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Diffstat (limited to '')
| -rw-r--r-- | fs/gfs2/bmap.c | 2536 |
1 files changed, 2536 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c new file mode 100644 index 000000000..eaee95d2a --- /dev/null +++ b/fs/gfs2/bmap.c @@ -0,0 +1,2536 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/blkdev.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> +#include <linux/iomap.h> +#include <linux/ktime.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.h" +#include "glock.h" +#include "inode.h" +#include "meta_io.h" +#include "quota.h" +#include "rgrp.h" +#include "log.h" +#include "super.h" +#include "trans.h" +#include "dir.h" +#include "util.h" +#include "aops.h" +#include "trace_gfs2.h" + +/* This doesn't need to be that large as max 64 bit pointers in a 4k + * block is 512, so __u16 is fine for that. It saves stack space to + * keep it small. + */ +struct metapath { + struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT]; + __u16 mp_list[GFS2_MAX_META_HEIGHT]; + int mp_fheight; /* find_metapath height */ + int mp_aheight; /* actual height (lookup height) */ +}; + +static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length); + +/** + * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page + * @ip: the inode + * @dibh: the dinode buffer + * @block: the block number that was allocated + * @page: The (optional) page. This is looked up if @page is NULL + * + * Returns: errno + */ + +static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, + u64 block, struct page *page) +{ + struct inode *inode = &ip->i_inode; + int release = 0; + + if (!page || page->index) { + page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS); + if (!page) + return -ENOMEM; + release = 1; + } + + if (!PageUptodate(page)) { + void *kaddr = kmap(page); + u64 dsize = i_size_read(inode); + + memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); + memset(kaddr + dsize, 0, PAGE_SIZE - dsize); + kunmap(page); + + SetPageUptodate(page); + } + + if (gfs2_is_jdata(ip)) { + struct buffer_head *bh; + + if (!page_has_buffers(page)) + create_empty_buffers(page, BIT(inode->i_blkbits), + BIT(BH_Uptodate)); + + bh = page_buffers(page); + if (!buffer_mapped(bh)) + map_bh(bh, inode->i_sb, block); + + set_buffer_uptodate(bh); + gfs2_trans_add_data(ip->i_gl, bh); + } else { + set_page_dirty(page); + gfs2_ordered_add_inode(ip); + } + + if (release) { + unlock_page(page); + put_page(page); + } + + return 0; +} + +/** + * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big + * @ip: The GFS2 inode to unstuff + * @page: The (optional) page. This is looked up if the @page is NULL + * + * This routine unstuffs a dinode and returns it to a "normal" state such + * that the height can be grown in the traditional way. + * + * Returns: errno + */ + +int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page) +{ + struct buffer_head *bh, *dibh; + struct gfs2_dinode *di; + u64 block = 0; + int isdir = gfs2_is_dir(ip); + int error; + + down_write(&ip->i_rw_mutex); + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out; + + if (i_size_read(&ip->i_inode)) { + /* Get a free block, fill it with the stuffed data, + and write it out to disk */ + + unsigned int n = 1; + error = gfs2_alloc_blocks(ip, &block, &n, 0, NULL); + if (error) + goto out_brelse; + if (isdir) { + gfs2_trans_remove_revoke(GFS2_SB(&ip->i_inode), block, 1); + error = gfs2_dir_get_new_buffer(ip, block, &bh); + if (error) + goto out_brelse; + gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header), + dibh, sizeof(struct gfs2_dinode)); + brelse(bh); + } else { + error = gfs2_unstuffer_page(ip, dibh, block, page); + if (error) + goto out_brelse; + } + } + + /* Set up the pointer to the new block */ + + gfs2_trans_add_meta(ip->i_gl, dibh); + di = (struct gfs2_dinode *)dibh->b_data; + gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); + + if (i_size_read(&ip->i_inode)) { + *(__be64 *)(di + 1) = cpu_to_be64(block); + gfs2_add_inode_blocks(&ip->i_inode, 1); + di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode)); + } + + ip->i_height = 1; + di->di_height = cpu_to_be16(1); + +out_brelse: + brelse(dibh); +out: + up_write(&ip->i_rw_mutex); + return error; +} + + +/** + * find_metapath - Find path through the metadata tree + * @sdp: The superblock + * @block: The disk block to look up + * @mp: The metapath to return the result in + * @height: The pre-calculated height of the metadata tree + * + * This routine returns a struct metapath structure that defines a path + * through the metadata of inode "ip" to get to block "block". + * + * Example: + * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a + * filesystem with a blocksize of 4096. + * + * find_metapath() would return a struct metapath structure set to: + * mp_fheight = 3, mp_list[0] = 0, mp_list[1] = 48, and mp_list[2] = 165. + * + * That means that in order to get to the block containing the byte at + * offset 101342453, we would load the indirect block pointed to by pointer + * 0 in the dinode. We would then load the indirect block pointed to by + * pointer 48 in that indirect block. We would then load the data block + * pointed to by pointer 165 in that indirect block. + * + * ---------------------------------------- + * | Dinode | | + * | | 4| + * | |0 1 2 3 4 5 9| + * | | 6| + * ---------------------------------------- + * | + * | + * V + * ---------------------------------------- + * | Indirect Block | + * | 5| + * | 4 4 4 4 4 5 5 1| + * |0 5 6 7 8 9 0 1 2| + * ---------------------------------------- + * | + * | + * V + * ---------------------------------------- + * | Indirect Block | + * | 1 1 1 1 1 5| + * | 6 6 6 6 6 1| + * |0 3 4 5 6 7 2| + * ---------------------------------------- + * | + * | + * V + * ---------------------------------------- + * | Data block containing offset | + * | 101342453 | + * | | + * | | + * ---------------------------------------- + * + */ + +static void find_metapath(const struct gfs2_sbd *sdp, u64 block, + struct metapath *mp, unsigned int height) +{ + unsigned int i; + + mp->mp_fheight = height; + for (i = height; i--;) + mp->mp_list[i] = do_div(block, sdp->sd_inptrs); +} + +static inline unsigned int metapath_branch_start(const struct metapath *mp) +{ + if (mp->mp_list[0] == 0) + return 2; + return 1; +} + +/** + * metaptr1 - Return the first possible metadata pointer in a metapath buffer + * @height: The metadata height (0 = dinode) + * @mp: The metapath + */ +static inline __be64 *metaptr1(unsigned int height, const struct metapath *mp) +{ + struct buffer_head *bh = mp->mp_bh[height]; + if (height == 0) + return ((__be64 *)(bh->b_data + sizeof(struct gfs2_dinode))); + return ((__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header))); +} + +/** + * metapointer - Return pointer to start of metadata in a buffer + * @height: The metadata height (0 = dinode) + * @mp: The metapath + * + * Return a pointer to the block number of the next height of the metadata + * tree given a buffer containing the pointer to the current height of the + * metadata tree. + */ + +static inline __be64 *metapointer(unsigned int height, const struct metapath *mp) +{ + __be64 *p = metaptr1(height, mp); + return p + mp->mp_list[height]; +} + +static inline const __be64 *metaend(unsigned int height, const struct metapath *mp) +{ + const struct buffer_head *bh = mp->mp_bh[height]; + return (const __be64 *)(bh->b_data + bh->b_size); +} + +static void clone_metapath(struct metapath *clone, struct metapath *mp) +{ + unsigned int hgt; + + *clone = *mp; + for (hgt = 0; hgt < mp->mp_aheight; hgt++) + get_bh(clone->mp_bh[hgt]); +} + +static void gfs2_metapath_ra(struct gfs2_glock *gl, __be64 *start, __be64 *end) +{ + const __be64 *t; + + for (t = start; t < end; t++) { + struct buffer_head *rabh; + + if (!