(handle_t *handle, struct inode *inode, + ext4_lblk_t lblk, + struct ext4_ext_path *path, + unsigned int len) +{ + int i, depth; + struct ext4_extent_header *eh; + struct ext4_extent *last_ex; + + if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) + return 0; + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + + /* + * We're going to remove EOFBLOCKS_FL entirely in future so we + * do not care for this case anymore. Simply remove the flag + * if there are no extents. + */ + if (unlikely(!eh->eh_entries)) + goto out; + last_ex = EXT_LAST_EXTENT(eh); + /* + * We should clear the EOFBLOCKS_FL flag if we are writing the + * last block in the last extent in the file. We test this by + * first checking to see if the caller to + * ext4_ext_get_blocks() was interested in the last block (or + * a block beyond the last block) in the current extent. If + * this turns out to be false, we can bail out from this + * function immediately. + */ + if (lblk + len < le32_to_cpu(last_ex->ee_block) + + ext4_ext_get_actual_len(last_ex)) + return 0; + /* + * If the caller does appear to be planning to write at or + * beyond the end of the current extent, we then test to see + * if the current extent is the last extent in the file, by + * checking to make sure it was reached via the rightmost node + * at each level of the tree. + */ + for (i = depth-1; i >= 0; i--) + if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) + return 0; +out: + ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); + return ext4_mark_inode_dirty(handle, inode); +} + +/** + * ext4_find_delalloc_range: find delayed allocated block in the given range. + * + * Return 1 if there is a delalloc block in the range, otherwise 0. + */ +int ext4_find_delalloc_range(struct inode *inode, + ext4_lblk_t lblk_start, + ext4_lblk_t lblk_end) +{ + struct extent_status es; + + ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es); + if (es.es_len == 0) + return 0; /* there is no delay extent in this tree */ + else if (es.es_lblk <= lblk_start && + lblk_start < es.es_lblk + es.es_len) + return 1; + else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end) + return 1; + else + return 0; +} + +int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_lblk_t lblk_start, lblk_end; + lblk_start = EXT4_LBLK_CMASK(sbi, lblk); + lblk_end = lblk_start + sbi->s_cluster_ratio - 1; + + return ext4_find_delalloc_range(inode, lblk_start, lblk_end); +} + +/** + * Determines how many complete clusters (out of those specified by the 'map') + * are under delalloc and were reserved quota for. + * This function is called when we are writing out the blocks that were + * originally written with their allocation delayed, but then the space was + * allocated using fallocate() before the delayed allocation could be resolved. + * The cases to look for are: + * ('=' indicated delayed allocated blocks + * '-' indicates non-delayed allocated blocks) + * (a) partial clusters towards beginning and/or end outside of allocated range + * are not delalloc'ed. + * Ex: + * |----c---=|====c====|====c====|===-c----| + * |++++++ allocated ++++++| + * ==> 4 complete clusters in above example + * + * (b) partial cluster (outside of allocated range) towards either end is + * marked for delayed allocation. In this case, we will exclude that + * cluster. + * Ex: + * |----====c========|========c========| + * |++++++ allocated ++++++| + * ==> 1 complete clusters in above example + * + * Ex: + * |================c================| + * |++++++ allocated ++++++| + * ==> 0 complete clusters in above example + * + * The ext4_da_update_reserve_space will be called only if we + * determine here that there were some "entire" clusters that span + * this 'allocated' range. + * In the non-bigalloc case, this function will just end up returning num_blks + * without ever calling ext4_find_delalloc_range. + */ +static unsigned int +get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start, + unsigned int num_blks) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_lblk_t alloc_cluster_start, alloc_cluster_end; + ext4_lblk_t lblk_from, lblk_to, c_offset; + unsigned int allocated_clusters = 0; + + alloc_cluster_start = EXT4_B2C(sbi, lblk_start); + alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1); + + /* max possible clusters for this allocation */ + allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1; + + trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks); + + /* Check towards left side */ + c_offset = EXT4_LBLK_COFF(sbi, lblk_start); + if (c_offset) { + lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start); + lblk_to = lblk_from + c_offset - 1; + + if (ext4_find_delalloc_range(inode, lblk_from, lblk_to)) + allocated_clusters--; + } + + /* Now check towards right. */ + c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks); + if (allocated_clusters && c_offset) { + lblk_from = lblk_start + num_blks; + lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1; + + if (ext4_find_delalloc_range(inode, lblk_from, lblk_to)) + allocated_clusters--; + } + + return allocated_clusters; +} + +static int +convert_initialized_extent(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path **ppath, + unsigned int allocated) +{ + struct ext4_ext_path *path = *ppath; + struct ext4_extent *ex; + ext4_lblk_t ee_block; + unsigned int ee_len; + int depth; + int err = 0; + + /* + * Make sure that the extent is no bigger than we support with + * unwritten extent + */ + if (map->m_len > EXT_UNWRITTEN_MAX_LEN) + map->m_len = EXT_UNWRITTEN_MAX_LEN / 2; + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + + ext_debug("%s: inode %lu, logical" + "block %llu, max_blocks %u\n", __func__, inode->i_ino, + (unsigned long long)ee_block, ee_len); + + if (ee_block != map->m_lblk || ee_len > map->m_len) { + err = ext4_split_convert_extents(handle, inode, map, ppath, + EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); + if (err < 0) + return err; + path = ext4_find_extent(inode, map->m_lblk, ppath, 0); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = ext_depth(inode); + ex = path[depth].p_ext; + if (!ex) { + EXT4_ERROR_INODE(inode, "unexpected hole at %lu", + (unsigned long) map->m_lblk); + return -EFSCORRUPTED; + } + } + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + return err; + /* first mark the extent as unwritten */ + ext4_ext_mark_unwritten(ex); + + /* note: ext4_ext_correct_indexes() isn't needed here because + * borders are not changed + */ + ext4_ext_try_to_merge(handle, inode, path, ex); + + /* Mark modified extent as dirty */ + err = ext4_ext_dirty(handle, inode, path + path->p_depth); + if (err) + return err; + ext4_ext_show_leaf(inode, path); + + ext4_update_inode_fsync_trans(handle, inode, 1); + err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len); + if (err) + return err; + map->m_flags |= EXT4_MAP_UNWRITTEN; + if (allocated > map->m_len) + allocated = map->m_len; + map->m_len = allocated; + return allocated; +} + +static int +ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path **ppath, int flags, + unsigned int allocated, ext4_fsblk_t newblock) +{ + struct ext4_ext_path *path = *ppath; + int ret = 0; + int err = 0; + + ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical " + "block %llu, max_blocks %u, flags %x, allocated %u\n", + inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, + flags, allocated); + ext4_ext_show_leaf(inode, path); + + /* + * When writing into unwritten space, we should not fail to + * allocate metadata blocks for the new extent block if needed. + */ + flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL; + + trace_ext4_ext_handle_unwritten_extents(inode, map, flags, + allocated, newblock); + + /* get_block() before submit the IO, split the extent */ + if (flags & EXT4_GET_BLOCKS_PRE_IO) { + ret = ext4_split_convert_extents(handle, inode, map, ppath, + flags | EXT4_GET_BLOCKS_CONVERT); + if (ret <= 0) + goto out; + map->m_flags |= EXT4_MAP_UNWRITTEN; + goto out; + } + /* IO end_io complete, convert the filled extent to written */ + if (flags & EXT4_GET_BLOCKS_CONVERT) { + if (flags & EXT4_GET_BLOCKS_ZERO) { + if (allocated > map->m_len) + allocated = map->m_len; + err = ext4_issue_zeroout(inode, map->m_lblk, newblock, + allocated); + if (err < 0) + goto out2; + } + ret = ext4_convert_unwritten_extents_endio(handle, inode, map, + ppath); + if (ret >= 0) { + ext4_update_inode_fsync_trans(handle, inode, 1); + err = check_eofblocks_fl(handle, inode, map->m_lblk, + path, map->m_len); + } else + err = ret; + map->m_flags |= EXT4_MAP_MAPPED; + map->m_pblk = newblock; + if (allocated > map->m_len) + allocated = map->m_len; + map->m_len = allocated; + goto out2; + } + /* buffered IO case */ + /* + * repeat fallocate creation request + * we already have an unwritten extent + */ + if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { + map->m_flags |= EXT4_MAP_UNWRITTEN; + goto map_out; + } + + /* buffered READ or buffered write_begin() lookup */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + /* + * We have blocks reserved already. We + * return allocated blocks so that delalloc + * won't do block reservation for us. But + * the buffer head will be unmapped so that + * a read from the block returns 0s. + */ + map->m_flags |= EXT4_MAP_UNWRITTEN; + goto out1; + } + + /* buffered write, writepage time, convert*/ + ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags); + if (ret >= 0) + ext4_update_inode_fsync_trans(handle, inode, 1); +out: + if (ret <= 0) { + err = ret; + goto out2; + } else + allocated = ret; + map->m_flags |= EXT4_MAP_NEW; + /* + * if we allocated more blocks than requested + * we need to make sure we unmap the extra block + * allocated. The actual needed block will get + * unmapped later when we find the buffer_head marked + * new. + */ + if (allocated > map->m_len) { + clean_bdev_aliases(inode->i_sb->s_bdev, newblock + map->m_len, + allocated - map->m_len); + allocated = map->m_len; + } + map->m_len = allocated; + + /* + * If we have done fallocate with the offset that is already + * delayed allocated, we would have block reservation + * and quota reservation done in the delayed write path. + * But fallocate would have already updated quota and block + * count for this offset. So cancel these reservation + */ + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { + unsigned int reserved_clusters; + reserved_clusters = get_reserved_cluster_alloc(inode, + map->m_lblk, map->m_len); + if (reserved_clusters) + ext4_da_update_reserve_space(inode, + reserved_clusters, + 0); + } + +map_out: + map->m_flags |= EXT4_MAP_MAPPED; + if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) { + err = check_eofblocks_fl(handle, inode, map->m_lblk, path, + map->m_len); + if (err < 0) + goto out2; + } +out1: + if (allocated > map->m_len) + allocated = map->m_len; + ext4_ext_show_leaf(inode, path); + map->m_pblk = newblock; + map->m_len = allocated; +out2: + return err ? err : allocated; +} + +/* + * get_implied_cluster_alloc - check to see if the requested + * allocation (in the map structure) overlaps with a cluster already + * allocated in an extent. + * @sb The filesystem superblock structure + * @map The requested lblk->pblk mapping + * @ex The extent structure which might contain an implied + * cluster allocation + * + * This function is called by ext4_ext_map_blocks() after we failed to + * find blocks that were already in the inode's extent tree. Hence, + * we know that the beginning of the requested region cannot overlap + * the extent from the inode's extent tree. There are three cases we + * want to catch. The first is this case: + * + * |--- cluster # N--| + * |--- extent ---| |---- requested region ---| + * |==========| + * + * The second case that we need to test for is this one: + * + * |--------- cluster # N ----------------| + * |--- requested region --| |------- extent ----| + * |=======================| + * + * The third case is when the requested region lies between two extents + * within the same cluster: + * |------------- cluster # N-------------| + * |----- ex -----| |---- ex_right ----| + * |------ requested region ------| + * |================| + * + * In each of the above cases, we need to set the map->m_pblk and + * map->m_len so it corresponds to the return the extent labelled as + * "|====|" from cluster #N, since it is already in use for data in + * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to + * signal to ext4_ext_map_blocks() that map->m_pblk should be treated + * as a new "allocated" block region. Otherwise, we will return 0 and + * ext4_ext_map_blocks() will then allocate one or more new clusters + * by calling ext4_mb_new_blocks(). + */ +static int get_implied_cluster_alloc(struct super_block *sb, + struct ext4_map_blocks *map, + struct ext4_extent *ex, + struct ext4_ext_path *path) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); + ext4_lblk_t ex_cluster_start, ex_cluster_end; + ext4_lblk_t rr_cluster_start; + ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); + ext4_fsblk_t ee_start = ext4_ext_pblock(ex); + unsigned short ee_len = ext4_ext_get_actual_len(ex); + + /* The extent passed in that we are trying to match */ + ex_cluster_start = EXT4_B2C(sbi, ee_block); + ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); + + /* The requested region passed into ext4_map_blocks() */ + rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); + + if ((rr_cluster_start == ex_cluster_end) || + (rr_cluster_start == ex_cluster_start)) { + if (rr_cluster_start == ex_cluster_end) + ee_start += ee_len - 1; + map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset; + map->m_len = min(map->m_len, + (unsigned) sbi->s_cluster_ratio - c_offset); + /* + * Check for and handle this case: + * + * |--------- cluster # N-------------| + * |------- extent ----| + * |--- requested region ---| + * |===========| + */ + + if (map->m_lblk < ee_block) + map->m_len = min(map->m_len, ee_block - map->m_lblk); + + /* + * Check for the case where there is already another allocated + * block to the right of 'ex' but before the end of the cluster. + * + * |------------- cluster # N-------------| + * |----- ex -----| |---- ex_right ----| + * |------ requested region ------| + * |================| + */ + if (map->m_lblk > ee_block) { + ext4_lblk_t next = ext4_ext_next_allocated_block(path); + map->m_len = min(map->m_len, next - map->m_lblk); + } + + trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); + return 1; + } + + trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); + return 0; +} + + +/* + * Block allocation/map/preallocation routine for extents based files + * + * + * Need to be called with + * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block + * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) + * + * return > 0, number of of blocks already mapped/allocated + * if create == 0 and these are pre-allocated blocks + * buffer head is unmapped + * otherwise blocks are mapped + * + * return = 0, if plain look up failed (blocks have not been allocated) + * buffer head is unmapped + * + * return < 0, error case. + */ +int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, int flags) +{ + struct ext4_ext_path *path = NULL; + struct ext4_extent newex, *ex, *ex2; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_fsblk_t