diff options
Diffstat (limited to 'fs/gfs2/dir.c')
| -rw-r--r-- | fs/gfs2/dir.c | 2188 |
1 files changed, 2188 insertions, 0 deletions
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c new file mode 100644 index 000000000..1a2afa88f --- /dev/null +++ b/fs/gfs2/dir.c @@ -0,0 +1,2188 @@ +// 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. + */ + +/* + * Implements Extendible Hashing as described in: + * "Extendible Hashing" by Fagin, et al in + * __ACM Trans. on Database Systems__, Sept 1979. + * + * + * Here's the layout of dirents which is essentially the same as that of ext2 + * within a single block. The field de_name_len is the number of bytes + * actually required for the name (no null terminator). The field de_rec_len + * is the number of bytes allocated to the dirent. The offset of the next + * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is + * deleted, the preceding dirent inherits its allocated space, ie + * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained + * by adding de_rec_len to the current dirent, this essentially causes the + * deleted dirent to get jumped over when iterating through all the dirents. + * + * When deleting the first dirent in a block, there is no previous dirent so + * the field de_ino is set to zero to designate it as deleted. When allocating + * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the + * first dirent has (de_ino == 0) and de_rec_len is large enough, this first + * dirent is allocated. Otherwise it must go through all the 'used' dirents + * searching for one in which the amount of total space minus the amount of + * used space will provide enough space for the new dirent. + * + * There are two types of blocks in which dirents reside. In a stuffed dinode, + * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of + * the block. In leaves, they begin at offset sizeof(struct gfs2_leaf) from the + * beginning of the leaf block. The dirents reside in leaves when + * + * dip->i_diskflags & GFS2_DIF_EXHASH is true + * + * Otherwise, the dirents are "linear", within a single stuffed dinode block. + * + * When the dirents are in leaves, the actual contents of the directory file are + * used as an array of 64-bit block pointers pointing to the leaf blocks. The + * dirents are NOT in the directory file itself. There can be more than one + * block pointer in the array that points to the same leaf. In fact, when a + * directory is first converted from linear to exhash, all of the pointers + * point to the same leaf. + * + * When a leaf is completely full, the size of the hash table can be + * doubled unless it is already at the maximum size which is hard coded into + * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list, + * but never before the maximum hash table size has been reached. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/buffer_head.h> +#include <linux/sort.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> +#include <linux/vmalloc.h> +#include <linux/bio.h> + +#include "gfs2.h" +#include "incore.h" +#include "dir.h" +#include "glock.h" +#include "inode.h" +#include "meta_io.h" +#include "quota.h" +#include "rgrp.h" +#include "trans.h" +#include "bmap.h" +#include "util.h" + +#define MAX_RA_BLOCKS 32 /* max read-ahead blocks */ + +#define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1) +#define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1)) +#define GFS2_HASH_INDEX_MASK 0xffffc000 +#define GFS2_USE_HASH_FLAG 0x2000 + +struct qstr gfs2_qdot __read_mostly; +struct qstr gfs2_qdotdot __read_mostly; + +typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent, + const struct qstr *name, void *opaque); + +int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block, + struct buffer_head **bhp) +{ + struct buffer_head *bh; + + bh = gfs2_meta_new(ip->i_gl, block); + gfs2_trans_add_meta(ip->i_gl, bh); + gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD); + gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header)); + *bhp = bh; + return 0; +} + +static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block, + struct buffer_head **bhp) +{ + struct buffer_head *bh; + int error; + + error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, 0, &bh); + if (error) + return error; + if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) { + brelse(bh); + return -EIO; + } + *bhp = bh; + return 0; +} + +static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf, + unsigned int offset, unsigned int size) +{ + struct buffer_head *dibh; + int error; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + + gfs2_trans_add_meta(ip->i_gl, dibh); + memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size); + if (ip->i_inode.i_size < offset + size) + i_size_write(&ip->i_inode, offset + size); + ip->i_inode.i_mtime = inode_set_ctime_current(&ip->i_inode); + gfs2_dinode_out(ip, dibh->b_data); + + brelse(dibh); + + return size; +} + + + +/** + * gfs2_dir_write_data - Write directory information to the inode + * @ip: The GFS2 inode + * @buf: The buffer containing information to be written + * @offset: The file offset to start writing at + * @size: The amount of data to write + * + * Returns: The number of bytes correctly written or error code + */ +static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf, + u64 offset, unsigned int size) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct buffer_head *dibh; + u64 lblock, dblock; + u32 extlen = 0; + unsigned int o; + int copied = 0; + int error = 0; + bool new = false; + + if (!size) + return 0; + + if (gfs2_is_stuffed(ip) && offset + size <= gfs2_max_stuffed_size(ip)) + return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset, + size); + + if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip))) + return -EINVAL; + + if (gfs2_is_stuffed(ip)) { + error = gfs2_unstuff_dinode(ip); + if (error) + return error; + } + + lblock = offset; + o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header); + + while (copied < size) { + unsigned int amount; + struct buffer_head *bh; + + amount = size - copied; + if (amount > sdp->sd_sb.sb_bsize - o) + amount = sdp->sd_sb.sb_bsize - o; + + if (!extlen) { + extlen = 1; + error = gfs2_alloc_extent(&ip->i_inode, lblock, &dblock, + &extlen, &new); + if (error) + goto fail; + error = -EIO; + if (gfs2_assert_withdraw(sdp, dblock)) + goto fail; + } + + if (amount == sdp->sd_jbsize || new) + error = gfs2_dir_get_new_buffer(ip, dblock, &bh); + else + error = gfs2_dir_get_existing_buffer(ip, dblock, &bh); + + if (error) + goto fail; + + gfs2_trans_add_meta(ip->i_gl, bh); + memcpy(bh->b_data + o, buf, amount); + brelse(bh); + + buf += amount; + copied += amount; + lblock++; + dblock++; + extlen--; + + o = sizeof(struct