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| author | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-02-07 12:58:51 +0400 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-02-29 18:10:20 +0400 |
| commit | c43be1085f8480ab36d5c8c76a08e67bdf6d2e18 (patch) | |
| tree | 5d77b528c065e6d5c542c631634cd440ae3938ac /fs/ubifs | |
| parent | b06283c7df35b5a49ab141ed38e0280821379096 (diff) | |
| download | linux-c43be1085f8480ab36d5c8c76a08e67bdf6d2e18.tar.xz | |
UBIFS: do not use inc_link when i_nlink is zero
This patch changes the 'i_nlink' counter handling in 'ubifs_unlink()',
'ubifs_rmdir()' and 'ubifs_rename()'. In these function 'i_nlink' may become 0,
and if 'ubifs_jnl_update()' failed, we would use 'inc_nlink()' to restore
the previous 'i_nlink' value, which is incorrect from the VFS point of view and
would cause a 'WARN_ON()' (see 'inc_nlink() implementation).
This patches saves the previous 'i_nlink' value in a local variable and uses it
at the error path instead of calling 'inc_nlink()'. We do this only for the
inodes where 'i_nlink' may potentially become zero.
This change has been requested by Al Viro <viro@ZenIV.linux.org.uk>.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/dir.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index d6fe1c79f18b..ec9f1870ab7f 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -566,6 +566,7 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry) int sz_change = CALC_DENT_SIZE(dentry->d_name.len); int err, budgeted = 1; struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; + unsigned int saved_nlink = inode->i_nlink; /* * Budget request settings: deletion direntry, deletion inode (+1 for @@ -613,7 +614,7 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry) out_cancel: dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; - inc_nlink(inode); + set_nlink(inode, saved_nlink); unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); @@ -704,8 +705,7 @@ out_cancel: dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; inc_nlink(dir); - inc_nlink(inode); - inc_nlink(inode); + set_nlink(inode, 2); unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); @@ -977,6 +977,7 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; struct timespec time; + unsigned int saved_nlink; /* * Budget request settings: deletion direntry, new direntry, removing @@ -1059,13 +1060,14 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, if (unlink) { /* * Directories cannot have hard-links, so if this is a - * directory, decrement its @i_nlink twice because an empty - * directory has @i_nlink 2. + * directory, just clear @i_nlink. */ + saved_nlink = new_inode->i_nlink; if (is_dir) + clear_nlink(new_inode); + else drop_nlink(new_inode); new_inode->i_ctime = time; - drop_nlink(new_inode); } else { new_dir->i_size += new_sz; ubifs_inode(new_dir)->ui_size = new_dir->i_size; @@ -1102,9 +1104,7 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, out_cancel: if (unlink) { - if (is_dir) - inc_nlink(new_inode); - inc_nlink(new_inode); + set_nlink(new_inode, saved_nlink); } else { new_dir->i_size -= new_sz; ubifs_inode(new_dir)->ui_size = new_dir->i_size; |