*t) + continue; + + rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE); + if (trylock_buffer(rabh)) { + if (!buffer_uptodate(rabh)) { + rabh->b_end_io = end_buffer_read_sync; + submit_bh(REQ_OP_READ, + REQ_RAHEAD | REQ_META | REQ_PRIO, + rabh); + continue; + } + unlock_buffer(rabh); + } + brelse(rabh); + } +} + +static int __fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, + unsigned int x, unsigned int h) +{ + for (; x < h; x++) { + __be64 *ptr = metapointer(x, mp); + u64 dblock = be64_to_cpu(*ptr); + int ret; + + if (!dblock) + break; + ret = gfs2_meta_indirect_buffer(ip, x + 1, dblock, &mp->mp_bh[x + 1]); + if (ret) + return ret; + } + mp->mp_aheight = x + 1; + return 0; +} + +/** + * lookup_metapath - Walk the metadata tree to a specific point + * @ip: The inode + * @mp: The metapath + * + * Assumes that the inode's buffer has already been looked up and + * hooked onto mp->mp_bh[0] and that the metapath has been initialised + * by find_metapath(). + * + * If this function encounters part of the tree which has not been + * allocated, it returns the current height of the tree at the point + * at which it found the unallocated block. Blocks which are found are + * added to the mp->mp_bh[] list. + * + * Returns: error + */ + +static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp) +{ + return __fillup_metapath(ip, mp, 0, ip->i_height - 1); +} + +/** + * fillup_metapath - fill up buffers for the metadata path to a specific height + * @ip: The inode + * @mp: The metapath + * @h: The height to which it should be mapped + * + * Similar to lookup_metapath, but does lookups for a range of heights + * + * Returns: error or the number of buffers filled + */ + +static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h) +{ + unsigned int x = 0; + int ret; + + if (h) { + /* find the first buffer we need to look up. */ + for (x = h - 1; x > 0; x--) { + if (mp->mp_bh[x]) + break; + } + } + ret = __fillup_metapath(ip, mp, x, h); + if (ret) + return ret; + return mp->mp_aheight - x - 1; +} + +static sector_t metapath_to_block(struct gfs2_sbd *sdp, struct metapath *mp) +{ + sector_t factor = 1, block = 0; + int hgt; + + for (hgt = mp->mp_fheight - 1; hgt >= 0; hgt--) { + if (hgt < mp->mp_aheight) + block += mp->mp_list[hgt] * factor; + factor *= sdp->sd_inptrs; + } + return block; +} + +static void release_metapath(struct metapath *mp) +{ + int i; + + for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) { + if (mp->mp_bh[i] == NULL) + break; + brelse(mp->mp_bh[i]); + mp->mp_bh[i] = NULL; + } +} + +/** + * gfs2_extent_length - Returns length of an extent of blocks + * @bh: The metadata block + * @ptr: Current position in @bh + * @limit: Max extent length to return + * @eob: Set to 1 if we hit "end of block" + * + * Returns: The length of the extent (minimum of one block) + */ + +static inline unsigned int gfs2_extent_length(struct buffer_head *bh, __be64 *ptr, size_t limit, int *eob) +{ + const __be64 *end = (__be64 *)(bh->b_data + bh->b_size); + const __be64 *first = ptr; + u64 d = be64_to_cpu(*ptr); + + *eob = 0; + do { + ptr++; + if (ptr >= end) + break; + d++; + } while(be64_to_cpu(*ptr) == d); + if (ptr >= end) + *eob = 1; + return ptr - first; +} + +enum walker_status { WALK_STOP, WALK_FOLLOW, WALK_CONTINUE }; + +/* + * gfs2_metadata_walker - walk an indirect block + * @mp: Metapath to indirect block + * @ptrs: Number of pointers to look at + * + * When returning WALK_FOLLOW, the walker must update @mp to point at the right + * indirect block to follow. + */ +typedef enum walker_status (*gfs2_metadata_walker)(struct metapath *mp, + unsigned int ptrs); + +/* + * gfs2_walk_metadata - walk a tree of indirect blocks + * @inode: The inode + * @mp: Starting point of walk + * @max_len: Maximum number of blocks to walk + * @walker: Called during the walk + * + * Returns 1 if the walk was stopped by @walker, 0 if we went past @max_len or + * past the end of metadata, and a negative error code otherwise. + */ + +static int gfs2_walk_metadata(struct inode *inode, struct metapath *mp, + u64 max_len, gfs2_metadata_walker walker) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + u64 factor = 1; + unsigned int hgt; + int ret; + + /* + * The walk starts in the lowest allocated indirect block, which may be + * before the position indicated by @mp. Adjust @max_len accordingly + * to avoid a short walk. + */ + for (hgt = mp->mp_fheight - 1; hgt >= mp->mp_aheight; hgt--) { + max_len += mp->mp_list[hgt] * factor; + mp->mp_list[hgt] = 0; + factor *= sdp->sd_inptrs; + } + + for (;;) { + u16 start = mp->mp_list[hgt]; + enum walker_status status; + unsigned int ptrs; + u64 len; + + /* Walk indirect block. */ + ptrs = (hgt >= 1 ? sdp->sd_inptrs : sdp->sd_diptrs) - start; + len = ptrs * factor; + if (len > max_len) + ptrs = DIV_ROUND_UP_ULL(max_len, factor); + status = walker(mp, ptrs); + switch (status) { + case WALK_STOP: + return 1; + case WALK_FOLLOW: + BUG_ON(mp->mp_aheight == mp->mp_fheight); + ptrs = mp->mp_list[hgt] - start; + len = ptrs * factor; + break; + case WALK_CONTINUE: + break; + } + if (len >= max_len) + break; + max_len -= len; + if (status == WALK_FOLLOW) + goto fill_up_metapath; + +lower_metapath: + /* Decrease height of metapath. */ + brelse(mp->mp_bh[hgt]); + mp->mp_bh[hgt] = NULL; + mp->mp_list[hgt] = 0; + if (!hgt) + break; + hgt--; + factor *= sdp->sd_inptrs; + + /* Advance in metadata tree. */ + (mp->mp_list[hgt])++; + if (hgt) { + if (mp->mp_list[hgt] >= sdp->sd_inptrs) + goto lower_metapath; + } else { + if (mp->mp_list[hgt] >= sdp->sd_diptrs) + break; + } + +fill_up_metapath: + /* Increase height of metapath. */ + ret = fillup_metapath(ip, mp, ip->i_height - 1); + if (ret < 0) + return ret; + hgt += ret; + for (; ret; ret--) + do_div(factor, sdp->sd_inptrs); + mp->mp_aheight = hgt + 1; + } + return 0; +} + +static enum walker_status gfs2_hole_walker(struct metapath *mp, + unsigned int ptrs) +{ + const __be64 *start, *ptr, *end; + unsigned int hgt; + + hgt = mp->mp_aheight - 1; + start = metapointer(hgt, mp); + end = start + ptrs; + + for (ptr = start; ptr < end; ptr++) { + if (*ptr) { + mp->mp_list[hgt] += ptr - start; + if (mp->mp_aheight == mp->mp_fheight) + return WALK_STOP; + return WALK_FOLLOW; + } + } + return WALK_CONTINUE; +} + +/** + * gfs2_hole_size - figure out the size of a hole + * @inode: The inode + * @lblock: The logical starting block number + * @len: How far to look (in blocks) + * @mp: The metapath at lblock + * @iomap: The iomap to store the hole size in + * + * This function modifies @mp. + * + * Returns: errno on error + */ +static int gfs2_hole_size(struct inode *inode, sector_t lblock, u64 len, + struct metapath *mp, struct iomap *iomap) +{ + struct metapath clone; + u64 hole_size; + int ret; + + clone_metapath(&clone, mp); + ret = gfs2_walk_metadata(inode, &clone, len, gfs2_hole_walker); + if (ret < 0) + goto out; + + if (ret == 1) + hole_size = metapath_to_block(GFS2_SB(inode), &clone) - lblock; + else + hole_size = len; + iomap->length = hole_size << inode->i_blkbits; + ret = 0; + +out: + release_metapath(&clone); + return ret; +} + +static inline __be64 *gfs2_indirect_init(struct metapath *mp, + struct gfs2_glock *gl, unsigned int i, + unsigned offset, u64 bn) +{ + __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data + + ((i > 1) ? sizeof(struct gfs2_meta_header) : + sizeof(struct gfs2_dinode))); + BUG_ON(i < 1); + BUG_ON(mp->mp_bh[i] != NULL); + mp->mp_bh[i] = gfs2_meta_new(gl, bn); + gfs2_trans_add_meta(gl, mp->mp_bh[i]); + gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN); + gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header)); + ptr += offset; + *ptr = cpu_to_be64(bn); + return ptr; +} + +enum alloc_state { + ALLOC_DATA = 0, + ALLOC_GROW_DEPTH = 1, + ALLOC_GROW_HEIGHT = 2, + /* ALLOC_UNSTUFF = 3, TBD and rather complicated */ +}; + +/** + * gfs2_iomap_alloc - Build a metadata tree of the requested height + * @inode: The GFS2 inode + * @iomap: The iomap structure + * @mp: The metapath, with proper height information calculated + * + * In this routine we may have to alloc: + * i) Indirect blocks to grow the metadata tree height + * ii) Indirect blocks to fill in lower part of the metadata tree + * iii) Data blocks + * + * This function is called after gfs2_iomap_get, which works out the + * total number of blocks which we need via gfs2_alloc_size. + * + * We then do the actual allocation asking for an extent at a time (if + * enough contiguous free blocks are available, there will only be one + * allocation request per call) and uses the state machine to initialise + * the blocks in order. + * + * Right now, this function