gfs2_meta_header); + } + +out: + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + + if (ip->i_inode.i_size < offset + copied) + i_size_write(&ip->i_inode, offset + copied); + ip->i_inode.i_mtime = inode_set_ctime_current(&ip->i_inode); + + gfs2_trans_add_meta(ip->i_gl, dibh); + gfs2_dinode_out(ip, dibh->b_data); + brelse(dibh); + + return copied; +fail: + if (copied) + goto out; + return error; +} + +static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf, + unsigned int size) +{ + struct buffer_head *dibh; + int error; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (!error) { + memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size); + brelse(dibh); + } + + return (error) ? error : size; +} + + +/** + * gfs2_dir_read_data - Read a data from a directory inode + * @ip: The GFS2 Inode + * @buf: The buffer to place result into + * @size: Amount of data to transfer + * + * Returns: The amount of data actually copied or the error + */ +static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf, + unsigned int size) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + u64 lblock, dblock; + u32 extlen = 0; + unsigned int o; + int copied = 0; + int error = 0; + + if (gfs2_is_stuffed(ip)) + return gfs2_dir_read_stuffed(ip, buf, size); + + if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip))) + return -EINVAL; + + lblock = 0; + o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header); + + while (copied < size) { + unsigned int amount; + struct buffer_head *bh; + + amount = size - copied; + if (amount > sdp->sd_sb.sb_bsize - o) + amount = sdp->sd_sb.sb_bsize - o; + + if (!extlen) { + extlen = 32; + error = gfs2_get_extent(&ip->i_inode, lblock, + &dblock, &extlen); + if (error || !dblock) + goto fail; + BUG_ON(extlen < 1); + bh = gfs2_meta_ra(ip->i_gl, dblock, extlen); + } else { + error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, 0, &bh); + if (error) + goto fail; + } + error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD); + if (error) { + brelse(bh); + goto fail; + } + dblock++; + extlen--; + memcpy(buf, bh->b_data + o, amount); + brelse(bh); + buf += (amount/sizeof(__be64)); + copied += amount; + lblock++; + o = sizeof(struct gfs2_meta_header); + } + + return copied; +fail: + return (copied) ? copied : error; +} + +/** + * gfs2_dir_get_hash_table - Get pointer to the dir hash table + * @ip: The inode in question + * + * Returns: The hash table or an error + */ + +static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip) +{ + struct inode *inode = &ip->i_inode; + int ret; + u32 hsize; + __be64 *hc; + + BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH)); + + hc = ip->i_hash_cache; + if (hc) + return hc; + + hsize = BIT(ip->i_depth); + hsize *= sizeof(__be64); + if (hsize != i_size_read(&ip->i_inode)) { + gfs2_consist_inode(ip); + return ERR_PTR(-EIO); + } + + hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN); + if (hc == NULL) + hc = __vmalloc(hsize, GFP_NOFS); + + if (hc == NULL) + return ERR_PTR(-ENOMEM); + + ret = gfs2_dir_read_data(ip, hc, hsize); + if (ret < 0) { + kvfree(hc); + return ERR_PTR(ret); + } + + spin_lock(&inode->i_lock); + if (likely(!ip->i_hash_cache)) { + ip->i_hash_cache = hc; + hc = NULL; + } + spin_unlock(&inode->i_lock); + kvfree(hc); + + return ip->i_hash_cache; +} + +/** + * gfs2_dir_hash_inval - Invalidate dir hash + * @ip: The directory inode + * + * Must be called with an exclusive glock, or during glock invalidation. + */ +void gfs2_dir_hash_inval(struct gfs2_inode *ip) +{ + __be64 *hc; + + spin_lock(&ip->i_inode.i_lock); + hc = ip->i_hash_cache; + ip->i_hash_cache = NULL; + spin_unlock(&ip->i_inode.i_lock); + + kvfree(hc); +} + +static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent) +{ + return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0; +} + +static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent, + const struct qstr *name, int ret) +{ + if (!gfs2_dirent_sentinel(dent) && + be32_to_cpu(dent->de_hash) == name->hash && + be16_to_cpu(dent->de_name_len) == name->len && + memcmp(dent+1, name->name, name->len) == 0) + return ret; + return 0; +} + +static int gfs2_dirent_find(const struct gfs2_dirent *dent, + const struct qstr *name, + void *opaque) +{ + return __gfs2_dirent_find(dent, name, 1); +} + +static int gfs2_dirent_prev(const struct gfs2_dirent *dent, + const struct qstr *name, + void *opaque) +{ + return __gfs2_dirent_find(dent, name, 2); +} + +/* + * name->name holds ptr to start of block. + * name->len holds size of block. + */ +static int gfs2_dirent_last(const struct gfs2_dirent *dent, + const struct qstr *name, + void *opaque) +{ + const char *start = name->name; + const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len); + if (name->len == (end - start)) + return 1; + return 0; +} + +/* Look for the dirent that contains the offset specified in data. Once we + * find that dirent, there must be space available there for the new dirent */ +static int gfs2_dirent_find_offset(const struct gfs2_dirent *dent, + const struct qstr *name, + void *ptr) +{ + unsigned required = GFS2_DIRENT_SIZE(name->len); + unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len)); + unsigned totlen = be16_to_cpu(dent->de_rec_len); + + if (ptr < (void *)dent || ptr >= (void *)dent + totlen) + return 0; + if (gfs2_dirent_sentinel(dent)) + actual = 0; + if (ptr < (void *)dent + actual) + return -1; + if ((void *)dent + totlen >= ptr + required) + return 1; + return -1; +} + +static int gfs2_dirent_find_space(const struct gfs2_dirent *dent, + const struct qstr *name, + void *opaque) +{ + unsigned required = GFS2_DIRENT_SIZE(name->len); + unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len)); + unsigned totlen = be16_to_cpu(dent->de_rec_len); + + if (gfs2_dirent_sentinel(dent)) + actual = 0; + if (totlen - actual >= required) + return 1; + return 0; +} + +struct dirent_gather { + const struct gfs2_dirent **pdent; + unsigned offset; +}; + +static int gfs2_dirent_gather(const struct gfs2_dirent *dent, + const struct qstr *name, + void *opaque) +{ + struct dirent_gather *g = opaque; + if (!gfs2_dirent_sentinel(dent)) { + g->pdent[g->offset++] = dent; + } + return 0; +} + +/* + * Other possible things to check: + * - Inode located within filesystem size (and on valid block) + * - Valid directory entry type + * Not sure how heavy-weight we want to make this... could also check + * hash is correct for example, but that would take a lot of extra time. + * For now the most important thing is to check that the various sizes + * are correct. + */ +static int gfs2_check_dirent(struct gfs2_sbd *sdp, + struct gfs2_dirent *dent, unsigned int offset, + unsigned int size, unsigned int len, int first) +{ + const