newblock = 0; + int free_on_err = 0, err = 0, depth, ret; + unsigned int allocated = 0, offset = 0; + unsigned int allocated_clusters = 0; + struct ext4_allocation_request ar; + ext4_lblk_t cluster_offset; + bool map_from_cluster = false; + + ext_debug("blocks %u/%u requested for inode %lu\n", + map->m_lblk, map->m_len, inode->i_ino); + trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); + + /* find extent for this block */ + path = ext4_find_extent(inode, map->m_lblk, NULL, 0); + if (IS_ERR(path)) { + err = PTR_ERR(path); + path = NULL; + goto out2; + } + + depth = ext_depth(inode); + + /* + * consistent leaf must not be empty; + * this situation is possible, though, _during_ tree modification; + * this is why assert can't be put in ext4_find_extent() + */ + if (unlikely(path[depth].p_ext == NULL && depth != 0)) { + EXT4_ERROR_INODE(inode, "bad extent address " + "lblock: %lu, depth: %d pblock %lld", + (unsigned long) map->m_lblk, depth, + path[depth].p_block); + err = -EFSCORRUPTED; + goto out2; + } + + ex = path[depth].p_ext; + if (ex) { + ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); + ext4_fsblk_t ee_start = ext4_ext_pblock(ex); + unsigned short ee_len; + + + /* + * unwritten extents are treated as holes, except that + * we split out initialized portions during a write. + */ + ee_len = ext4_ext_get_actual_len(ex); + + trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); + + /* if found extent covers block, simply return it */ + if (in_range(map->m_lblk, ee_block, ee_len)) { + newblock = map->m_lblk - ee_block + ee_start; + /* number of remaining blocks in the extent */ + allocated = ee_len - (map->m_lblk - ee_block); + ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, + ee_block, ee_len, newblock); + + /* + * If the extent is initialized check whether the + * caller wants to convert it to unwritten. + */ + if ((!ext4_ext_is_unwritten(ex)) && + (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) { + allocated = convert_initialized_extent( + handle, inode, map, &path, + allocated); + goto out2; + } else if (!ext4_ext_is_unwritten(ex)) + goto out; + + ret = ext4_ext_handle_unwritten_extents( + handle, inode, map, &path, flags, + allocated, newblock); + if (ret < 0) + err = ret; + else + allocated = ret; + goto out2; + } + } + + /* + * requested block isn't allocated yet; + * we couldn't try to create block if create flag is zero + */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + ext4_lblk_t hole_start, hole_len; + + hole_start = map->m_lblk; + hole_len = ext4_ext_determine_hole(inode, path, &hole_start); + /* + * put just found gap into cache to speed up + * subsequent requests + */ + ext4_ext_put_gap_in_cache(inode, hole_start, hole_len); + + /* Update hole_len to reflect hole size after map->m_lblk */ + if (hole_start != map->m_lblk) + hole_len -= map->m_lblk - hole_start; + map->m_pblk = 0; + map->m_len = min_t(unsigned int, map->m_len, hole_len); + + goto out2; + } + + /* + * Okay, we need to do block allocation. + */ + newex.ee_block = cpu_to_le32(map->m_lblk); + cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); + + /* + * If we are doing bigalloc, check to see if the extent returned + * by ext4_find_extent() implies a cluster we can use. + */ + if (cluster_offset && ex && + get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { + ar.len = allocated = map->m_len; + newblock = map->m_pblk; + map_from_cluster = true; + goto got_allocated_blocks; + } + + /* find neighbour allocated blocks */ + ar.lleft = map->m_lblk; + err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); + if (err) + goto out2; + ar.lright = map->m_lblk; + ex2 = NULL; + err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); + if (err) + goto out2; + + /* Check if the extent after searching to the right implies a + * cluster we can use. */ + if ((sbi->s_cluster_ratio > 1) && ex2 && + get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) { + ar.len = allocated = map->m_len; + newblock = map->m_pblk; + map_from_cluster = true; + goto got_allocated_blocks; + } + + /* + * See if request is beyond maximum number of blocks we can have in + * a single extent. For an initialized extent this limit is + * EXT_INIT_MAX_LEN and for an unwritten extent this limit is + * EXT_UNWRITTEN_MAX_LEN. + */ + if (map->m_len > EXT_INIT_MAX_LEN && + !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) + map->m_len = EXT_INIT_MAX_LEN; + else if (map->m_len > EXT_UNWRITTEN_MAX_LEN && + (flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) + map->m_len = EXT_UNWRITTEN_MAX_LEN; + + /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ + newex.ee_len = cpu_to_le16(map->m_len); + err = ext4_ext_check_overlap(sbi, inode, &newex, path); + if (err) + allocated = ext4_ext_get_actual_len(&newex); + else + allocated = map->m_len; + + /* allocate new block */ + ar.inode = inode; + ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); + ar.logical = map->m_lblk; + /* + * We calculate the offset from the beginning of the cluster + * for the logical block number, since when we allocate a + * physical cluster, the physical block should start at the + * same offset from the beginning of the cluster. This is + * needed so that future calls to get_implied_cluster_alloc() + * work correctly. + */ + offset = EXT4_LBLK_COFF(sbi, map->m_lblk); + ar.len = EXT4_NUM_B2C(sbi, offset+allocated); + ar.goal -= offset; + ar.logical -= offset; + if (S_ISREG(inode->i_mode)) + ar.flags = EXT4_MB_HINT_DATA; + else + /* disable in-core preallocation for non-regular files */ + ar.flags = 0; + if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) + ar.flags |= EXT4_MB_HINT_NOPREALLOC; + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) + ar.flags |= EXT4_MB_DELALLOC_RESERVED; + if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) + ar.flags |= EXT4_MB_USE_RESERVED; + newblock = ext4_mb_new_blocks(handle, &ar, &err); + if (!newblock) + goto out2; + ext_debug("allocate new block: goal %llu, found %llu/%u\n", + ar.goal, newblock, allocated); + free_on_err = 1; + allocated_clusters = ar.len; + ar.len = EXT4_C2B(sbi, ar.len) - offset; + if (ar.len > allocated) + ar.len = allocated; + +got_allocated_blocks: + /* try to insert new extent into found leaf and return */ + ext4_ext_store_pblock(&newex, newblock + offset); + newex.ee_len = cpu_to_le16(ar.len); + /* Mark unwritten */ + if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){ + ext4_ext_mark_unwritten(&newex); + map->m_flags |= EXT4_MAP_UNWRITTEN; + } + + err = 0; + if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) + err = check_eofblocks_fl(handle, inode, map->m_lblk, + path, ar.len); + if (!err) + err = ext4_ext_insert_extent(handle, inode, &path, + &newex, flags); + + if (err && free_on_err) { + int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? + EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; + /* free data blocks we just allocated */ + /* not a good idea to call discard here directly, + * but otherwise we'd need to call it every free() */ + ext4_discard_preallocations(inode); + ext4_free_blocks(handle, inode, NULL, newblock, + EXT4_C2B(sbi, allocated_clusters), fb_flags); + goto out2; + } + + /* previous routine could use block we allocated */ + newblock = ext4_ext_pblock(&newex); + allocated = ext4_ext_get_actual_len(&newex); + if (allocated > map->m_len) + allocated = map->m_len; + map->m_flags |= EXT4_MAP_NEW; + + /* + * Update reserved blocks/metadata blocks after successful + * block allocation which had been deferred till now. + */ + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { + unsigned