will allocate at most one indirect block + * worth of data -- with a default block size of 4K, that's slightly + * less than 2M. If this limitation is ever removed to allow huge + * allocations, we would probably still want to limit the iomap size we + * return to avoid stalling other tasks during huge writes; the next + * iomap iteration would then find the blocks already allocated. + * + * Returns: errno on error + */ + +static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, + struct metapath *mp) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct buffer_head *dibh = mp->mp_bh[0]; + u64 bn; + unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0; + size_t dblks = iomap->length >> inode->i_blkbits; + const unsigned end_of_metadata = mp->mp_fheight - 1; + int ret; + enum alloc_state state; + __be64 *ptr; + __be64 zero_bn = 0; + + BUG_ON(mp->mp_aheight < 1); + BUG_ON(dibh == NULL); + BUG_ON(dblks < 1); + + gfs2_trans_add_meta(ip->i_gl, dibh); + + down_write(&ip->i_rw_mutex); + + if (mp->mp_fheight == mp->mp_aheight) { + /* Bottom indirect block exists */ + state = ALLOC_DATA; + } else { + /* Need to allocate indirect blocks */ + if (mp->mp_fheight == ip->i_height) { + /* Writing into existing tree, extend tree down */ + iblks = mp->mp_fheight - mp->mp_aheight; + state = ALLOC_GROW_DEPTH; + } else { + /* Building up tree height */ + state = ALLOC_GROW_HEIGHT; + iblks = mp->mp_fheight - ip->i_height; + branch_start = metapath_branch_start(mp); + iblks += (mp->mp_fheight - branch_start); + } + } + + /* start of the second part of the function (state machine) */ + + blks = dblks + iblks; + i = mp->mp_aheight; + do { + n = blks - alloced; + ret = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL); + if (ret) + goto out; + alloced += n; + if (state != ALLOC_DATA || gfs2_is_jdata(ip)) + gfs2_trans_remove_revoke(sdp, bn, n); + switch (state) { + /* Growing height of tree */ + case ALLOC_GROW_HEIGHT: + if (i == 1) { + ptr = (__be64 *)(dibh->b_data + + sizeof(struct gfs2_dinode)); + zero_bn = *ptr; + } + for (; i - 1 < mp->mp_fheight - ip->i_height && n > 0; + i++, n--) + gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++); + if (i - 1 == mp->mp_fheight - ip->i_height) { + i--; + gfs2_buffer_copy_tail(mp->mp_bh[i], + sizeof(struct gfs2_meta_header), + dibh, sizeof(struct gfs2_dinode)); + gfs2_buffer_clear_tail(dibh, + sizeof(struct gfs2_dinode) + + sizeof(__be64)); + ptr = (__be64 *)(mp->mp_bh[i]->b_data + + sizeof(struct gfs2_meta_header)); + *ptr = zero_bn; + state = ALLOC_GROW_DEPTH; + for(i = branch_start; i < mp->mp_fheight; i++) { + if (mp->mp_bh[i] == NULL) + break; + brelse(mp->mp_bh[i]); + mp->mp_bh[i] = NULL; + } + i = branch_start; + } + if (n == 0) + break; + fallthrough; /* To branching from existing tree */ + case ALLOC_GROW_DEPTH: + if (i > 1 && i < mp->mp_fheight) + gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[i-1]); + for (; i < mp->mp_fheight && n > 0; i++, n--) + gfs2_indirect_init(mp, ip->i_gl, i, + mp->mp_list[i-1], bn++); + if (i == mp->mp_fheight) + state = ALLOC_DATA; + if (n == 0) + break; + fallthrough; /* To tree complete, adding data blocks */ + case ALLOC_DATA: + BUG_ON(n > dblks); + BUG_ON(mp->mp_bh[end_of_metadata] == NULL); + gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[end_of_metadata]); + dblks = n; + ptr = metapointer(end_of_metadata, mp); + iomap->addr = bn << inode->i_blkbits; + iomap->flags |= IOMAP_F_MERGED | IOMAP_F_NEW; + while (n-- > 0) + *ptr++ = cpu_to_be64(bn++); + break; + } + } while (iomap->addr == IOMAP_NULL_ADDR); + + iomap->type = IOMAP_MAPPED; + iomap->length = (u64)dblks << inode->i_blkbits; + ip->i_height = mp->mp_fheight; + gfs2_add_inode_blocks(&ip->i_inode, alloced); + gfs2_dinode_out(ip, dibh->b_data); +out: + up_write(&ip->i_rw_mutex); + return ret; +} + +#define IOMAP_F_GFS2_BOUNDARY IOMAP_F_PRIVATE + +/** + * gfs2_alloc_size - Compute the maximum allocation size + * @inode: The inode + * @mp: The metapath + * @size: Requested size in blocks + * + * Compute the maximum size of the next allocation at @mp. + * + * Returns: size in blocks + */ +static u64 gfs2_alloc_size(struct inode *inode, struct metapath *mp, u64 size) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + const __be64 *first, *ptr, *end; + + /* + * For writes to stuffed files, this function is called twice via + * gfs2_iomap_get, before and after unstuffing. The size we return the + * first time needs to be large enough to get the reservation and + * allocation sizes right. The size we return the second time must + * be exact or else gfs2_iomap_alloc won't do the right thing. + */ + + if (gfs2_is_stuffed(ip) || mp->mp_fheight != mp->mp_aheight) { + unsigned int maxsize = mp->mp_fheight > 1 ? + sdp->sd_inptrs : sdp->sd_diptrs; + maxsize -= mp->mp_list[mp->mp_fheight - 1]; + if (size > maxsize) + size = maxsize; + return size; + } + + first = metapointer(ip->i_height - 1, mp); + end = metaend(ip->i_height - 1, mp); + if (end - first > size) + end = first + size; + for (ptr = first; ptr < end; ptr++) { + if (*ptr) + break; + } + return ptr - first; +} + +/** + * gfs2_iomap_get - Map blocks from an inode to disk blocks + * @inode: The inode + * @pos: Starting position in bytes + * @length: Length to map, in bytes + * @flags: iomap flags + * @iomap: The iomap structure + * @mp: The metapath + * + * Returns: errno + */ +static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length, + unsigned flags, struct iomap *iomap, + struct metapath *mp) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + loff_t size = i_size_read(inode); + __be64 *ptr; + sector_t lblock; + sector_t lblock_stop; + int ret; + int eob; + u64 len; + struct buffer_head *dibh = NULL, *bh; + u8 height; + + if (!length) + return -EINVAL; + + down_read(&ip->i_rw_mutex); + + ret = gfs2_meta_inode_buffer(ip, &dibh); + if (ret) + goto unlock; + mp->mp_bh[0] = dibh; + + if (gfs2_is_stuffed(ip)) { + if (flags & IOMAP_WRITE) { + loff_t max_size = gfs2_max_stuffed_size(ip); + + if (pos + length > max_size) + goto unstuff; + iomap->length = max_size; + } else { + if (pos >= size) { + if (flags & IOMAP_REPORT) { + ret = -ENOENT; + goto unlock; + } else { + iomap->offset = pos; + iomap->length = length; + goto hole_found; + } + } + iomap->length = size; + } + iomap->addr = (ip->i_no_addr << inode->i_blkbits) + + sizeof(struct gfs2_dinode); + iomap->type = IOMAP_INLINE; + iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode); + goto out; + } + +unstuff: + lblock = pos >> inode->i_blkbits; + iomap->offset = lblock << inode->i_blkbits; + lblock_stop = (pos + length - 1) >> inode->i_blkbits; + len = lblock_stop - lblock + 1; + iomap->length = len << inode->i_blkbits; + + height = ip->i_height; + while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height]) + height++; + find_metapath(sdp, lblock, mp, height); + if (height > ip->i_height || gfs2_is_stuffed(ip)) + goto do_alloc; + + ret = lookup_metapath(ip, mp); + if (ret) + goto unlock; + + if (mp->mp_aheight != ip->i_height) + goto do_alloc; + + ptr = metapointer(ip->i_height - 1, mp); + if (*ptr == 0) + goto do_alloc; + + bh = mp->mp_bh[ip->i_height - 1]; + len = gfs2_extent_length(bh, ptr, len, &eob); + + iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits; + iomap->length = len << inode->i_blkbits; + iomap->type = IOMAP_MAPPED; + iomap->flags |= IOMAP_F_MERGED; + if (eob) + iomap->flags |= IOMAP_F_GFS2_BOUNDARY; + +out: + iomap->bdev = inode->i_sb->s_bdev; +unlock: + up_read(&ip->i_rw_mutex); + return ret; + +do_alloc: + if (flags & IOMAP_REPORT) { + if (pos >= size) + ret = -ENOENT; + else if (height == ip->i_height) + ret = gfs2_hole_size(inode, lblock, len, mp, iomap); + else + iomap->length = size - iomap->offset; + } else if (flags & IOMAP_WRITE) { + u64 alloc_size; + + if (flags & IOMAP_DIRECT) + goto out; /* (see gfs2_file_direct_write) */ + + len = gfs2_alloc_size(inode, mp, len); + alloc_size = len << inode->i_blkbits; + if (alloc_size < iomap->length) + iomap->length = alloc_size; + } else { + if (pos < size && height == ip->i_height) + ret = gfs2_hole_size(inode, lblock, len, mp, iomap); + } +hole_found: + iomap->addr = IOMAP_NULL_ADDR; + iomap->type = IOMAP_HOLE; + goto out; +} + +/** + * gfs2_lblk_to_dblk - convert logical block to disk block + * @inode: the inode of the file we're mapping + * @lblock: the block relative to the start of the file + * @dblock: the returned dblock, if no error + * + * This function maps a single block from a file logical block (relative to + * the start of the file) to a file system absolute block using iomap. + * + * Returns: the absolute file system block, or an error + */ +int gfs2_lblk_to_dblk(struct inode *inode, u32 lblock, u64 *dblock) +{ + struct iomap iomap = { }; + struct metapath mp = { .mp_aheight = 1, }; + loff_t pos = (loff_t)lblock << inode->i_blkbits; + int ret; + + ret = gfs2_iomap_get(inode, pos, i_blocksize(inode), 0, &iomap, &mp); + release_metapath(&mp); + if (ret == 0) + *dblock = iomap.addr >> inode->i_blkbits; + + return ret; +} + +static int gfs2_write_lock(struct inode *inode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + int error; + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); + error = gfs2_glock_nq(&ip->i_gh); + if (error) + goto out_uninit; + if (&ip->i_inode == sdp->sd_rindex) { + struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); + + error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, + GL_NOCACHE, &m_ip->i_gh); + if (error) + goto out_unlock; + } + return 0; + +out_unlock: + gfs2_glock_dq(&ip->i_gh); +out_uninit: + gfs2_holder_uninit(&ip->i_gh); + return error; +} + +static void gfs2_write_unlock(struct inode *inode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + + if (&ip->i_inode == sdp->sd_rindex) { + struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); + + gfs2_glock_dq_uninit(&m_ip->i_gh); + } + gfs2_glock_dq_uninit(&ip->i_gh); +} + +static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, + unsigned len, struct iomap *iomap) +{ + unsigned int blockmask = i_blocksize(inode) - 1; + struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned int blocks; + + blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits; + return gfs2_trans_begin(sdp, RES_DINODE + blocks, 0); +} + +static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, + unsigned copied, struct page *page, + struct iomap *iomap) +{ + struct gfs2_trans *tr = current->journal_info; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + + if (page && !gfs2_is_stuffed(ip)) + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); + + if (tr->tr_num_buf_new) + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + + gfs2_trans_end(sdp); +} + +static const struct iomap_page_ops gfs2_iomap_page_ops = { + .page_prepare = gfs2_iomap_page_prepare, + .page_done = gfs2_iomap_page_done, +}; + +static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, + loff_t length, unsigned flags, + struct iomap *iomap, + struct metapath *mp) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + bool unstuff; + int ret; + + unstuff = gfs2_is_stuffed(ip) && + pos + length > gfs2_max_stuffed_size(ip); + + if (unstuff || iomap->type == IOMAP_HOLE) { + unsigned int data_blocks, ind_blocks; + struct gfs2_alloc_parms ap = {}; + unsigned int rblocks; + struct gfs2_trans *tr; + + gfs2_write_calc_reserv(ip, iomap->length, &data_blocks, + &ind_blocks); + ap.target = data_blocks + ind_blocks; + ret = gfs2_quota_lock_check(ip, &ap); + if (ret) + return ret; + + ret = gfs2_inplace_reserve(ip, &ap); + if (ret) + goto out_qunlock; + + rblocks = RES_DINODE + ind_blocks; + if (gfs2_is_jdata(ip)) + rblocks += data_blocks; + if (ind_blocks || data_blocks) + rblocks += RES_STATFS + RES_QUOTA; + if (inode == sdp->sd_rindex) + rblocks += 2 * RES_STATFS; + rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); + + ret = gfs2_trans_begin(sdp, rblocks, + iomap->length >> inode->i_blkbits); + if (ret) + goto out_trans_fail; + + if (unstuff) { + ret = gfs2_unstuff_dinode(ip, NULL); + if (ret) + goto out_trans_end; + release_metapath(mp); + ret = gfs2_iomap_get(inode, iomap->offset, + iomap->length, flags, iomap, mp); + if (ret) + goto out_trans_end; + } + + if (iomap->type == IOMAP_HOLE) { + ret = gfs2_iomap_alloc(inode, iomap, mp); + if (ret) { + gfs2_trans_end(sdp); + gfs2_inplace_release(ip); + punch_hole(ip, iomap->offset, iomap->length); + goto out_qunlock; + } + } + + tr = current->journal_info; + if (tr->tr_num_buf_new) + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + + gfs2_trans_end(sdp); + } + + if (gfs2_is_stuffed(ip) || gfs2_is_jdata(ip)) + iomap->page_ops = &gfs2_iomap_page_ops; + return 0; + +out_trans_end: + gfs2_trans_end(sdp); +out_trans_fail: + gfs2_inplace_release(ip); +out_qunlock: + gfs2_quota_unlock(ip); + return ret; +} + +static inline bool gfs2_iomap_need_write_lock(unsigned flags) +{ + return (flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT); +} + +static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length, + unsigned flags, struct iomap *iomap, + struct iomap *srcmap) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct metapath mp = { .mp_aheight = 1, }; + int ret; + + if (gfs2_is_jdata(ip)) + iomap->flags |= IOMAP_F_BUFFER_HEAD; + + trace_gfs2_iomap_start(ip, pos, length, flags); + if (gfs2_iomap_need_write_lock(flags)) { + ret = gfs2_write_lock(inode); + if (ret) + goto out; + } + + ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp); + if (ret) + goto out_unlock; + + switch(flags & (IOMAP_WRITE | IOMAP_ZERO)) { + case IOMAP_WRITE: + if (flags & IOMAP_DIRECT) { + /* + * Silently fall back to buffered I/O for stuffed files + * or if we've got a hole (see gfs2_file_direct_write). + */ + if (iomap->type != IOMAP_MAPPED) + ret = -ENOTBLK; + goto out_unlock; + } + break; + case IOMAP_ZERO: + if (iomap->type == IOMAP_HOLE) + goto out_unlock; + break; + default: + goto out_unlock; + } + + ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp); + +out_unlock: + if (ret && gfs2_iomap_need_write_lock(flags)) + gfs2_write_unlock(inode); + release_metapath(&mp); +out: + trace_gfs2_iomap_end(ip, iomap, ret); + return ret; +} + +static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned flags, struct iomap *iomap) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + + switch (flags & (IOMAP_WRITE | IOMAP_ZERO)) { + case IOMAP_WRITE: + if (flags & IOMAP_DIRECT) + return 0; + break; + case IOMAP_ZERO: + if (iomap->type == IOMAP_HOLE) + return 0; + break; + default: + return 0; + } + + if (!gfs2_is_stuffed(ip)) + gfs2_ordered_add_inode(ip); + + if (inode == sdp->sd_rindex) + adjust_fs_space(inode); + + gfs2_inplace_release(ip); + + if (ip->i_qadata && ip->i_qadata->qa_qd_num) + gfs2_quota_unlock(ip); + + if (length != written && (iomap->flags & IOMAP_F_NEW)) { + /* Deallocate blocks that were just allocated. */ + loff_t hstart = round_up(pos + written, i_blocksize(inode)); + loff_t hend = iomap->offset + iomap->length; + + if (hstart < hend) { + truncate_pagecache_range(inode, hstart, hend - 1); + punch_hole(ip, hstart, hend - hstart); + } + } + + if (unlikely(!written)) + goto out_unlock; + + if (iomap->flags & IOMAP_F_SIZE_CHANGED) + mark_inode_dirty(inode); + set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); + +out_unlock: + if (gfs2_iomap_need_write_lock(flags)) + gfs2_write_unlock(inode); + return 0; +} + +const struct iomap_ops gfs2_iomap_ops = { + .iomap_begin = gfs2_iomap_begin, + .iomap_end = gfs2_iomap_end, +}; + +/** + * gfs2_block_map - Map one or more blocks of an inode to a disk block + * @inode: The inode + * @lblock: The logical block number + * @bh_map: The bh to be mapped + * @create: True if its ok to alloc blocks to satify the request + * + * The size of the requested mapping is defined in bh_map->b_size. + * + * Clears buffer_mapped(bh_map) and leaves bh_map->b_size unchanged + * when @lblock is not mapped. Sets buffer_mapped(bh_map) and + * bh_map->b_size to indicate the size of the mapping when @lblock and + * successive blocks are mapped, up to the requested size. + * + * Sets buffer_boundary() if a read of metadata will be required + * before the next block can be mapped. Sets buffer_new() if new + * blocks were allocated. + * + * Returns: errno + */ + +int gfs2_block_map(struct inode *inode, sector_t lblock, + struct buffer_head *bh_map, int create) +{ + struct gfs2_inode *ip = GFS2_I(inode); + loff_t pos = (loff_t)lblock << inode->i_blkbits; + loff_t length = bh_map->b_size; + struct metapath mp = { .mp_aheight = 1, }; + struct iomap iomap = { }; + int flags = create ? IOMAP_WRITE : 0; + int ret; + + clear_buffer_mapped(bh_map); + clear_buffer_new(bh_map); + clear_buffer_boundary(bh_map); + trace_gfs2_bmap(ip, bh_map, lblock, create, 1); + + ret = gfs2_iomap_get(inode, pos, length, flags, &iomap, &mp); + if (create && !ret && iomap.type == IOMAP_HOLE) + ret = gfs2_iomap_alloc(inode, &iomap, &mp); + release_metapath(&mp); + if (ret) + goto out; + + if (iomap.length > bh_map->b_size) { + iomap.length = bh_map->b_size; + iomap.flags &= ~IOMAP_F_GFS2_BOUNDARY; + } + if (iomap.addr != IOMAP_NULL_ADDR) + map_bh(bh_map, inode->i_sb, iomap.addr >> inode->i_blkbits); + bh_map->b_size = iomap.length; + if (iomap.flags & IOMAP_F_GFS2_BOUNDARY) + set_buffer_boundary(bh_map); + if (iomap.flags & IOMAP_F_NEW) + set_buffer_new(bh_map); + +out: + trace_gfs2_bmap(ip, bh_map, lblock, create, ret); + return ret; +} + +/* + * Deprecated: do not use in new code + */ +int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen) +{ + struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 }; + int ret; + int create = *new; + + BUG_ON(!extlen); + BUG_ON(!dblock); + BUG_ON(!new); + + bh.b_size = BIT(inode->i_blkbits + (create ? 0 : 5)); + ret = gfs2_block_map(inode, lblock, &bh, create); + *extlen = bh.b_size >> inode->i_blkbits; + *dblock = bh.b_blocknr; + if (buffer_new(&bh)) + *new = 1; + else + *new = 0; + return ret; +} + +/* + * NOTE: Never call gfs2_block_zero_range with an open transaction because it + * uses iomap write to perform its actions, which begin their own transactions + * (iomap_begin, page_prepare, etc.) + */ +static int gfs2_block_zero_range(struct inode *inode, loff_t from, + unsigned int length) +{ + BUG_ON(current->journal_info); + return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops); +} + +#define GFS2_JTRUNC_REVOKES 8192 + +/** + * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files + * @inode: The inode being truncated + * @oldsize: The original (larger) size + * @newsize: The new smaller size + * + * With jdata files, we have to journal a revoke for each block which is + * truncated. As a result, we need to split this into separate transactions + * if the number of pages being truncated gets too large. + */ + +static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize) +{ + struct gfs2_sbd *sdp = GFS2_SB(inode); + u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize; + u64 chunk; + int error; + + while (oldsize != newsize) { + struct gfs2_trans *tr; + unsigned int offs; + + chunk = oldsize - newsize; + if (chunk > max_chunk) + chunk = max_chunk; + + offs = oldsize & ~PAGE_MASK; + if (offs && chunk > PAGE_SIZE) + chunk = offs + ((chunk - offs) & PAGE_MASK); + + truncate_pagecache(inode, oldsize - chunk); + oldsize -= chunk; + + tr = current->journal_info; + if (!test_bit(TR_TOUCHED, &tr->tr_flags)) + continue; + + gfs2_trans_end(sdp); + error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES); + if (error) + return error; + } + + return 0; +} + +static int trunc_start(struct inode *inode, u64 newsize) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct buffer_head *dibh = NULL; + int journaled = gfs2_is_jdata(ip); + u64 oldsize = inode->i_size; + int error; + + if (!gfs2_is_stuffed(ip)) { + unsigned int blocksize = i_blocksize(inode); + unsigned int offs = newsize & (blocksize - 1); + if (offs) { + error = gfs2_block_zero_range(inode, newsize, + blocksize - offs); + if (error) + return error; + } + } + if (journaled) + error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES); + else + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out; + + gfs2_trans_add_meta(ip->i_gl, dibh); + + if (gfs2_is_stuffed(ip)) + gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize); + else + ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; + + i_size_write(inode, newsize); + ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode); + gfs2_dinode_out(ip, dibh->b_data); + + if (journaled) + error = gfs2_journaled_truncate(inode, oldsize, newsize); + else + truncate_pagecache(inode, newsize); + +out: + brelse(dibh); + if (current->journal_info) + gfs2_trans_end(sdp); + return error; +} + +int gfs2_iomap_get_alloc(struct inode *inode, loff_t pos, loff_t length, + struct iomap *iomap) +{ + struct metapath mp = { .mp_aheight = 1, }; + int ret; + + ret = gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, iomap, &mp); + if (!ret && iomap->type == IOMAP_HOLE) + ret = gfs2_iomap_alloc(inode, iomap, &mp); + release_metapath(&mp); + return ret; +} + +/** + * sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein + * @ip: inode + * @rg_gh: holder of resource group glock + * @bh: buffer head to sweep + * @start: starting point in bh + * @end: end point in bh + * @meta: true if bh points to metadata (rather than data) + * @btotal: place to keep count of total blocks freed + * + * We sweep a metadata buffer (provided by the metapath) for blocks we need to + * free, and free them all. However, we do it one rgrp at a time. If this + * block has references to multiple rgrps, we break it into individual + * transactions. This allows other processes to use the rgrps while we're + * focused on a single one, for better concurrency / performance. + * At every transaction boundary, we rewrite the inode into the journal. + * That way the bitmaps are kept consistent with the inode and we can recover + * if we're interrupted by power-outages. + * + * Returns: 0, or return code if an error occurred. + * *btotal has the total number of blocks freed + */ +static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh, + struct buffer_head *bh, __be64 *start, __be64 *end, + bool meta, u32 *btotal) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct gfs2_rgrpd *rgd; + struct gfs2_trans *tr; + __be64 *p; + int blks_outside_rgrp; + u64 bn, bstart, isize_blks; + s64 blen; /* needs to be s64 or gfs2_add_inode_blocks breaks */ + int ret = 0; + bool buf_in_tr = false; /* buffer was added to transaction */ + +more_rgrps: + rgd = NULL; + if (gfs2_holder_initialized(rd_gh)) { + rgd = gfs2_glock2rgrp(rd_gh->gh_gl); + gfs2_assert_withdraw(sdp, + gfs2_glock_is_locked_by_me(rd_gh->gh_gl)); + } + blks_outside_rgrp = 0; + bstart = 0; + blen = 0; + + for (p = start; p < end; p++) { + if (!*p) + continue; + bn = be64_to_cpu(*p); + + if (rgd) { + if (!rgrp_contains_block(rgd, bn)) { + blks_outside_rgrp++; + continue; + } + } else { + rgd = gfs2_blk2rgrpd(sdp, bn, true); + if (unlikely(!rgd)) { + ret = -EIO; + goto out; + } + ret = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, + 0, rd_gh); + if (ret) + goto out; + + /* Must be done with the rgrp glock held: */ + if (gfs2_rs_active(&ip->i_res) && + rgd == ip->i_res.rs_rbm.rgd) + gfs2_rs_deltree(&ip->i_res); + } + + /* The size of our transactions will be unknown until we + actually process all the metadata blocks that relate to + the rgrp. So we estimate. We know it can't be more than + the dinode's i_blocks and we don't want to exceed the + journal flush threshold, sd_log_thresh2. */ + if (current->journal_info == NULL) { + unsigned int jblocks_rqsted, revokes; + + jblocks_rqsted = rgd->rd_length + RES_DINODE + + RES_INDIRECT; + isize_blks = gfs2_get_inode_blocks(&ip->i_inode); + if (isize_blks > atomic_read(&sdp->sd_log_thresh2)) + jblocks_rqsted += + atomic_read(&sdp->sd_log_thresh2); + else + jblocks_rqsted += isize_blks; + revokes = jblocks_rqsted; + if (meta) + revokes += end - start; + else if (ip->i_depth) + revokes += sdp->sd_inptrs; + ret = gfs2_trans_begin(sdp, jblocks_rqsted, revokes); + if (ret) + goto out_unlock; + down_write(&ip->i_rw_mutex); + } + /* check if we will exceed the transaction blocks requested */ + tr = current->journal_info; + if (tr->tr_num_buf_new + RES_STATFS + + RES_QUOTA >= atomic_read(&sdp->sd_log_thresh2)) { + /* We set blks_outside_rgrp to ensure the loop will + be repeated for the same rgrp, but with a new + transaction. */ + blks_outside_rgrp++; + /* This next part is tricky. If the buffer was added + to the transaction, we've already set some block + pointers to 0, so we better follow through and free + them, or we will introduce corruption (so break). + This may