char *msg = "gfs2_dirent too small"; + if (unlikely(size < sizeof(struct gfs2_dirent))) + goto error; + msg = "gfs2_dirent misaligned"; + if (unlikely(offset & 0x7)) + goto error; + msg = "gfs2_dirent points beyond end of block"; + if (unlikely(offset + size > len)) + goto error; + msg = "zero inode number"; + if (unlikely(!first && gfs2_dirent_sentinel(dent))) + goto error; + msg = "name length is greater than space in dirent"; + if (!gfs2_dirent_sentinel(dent) && + unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) > + size)) + goto error; + return 0; +error: + fs_warn(sdp, "%s: %s (%s)\n", + __func__, msg, first ? "first in block" : "not first in block"); + return -EIO; +} + +static int gfs2_dirent_offset(struct gfs2_sbd *sdp, const void *buf) +{ + const struct gfs2_meta_header *h = buf; + int offset; + + BUG_ON(buf == NULL); + + switch(be32_to_cpu(h->mh_type)) { + case GFS2_METATYPE_LF: + offset = sizeof(struct gfs2_leaf); + break; + case GFS2_METATYPE_DI: + offset = sizeof(struct gfs2_dinode); + break; + default: + goto wrong_type; + } + return offset; +wrong_type: + fs_warn(sdp, "%s: wrong block type %u\n", __func__, + be32_to_cpu(h->mh_type)); + return -1; +} + +static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf, + unsigned int len, gfs2_dscan_t scan, + const struct qstr *name, + void *opaque) +{ + struct gfs2_dirent *dent, *prev; + unsigned offset; + unsigned size; + int ret = 0; + + ret = gfs2_dirent_offset(GFS2_SB(inode), buf); + if (ret < 0) + goto consist_inode; + + offset = ret; + prev = NULL; + dent = buf + offset; + size = be16_to_cpu(dent->de_rec_len); + if (gfs2_check_dirent(GFS2_SB(inode), dent, offset, size, len, 1)) + goto consist_inode; + do { + ret = scan(dent, name, opaque); + if (ret) + break; + offset += size; + if (offset == len) + break; + prev = dent; + dent = buf + offset; + size = be16_to_cpu(dent->de_rec_len); + if (gfs2_check_dirent(GFS2_SB(inode), dent, offset, size, + len, 0)) + goto consist_inode; + } while(1); + + switch(ret) { + case 0: + return NULL; + case 1: + return dent; + case 2: + return prev ? prev : dent; + default: + BUG_ON(ret > 0); + return ERR_PTR(ret); + } + +consist_inode: + gfs2_consist_inode(GFS2_I(inode)); + return ERR_PTR(-EIO); +} + +static int dirent_check_reclen(struct gfs2_inode *dip, + const struct gfs2_dirent *d, const void *end_p) +{ + const void *ptr = d; + u16 rec_len = be16_to_cpu(d->de_rec_len); + + if (unlikely(rec_len < sizeof(struct gfs2_dirent))) + goto broken; + ptr += rec_len; + if (ptr < end_p) + return rec_len; + if (ptr == end_p) + return -ENOENT; +broken: + gfs2_consist_inode(dip); + return -EIO; +} + +/** + * dirent_next - Next dirent + * @dip: the directory + * @bh: The buffer + * @dent: Pointer to list of dirents + * + * Returns: 0 on success, error code otherwise + */ + +static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh, + struct gfs2_dirent **dent) +{ + struct gfs2_dirent *cur = *dent, *tmp; + char *bh_end = bh->b_data + bh->b_size; + int ret; + + ret = dirent_check_reclen(dip, cur, bh_end); + if (ret < 0) + return ret; + + tmp = (void *)cur + ret; + ret = dirent_check_reclen(dip, tmp, bh_end); + if (ret == -EIO) + return ret; + + /* Only the first dent could ever have de_inum.no_addr == 0 */ + if (gfs2_dirent_sentinel(tmp)) { + gfs2_consist_inode(dip); + return -EIO; + } + + *dent = tmp; + return 0; +} + +/** + * dirent_del - Delete a dirent + * @dip: The GFS2 inode + * @bh: The buffer + * @prev: The previous dirent + * @cur: The current dirent + * + */ + +static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh, + struct gfs2_dirent *prev, struct gfs2_dirent *cur) +{ + u16 cur_rec_len, prev_rec_len; + + if (gfs2_dirent_sentinel(cur)) { + gfs2_consist_inode(dip); + return; + } + + gfs2_trans_add_meta(dip->i_gl, bh); + + /* If there is no prev entry, this is the first entry in the block. + The de_rec_len is already as big as it needs to be. Just zero + out the inode number and return. */ + + if (!prev) { + cur->de_inum.no_addr = 0; + cur->de_inum.no_formal_ino = 0; + return; + } + + /* Combine this dentry with the previous one. */ + + prev_rec_len = be16_to_cpu(prev->de_rec_len); + cur_rec_len = be16_to_cpu(cur->de_rec_len); + + if ((char *)prev + prev_rec_len != (char *)cur) + gfs2_consist_inode(dip); + if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size) + gfs2_consist_inode(dip); + + prev_rec_len += cur_rec_len; + prev->de_rec_len = cpu_to_be16(prev_rec_len); +} + + +static struct gfs2_dirent *do_init_dirent(struct inode *inode, + struct gfs2_dirent *dent, + const struct qstr *name, + struct buffer_head *bh, + unsigned offset) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_dirent *ndent; + unsigned totlen; + + totlen = be16_to_cpu(dent->de_rec_len); + BUG_ON(offset + name->len > totlen); + gfs2_trans_add_meta(ip->i_gl, bh); + ndent = (struct gfs2_dirent *)((char *)dent + offset); + dent->de_rec_len = cpu_to_be16(offset); + gfs2_qstr2dirent(name, totlen - offset, ndent); + return ndent; +} + + +/* + * Takes a dent from which to grab space as an argument. Returns the + * newly created dent. + */ +static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode, + struct gfs2_dirent *dent, + const struct qstr *name, + struct buffer_head *bh) +{ + unsigned offset = 0; + + if (!gfs2_dirent_sentinel(dent)) + offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len)); + return do_init_dirent(inode, dent, name, bh, offset); +} + +static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode, + struct buffer_head *bh, + const struct qstr *name, + void *ptr) +{ + struct gfs2_dirent *dent; + dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, + gfs2_dirent_find_offset, name, ptr); + if (IS_ERR_OR_NULL(dent)) + return dent; + return do_init_dirent(inode, dent, name, bh, + (unsigned)(ptr - (void *)dent)); +} + +static int get_leaf(struct gfs2_inode *dip, u64 leaf_no, + struct buffer_head **bhp) +{ + int error; + + error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, 0, bhp); + if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) { + /* pr_info("block num=%llu\n", leaf_no); */ + error = -EIO; + } + + return error; +} + +/** + * get_leaf_nr - Get a leaf number associated with the index + * @dip: The GFS2 inode + * @index: hash table index of the targeted leaf + * @leaf_out: Resulting leaf block number + * + * Returns: 0 on success, error code otherwise + */ + +static int get_leaf_nr(struct gfs2_inode *dip, u32 index, u64 *leaf_out) +{ + __be64 *hash; + int error; + + hash = gfs2_dir_get_hash_table(dip); + error = PTR_ERR_OR_ZERO(hash); + + if (!error) + *leaf_out = be64_to_cpu(*(hash + index)); + + return error; +} + +static int get_first_leaf(struct gfs2_inode *dip, u32 index, + struct