From 36de928641ee48b2078d3fe9514242aaa2f92013 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 23 Aug 2014 17:47:19 -0400 Subject: ext4: propagate errors up to ext4_find_entry()'s callers If we run into some kind of error, such as ENOMEM, while calling ext4_getblk() or ext4_dx_find_entry(), we need to make sure this error gets propagated up to ext4_find_entry() and then to its callers. This way, transient errors such as ENOMEM can get propagated to the VFS. This is important so that the system calls return the appropriate error, and also so that in the case of ext4_lookup(), we return an error instead of a NULL inode, since that will result in a negative dentry cache entry that will stick around long past the OOM condition which caused a transient ENOMEM error. Google-Bug-Id: #17142205 Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/namei.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) (limited to 'fs/ext4/namei.c') diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index b147a67baa0..ae7088b446d 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1227,7 +1227,7 @@ static struct buffer_head * ext4_find_entry (struct inode *dir, buffer */ int num = 0; ext4_lblk_t nblocks; - int i, err; + int i, err = 0; int namelen; *res_dir = NULL; @@ -1264,7 +1264,11 @@ static struct buffer_head * ext4_find_entry (struct inode *dir, * return. Otherwise, fall back to doing a search the * old fashioned way. */ - if (bh || (err != ERR_BAD_DX_DIR)) + if (err == -ENOENT) + return NULL; + if (err && err != ERR_BAD_DX_DIR) + return ERR_PTR(err); + if (bh) return bh; dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " "falling back\n")); @@ -1295,6 +1299,11 @@ restart: } num++; bh = ext4_getblk(NULL, dir, b++, 0, &err); + if (unlikely(err)) { + if (ra_max == 0) + return ERR_PTR(err); + break; + } bh_use[ra_max] = bh; if (bh) ll_rw_block(READ | REQ_META | REQ_PRIO, @@ -1417,6 +1426,8 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi return ERR_PTR(-ENAMETOOLONG); bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); + if (IS_ERR(bh)) + return (struct dentry *) bh; inode = NULL; if (bh) { __u32 ino = le32_to_cpu(de->inode); @@ -1450,6 +1461,8 @@ struct dentry *ext4_get_parent(struct dentry *child) struct buffer_head *bh; bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL); + if (IS_ERR(bh)) + return (struct dentry *) bh; if (!bh) return ERR_PTR(-ENOENT); ino = le32_to_cpu(de->inode); @@ -2727,6 +2740,8 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry) retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); if (!bh) goto end_rmdir; @@ -2794,6 +2809,8 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry) retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); if (!bh) goto end_unlink; @@ -3121,6 +3138,8 @@ static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, struct ext4_dir_entry_2 *de; bh = ext4_find_entry(dir, d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); if (bh) { retval = ext4_delete_entry(handle, dir, de, bh); brelse(bh); @@ -3202,6 +3221,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, dquot_initialize(new.inode); old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); + if (IS_ERR(old.bh)) + return PTR_ERR(old.bh); /* * Check for inode number is _not_ due to possible IO errors. * We might rmdir the source, keep it as pwd of some process @@ -3214,6 +3235,10 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, &new.de, &new.inlined); + if (IS_ERR(new.bh)) { + retval = PTR_ERR(new.bh); + goto end_rename; + } if (new.bh) { if (!new.inode) { brelse(new.bh); @@ -3330,6 +3355,8 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, &old.inlined); + if (IS_ERR(old.bh)) + return PTR_ERR(old.bh); /* * Check for inode number is _not_ due to possible IO errors. * We might rmdir the source, keep it as pwd of some process @@ -3342,6 +3369,10 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, &new.de, &new.inlined); + if (IS_ERR(new.bh)) { + retval = PTR_ERR(new.bh); + goto end_rename; + } /* RENAME_EXCHANGE case: old *and* new must both exist */ if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) -- cgit v1.2.3-70-g09d2 From d80d448c6c5bdd32605b78a60fe8081d82d4da0f Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 27 Aug 2014 18:40:09 -0400 Subject: ext4: fix same-dir rename when inline data directory overflows When performing a same-directory rename, it's possible that adding or setting the new directory entry will cause the directory to overflow the inline data area, which causes the directory to be converted to an extent-based directory. Under this circumstance it is necessary to re-read the directory when deleting the old dirent because the "old directory" context still points to i_block in the inode table, which is now an extent tree root! The delete fails with an FS error, and the subsequent fsck complains about incorrect link counts and hardlinked directories. Test case (originally found with flat_dir_test in the metadata_csum test program): # mkfs.ext4 -O inline_data /dev/sda # mount /dev/sda /mnt # mkdir /mnt/x # touch /mnt/x/changelog.gz /mnt/x/copyright /mnt/x/README.Debian # sync # for i in /mnt/x/*; do mv $i $i.longer; done # ls -la /mnt/x/ total 0 -rw-r--r-- 1 root root 0 Aug 25 12:03 changelog.gz.longer -rw-r--r-- 1 root root 0 Aug 25 12:03 copyright -rw-r--r-- 1 root root 0 Aug 25 12:03 copyright.longer -rw-r--r-- 1 root root 0 Aug 25 12:03 README.Debian.longer (Hey! Why are there four files now??) Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/namei.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'fs/ext4/namei.c') diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index ae7088b446d..90a3cdca3f8 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3147,7 +3147,8 @@ static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, return retval; } -static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent) +static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, + int force_reread) { int retval; /* @@ -3159,7 +3160,8 @@ static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent) if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || ent->de->name_len != ent->dentry->d_name.len || strncmp(ent->de->name, ent->dentry->d_name.name, - ent->de->name_len)) { + ent->de->name_len) || + force_reread) { retval = ext4_find_delete_entry(handle, ent->dir, &ent->dentry->d_name); } else { @@ -3210,6 +3212,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, .dentry = new_dentry, .inode = new_dentry->d_inode, }; + int force_reread; int retval; dquot_initialize(old.dir); @@ -3271,6 +3274,15 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, if (retval) goto end_rename; } + /* + * If we're renaming a file within an inline_data dir and adding or + * setting the new dirent causes a conversion from inline_data to + * extents/blockmap, we need to force the dirent delete code to + * re-read the directory, or else we end up trying to delete a dirent + * from what is now the extent tree root (or a block map). + */ + force_reread = (new.dir->i_ino == old.dir->i_ino && + ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); if (!new.bh) { retval = ext4_add_entry(handle, new.dentry, old.inode); if (retval) @@ -3281,6 +3293,9 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, if (retval) goto end_rename; } + if (force_reread) + force_reread = !ext4_test_inode_flag(new.dir, + EXT4_INODE_INLINE_DATA); /* * Like most other Unix systems, set the ctime for inodes on a @@ -3292,7 +3307,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, /* * ok, that's it */ - ext4_rename_delete(handle, &old); + ext4_rename_delete(handle, &old, force_reread); if (new.inode) { ext4_dec_count(handle, new.inode); -- cgit v1.2.3-70-g09d2