be impossible, or at least rare, but I + decided to cover the case regardless. + + If the buffer was not added to the transaction + (this call), doing so would exceed our transaction + size, so we need to end the transaction and start a + new one (so goto). */ + + if (buf_in_tr) + break; + goto out_unlock; + } + + gfs2_trans_add_meta(ip->i_gl, bh); + buf_in_tr = true; + *p = 0; + if (bstart + blen == bn) { + blen++; + continue; + } + if (bstart) { + __gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta); + (*btotal) += blen; + gfs2_add_inode_blocks(&ip->i_inode, -blen); + } + bstart = bn; + blen = 1; + } + if (bstart) { + __gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta); + (*btotal) += blen; + gfs2_add_inode_blocks(&ip->i_inode, -blen); + } +out_unlock: + if (!ret && blks_outside_rgrp) { /* If buffer still has non-zero blocks + outside the rgrp we just processed, + do it all over again. */ + if (current->journal_info) { + struct buffer_head *dibh; + + ret = gfs2_meta_inode_buffer(ip, &dibh); + if (ret) + goto out; + + /* Every transaction boundary, we rewrite the dinode + to keep its di_blocks current in case of failure. */ + ip->i_inode.i_mtime = ip->i_inode.i_ctime = + current_time(&ip->i_inode); + gfs2_trans_add_meta(ip->i_gl, dibh); + gfs2_dinode_out(ip, dibh->b_data); + brelse(dibh); + up_write(&ip->i_rw_mutex); + gfs2_trans_end(sdp); + buf_in_tr = false; + } + gfs2_glock_dq_uninit(rd_gh); + cond_resched(); + goto more_rgrps; + } +out: + return ret; +} + +static bool mp_eq_to_hgt(struct metapath *mp, __u16 *list, unsigned int h) +{ + if (memcmp(mp->mp_list, list, h * sizeof(mp->mp_list[0]))) + return false; + return true; +} + +/** + * find_nonnull_ptr - find a non-null pointer given a metapath and height + * @mp: starting metapath + * @h: desired height to search + * + * Assumes the metapath is valid (with buffers) out to height h. + * Returns: true if a non-null pointer was found in the metapath buffer + * false if all remaining pointers are NULL in the buffer + */ +static bool find_nonnull_ptr(struct gfs2_sbd *sdp, struct metapath *mp, + unsigned int h, + __u16 *end_list, unsigned int end_aligned) +{ + struct buffer_head *bh = mp->mp_bh[h]; + __be64 *first, *ptr, *end; + + first = metaptr1(h, mp); + ptr = first + mp->mp_list[h]; + end = (__be64 *)(bh->b_data + bh->b_size); + if (end_list && mp_eq_to_hgt(mp, end_list, h)) { + bool keep_end = h < end_aligned; + end = first + end_list[h] + keep_end; + } + + while (ptr < end) { + if (*ptr) { /* if we have a non-null pointer */ + mp->mp_list[h] = ptr - first; + h++; + if (h < GFS2_MAX_META_HEIGHT) + mp->mp_list[h] = 0; + return true; + } + ptr++; + } + return false; +} + +enum dealloc_states { + DEALLOC_MP_FULL = 0, /* Strip a metapath with all buffers read in */ + DEALLOC_MP_LOWER = 1, /* lower the metapath strip height */ + DEALLOC_FILL_MP = 2, /* Fill in the metapath to the given height. */ + DEALLOC_DONE = 3, /* process complete */ +}; + +static inline void +metapointer_range(struct metapath *mp, int height, + __u16 *start_list, unsigned int start_aligned, + __u16 *end_list, unsigned int end_aligned, + __be64 **start, __be64 **end) +{ + struct buffer_head *bh = mp->mp_bh[height]; + __be64 *first; + + first = metaptr1(height, mp); + *start = first; + if (mp_eq_to_hgt(mp, start_list, height)) { + bool keep_start = height < start_aligned; + *start = first + start_list[height] + keep_start; + } + *end = (__be64 *)(bh->b_data + bh->b_size); + if (end_list && mp_eq_to_hgt(mp, end_list, height)) { + bool keep_end = height < end_aligned; + *end = first + end_list[height] + keep_end; + } +} + +static inline bool walk_done(struct gfs2_sbd *sdp, + struct metapath *mp, int height, + __u16 *end_list, unsigned int end_aligned) +{ + __u16 end; + + if (end_list) { + bool keep_end = height < end_aligned; + if (!mp_eq_to_hgt(mp, end_list, height)) + return false; + end = end_list[height] + keep_end; + } else + end = (height > 0) ? sdp->sd_inptrs : sdp->sd_diptrs; + return mp->mp_list[height] >= end; +} + +/** + * punch_hole - deallocate blocks in a file + * @ip: inode to truncate + * @offset: the start of the hole + * @length: the size of the hole (or 0 for truncate) + * + * Punch a hole into a file or truncate a file at a given position. This + * function operates in whole blocks (@offset and @length are rounded + * accordingly); partially filled blocks must be cleared otherwise. + * + * This function works from the bottom up, and from the right to the left. In + * other words, it strips off the highest layer (data) before stripping any of + * the metadata. Doing it this way is best in case the operation is interrupted + * by power failure, etc. The dinode is rewritten in every transaction to + * guarantee integrity. + */ +static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + u64 maxsize = sdp->sd_heightsize[ip->i_height]; + struct metapath mp = {}; + struct buffer_head *dibh, *bh; + struct gfs2_holder rd_gh; + unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift; + u64 lblock = (offset + (1 << bsize_shift) - 1) >> bsize_shift; + __u16 start_list[GFS2_MAX_META_HEIGHT]; + __u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL; + unsigned int start_aligned, end_aligned; + unsigned int strip_h = ip->i_height - 1; + u32 btotal = 0; + int ret, state; + int mp_h; /* metapath buffers are read in to this height */ + u64 prev_bnr = 0; + __be64 *start, *end; + + if (offset >= maxsize) { + /* + * The starting point lies beyond the allocated meta-data; + * there are no blocks do deallocate. + */ + return 0; + } + + /* + * The start position of the hole is defined by lblock, start_list, and + * start_aligned. The end position of the hole is defined by lend, + * end_list, and end_aligned. + * + * start_aligned and end_aligned define down to which height the start + * and end positions are aligned to the metadata tree (i.e., the + * position is a multiple of the metadata granularity at the height + * above). This determines at which heights additional meta pointers + * needs to be preserved for the remaining data. + */ + + if (length) { + u64 end_offset = offset + length; + u64 lend; + + /* + * Clip the end at the maximum file size for the given height: + * that's how far the metadata goes; files bigger than that + * will have additional layers of indirection. + */ + if (end_offset > maxsize) + end_offset = maxsize; + lend = end_offset >> bsize_shift; + + if (lblock >= lend) + return 0; + + find_metapath(sdp, lend, &mp, ip->i_height); + end_list = __end_list; + memcpy(end_list, mp.mp_list, sizeof(mp.mp_list)); + + for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) { + if (end_list[mp_h]) + break; + } + end_aligned = mp_h; + } + + find_metapath(sdp, lblock, &mp, ip->i_height); + memcpy(start_list, mp.mp_list, sizeof(start_list)); + + for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) { + if (start_list[mp_h]) + break; + } + start_aligned = mp_h; + + ret = gfs2_meta_inode_buffer(ip, &dibh); + if (ret) + return ret; + + mp.mp_bh[0] = dibh; + ret = lookup_metapath(ip, &mp); + if (ret) + goto out_metapath; + + /* issue read-ahead on metadata */ + for (mp_h = 0; mp_h < mp.mp_aheight - 1; mp_h++) { + metapointer_range(&mp, mp_h, start_list, start_aligned, + end_list, end_aligned, &start, &end); + gfs2_metapath_ra(ip->i_gl, start, end); + } + + if (mp.mp_aheight == ip->i_height) + state = DEALLOC_MP_FULL; /* We have a complete metapath */ + else + state = DEALLOC_FILL_MP; /* deal with partial metapath */ + + ret = gfs2_rindex_update(sdp); + if (ret) + goto out_metapath; + + ret = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE); + if (ret) + goto out_metapath; + gfs2_holder_mark_uninitialized(&rd_gh); + + mp_h = strip_h; + + while (state != DEALLOC_DONE) { + switch (state) { + /* Truncate a full metapath at the given strip height. + * Note that strip_h == mp_h in order to be in this state. */ + case DEALLOC_MP_FULL: + bh = mp.mp_bh[mp_h]; + gfs2_assert_withdraw(sdp, bh); + if (gfs2_assert_withdraw(sdp, + prev_bnr != bh->b_blocknr)) { + fs_emerg(sdp, "inode %llu, block:%llu, i_h:%u," + "s_h:%u, mp_h:%u\n", + (unsigned long long)ip->i_no_addr, + prev_bnr, ip->i_height, strip_h, mp_h); + } + prev_bnr = bh->b_blocknr; + + if (gfs2_metatype_check(sdp, bh, + (mp_h ? GFS2_METATYPE_IN : + GFS2_METATYPE_DI))) { + ret = -EIO; + goto out; + } + + /* + * Below, passing end_aligned as 0 gives us the + * metapointer range excluding the end point: the end + * point is the first metapath we must not deallocate! + */ + + metapointer_range(&mp, mp_h, start_list, start_aligned, + end_list, 0 /* end_aligned */, + &start, &end); + ret = sweep_bh_for_rgrps(ip, &rd_gh, mp.mp_bh[mp_h], + start, end, + mp_h != ip->i_height - 1, + &btotal); + + /* If we hit an error or just swept dinode buffer, + just exit. */ + if (ret || !mp_h) { + state = DEALLOC_DONE; + break; + } + state = DEALLOC_MP_LOWER; + break; + + /* lower the metapath strip height */ + case DEALLOC_MP_LOWER: + /* We're done with the current buffer, so release it, + unless it's the dinode buffer. Then back up to the + previous pointer. */ + if (mp_h) { + brelse(mp.mp_bh[mp_h]); + mp.mp_bh[mp_h] = NULL; + } + /* If we can't get any lower in height, we've stripped + off all we can. Next step is to back up and start + stripping the previous level of metadata. */ + if (mp_h == 0) { + strip_h--; + memcpy(mp.mp_list, start_list, sizeof(start_list)); + mp_h = strip_h; + state = DEALLOC_FILL_MP; + break; + } + mp.mp_list[mp_h] = 0; + mp_h--; /* search one metadata height down */ + mp.mp_list[mp_h]++; + if (walk_done(sdp, &mp, mp_h, end_list, end_aligned)) + break; + /* Here we've found a part of the metapath that is not + * allocated. We need to search at that height for the + * next non-null pointer. */ + if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned)) { + state = DEALLOC_FILL_MP; + mp_h++; + } + /* No more non-null pointers at this height. Back up + to the previous height and try again. */ + break; /* loop around in the same state */ + + /* Fill the metapath with buffers to the given height. */ + case DEALLOC_FILL_MP: + /* Fill the buffers out to the current height. */ + ret = fillup_metapath(ip, &mp, mp_h); + if (ret < 0) + goto out; + + /* On the first pass, issue read-ahead on metadata. */ + if (mp.mp_aheight > 1 && strip_h == ip->i_height - 1) { + unsigned int height = mp.mp_aheight - 1; + + /* No read-ahead for data blocks. */ + if (mp.mp_aheight - 1 == strip_h) + height--; + + for (; height >= mp.mp_aheight - ret; height--) { + metapointer_range(&mp, height, + start_list, start_aligned, + end_list, end_aligned, + &start, &end); + gfs2_metapath_ra(ip->i_gl, start, end); + } + } + + /* If buffers found for the entire strip height */ + if (mp.mp_aheight - 1 == strip_h) { + state = DEALLOC_MP_FULL; + break; + } + if (mp.mp_aheight < ip->i_height) /* We have a partial height */ + mp_h = mp.mp_aheight - 1; + + /* If we find a non-null block pointer, crawl a bit + higher up in the metapath and try again, otherwise + we need to look lower for a new starting point. */ + if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned)) + mp_h++; + else + state = DEALLOC_MP_LOWER; + break; + } + } + + if (btotal) { + if (current->journal_info == NULL) { + ret = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + + RES_QUOTA, 0); + if (ret) + goto out; + down_write(&ip->i_rw_mutex); + } + gfs2_statfs_change(sdp, 0, +btotal, 0); + gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid, + ip->i_inode.i_gid); + ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode); + gfs2_trans_add_meta(ip->i_gl, dibh); + gfs2_dinode_out(ip, dibh->b_data); + up_write(&ip->i_rw_mutex); + gfs2_trans_end(sdp); + } + +out: + if (gfs2_holder_initialized(&rd_gh)) + gfs2_glock_dq_uninit(&rd_gh); + if (current->journal_info) { + up_write(&ip->i_rw_mutex); + gfs2_trans_end(sdp); + cond_resched(); + } + gfs2_quota_unhold(ip); +out_metapath: + release_metapath(&mp); + return ret; +} + +static int trunc_end(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct buffer_head *dibh; + int error; + + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + down_write(&ip->i_rw_mutex); + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out; + + if (!i_size_read(&ip->i_inode)) { + ip->i_height = 0; + ip->i_goal = ip->i_no_addr; + gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); + gfs2_ordered_del_inode(ip); + } + ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode); + ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG; + + gfs2_trans_add_meta(ip->i_gl, dibh); + gfs2_dinode_out(ip, dibh->b_data); + brelse(dibh); + +out: + up_write(&ip->i_rw_mutex); + gfs2_trans_end(sdp); + return error; +} + +/** + * do_shrink - make a file smaller + * @inode: the inode + * @newsize: the size to make the file + * + * Called with an exclusive lock on @inode. The @size must + * be equal to or smaller than the current inode size. + * + * Returns: errno + */ + +static int do_shrink(struct inode *inode, u64 newsize) +{ + struct gfs2_inode *ip = GFS2_I(inode); + int error; + + error = trunc_start(inode, newsize); + if (error < 0) + return error; + if (gfs2_is_stuffed(ip)) + return 0; + + error = punch_hole(ip, newsize, 0); + if (error == 0) + error = trunc_end(ip); + + return error; +} + +void gfs2_trim_blocks(struct inode *inode) +{ + int ret; + + ret = do_shrink(inode, inode->i_size); + WARN_ON(ret != 0); +} + +/** + * do_grow - Touch and update inode size + * @inode: The inode + * @size: The new size + * + * This function updates the timestamps on the inode and + * may also increase the size of the inode. This function + * must not be called with @size any smaller than the current + * inode size. + * + * Although it is not strictly required to unstuff files here, + * earlier versions of GFS2 have a bug in the stuffed file reading + * code which will result in a buffer overrun if the size is larger + * than the max stuffed file size. In order to prevent this from + * occurring, such files are unstuffed, but in other cases we can + * just update the inode size directly. + * + * Returns: 0 on success, or -ve on error + */ + +static int do_grow(struct inode *inode, u64 size) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_alloc_parms ap = { .target = 1, }; + struct buffer_head *dibh; + int error; + int unstuff = 0; + + if (gfs2_is_stuffed(ip) && size > gfs2_max_stuffed_size(ip)) { + error = gfs2_quota_lock_check(ip, &ap); + if (error) + return error; + + error = gfs2_inplace_reserve(ip, &ap); + if (error) + goto do_grow_qunlock; + unstuff = 1; + } + + error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT + + (unstuff && + gfs2_is_jdata(ip) ? RES_JDATA : 0) + + (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF ? + 0 : RES_QUOTA), 0); + if (error) + goto do_grow_release; + + if (unstuff) { + error = gfs2_unstuff_dinode(ip, NULL); + if (error) + goto do_end_trans; + } + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto do_end_trans; + + truncate_setsize(inode, size); + ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode); + gfs2_trans_add_meta(ip->i_gl, dibh); + gfs2_dinode_out(ip, dibh->b_data); + brelse(dibh); + +do_end_trans: + gfs2_trans_end(sdp); +do_grow_release: + if (unstuff) { + gfs2_inplace_release(ip); +do_grow_qunlock: + gfs2_quota_unlock(ip); + } + return error; +} + +/** + * gfs2_setattr_size - make a file a given size + * @inode: the inode + * @newsize: the size to make the file + * + * The file size can grow, shrink, or stay the same size. This + * is called holding i_rwsem and an exclusive glock on the inode + * in question. + * + * Returns: errno + */ + +int gfs2_setattr_size(struct inode *inode, u64 newsize) +{ + struct gfs2_inode *ip = GFS2_I(inode); + int ret; + + BUG_ON(!S_ISREG(inode->i_mode)); + + ret = inode_newsize_ok(inode, newsize); + if (ret) + return ret; + + inode_dio_wait(inode); + + ret = gfs2_qa_get(ip); + if (ret) + goto out; + + if (newsize >= inode->i_size) { + ret = do_grow(inode, newsize); + goto out; + } + + ret = do_shrink(inode, newsize); +out: + gfs2_rs_delete(ip); + gfs2_qa_put(ip); + return ret; +} + +int gfs2_truncatei_resume(struct gfs2_inode *ip) +{ + int error; + error = punch_hole(ip, i_size_read(&ip->i_inode), 0); + if (!error) + error = trunc_end(ip); + return error; +} + +int gfs2_file_dealloc(struct gfs2_inode *ip) +{ + return punch_hole(ip, 0, 0); +} + +/** + * gfs2_free_journal_extents - Free cached journal bmap info + * @jd: The