buffer_head **bh_out) +{ + u64 leaf_no; + int error; + + error = get_leaf_nr(dip, index, &leaf_no); + if (!error) + error = get_leaf(dip, leaf_no, bh_out); + + return error; +} + +static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode, + const struct qstr *name, + gfs2_dscan_t scan, + struct buffer_head **pbh) +{ + struct buffer_head *bh; + struct gfs2_dirent *dent; + struct gfs2_inode *ip = GFS2_I(inode); + int error; + + if (ip->i_diskflags & GFS2_DIF_EXHASH) { + struct gfs2_leaf *leaf; + unsigned int hsize = BIT(ip->i_depth); + unsigned int index; + u64 ln; + if (hsize * sizeof(u64) != i_size_read(inode)) { + gfs2_consist_inode(ip); + return ERR_PTR(-EIO); + } + + index = name->hash >> (32 - ip->i_depth); + error = get_first_leaf(ip, index, &bh); + if (error) + return ERR_PTR(error); + do { + dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, + scan, name, NULL); + if (dent) + goto got_dent; + leaf = (struct gfs2_leaf *)bh->b_data; + ln = be64_to_cpu(leaf->lf_next); + brelse(bh); + if (!ln) + break; + + error = get_leaf(ip, ln, &bh); + } while(!error); + + return error ? ERR_PTR(error) : NULL; + } + + + error = gfs2_meta_inode_buffer(ip, &bh); + if (error) + return ERR_PTR(error); + dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL); +got_dent: + if (IS_ERR_OR_NULL(dent)) { + brelse(bh); + bh = NULL; + } + *pbh = bh; + return dent; +} + +static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth) +{ + struct gfs2_inode *ip = GFS2_I(inode); + unsigned int n = 1; + u64 bn; + int error; + struct buffer_head *bh; + struct gfs2_leaf *leaf; + struct gfs2_dirent *dent; + struct timespec64 tv = current_time(inode); + + error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL); + if (error) + return NULL; + bh = gfs2_meta_new(ip->i_gl, bn); + if (!bh) + return NULL; + + gfs2_trans_remove_revoke(GFS2_SB(inode), bn, 1); + gfs2_trans_add_meta(ip->i_gl, bh); + gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF); + leaf = (struct gfs2_leaf *)bh->b_data; + leaf->lf_depth = cpu_to_be16(depth); + leaf->lf_entries = 0; + leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE); + leaf->lf_next = 0; + leaf->lf_inode = cpu_to_be64(ip->i_no_addr); + leaf->lf_dist = cpu_to_be32(1); + leaf->lf_nsec = cpu_to_be32(tv.tv_nsec); + leaf->lf_sec = cpu_to_be64(tv.tv_sec); + memset(leaf->lf_reserved2, 0, sizeof(leaf->lf_reserved2)); + dent = (struct gfs2_dirent *)(leaf+1); + gfs2_qstr2dirent(&empty_name, bh->b_size - sizeof(struct gfs2_leaf), dent); + *pbh = bh; + return leaf; +} + +/** + * dir_make_exhash - Convert a stuffed directory into an ExHash directory + * @inode: The directory inode to be converted to exhash + * + * Returns: 0 on success, error code otherwise + */ + +static int dir_make_exhash(struct inode *inode) +{ + struct gfs2_inode *dip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_dirent *dent; + struct qstr args; + struct buffer_head *bh, *dibh; + struct gfs2_leaf *leaf; + int y; + u32 x; + __be64 *lp; + u64 bn; + int error; + + error = gfs2_meta_inode_buffer(dip, &dibh); + if (error) + return error; + + /* Turn over a new leaf */ + + leaf = new_leaf(inode, &bh, 0); + if (!leaf) + return -ENOSPC; + bn = bh->b_blocknr; + + gfs2_assert(sdp, dip->i_entries < BIT(16)); + leaf->lf_entries = cpu_to_be16(dip->i_entries); + + /* Copy dirents */ + + gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh, + sizeof(struct gfs2_dinode)); + + /* Find last entry */ + + x = 0; + args.len = bh->b_size - sizeof(struct gfs2_dinode) + + sizeof(struct gfs2_leaf); + args.name = bh->b_data; + dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size, + gfs2_dirent_last, &args, NULL); + if (!dent) { + brelse(bh); + brelse(dibh); + return -EIO; + } + if (IS_ERR(dent)) { + brelse(bh); + brelse(dibh); + return PTR_ERR(dent); + } + + /* Adjust the last dirent's record length + (Remember that dent still points to the last entry.) */ + + dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) + + sizeof(struct gfs2_dinode) - + sizeof(struct gfs2_leaf)); + + brelse(bh); + + /* We're done with the new leaf block, now setup the new + hash table. */ + + gfs2_trans_add_meta(dip->i_gl, dibh); + gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); + + lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode)); + + for (x = sdp->sd_hash_ptrs; x--; lp++) + *lp = cpu_to_be64(bn); + + i_size_write(inode, sdp->sd_sb.sb_bsize / 2); + gfs2_add_inode_blocks(&dip->i_inode, 1); + dip->i_diskflags |= GFS2_DIF_EXHASH; + + for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ; + dip->i_depth = y; + + gfs2_dinode_out(dip, dibh->b_data); + + brelse(dibh); + + return 0; +} + +/** + * dir_split_leaf - Split a leaf block into two + * @inode: The directory inode to be split + * @name: name of the dirent we're trying to insert + * + * Returns: 0 on success, error code on failure + */ + +static int dir_split_leaf(struct inode *inode, const struct qstr *name) +{ + struct gfs2_inode *dip = GFS2_I(inode); + struct buffer_head *nbh, *obh, *dibh; + struct gfs2_leaf *nleaf, *oleaf; + struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new; + u32 start, len, half_len, divider; + u64 bn, leaf_no; + __be64 *lp; + u32 index; + int x; + int error; + + index = name->hash >> (32 - dip->i_depth); + error = get_leaf_nr(dip, index, &leaf_no); + if (error) + return error; + + /* Get the old leaf block */ + error = get_leaf(dip, leaf_no, &obh); + if (error) + return error; + + oleaf = (struct gfs2_leaf *)obh->b_data; + if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) { + brelse(obh); + return 1; /* can't split */ + } + + gfs2_trans_add_meta(dip->i_gl, obh); + + nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1); + if (!nleaf) { + brelse(obh); + return -ENOSPC; + } + bn = nbh->b_blocknr; + + /* Compute the start and len of leaf pointers in the hash table. */ + len = BIT(dip->i_depth - be16_to_cpu(oleaf->lf_depth)); + half_len = len >> 1; + if (!half_len) { + fs_warn(GFS2_SB(inode), "i_depth %u lf_depth %u index %u\n", + dip->i_depth, be16_to_cpu(oleaf->lf_depth), index); + gfs2_consist_inode(dip); + error = -EIO; + goto fail_brelse; + } + + start = (index & ~(len - 1)); + + /* Change the pointers. + Don't bother distinguishing stuffed from non-stuffed. + This code is complicated enough already. */ + lp = kmalloc_array(half_len, sizeof(__be64), GFP_NOFS); + if (!lp) { + error = -ENOMEM; + goto fail_brelse; + } + + /* Change the pointers */ + for (x = 0; x < half_len; x++) + lp[x] = cpu_to_be64(bn); + + gfs2_dir_hash_inval(dip); + + error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64), + half_len * sizeof(u64)); + if (error != half_len * sizeof(u64)) { + if (error >= 0) + error = -EIO; + goto fail_lpfree; + } + + kfree(lp); + + /* Compute