int reserved_clusters; + /* + * Check how many clusters we had reserved this allocated range + */ + reserved_clusters = get_reserved_cluster_alloc(inode, + map->m_lblk, allocated); + if (!map_from_cluster) { + BUG_ON(allocated_clusters < reserved_clusters); + if (reserved_clusters < allocated_clusters) { + struct ext4_inode_info *ei = EXT4_I(inode); + int reservation = allocated_clusters - + reserved_clusters; + /* + * It seems we claimed few clusters outside of + * the range of this allocation. We should give + * it back to the reservation pool. This can + * happen in the following case: + * + * * Suppose s_cluster_ratio is 4 (i.e., each + * cluster has 4 blocks. Thus, the clusters + * are [0-3],[4-7],[8-11]... + * * First comes delayed allocation write for + * logical blocks 10 & 11. Since there were no + * previous delayed allocated blocks in the + * range [8-11], we would reserve 1 cluster + * for this write. + * * Next comes write for logical blocks 3 to 8. + * In this case, we will reserve 2 clusters + * (for [0-3] and [4-7]; and not for [8-11] as + * that range has a delayed allocated blocks. + * Thus total reserved clusters now becomes 3. + * * Now, during the delayed allocation writeout + * time, we will first write blocks [3-8] and + * allocate 3 clusters for writing these + * blocks. Also, we would claim all these + * three clusters above. + * * Now when we come here to writeout the + * blocks [10-11], we would expect to claim + * the reservation of 1 cluster we had made + * (and we would claim it since there are no + * more delayed allocated blocks in the range + * [8-11]. But our reserved cluster count had + * already gone to 0. + * + * Thus, at the step 4 above when we determine + * that there are still some unwritten delayed + * allocated blocks outside of our current + * block range, we should increment the + * reserved clusters count so that when the + * remaining blocks finally gets written, we + * could claim them. + */ + dquot_reserve_block(inode, + EXT4_C2B(sbi, reservation)); + spin_lock(&ei->i_block_reservation_lock); + ei->i_reserved_data_blocks += reservation; + spin_unlock(&ei->i_block_reservation_lock); + } + /* + * We will claim quota for all newly allocated blocks. + * We're updating the reserved space *after* the + * correction above so we do not accidentally free + * all the metadata reservation because we might + * actually need it later on. + */ + ext4_da_update_reserve_space(inode, allocated_clusters, + 1); + } + } + + /* + * Cache the extent and update transaction to commit on fdatasync only + * when it is _not_ an unwritten extent. + */ + if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0) + ext4_update_inode_fsync_trans(handle, inode, 1); + else + ext4_update_inode_fsync_trans(handle, inode, 0); +out: + if (allocated > map->m_len) + allocated = map->m_len; + ext4_ext_show_leaf(inode, path); + map->m_flags |= EXT4_MAP_MAPPED; + map->m_pblk = newblock; + map->m_len = allocated; +out2: + ext4_ext_drop_refs(path); + kfree(path); + + trace_ext4_ext_map_blocks_exit(inode, flags, map, + err ? err : allocated); + return err ? err : allocated; +} + +int ext4_ext_truncate(handle_t *handle, struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + ext4_lblk_t last_block; + int err = 0; + + /* + * TODO: optimization is possible here. + * Probably we need not scan at all, + * because page truncation is enough. + */ + + /* we have to know where to truncate from in crash case */ + EXT4_I(inode)->i_disksize = inode->i_size; + err = ext4_mark_inode_dirty(handle, inode); + if (err) + return err; + + last_block = (inode->i_size + sb->s_blocksize - 1) + >> EXT4_BLOCK_SIZE_BITS(sb); +retry: + err = ext4_es_remove_extent(inode, last_block, + EXT_MAX_BLOCKS - last_block); + if (err == -ENOMEM) { + cond_resched(); + congestion_wait(BLK_RW_ASYNC, HZ/50); + goto retry; + } + if (err) + return err; + return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); +} + +static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, + ext4_lblk_t len, loff_t new_size, + int flags) +{ + struct inode *inode = file_inode(file); + handle_t *handle; + int ret = 0; + int ret2 = 0; + int retries = 0; + int depth = 0; + struct ext4_map_blocks map; + unsigned int credits; + loff_t epos; + + BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)); + map.m_lblk = offset; + map.m_len = len; + /* + * Don't normalize the request if it can fit in one extent so + * that it doesn't get unnecessarily split into multiple + * extents. + */ + if (len <= EXT_UNWRITTEN_MAX_LEN) + flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; + + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, len); + depth = ext_depth(inode); + +retry: + while (ret >= 0 && len) { + /* + * Recalculate credits when extent tree depth changes. + */ + if (depth != ext_depth(inode)) { + credits = ext4_chunk_trans_blocks(inode, len); + depth = ext_depth(inode); + } + + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, + credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + ret = ext4_map_blocks(handle, inode, &map, flags); + if (ret <= 0) { + ext4_debug("inode #%lu: block %u: len %u: " + "ext4_ext_map_blocks returned %d", + inode->i_ino, map.m_lblk, + map.m_len, ret); + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + break; + } + map.m_lblk += ret; + map.m_len = len = len - ret; + epos = (loff_t)map.m_lblk << inode->i_blkbits; + inode->i_ctime = current_time(inode); + if (new_size) { + if (epos > new_size) + epos = new_size; + if (ext4_update_inode_size(inode, epos) & 0x1) + inode->i_mtime = inode->i_ctime; + } else { + if (epos > inode->i_size) + ext4_set_inode_flag(inode, + EXT4_INODE_EOFBLOCKS); + } + ext4_mark_inode_dirty(handle, inode); + ext4_update_inode_fsync_trans(handle, inode, 1); + ret2 = ext4_journal_stop(handle); + if (ret2) + break; + } + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) { + ret = 0; + goto retry; + } + + return ret > 0 ? ret2 : ret; +} + +static long ext4_zero_range(struct file *file, loff_t offset, + loff_t len, int mode) +{ + struct inode *inode = file_inode(file); + handle_t *handle = NULL; + unsigned int max_blocks; + loff_t new_size = 0; + int ret = 0; + int flags; + int credits; + int partial_begin, partial_end; + loff_t start, end; + ext4_lblk_t lblk; + unsigned int blkbits = inode->i_blkbits; + + trace_ext4_zero_range(inode, offset, len, mode); + + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + + /* Call ext4_force_commit to flush all data in case of data=journal. */ + if (ext4_should_journal_data(inode)) { + ret = ext4_force_commit(inode->i_sb); + if (ret) + return ret; + } + + /* + * Round up offset. This is not fallocate, we neet to zero out + * blocks, so convert interior block aligned part of the range to + * unwritten and possibly manually zero out unaligned parts of the + * range. + */ + start = round_up(offset, 1 << blkbits); + end = round_down((offset + len), 1 << blkbits); + + if (start < offset || end > offset + len) + return -EINVAL; + partial_begin = offset & ((1 << blkbits) - 1); + partial_end = (offset + len) & ((1 << blkbits) - 1); + + lblk = start >> blkbits; + max_blocks = (end >> blkbits); + if (max_blocks < lblk) + max_blocks = 0; + else + max_blocks -= lblk; + + inode_lock(inode); + + /* + * Indirect files do not support unwritten extnets + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + ret = -EOPNOTSUPP; + goto out_mutex; + } + + if (!