journal + * + */ + +void gfs2_free_journal_extents(struct gfs2_jdesc *jd) +{ + struct gfs2_journal_extent *jext; + + while(!list_empty(&jd->extent_list)) { + jext = list_first_entry(&jd->extent_list, struct gfs2_journal_extent, list); + list_del(&jext->list); + kfree(jext); + } +} + +/** + * gfs2_add_jextent - Add or merge a new extent to extent cache + * @jd: The journal descriptor + * @lblock: The logical block at start of new extent + * @dblock: The physical block at start of new extent + * @blocks: Size of extent in fs blocks + * + * Returns: 0 on success or -ENOMEM + */ + +static int gfs2_add_jextent(struct gfs2_jdesc *jd, u64 lblock, u64 dblock, u64 blocks) +{ + struct gfs2_journal_extent *jext; + + if (!list_empty(&jd->extent_list)) { + jext = list_last_entry(&jd->extent_list, struct gfs2_journal_extent, list); + if ((jext->dblock + jext->blocks) == dblock) { + jext->blocks += blocks; + return 0; + } + } + + jext = kzalloc(sizeof(struct gfs2_journal_extent), GFP_NOFS); + if (jext == NULL) + return -ENOMEM; + jext->dblock = dblock; + jext->lblock = lblock; + jext->blocks = blocks; + list_add_tail(&jext->list, &jd->extent_list); + jd->nr_extents++; + return 0; +} + +/** + * gfs2_map_journal_extents - Cache journal bmap info + * @sdp: The super block + * @jd: The journal to map + * + * Create a reusable "extent" mapping from all logical + * blocks to all physical blocks for the given journal. This will save + * us time when writing journal blocks. Most journals will have only one + * extent that maps all their logical blocks. That's because gfs2.mkfs + * arranges the journal blocks sequentially to maximize performance. + * So the extent would map the first block for the entire file length. + * However, gfs2_jadd can happen while file activity is happening, so + * those journals may not be sequential. Less likely is the case where + * the users created their own journals by mounting the metafs and + * laying it out. But it's still possible. These journals might have + * several extents. + * + * Returns: 0 on success, or error on failure + */ + +int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd) +{ + u64 lblock = 0; + u64 lblock_stop; + struct gfs2_inode *ip = GFS2_I(jd->jd_inode); + struct buffer_head bh; + unsigned int shift = sdp->sd_sb.sb_bsize_shift; + u64 size; + int rc; + ktime_t start, end; + + start = ktime_get(); + lblock_stop = i_size_read(jd->jd_inode) >> shift; + size = (lblock_stop - lblock) << shift; + jd->nr_extents = 0; + WARN_ON(!list_empty(&jd->extent_list)); + + do { + bh.b_state = 0; + bh.b_blocknr = 0; + bh.b_size = size; + rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0); + if (rc || !buffer_mapped(&bh)) + goto fail; + rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift); + if (rc) + goto fail; + size -= bh.b_size; + lblock += (bh.b_size >> ip->i_inode.i_blkbits); + } while(size > 0); + + end = ktime_get(); + fs_info(sdp, "journal %d mapped with %u extents in %lldms\n", jd->jd_jid, + jd->nr_extents, ktime_ms_delta(end, start)); + return 0; + +fail: + fs_warn(sdp, "error %d mapping journal %u at offset %llu (extent %u)\n", + rc, jd->jd_jid, + (unsigned long long)(i_size_read(jd->jd_inode) - size), + jd->nr_extents); + fs_warn(sdp, "bmap=%d lblock=%llu block=%llu, state=0x%08lx, size=%llu\n", + rc, (unsigned long long)lblock, (unsigned long long)bh.b_blocknr, + bh.b_state, (unsigned long long)bh.b_size); + gfs2_free_journal_extents(jd); + return rc; +} + +/** + * gfs2_write_alloc_required - figure out if a write will require an allocation + * @ip: the file being written to + * @offset: the offset to write to + * @len: the number of bytes being written + * + * Returns: 1 if an alloc is required, 0 otherwise + */ + +int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, + unsigned int len) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct buffer_head bh; + unsigned int shift; + u64 lblock, lblock_stop, size; + u64 end_of_file; + + if (!len) + return 0; + + if (gfs2_is_stuffed(ip)) { + if (offset + len > gfs2_max_stuffed_size(ip)) + return 1; + return 0; + } + + shift = sdp->sd_sb.sb_bsize_shift; + BUG_ON(gfs2_is_dir(ip)); + end_of_file = (i_size_read(&ip->i_inode) + sdp->sd_sb.sb_bsize - 1) >> shift; + lblock = offset >> shift; + lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; + if (lblock_stop > end_of_file && ip != GFS2_I(sdp->sd_rindex)) + return 1; + + size = (lblock_stop - lblock) << shift; + do { + bh.b_state = 0; + bh.b_size = size; + gfs2_block_map(&ip->i_inode, lblock, &bh, 0); + if (!buffer_mapped(&bh)) + return 1; + size -= bh.b_size; + lblock += (bh.b_size >> ip->i_inode.i_blkbits); + } while(size > 0); + + return 0; +} + +static int stuffed_zero_range(struct inode *inode, loff_t offset, loff_t length) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct buffer_head *dibh; + int error; + + if (offset >= inode->i_size) + return 0; + if (offset + length > inode->i_size) + length = inode->i_size - offset; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + gfs2_trans_add_meta(ip->i_gl, dibh); + memset(dibh->b_data + sizeof(struct gfs2_dinode) + offset, 0, + length); + brelse(dibh); + return 0; +} + +static int gfs2_journaled_truncate_range(struct inode *inode, loff_t offset, + loff_t length) +{ + struct gfs2_sbd *sdp = GFS2_SB(inode); + loff_t max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize; + int error; + + while (length) { + struct gfs2_trans *tr; + loff_t chunk; + unsigned int offs; + + chunk = length; + if (chunk > max_chunk) + chunk = max_chunk; + + offs = offset & ~PAGE_MASK; + if (offs && chunk > PAGE_SIZE) + chunk = offs + ((chunk - offs) & PAGE_MASK); + + truncate_pagecache_range(inode, offset, chunk); + offset += chunk; + length -= chunk; + + tr = current->journal_info; + if (!test_bit(TR_TOUCHED, &tr->tr_flags)) + continue; + + gfs2_trans_end(sdp); + error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES); + if (error) + return error; + } + return 0; +} + +int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length) +{ + struct inode *inode = file_inode(file); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned int blocksize = i_blocksize(inode); + loff_t start, end; + int error; + + if (!gfs2_is_stuffed(ip)) { + unsigned int start_off, end_len; + + start_off = offset & (blocksize - 1); + end_len = (offset + length) & (blocksize - 1); + if (start_off) { + unsigned int len = length; + if (length > blocksize - start_off) + len = blocksize - start_off; + error = gfs2_block_zero_range(inode, offset, len); + if (error) + goto out; + if (start_off + length < blocksize) + end_len = 0; + } + if (end_len) { + error = gfs2_block_zero_range(inode, + offset + length - end_len, end_len); + if (error) + goto out; + } + } + + start = round_down(offset, blocksize); + end = round_up(offset + length, blocksize) - 1; + error = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (error) + return error; + + if (gfs2_is_jdata(ip)) + error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA, + GFS2_JTRUNC_REVOKES); + else + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + if (gfs2_is_stuffed(ip)) { + error = stuffed_zero_range(inode, offset, length); + if (error) + goto out; + } + + if (gfs2_is_jdata(ip)) { + BUG_ON(!current->journal_info); + gfs2_journaled_truncate_range(inode, offset, length); + } else + truncate_pagecache_range(inode, offset, offset + length - 1); + + file_update_time(file); + mark_inode_dirty(inode); + + if (current->journal_info) + gfs2_trans_end(sdp); + + if (!gfs2_is_stuffed(ip)) + error = punch_hole(ip, offset, length); + +out: + if (current->journal_info) + gfs2_trans_end(sdp); + return error; +} + +static int gfs2_map_blocks(struct iomap_writepage_ctx *wpc, struct inode *inode, + loff_t offset) +{ + struct metapath mp = { .mp_aheight = 1, }; + int ret; + + if (WARN_ON_ONCE(gfs2_is_stuffed(GFS2_I(inode)))) + return -EIO; + + if (offset >= wpc->iomap.offset && + offset < wpc->iomap.offset + wpc->iomap.length) + return 0; + + memset(&wpc->iomap, 0, sizeof(wpc->iomap)); + ret = gfs2_iomap_get(inode, offset, INT_MAX, 0, &wpc->iomap, &mp); + release_metapath(&mp); + return ret; +} + +const struct iomap_writeback_ops gfs2_writeback_ops = { + .map_blocks = gfs2_map_blocks, +}; |