the divider */ + divider = (start + half_len) << (32 - dip->i_depth); + + /* Copy the entries */ + dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf)); + + do { + next = dent; + if (dirent_next(dip, obh, &next)) + next = NULL; + + if (!gfs2_dirent_sentinel(dent) && + be32_to_cpu(dent->de_hash) < divider) { + struct qstr str; + void *ptr = ((char *)dent - obh->b_data) + nbh->b_data; + str.name = (char*)(dent+1); + str.len = be16_to_cpu(dent->de_name_len); + str.hash = be32_to_cpu(dent->de_hash); + new = gfs2_dirent_split_alloc(inode, nbh, &str, ptr); + if (IS_ERR(new)) { + error = PTR_ERR(new); + break; + } + + new->de_inum = dent->de_inum; /* No endian worries */ + new->de_type = dent->de_type; /* No endian worries */ + be16_add_cpu(&nleaf->lf_entries, 1); + + dirent_del(dip, obh, prev, dent); + + if (!oleaf->lf_entries) + gfs2_consist_inode(dip); + be16_add_cpu(&oleaf->lf_entries, -1); + + if (!prev) + prev = dent; + } else { + prev = dent; + } + dent = next; + } while (dent); + + oleaf->lf_depth = nleaf->lf_depth; + + error = gfs2_meta_inode_buffer(dip, &dibh); + if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) { + gfs2_trans_add_meta(dip->i_gl, dibh); + gfs2_add_inode_blocks(&dip->i_inode, 1); + gfs2_dinode_out(dip, dibh->b_data); + brelse(dibh); + } + + brelse(obh); + brelse(nbh); + + return error; + +fail_lpfree: + kfree(lp); + +fail_brelse: + brelse(obh); + brelse(nbh); + return error; +} + +/** + * dir_double_exhash - Double size of ExHash table + * @dip: The GFS2 dinode + * + * Returns: 0 on success, error code on failure + */ + +static int dir_double_exhash(struct gfs2_inode *dip) +{ + struct buffer_head *dibh; + u32 hsize; + u32 hsize_bytes; + __be64 *hc; + __be64 *hc2, *h; + int x; + int error = 0; + + hsize = BIT(dip->i_depth); + hsize_bytes = hsize * sizeof(__be64); + + hc = gfs2_dir_get_hash_table(dip); + if (IS_ERR(hc)) + return PTR_ERR(hc); + + hc2 = kmalloc_array(hsize_bytes, 2, GFP_NOFS | __GFP_NOWARN); + if (hc2 == NULL) + hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS); + + if (!hc2) + return -ENOMEM; + + h = hc2; + error = gfs2_meta_inode_buffer(dip, &dibh); + if (error) + goto out_kfree; + + for (x = 0; x < hsize; x++) { + *h++ = *hc; + *h++ = *hc; + hc++; + } + + error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2); + if (error != (hsize_bytes * 2)) + goto fail; + + gfs2_dir_hash_inval(dip); + dip->i_hash_cache = hc2; + dip->i_depth++; + gfs2_dinode_out(dip, dibh->b_data); + brelse(dibh); + return 0; + +fail: + /* Replace original hash table & size */ + gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes); + i_size_write(&dip->i_inode, hsize_bytes); + gfs2_dinode_out(dip, dibh->b_data); + brelse(dibh); +out_kfree: + kvfree(hc2); + return error; +} + +/** + * compare_dents - compare directory entries by hash value + * @a: first dent + * @b: second dent + * + * When comparing the hash entries of @a to @b: + * gt: returns 1 + * lt: returns -1 + * eq: returns 0 + */ + +static int compare_dents(const void *a, const void *b) +{ + const struct gfs2_dirent *dent_a, *dent_b; + u32 hash_a, hash_b; + int ret = 0; + + dent_a = *(const struct gfs2_dirent **)a; + hash_a = dent_a->de_cookie; + + dent_b = *(const struct gfs2_dirent **)b; + hash_b = dent_b->de_cookie; + + if (hash_a > hash_b) + ret = 1; + else if (hash_a < hash_b) + ret = -1; + else { + unsigned int len_a = be16_to_cpu(dent_a->de_name_len); + unsigned int len_b = be16_to_cpu(dent_b->de_name_len); + + if (len_a > len_b) + ret = 1; + else if (len_a < len_b) + ret = -1; + else + ret = memcmp(dent_a + 1, dent_b + 1, len_a); + } + + return ret; +} + +/** + * do_filldir_main - read out directory entries + * @dip: The GFS2 inode + * @ctx: what to feed the entries to + * @darr: an array of struct gfs2_dirent pointers to read + * @entries: the number of entries in darr + * @sort_start: index of the directory array to start our sort + * @copied: pointer to int that's non-zero if a entry has been copied out + * + * Jump through some hoops to make sure that if there are hash collsions, + * they are read out at the beginning of a buffer. We want to minimize + * the possibility that they will fall into different readdir buffers or + * that someone will want to seek to that location. + * + * Returns: errno, >0 if the actor tells you to stop + */ + +static int do_filldir_main(struct gfs2_inode *dip, struct dir_context *ctx, + struct gfs2_dirent **darr, u32 entries, + u32 sort_start, int *copied) +{ + const struct gfs2_dirent *dent, *dent_next; + u64 off, off_next; + unsigned int x, y; + int run = 0; + + if (sort_start < entries) + sort(&darr[sort_start], entries - sort_start, + sizeof(struct gfs2_dirent *), compare_dents, NULL); + + dent_next = darr[0]; + off_next = dent_next->de_cookie; + + for (x = 0, y = 1; x < entries; x++, y++) { + dent = dent_next; + off = off_next; + + if (y < entries) { + dent_next = darr[y]; + off_next = dent_next->de_cookie; + + if (off < ctx->pos) + continue; + ctx->pos = off; + + if (off_next == off) { + if (*copied && !run) + return 1; + run = 1; + } else + run = 0; + } else { + if (off < ctx->pos) + continue; + ctx->pos = off; + } + + if (!dir_emit(ctx, (const char *)(dent + 1), + be16_to_cpu(dent->de_name_len), + be64_to_cpu(dent->de_inum.no_addr), + be16_to_cpu(dent->de_type))) + return 1; + + *copied = 1; + } + + /* Increment the ctx->pos by one, so the next time we come into the + do_filldir fxn, we get the next entry instead of the last one in the + current leaf */ + + ctx->pos++; + + return 0; +} + +static void *gfs2_alloc_sort_buffer(unsigned size) +{ + void *ptr = NULL; + + if (size < KMALLOC_MAX_SIZE) + ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN); + if (!ptr) + ptr = __vmalloc(size, GFP_NOFS); + return ptr; +} + + +static int gfs2_set_cookies(struct gfs2_sbd *sdp, struct buffer_head *bh, + unsigned leaf_nr, struct gfs2_dirent **darr, + unsigned entries) +{ + int sort_id = -1; + int i; + + for (i = 0; i < entries; i++) { + unsigned offset; + + darr[i]->de_cookie = be32_to_cpu(darr[i]->de_hash); + darr[i]->de_cookie = gfs2_disk_hash2offset(darr[i]->de_cookie); + + if (!sdp->sd_args.ar_loccookie) + continue; + offset = (char *)(darr[i]) - + (bh->b_data + gfs2_dirent_offset(sdp, bh->b_data)); + offset /= GFS2_MIN_DIRENT_SIZE; + offset += leaf_nr * sdp->sd_max_dents_per_leaf; + if (offset >= GFS2_USE_HASH_FLAG || + leaf_nr >= GFS2_USE_HASH_FLAG) { + darr[i]->de_cookie |= GFS2_USE_HASH_FLAG; + if (sort_id < 0) + sort_id = i; + continue; + } + darr[i]->de_cookie &= GFS2_HASH_INDEX_MASK; + darr[i]->de_cookie |= offset; + } + return sort_id; +} + + +static int gfs2_dir_read_leaf(struct inode *inode, struct dir_context *ctx, + int *copied, unsigned *depth, + u64 