(mode & FALLOC_FL_KEEP_SIZE) && + (offset + len > i_size_read(inode) || + offset + len > EXT4_I(inode)->i_disksize)) { + new_size = offset + len; + ret = inode_newsize_ok(inode, new_size); + if (ret) + goto out_mutex; + } + + flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; + if (mode & FALLOC_FL_KEEP_SIZE) + flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + + /* Wait all existing dio workers, newcomers will block on i_mutex */ + inode_dio_wait(inode); + + /* Preallocate the range including the unaligned edges */ + if (partial_begin || partial_end) { + ret = ext4_alloc_file_blocks(file, + round_down(offset, 1 << blkbits) >> blkbits, + (round_up((offset + len), 1 << blkbits) - + round_down(offset, 1 << blkbits)) >> blkbits, + new_size, flags); + if (ret) + goto out_mutex; + + } + + /* Zero range excluding the unaligned edges */ + if (max_blocks > 0) { + flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN | + EXT4_EX_NOCACHE); + + /* + * Prevent page faults from reinstantiating pages we have + * released from page cache. + */ + down_write(&EXT4_I(inode)->i_mmap_sem); + + ret = ext4_break_layouts(inode); + if (ret) { + up_write(&EXT4_I(inode)->i_mmap_sem); + goto out_mutex; + } + + ret = ext4_update_disksize_before_punch(inode, offset, len); + if (ret) { + up_write(&EXT4_I(inode)->i_mmap_sem); + goto out_mutex; + } + /* Now release the pages and zero block aligned part of pages */ + truncate_pagecache_range(inode, start, end - 1); + inode->i_mtime = inode->i_ctime = current_time(inode); + + ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, + flags); + up_write(&EXT4_I(inode)->i_mmap_sem); + if (ret) + goto out_mutex; + } + if (!partial_begin && !partial_end) + goto out_mutex; + + /* + * In worst case we have to writeout two nonadjacent unwritten + * blocks and update the inode + */ + credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1; + if (ext4_should_journal_data(inode)) + credits += 2; + handle = ext4_journal_start(inode, EXT4_HT_MISC, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + ext4_std_error(inode->i_sb, ret); + goto out_mutex; + } + + inode->i_mtime = inode->i_ctime = current_time(inode); + if (new_size) { + ext4_update_inode_size(inode, new_size); + } else { + /* + * Mark that we allocate beyond EOF so the subsequent truncate + * can proceed even if the new size is the same as i_size. + */ + if ((offset + len) > i_size_read(inode)) + ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); + } + ext4_mark_inode_dirty(handle, inode); + + /* Zero out partial block at the edges of the range */ + ret = ext4_zero_partial_blocks(handle, inode, offset, len); + if (ret >= 0) + ext4_update_inode_fsync_trans(handle, inode, 1); + + if (file->f_flags & O_SYNC) + ext4_handle_sync(handle); + + ext4_journal_stop(handle); +out_mutex: + inode_unlock(inode); + return ret; +} + +/* + * preallocate space for a file. This implements ext4's fallocate file + * operation, which gets called from sys_fallocate system call. + * For block-mapped files, posix_fallocate should fall back to the method + * of writing zeroes to the required new blocks (the same behavior which is + * expected for file systems which do not support fallocate() system call). + */ +long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) +{ + struct inode *inode = file_inode(file); + loff_t new_size = 0; + unsigned int max_blocks; + int ret = 0; + int flags; + ext4_lblk_t lblk; + unsigned int blkbits = inode->i_blkbits; + + /* + * Encrypted inodes can't handle collapse range or insert + * range since we would need to re-encrypt blocks with a + * different IV or XTS tweak (which are based on the logical + * block number). + * + * XXX It's not clear why zero range isn't working, but we'll + * leave it disabled for encrypted inodes for now. This is a + * bug we should fix.... + */ + if (ext4_encrypted_inode(inode) && + (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | + FALLOC_FL_ZERO_RANGE))) + return -EOPNOTSUPP; + + /* Return error if mode is not supported */ + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | + FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | + FALLOC_FL_INSERT_RANGE)) + return -EOPNOTSUPP; + + if (mode & FALLOC_FL_PUNCH_HOLE) + return ext4_punch_hole(inode, offset, len); + + ret = ext4_convert_inline_data(inode); + if (ret) + return ret; + + if (mode & FALLOC_FL_COLLAPSE_RANGE) + return ext4_collapse_range(inode, offset, len); + + if (mode & FALLOC_FL_INSERT_RANGE) + return ext4_insert_range(inode, offset, len); + + if (mode & FALLOC_FL_ZERO_RANGE) + return ext4_zero_range(file, offset, len, mode); + + trace_ext4_fallocate_enter(inode, offset, len, mode); + lblk = offset >> blkbits; + + max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); + flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; + if (mode & FALLOC_FL_KEEP_SIZE) + flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + + inode_lock(inode); + + /* + * We only support preallocation for extent-based files only + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + ret = -EOPNOTSUPP; + goto out; + } + + if (!(mode & FALLOC_FL_KEEP_SIZE) && + (offset + len > i_size_read(inode) || + offset + len > EXT4_I(inode)->i_disksize)) { + new_size = offset + len; + ret = inode_newsize_ok(inode, new_size); + if (ret) + goto out; + } + + /* Wait all existing dio workers, newcomers will block on i_mutex */ + inode_dio_wait(inode); + + ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); + if (ret) + goto out; + + if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) { + ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal, + EXT4_I(inode)->i_sync_tid); + } +out: + inode_unlock(inode); + trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); + return ret; +} + +/* + * This function convert a range of blocks to written extents + * The caller of this function will pass the start offset and the size. + * all unwritten extents within this range will be converted to + * written extents. + * + * This function is called from the direct IO end io call back + * function, to convert the fallocated extents after IO is completed. + * Returns 0 on success. + */ +int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, + loff_t offset, ssize_t len) +{ + unsigned int max_blocks; + int ret = 0; + int ret2 = 0; + struct ext4_map_blocks map; + unsigned int credits, blkbits = inode->i_blkbits; + + map.m_lblk = offset >> blkbits; + max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); + + /* + * This is somewhat ugly but the idea is clear: When transaction is + * reserved, everything goes into it. Otherwise we rather start several + * smaller transactions for conversion of each extent separately. + */ + if (handle) { + handle = ext4_journal_start_reserved(handle, + EXT4_HT_EXT_CONVERT); + if (IS_ERR(handle)) + return PTR_ERR(handle); + credits = 0; + } else { + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, max_blocks); + } + while (ret >= 0 && ret < max_blocks) { + map.m_lblk += ret; + map.m_len = (max_blocks -= ret); + if (credits) { + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, + credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + } + ret = ext4_map_blocks(handle, inode, &map, + EXT4_GET_BLOCKS_IO_CONVERT_EXT); + if (ret <= 0) + ext4_warning(inode->i_sb, + "inode #%lu: block %u: len %u: " + "ext4_ext_map_blocks returned %d", + inode->i_ino, map.m_lblk, + map.m_len, ret); + ext4_mark_inode_dirty(handle, inode); + if (credits) + ret2 = ext4_journal_stop(handle); + if (ret <= 0 || ret2) + break; + } + if (!credits) + ret2 = ext4_journal_stop(handle); + return ret > 0 ? ret2 : ret; +} + +/* + * If newes is not existing extent (newes->ec_pblk equals zero) find + * delayed extent at start of newes and update newes accordingly and + * return start of the next delayed extent. + * + * If newes is existing extent (newes->ec_pblk