leaf_no) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct buffer_head *bh; + struct gfs2_leaf *lf; + unsigned entries = 0, entries2 = 0; + unsigned leaves = 0, leaf = 0, offset, sort_offset; + struct gfs2_dirent **darr, *dent; + struct dirent_gather g; + struct buffer_head **larr; + int error, i, need_sort = 0, sort_id; + u64 lfn = leaf_no; + + do { + error = get_leaf(ip, lfn, &bh); + if (error) + goto out; + lf = (struct gfs2_leaf *)bh->b_data; + if (leaves == 0) + *depth = be16_to_cpu(lf->lf_depth); + entries += be16_to_cpu(lf->lf_entries); + leaves++; + lfn = be64_to_cpu(lf->lf_next); + brelse(bh); + } while(lfn); + + if (*depth < GFS2_DIR_MAX_DEPTH || !sdp->sd_args.ar_loccookie) { + need_sort = 1; + sort_offset = 0; + } + + if (!entries) + return 0; + + error = -ENOMEM; + /* + * The extra 99 entries are not normally used, but are a buffer + * zone in case the number of entries in the leaf is corrupt. + * 99 is the maximum number of entries that can fit in a single + * leaf block. + */ + larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *)); + if (!larr) + goto out; + darr = (struct gfs2_dirent **)(larr + leaves); + g.pdent = (const struct gfs2_dirent **)darr; + g.offset = 0; + lfn = leaf_no; + + do { + error = get_leaf(ip, lfn, &bh); + if (error) + goto out_free; + lf = (struct gfs2_leaf *)bh->b_data; + lfn = be64_to_cpu(lf->lf_next); + if (lf->lf_entries) { + offset = g.offset; + entries2 += be16_to_cpu(lf->lf_entries); + dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, + gfs2_dirent_gather, NULL, &g); + error = PTR_ERR(dent); + if (IS_ERR(dent)) + goto out_free; + if (entries2 != g.offset) { + fs_warn(sdp, "Number of entries corrupt in dir " + "leaf %llu, entries2 (%u) != " + "g.offset (%u)\n", + (unsigned long long)bh->b_blocknr, + entries2, g.offset); + gfs2_consist_inode(ip); + error = -EIO; + goto out_free; + } + error = 0; + sort_id = gfs2_set_cookies(sdp, bh, leaf, &darr[offset], + be16_to_cpu(lf->lf_entries)); + if (!need_sort && sort_id >= 0) { + need_sort = 1; + sort_offset = offset + sort_id; + } + larr[leaf++] = bh; + } else { + larr[leaf++] = NULL; + brelse(bh); + } + } while(lfn); + + BUG_ON(entries2 != entries); + error = do_filldir_main(ip, ctx, darr, entries, need_sort ? + sort_offset : entries, copied); +out_free: + for(i = 0; i < leaf; i++) + brelse(larr[i]); + kvfree(larr); +out: + return error; +} + +/** + * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks. + * @inode: the directory inode + * @hsize: hash table size + * @index: index into the hash table + * @f_ra: read-ahead parameters + * + * Note: we can't calculate each index like dir_e_read can because we don't + * have the leaf, and therefore we don't have the depth, and therefore we + * don't have the length. So we have to just read enough ahead to make up + * for the loss of information. + */ +static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index, + struct file_ra_state *f_ra) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_glock *gl = ip->i_gl; + struct buffer_head *bh; + u64 blocknr = 0, last; + unsigned count; + + /* First check if we've already read-ahead for the whole range. */ + if (index + MAX_RA_BLOCKS < f_ra->start) + return; + + f_ra->start = max((pgoff_t)index, f_ra->start); + for (count = 0; count < MAX_RA_BLOCKS; count++) { + if (f_ra->start >= hsize) /* if exceeded the hash table */ + break; + + last = blocknr; + blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]); + f_ra->start++; + if (blocknr == last) + continue; + + bh = gfs2_getbuf(gl, blocknr, 1); + if (trylock_buffer(bh)) { + if (buffer_uptodate(bh)) { + unlock_buffer(bh); + brelse(bh); + continue; + } + bh->b_end_io = end_buffer_read_sync; + submit_bh(REQ_OP_READ | REQ_RAHEAD | REQ_META | + REQ_PRIO, bh); + continue; + } + brelse(bh); + } +} + +/** + * dir_e_read - Reads the entries from a directory into a filldir buffer + * @inode: the directory inode + * @ctx: actor to feed the entries to + * @f_ra: read-ahead parameters + * + * Returns: errno + */ + +static int dir_e_read(struct inode *inode, struct dir_context *ctx, + struct file_ra_state *f_ra) +{ + struct gfs2_inode *dip = GFS2_I(inode); + u32 hsize, len = 0; + u32 hash, index; + __be64 *lp; + int copied = 0; + int error = 0; + unsigned depth = 0; + + hsize = BIT(dip->i_depth); + hash = gfs2_dir_offset2hash(ctx->pos); + index = hash >> (32 - dip->i_depth); + + if (dip->i_hash_cache == NULL) + f_ra->start = 0; + lp = gfs2_dir_get_hash_table(dip); + if (IS_ERR(lp)) + return PTR_ERR(lp); + + gfs2_dir_readahead(inode, hsize, index, f_ra); + + while (index < hsize) { + error = gfs2_dir_read_leaf(inode, ctx, + &copied, &depth, + be64_to_cpu(lp[index])); + if (error) + break; + + len = BIT(dip->i_depth - depth); + index = (index & ~(len - 1)) + len; + } + + if (error > 0) + error = 0; + return error; +} + +int gfs2_dir_read(struct inode *inode, struct dir_context *ctx, + struct file_ra_state *f_ra) +{ + struct gfs2_inode *dip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct dirent_gather g; + struct gfs2_dirent **darr, *dent; + struct buffer_head *dibh; + int copied = 0; + int error; + + if (!dip->i_entries) + return 0; + + if (dip->i_diskflags & GFS2_DIF_EXHASH) + return dir_e_read(inode, ctx, f_ra); + + if (!gfs2_is_stuffed(dip)) { + gfs2_consist_inode(dip); + return -EIO; + } + + error = gfs2_meta_inode_buffer(dip, &dibh); + if (error) + return error; + + error = -ENOMEM; + /* 96 is max number of dirents which can be stuffed into an inode */ + darr = kmalloc_array(96, sizeof(struct gfs2_dirent *), GFP_NOFS); + if (darr) { + g.pdent = (const struct gfs2_dirent **)darr; + g.offset = 0; + dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size, + gfs2_dirent_gather, NULL, &g); + if (IS_ERR(dent)) { + error = PTR_ERR(dent); + goto out; + } + if (dip->i_entries != g.offset) { + fs_warn(sdp, "Number of entries corrupt in dir %llu, " + "ip->i_entries (%u) != g.offset (%u)\n", + (unsigned long long)dip->i_no_addr, + dip->i_entries, + g.offset); + gfs2_consist_inode(dip); + error = -EIO; + goto out; + } + gfs2_set_cookies(sdp, dibh, 0, darr, dip->i_entries); + error = do_filldir_main(dip, ctx, darr, + dip->i_entries, 0, &copied); +out: + kfree(darr); + } + + if (error > 0) + error = 0; + + brelse(dibh); + + return error; +} + +/** + * gfs2_dir_search - Search a directory + * @dir: The GFS2 directory inode + * @name: The name we are looking up + * @fail_on_exist: Fail if the name exists rather than looking it up + * + * This routine searches a directory for a file or another directory. + * Assumes a glock is held on dip. + * + * Returns: errno + */ + +struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name, + bool fail_on_exist) +{ + struct buffer_head *bh; + struct gfs2_dirent *dent; + u64 addr, formal_ino; + u16 dtype; + + dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh); + if (dent) { + struct inode *inode; + u16 rahead; + + if (IS_ERR(dent)) + return ERR_CAST(dent); + dtype = be16_to_cpu(dent->de_type); + rahead = be16_to_cpu(dent->de_rahead); + addr = be64_to_cpu(dent->de_inum.no_addr); + formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino); + brelse(bh); + if (fail_on_exist) + return ERR_PTR(-EEXIST); + inode = gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino, + GFS2_BLKST_FREE /* ignore */); + if (!IS_ERR(inode)) + GFS2_I(inode)->i_rahead = rahead; + return inode; + } + return ERR_PTR(-ENOENT); +} + +int gfs2_dir_check(struct inode *dir, const struct qstr *name, + const struct gfs2_inode *ip) +{ + struct buffer_head *bh; + struct gfs2_dirent *dent; + int ret = -ENOENT; + + dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh); + if (dent) { + if (IS_ERR(dent)) + return PTR_ERR(dent); + if (ip) { + if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr) + goto out; + if (be64_to_cpu(dent->de_inum.no_formal_ino) != + ip->i_no_formal_ino) + goto out; + if (unlikely(IF2DT(ip->i_inode.i_mode) != + be16_to_cpu(dent->de_type))) { + gfs2_consist_inode(GFS2_I(dir)); + ret = -EIO; + goto out; + } + } + ret = 0; +out: + brelse(bh); + } + return ret; +} + +/** + * dir_new_leaf - Add a new leaf onto hash chain + * @inode: The directory + * @name: The name we are adding + * + * This adds a new dir leaf onto an existing leaf when there is not + * enough space to add a new dir entry. This is a last resort after + * we've expanded the hash table to max size and also split existing + * leaf blocks, so it will only occur for very large directories. + * + * The dist parameter is set to 1 for leaf blocks directly attached + * to the hash table, 2 for one layer of indirection, 3 for two layers + * etc. We are thus able to tell the difference between an old leaf + * with dist set to zero (i.e. "don't know") and a new one where we + * set this information for debug/fsck purposes. + * + * Returns: 0 on success, or -ve on error + */ + +static int dir_new_leaf(struct inode *inode, const struct qstr *name) +{ + struct buffer_head *bh, *obh; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_leaf *leaf, *oleaf; + u32 dist = 1; + int error; + u32 index; + u64 bn; + + index = name->hash >> (32 - ip->i_depth); + error = get_first_leaf(ip, index, &obh); + if (error) + return error; + do { + dist++; + oleaf = (struct gfs2_leaf *)obh->b_data; + bn = be64_to_cpu(oleaf->lf_next); + if (!bn) + break; + brelse(obh); + error = get_leaf(ip, bn, &obh); + if (error) + return error; + } while(1); + + gfs2_trans_add_meta(ip->i_gl, obh); + + leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth)); + if (!leaf) { + brelse(obh); + return -ENOSPC; + } + leaf->lf_dist = cpu_to_be32(dist); + oleaf->lf_next = cpu_to_be64(bh->b_blocknr); + brelse(bh); + brelse(obh); + + error = gfs2_meta_inode_buffer(ip, &bh); + if (error) + return error; + gfs2_trans_add_meta(ip->i_gl, bh); + gfs2_add_inode_blocks(&ip->i_inode, 1); + gfs2_dinode_out(ip, bh->b_data); + brelse(bh); + return 0; +} + +static u16 gfs2_inode_ra_len(const struct gfs2_inode *ip) +{ + u64 where = ip->i_no_addr + 1; + if (ip->i_eattr == where) + return 1; + return 0; +} + +/** + * gfs2_dir_add - Add new filename into directory + * @inode: The directory inode + * @name: The new name + * @nip: The GFS2 inode to be linked in to the directory + * @da: The directory addition info + * + * If the call to gfs2_diradd_alloc_required resulted in there being + * no need to allocate any new directory blocks, then it will contain + * a pointer to the directory entry and the bh in which it resides. We + * can use that without having to repeat the search. If there was no + * free space, then we must now create more space. + * + * Returns: 0 on success, error code on failure + */ + +int gfs2_dir_add(struct inode *inode, const struct qstr *name, + const struct gfs2_inode *nip, struct gfs2_diradd *da) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct buffer_head *bh = da->bh; + struct gfs2_dirent *dent = da->dent; + struct timespec64 tv; + struct gfs2_leaf *leaf; + int error; + + while(1) { + if (da->bh == NULL) { + dent = gfs2_dirent_search(inode, name, + gfs2_dirent_find_space, &bh); + } + if (dent) { + if (IS_ERR(dent)) + return PTR_ERR(dent); + dent = gfs2_init_dirent(inode, dent, name, bh); + gfs2_inum_out(nip, dent); + dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode)); + dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip)); + tv = inode_set_ctime_current(&ip->i_inode); + if (ip->i_diskflags & GFS2_DIF_EXHASH) { + leaf = (struct gfs2_leaf *)bh->b_data; + be16_add_cpu(&leaf->lf_entries, 1); + leaf->lf_nsec = cpu_to_be32(tv.tv_nsec); + leaf->lf_sec = cpu_to_be64(tv.tv_sec); + } + da->dent = NULL; + da->bh = NULL; + brelse(bh); + ip->i_entries++; + ip->i_inode.i_mtime = tv; + if (S_ISDIR(nip->i_inode.i_mode)) + inc_nlink(&ip->i_inode); + mark_inode_dirty(inode); + error = 0; + break; + } + if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) { + error = dir_make_exhash(inode); + if (error) + break; + continue; + } + error = dir_split_leaf(inode, name); + if (error == 0) + continue; + if (error < 0) + break; + if (ip->i_depth < GFS2_DIR_MAX_DEPTH) { + error = dir_double_exhash(ip); + if (error) + break; + error = dir_split_leaf(inode, name); + if (error < 0) + break; + if (error == 0) + continue; + } + error = dir_new_leaf(inode, name); + if (!error) + continue; + error = -ENOSPC; + break; + } + return error; +} + + +/** + * gfs2_dir_del - Delete a directory entry + * @dip: The GFS2 inode + * @dentry: The directory entry we want to delete + * + * Returns: 0 on success, error code on failure + */ + +int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry) +{ + const struct qstr *name = &dentry->d_name; + struct gfs2_dirent *dent, *prev = NULL; + struct buffer_head *bh; + struct timespec64 tv; + + /* Returns _either_ the entry (if its first in block) or the + previous entry otherwise */ + dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh); + if (!dent) { + gfs2_consist_inode(dip); + return -EIO; + } + if (IS_ERR(dent)) { + gfs2_consist_inode(dip); + return PTR_ERR(dent); + } + /* If not first in block, adjust pointers accordingly */ + if (gfs2_dirent_find(dent, name, NULL) == 0) { + prev = dent; + dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len)); + } + + dirent_del(dip, bh, prev, dent); + tv = inode_set_ctime_current(&dip->i_inode); + if (dip->i_diskflags & GFS2_DIF_EXHASH) { + struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data; + u16 entries = be16_to_cpu(leaf->lf_entries); + if (!entries) + gfs2_consist_inode(dip); + leaf->lf_entries = cpu_to_be16(--entries); + leaf->lf_nsec = cpu_to_be32(tv.tv_nsec); + leaf->lf_sec = cpu_to_be64(tv.tv_sec); + } + brelse(bh); + + if (!dip->i_entries) + gfs2_consist_inode(dip); + dip->i_entries--; + dip->i_inode.i_mtime = tv; + if (d_is_dir(dentry)) + drop_nlink(&dip->i_inode); + mark_inode_dirty(&dip->i_inode); + + return 0; +} + +/** + * gfs2_dir_mvino - Change inode number of directory entry + * @dip: The GFS2 directory inode + * @filename: the filename to be moved + * @nip: the new GFS2 inode + * @new_type: the de_type of the new dirent + * + * This routine changes the inode number of a directory entry. It's used + * by rename to change ".." when a directory is moved. + * Assumes a glock is held on dvp. + * + * Returns: errno + */ + +int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename, + const struct gfs2_inode *nip, unsigned int new_type) +{ + struct buffer_head *bh; + struct gfs2_dirent *dent; + + dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh); + if (!dent) { + gfs2_consist_inode(dip); + return -EIO; + } + if (IS_ERR(dent)) + return PTR_ERR(dent); + + gfs2_trans_add_meta(dip->i_gl, bh); + gfs2_inum_out(nip, dent); + dent->de_type = cpu_to_be16(new_type); + brelse(bh); + + dip->i_inode.i_mtime = inode_set_ctime_current(&dip->i_inode); + mark_inode_dirty_sync(&dip->i_inode); + return 0; +} + +/** + * leaf_dealloc - Deallocate a directory leaf + * @dip: the directory + * @index: the hash table offset in the directory + * @len: the number of pointers to this leaf + * @leaf_no: the leaf number + * @leaf_bh: buffer_head for the starting leaf + * @last_dealloc: 1 if this is the final dealloc for the leaf, else 0 + * + * Returns: errno + */ + +static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len, + u64 leaf_no, struct buffer_head *leaf_bh, + int last_dealloc) +{ + struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); + struct gfs2_leaf *tmp_leaf; + struct gfs2_rgrp_list rlist; + struct buffer_head *bh, *dibh; + u64 blk, nblk; + unsigned int rg_blocks = 0, l_blocks = 0; + char *ht; + unsigned int x, size = len * sizeof(u64); + int error; + + error = gfs2_rindex_update(sdp); + if (error) + return error; + + memset(&rlist, 0, sizeof(struct gfs2_rgrp_list)); + + ht = kzalloc(size, GFP_NOFS | __GFP_NOWARN); + if (ht == NULL) + ht = __vmalloc(size, GFP_NOFS | __GFP_NOWARN | __GFP_ZERO); + if (!ht) + return -ENOMEM; + + error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE); + if (error) + goto out; + + /* Count the number of leaves */ + bh = leaf_bh; + + for (blk = leaf_no; blk; blk = nblk) { + if (blk != leaf_no) { + error = get_leaf(dip, blk, &bh); + if (error) + goto out_rlist; + } + tmp_leaf = (struct gfs2_leaf *)bh->b_data; + nblk = be64_to_cpu(tmp_leaf->lf_next); + if (blk != leaf_no) + brelse(bh); + + gfs2_rlist_add(dip, &rlist, blk); + l_blocks++; + } + + gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, LM_FLAG_NODE_SCOPE); + + for (x = 0; x < rlist.rl_rgrps; x++) { + struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl); + + rg_blocks += rgd->rd_length; + } + + error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs); + if (error) + goto out_rlist; + + error = gfs2_trans_begin(sdp, + rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) + + RES_DINODE + RES_STATFS + RES_QUOTA, RES_DINODE + + l_blocks); + if (error) + goto out_rg_gunlock; + + bh = leaf_bh; + + for (blk = leaf_no; blk; blk = nblk) { + struct gfs2_rgrpd *rgd; + + if (blk != leaf_no) { + error = get_leaf(dip, blk, &bh); + if (error) + goto out_end_trans; + } + tmp_leaf = (struct gfs2_leaf *)bh->b_data; + nblk = be64_to_cpu(tmp_leaf->lf_next); + if (blk != leaf_no) + brelse(bh); + + rgd = gfs2_blk2rgrpd(sdp, blk, true); + gfs2_free_meta(dip, rgd, blk, 1); + gfs2_add_inode_blocks(&dip->i_inode, -1); + } + + error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size); + if (error != size) { + if (error >= 0) + error = -EIO; + goto out_end_trans; + } + + error = gfs2_meta_inode_buffer(dip, &dibh); + if (error) + goto out_end_trans; + + gfs2_trans_add_meta(dip->i_gl, dibh); + /* On the last dealloc, make this a regular file in case we crash. + (We don't want to free these blocks a second time.) */ + if (last_dealloc) + dip->i_inode.i_mode = S_IFREG; + gfs2_dinode_out(dip, dibh->b_data); + brelse(dibh); + +out_end_trans: + gfs2_trans_end(sdp); +out_rg_gunlock: + gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs); +out_rlist: + gfs2_rlist_free(&rlist); + gfs2_quota_unhold(dip); +out: + kvfree(ht); + return error; +} + +/** + * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory + * @dip: the directory + * + * Dealloc all on-disk directory leaves to FREEMETA state + * Change on-disk inode type to "regular file" + * + * Returns: errno + */ + +int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip) +{ + struct buffer_head *bh; + struct gfs2_leaf *leaf; + u32 hsize, len; + u32 index = 0, next_index; + __be64 *lp; + u64 leaf_no; + int error = 0, last; + + hsize = BIT(dip->i_depth); + + lp = gfs2_dir_get_hash_table(dip); + if (IS_ERR(lp)) + return PTR_ERR(lp); + + while (index < hsize) { + leaf_no = be64_to_cpu(lp[index]); + if (leaf_no) { + error = get_leaf(dip, leaf_no, &bh); + if (error) + goto out; + leaf = (struct gfs2_leaf *)bh->b_data; + len = BIT(dip->i_depth - be16_to_cpu(leaf->lf_depth)); + + next_index = (index & ~(len - 1)) + len; + last = ((next_index >= hsize) ? 1 : 0); + error = leaf_dealloc(dip, index, len, leaf_no, bh, + last); + brelse(bh); + if (error) + goto out; + index = next_index; + } else + index++; + } + + if (index != hsize) { + gfs2_consist_inode(dip); + error = -EIO; + } + +out: + + return error; +} + +/** + * gfs2_diradd_alloc_required - find if adding entry will require an allocation + * @inode: the directory inode being written to + * @name: the filename that's going to be added + * @da: The structure to return dir alloc info + * + * Returns: 0 if ok, -ve on error + */ + +int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name, + struct gfs2_diradd *da) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + const unsigned int extra = sizeof(struct gfs2_dinode) - sizeof(struct gfs2_leaf); + struct gfs2_dirent *dent; + struct buffer_head *bh; + + da->nr_blocks = 0; + da->bh = NULL; + da->dent = NULL; + + dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh); + if (!dent) { + da->nr_blocks = sdp->sd_max_dirres; + if (!(ip->i_diskflags & GFS2_DIF_EXHASH) && + (GFS2_DIRENT_SIZE(name->len) < extra)) + da->nr_blocks = 1; + return 0; + } + if (IS_ERR(dent)) + return PTR_ERR(dent); + + if (da->save_loc) { + da->bh = bh; + da->dent = dent; + } else { + brelse(bh); + } + return 0; +} + |