is not equal zero) + * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed + * extent found. Leave newes unmodified. + */ +static int ext4_find_delayed_extent(struct inode *inode, + struct extent_status *newes) +{ + struct extent_status es; + ext4_lblk_t block, next_del; + + if (newes->es_pblk == 0) { + ext4_es_find_delayed_extent_range(inode, newes->es_lblk, + newes->es_lblk + newes->es_len - 1, &es); + + /* + * No extent in extent-tree contains block @newes->es_pblk, + * then the block may stay in 1)a hole or 2)delayed-extent. + */ + if (es.es_len == 0) + /* A hole found. */ + return 0; + + if (es.es_lblk > newes->es_lblk) { + /* A hole found. */ + newes->es_len = min(es.es_lblk - newes->es_lblk, + newes->es_len); + return 0; + } + + newes->es_len = es.es_lblk + es.es_len - newes->es_lblk; + } + + block = newes->es_lblk + newes->es_len; + ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es); + if (es.es_len == 0) + next_del = EXT_MAX_BLOCKS; + else + next_del = es.es_lblk; + + return next_del; +} +/* fiemap flags we can handle specified here */ +#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) + +static int ext4_xattr_fiemap(struct inode *inode, + struct fiemap_extent_info *fieinfo) +{ + __u64 physical = 0; + __u64 length; + __u32 flags = FIEMAP_EXTENT_LAST; + int blockbits = inode->i_sb->s_blocksize_bits; + int error = 0; + + /* in-inode? */ + if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { + struct ext4_iloc iloc; + int offset; /* offset of xattr in inode */ + + error = ext4_get_inode_loc(inode, &iloc); + if (error) + return error; + physical = (__u64)iloc.bh->b_blocknr << blockbits; + offset = EXT4_GOOD_OLD_INODE_SIZE + + EXT4_I(inode)->i_extra_isize; + physical += offset; + length = EXT4_SB(inode->i_sb)->s_inode_size - offset; + flags |= FIEMAP_EXTENT_DATA_INLINE; + brelse(iloc.bh); + } else { /* external block */ + physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits; + length = inode->i_sb->s_blocksize; + } + + if (physical) + error = fiemap_fill_next_extent(fieinfo, 0, physical, + length, flags); + return (error < 0 ? error : 0); +} + +int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + __u64 start, __u64 len) +{ + ext4_lblk_t start_blk; + int error = 0; + + if (ext4_has_inline_data(inode)) { + int has_inline = 1; + + error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline, + start, len); + + if (has_inline) + return error; + } + + if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { + error = ext4_ext_precache(inode); + if (error) + return error; + } + + /* fallback to generic here if not in extents fmt */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return generic_block_fiemap(inode, fieinfo, start, len, + ext4_get_block); + + if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) + return -EBADR; + + if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { + error = ext4_xattr_fiemap(inode, fieinfo); + } else { + ext4_lblk_t len_blks; + __u64 last_blk; + + start_blk = start >> inode->i_sb->s_blocksize_bits; + last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; + if (last_blk >= EXT_MAX_BLOCKS) + last_blk = EXT_MAX_BLOCKS-1; + len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; + + /* + * Walk the extent tree gathering extent information + * and pushing extents back to the user. + */ + error = ext4_fill_fiemap_extents(inode, start_blk, + len_blks, fieinfo); + } + return error; +} + +/* + * ext4_access_path: + * Function to access the path buffer for marking it dirty. + * It also checks if there are sufficient credits left in the journal handle + * to update path. + */ +static int +ext4_access_path(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + int credits, err; + + if (!ext4_handle_valid(handle)) + return 0; + + /* + * Check if need to extend journal credits + * 3 for leaf, sb, and inode plus 2 (bmap and group + * descriptor) for each block group; assume two block + * groups + */ + if (handle->h_buffer_credits < 7) { + credits = ext4_writepage_trans_blocks(inode); + err = ext4_ext_truncate_extend_restart(handle, inode, credits); + /* EAGAIN is success */ + if (err && err != -EAGAIN) + return err; + } + + err = ext4_ext_get_access(handle, inode, path); + return err; +} + +/* + * ext4_ext_shift_path_extents: + * Shift the extents of a path structure lying between path[depth].p_ext + * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells + * if it is right shift or left shift operation. + */ +static int +ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, + struct inode *inode, handle_t *handle, + enum SHIFT_DIRECTION SHIFT) +{ + int depth, err = 0; + struct ext4_extent *ex_start, *ex_last; + bool update = 0; + depth = path->p_depth; + + while (depth >= 0) { + if (depth == path->p_depth) { + ex_start = path[depth].p_ext; + if (!ex_start) + return -EFSCORRUPTED; + + ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); + + err = ext4_access_path(handle, inode, path + depth); + if (err) + goto out; + + if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) + update = 1; + + while (ex_start <= ex_last) { + if (SHIFT == SHIFT_LEFT) { + le32_add_cpu(&ex_start->ee_block, + -shift); + /* Try to merge to the left. */ + if ((ex_start > + EXT_FIRST_EXTENT(path[depth].p_hdr)) + && + ext4_ext_try_to_merge_right(inode, + path, ex_start - 1)) + ex_last--; + else + ex_start++; + } else { + le32_add_cpu(&ex_last->ee_block, shift); + ext4_ext_try_to_merge_right(inode, path, + ex_last); + ex_last--; + } + } + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + if (--depth < 0 || !update) + break; + } + + /* Update index too */ + err = ext4_access_path(handle, inode, path + depth); + if (err) + goto out; + + if (SHIFT == SHIFT_LEFT) + le32_add_cpu(&path[depth].p_idx->ei_block, -shift); + else + le32_add_cpu(&path[depth].p_idx->ei_block, shift); + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + /* we are done if current index is not a starting index */ + if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) + break; + + depth--; + } + +out: + return err; +} + +/* + * ext4_ext_shift_extents: + * All the extents which lies in the range from @start to the last allocated + * block for the @inode are shifted either towards left or right (depending + * upon @SHIFT) by @shift blocks. + * On success, 0 is returned, error otherwise. + */ +static int +ext4_ext_shift_extents(struct inode *inode, handle_t *handle, + ext4_lblk_t start, ext4_lblk_t shift, + enum SHIFT_DIRECTION SHIFT) +{ + struct ext4_ext_path *path; + int ret = 0, depth; + struct ext4_extent *extent; + ext4_lblk_t stop, *iterator, ex_start, ex_end; + + /* Let path point to the last extent */ + path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, + EXT4_EX_NOCACHE); + if (IS_ERR(path)) + return PTR_ERR(path); + + depth = path->p_depth; + extent = path[depth].p_ext; + if (!extent) + goto out; + + stop = le32_to_cpu(extent->ee_block); + + /* + * For left shifts, make sure the hole on the left is big enough to + * accommodate the shift. For right shifts, make sure the last extent + * won't be shifted beyond EXT_MAX_BLOCKS. + */ + if (SHIFT == SHIFT_LEFT) { + path = ext4_find_extent(inode, start - 1, &path, + EXT4_EX_NOCACHE); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = path->p_depth; + extent = path[depth].p_ext; + if (extent) { + ex_start = le32_to_cpu(extent->ee_block); + ex_end = le32_to_cpu(extent->ee_block) + + ext4_ext_get_actual_len(extent); + } else { + ex_start = 0; + ex_end = 0; + } + + if ((start == ex_start && shift > ex_start) || + (shift > start - ex_end)) { + ret = -EINVAL; + goto out; + } + } else { + if (shift > EXT_MAX_BLOCKS - + (stop + ext4_ext_get_actual_len(extent))) { + ret = -EINVAL; + goto out; + } + } + + /* + * In case of left shift, iterator points to start and it is increased + * till we reach stop. In case of right shift, iterator points to stop + * and it is decreased till we reach start. + */ + if (SHIFT == SHIFT_LEFT) + iterator = &start; + else + iterator = &stop; + + /* + * Its safe to start updating extents. Start and stop are unsigned, so + * in case of right shift if extent with 0 block is reached, iterator + * becomes NULL to indicate the end of the loop. + */ + while (iterator && start <= stop) { + path = ext4_find_extent(inode, *iterator, &path, + EXT4_EX_NOCACHE); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = path->p_depth; + extent = path[depth].p_ext; + if (!extent) { + EXT4_ERROR_INODE(inode, "unexpected hole at %lu", + (unsigned long) *iterator); + return -EFSCORRUPTED; + } + if (SHIFT == SHIFT_LEFT && *iterator > + le32_to_cpu(extent->ee_block)) { + /* Hole, move to the next extent */ + if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) { + path[depth].p_ext++; + } else { + *iterator = ext4_ext_next_allocated_block(path); + continue; + } + } + + if (SHIFT == SHIFT_LEFT) { + extent = EXT_LAST_EXTENT(path[depth].p_hdr); + *iterator = le32_to_cpu(extent->ee_block) + + ext4_ext_get_actual_len(extent); + } else { + extent = EXT_FIRST_EXTENT(path[depth].p_hdr); + if (le32_to_cpu(extent->ee_block) > 0) + *iterator = le32_to_cpu(extent->ee_block) - 1; + else + /* Beginning is reached, end of the loop */ + iterator = NULL; + /* Update path extent in case we need to stop */ + while (le32_to_cpu(extent->ee_block) < start) + extent++; + path[depth].p_ext = extent; + } + ret = ext4_ext_shift_path_extents(path, shift, inode, + handle, SHIFT); + if (ret) + break; + } +out: + ext4_ext_drop_refs(path); + kfree(path); + return ret; +} + +/* + * ext4_collapse_range: + * This implements the fallocate's collapse range functionality for ext4 + * Returns: 0 and non-zero on error. + */ +int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) +{ + struct super_block *sb = inode->i_sb; + ext4_lblk_t punch_start, punch_stop; + handle_t *handle; + unsigned int credits; + loff_t new_size, ioffset; + int ret; + + /* + * We need to test this early because xfstests assumes that a + * collapse range of (0, 1) will return EOPNOTSUPP if the file + * system does not support collapse range. + */ + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + return -EOPNOTSUPP; + + /* Collapse range works only on fs block size aligned offsets. */ + if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || + len & (EXT4_CLUSTER_SIZE(sb) - 1)) + return -EINVAL; + + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + + trace_ext4_collapse_range(inode, offset, len); + + punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); + punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); + + /* Call ext4_force_commit to flush all data in case of data=journal. */ + if (ext4_should_journal_data(inode)) { + ret = ext4_force_commit(inode->i_sb); + if (ret) + return ret; + } + + inode_lock(inode); + /* + * There is no need to overlap collapse range with EOF, in which case + * it is effectively a truncate operation + */ + if (offset + len >= i_size_read(inode)) { + ret = -EINVAL; + goto out_mutex; + } + + /* Currently just for extent based files */ + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + ret = -EOPNOTSUPP; + goto out_mutex; + } + + /* Wait for existing dio to complete */ + inode_dio_wait(inode); + + /* + * Prevent page faults from reinstantiating pages we have released from + * page cache. + */ + down_write(&EXT4_I(inode)->i_mmap_sem); + + ret = ext4_break_layouts(inode); + if (ret) + goto out_mmap; + + /* + * Need to round down offset to be aligned with page size boundary + * for page size > block size. + */ + ioffset = round_down(offset, PAGE_SIZE); + /* + * Write tail of the last page before removed range since it will get + * removed from the page cache below. + */ + ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset); + if (ret) + goto out_mmap; + /* + * Write data that will be shifted to preserve them when discarding + * page cache below. We are also protected from pages becoming dirty + * by i_mmap_sem. + */ + ret = filemap_write_and_wait_range(inode->i_mapping, offset + len, + LLONG_MAX); + if (ret) + goto out_mmap; + truncate_pagecache(inode, ioffset); + + credits = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_mmap; + } + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_discard_preallocations(inode); + + ret = ext4_es_remove_extent(inode, punch_start, + EXT_MAX_BLOCKS - punch_start); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + ext4_discard_preallocations(inode); + + ret = ext4_ext_shift_extents(inode, handle, punch_stop, + punch_stop - punch_start, SHIFT_LEFT); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + new_size = i_size_read(inode) - len; + i_size_write(inode, new_size); + EXT4_I(inode)->i_disksize = new_size; + + up_write(&EXT4_I(inode)->i_data_sem); + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + inode->i_mtime = inode->i_ctime = current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_update_inode_fsync_trans(handle, inode, 1); + +out_stop: + ext4_journal_stop(handle); +out_mmap: + up_write(&EXT4_I(inode)->i_mmap_sem); +out_mutex: + inode_unlock(inode); + return ret; +} + +/* + * ext4_insert_range: + * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. + * The data blocks starting from @offset to the EOF are shifted by @len + * towards right to create a hole in the @inode. Inode size is increased + * by len bytes. + * Returns 0 on success, error otherwise. + */ +int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) +{ + struct super_block *sb = inode->i_sb; + handle_t *handle; + struct ext4_ext_path *path; + struct ext4_extent *extent; + ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0; + unsigned int credits, ee_len; + int ret = 0, depth, split_flag = 0; + loff_t ioffset; + + /* + * We need to test this early because xfstests assumes that an + * insert range of (0, 1) will return EOPNOTSUPP if the file + * system does not support insert range. + */ + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + return -EOPNOTSUPP; + + /* Insert range works only on fs block size aligned offsets. */ + if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || + len & (EXT4_CLUSTER_SIZE(sb) - 1)) + return -EINVAL; + + if (!S_ISREG(inode->i_mode)) + return -EOPNOTSUPP; + + trace_ext4_insert_range(inode, offset, len); + + offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb); + len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb); + + /* Call ext4_force_commit to flush all data in case of data=journal */ + if (ext4_should_journal_data(inode)) { + ret = ext4_force_commit(inode->i_sb); + if (ret) + return ret; + } + + inode_lock(inode); + /* Currently just for extent based files */ + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + ret = -EOPNOTSUPP; + goto out_mutex; + } + + /* Check for wrap through zero */ + if (inode->i_size + len > inode->i_sb->s_maxbytes) { + ret = -EFBIG; + goto out_mutex; + } + + /* Offset should be less than i_size */ + if (offset >= i_size_read(inode)) { + ret = -EINVAL; + goto out_mutex; + } + + /* Wait for existing dio to complete */ + inode_dio_wait(inode); + + /* + * Prevent page faults from reinstantiating pages we have released from + * page cache. + */ + down_write(&EXT4_I(inode)->i_mmap_sem); + + ret = ext4_break_layouts(inode); + if (ret) + goto out_mmap; + + /* + * Need to round down to align start offset to page size boundary + * for page size > block size. + */ + ioffset = round_down(offset, PAGE_SIZE); + /* Write out all dirty pages */ + ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, + LLONG_MAX); + if (ret) + goto out_mmap; + truncate_pagecache(inode, ioffset); + + credits = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_mmap; + } + + /* Expand file to avoid data loss if there is error while shifting */ + inode->i_size += len; + EXT4_I(inode)->i_disksize += len; + inode->i_mtime = inode->i_ctime = current_time(inode); + ret = ext4_mark_inode_dirty(handle, inode); + if (ret) + goto out_stop; + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_discard_preallocations(inode); + + path = ext4_find_extent(inode, offset_lblk, NULL, 0); + if (IS_ERR(path)) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + depth = ext_depth(inode); + extent = path[depth].p_ext; + if (extent) { + ee_start_lblk = le32_to_cpu(extent->ee_block); + ee_len = ext4_ext_get_actual_len(extent); + + /* + * If offset_lblk is not the starting block of extent, split + * the extent @offset_lblk + */ + if ((offset_lblk > ee_start_lblk) && + (offset_lblk < (ee_start_lblk + ee_len))) { + if (ext4_ext_is_unwritten(extent)) + split_flag = EXT4_EXT_MARK_UNWRIT1 | + EXT4_EXT_MARK_UNWRIT2; + ret = ext4_split_extent_at(handle, inode, &path, + offset_lblk, split_flag, + EXT4_EX_NOCACHE | + EXT4_GET_BLOCKS_PRE_IO | + EXT4_GET_BLOCKS_METADATA_NOFAIL); + } + + ext4_ext_drop_refs(path); + kfree(path); + if (ret < 0) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + } else { + ext4_ext_drop_refs(path); + kfree(path); + } + + ret = ext4_es_remove_extent(inode, offset_lblk, + EXT_MAX_BLOCKS - offset_lblk); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + /* + * if offset_lblk lies in a hole which is at start of file, use + * ee_start_lblk to shift extents + */ + ret = ext4_ext_shift_extents(inode, handle, + ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk, + len_lblk, SHIFT_RIGHT); + + up_write(&EXT4_I(inode)->i_data_sem); + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + if (ret >= 0) + ext4_update_inode_fsync_trans(handle, inode, 1); + +out_stop: + ext4_journal_stop(handle); +out_mmap: + up_write(&EXT4_I(inode)->i_mmap_sem); +out_mutex: + inode_unlock(inode); + return ret; +} + +/** + * ext4_swap_extents - Swap extents between two inodes + * + * @inode1: First inode + * @inode2: Second inode + * @lblk1: Start block for first inode + * @lblk2: Start block for second inode + * @count: Number of blocks to swap + * @unwritten: Mark second inode's extents as unwritten after swap + * @erp: Pointer to save error value + * + * This helper routine does exactly what is promise "swap extents". All other + * stuff such as page-cache locking consistency, bh mapping consistency or + * extent's data copying must be performed by caller. + * Locking: + * i_mutex is held for both inodes + * i_data_sem is locked for write for both inodes + * Assumptions: + * All pages from requested range are locked for both inodes + */ +int +ext4_swap_extents(handle_t *handle, struct inode *inode1, + struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, + ext4_lblk_t count, int unwritten, int *erp) +{ + struct ext4_ext_path *path1 = NULL; + struct ext4_ext_path *path2 = NULL; + int replaced_count = 0; + + BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); + BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); + BUG_ON(!inode_is_locked(inode1)); + BUG_ON(!inode_is_locked(inode2)); + + *erp = ext4_es_remove_extent(inode1, lblk1, count); + if (unlikely(*erp)) + return 0; + *erp = ext4_es_remove_extent(inode2, lblk2, count); + if (unlikely(*erp)) + return 0; + + while (count) { + struct ext4_extent *ex1, *ex2, tmp_ex; + ext4_lblk_t e1_blk, e2_blk; + int e1_len, e2_len, len; + int split = 0; + + path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE); + if (IS_ERR(path1)) { + *erp = PTR_ERR(path1); + path1 = NULL; + finish: + count = 0; + goto repeat; + } + path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE); + if (IS_ERR(path2)) { + *erp = PTR_ERR(path2); + path2 = NULL; + goto finish; + } + ex1 = path1[path1->p_depth].p_ext; + ex2 = path2[path2->p_depth].p_ext; + /* Do we have somthing to swap ? */ + if (unlikely(!ex2 || !ex1)) + goto finish; + + e1_blk = le32_to_cpu(ex1->ee_block); + e2_blk = le32_to_cpu(ex2->ee_block); + e1_len = ext4_ext_get_actual_len(ex1); + e2_len = ext4_ext_get_actual_len(ex2); + + /* Hole handling */ + if (!in_range(lblk1, e1_blk, e1_len) || + !in_range(lblk2, e2_blk, e2_len)) { + ext4_lblk_t next1, next2; + + /* if hole after extent, then go to next extent */ + next1 = ext4_ext_next_allocated_block(path1); + next2 = ext4_ext_next_allocated_block(path2); + /* If hole before extent, then shift to that extent */ + if (e1_blk > lblk1) + next1 = e1_blk; + if (e2_blk > lblk2) + next2 = e2_blk; + /* Do we have something to swap */ + if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS) + goto finish; + /* Move to the rightest boundary */ + len = next1 - lblk1; + if (len < next2 - lblk2) + len = next2 - lblk2; + if (len > count) + len = count; + lblk1 += len; + lblk2 += len; + count -= len; + goto repeat; + } + + /* Prepare left boundary */ + if (e1_blk < lblk1) { + split = 1; + *erp = ext4_force_split_extent_at(handle, inode1, + &path1, lblk1, 0); + if (unlikely(*erp)) + goto finish; + } + if (e2_blk < lblk2) { + split = 1; + *erp = ext4_force_split_extent_at(handle, inode2, + &path2, lblk2, 0); + if (unlikely(*erp)) + goto finish; + } + /* ext4_split_extent_at() may result in leaf extent split, + * path must to be revalidated. */ + if (split) + goto repeat; + + /* Prepare right boundary */ + len = count; + if (len > e1_blk + e1_len - lblk1) + len = e1_blk + e1_len - lblk1; + if (len > e2_blk + e2_len - lblk2) + len = e2_blk + e2_len - lblk2; + + if (len != e1_len) { + split = 1; + *erp = ext4_force_split_extent_at(handle, inode1, + &path1, lblk1 + len, 0); + if (unlikely(*erp)) + goto finish; + } + if (len != e2_len) { + split = 1; + *erp = ext4_force_split_extent_at(handle, inode2, + &path2, lblk2 + len, 0); + if (*erp) + goto finish; + } + /* ext4_split_extent_at() may result in leaf extent split, + * path must to be revalidated. */ + if (split) + goto repeat; + + BUG_ON(e2_len != e1_len); + *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth); + if (unlikely(*erp)) + goto finish; + *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth); + if (unlikely(*erp)) + goto finish; + + /* Both extents are fully inside boundaries. Swap it now */ + tmp_ex = *ex1; + ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2)); + ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex)); + ex1->ee_len = cpu_to_le16(e2_len); + ex2->ee_len = cpu_to_le16(e1_len); + if (unwritten) + ext4_ext_mark_unwritten(ex2); + if (ext4_ext_is_unwritten(&tmp_ex)) + ext4_ext_mark_unwritten(ex1); + + ext4_ext_try_to_merge(handle, inode2, path2, ex2); + ext4_ext_try_to_merge(handle, inode1, path1, ex1); + *erp = ext4_ext_dirty(handle, inode2, path2 + + path2->p_depth); + if (unlikely(*erp)) + goto finish; + *erp = ext4_ext_dirty(handle, inode1, path1 + + path1->p_depth); + /* + * Looks scarry ah..? second inode already points to new blocks, + * and it was successfully dirtied. But luckily error may happen + * only due to journal error, so full transaction will be + * aborted anyway. + */ + if (unlikely(*erp)) + goto finish; + lblk1 += len; + lblk2 += len; + replaced_count += len; + count -= len; + + repeat: + ext4_ext_drop_refs(path1); + kfree(path1); + ext4_ext_drop_refs(path2); + kfree(path2); + path1 = path2 = NULL; + } + return replaced_count; +} |