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authorJan Kara <jack@suse.cz>2020-10-15 14:03:30 +0300
committerTheodore Ts'o <tytso@mit.edu>2020-10-18 17:37:26 +0300
commite0770e91424f694b461141cbc99adf6b23006b60 (patch)
tree9cc0167aece66eb6ebbb1df81db47b31ee83af5b /fs/ext4
parentfc750a3b44bdccb9fb96d6abbc48a9b8e480ce7b (diff)
downloadlinux-e0770e91424f694b461141cbc99adf6b23006b60.tar.xz
ext4: Detect already used quota file early
When we try to use file already used as a quota file again (for the same or different quota type), strange things can happen. At the very least lockdep annotations may be wrong but also inode flags may be wrongly set / reset. When the file is used for two quota types at once we can even corrupt the file and likely crash the kernel. Catch all these cases by checking whether passed file is already used as quota file and bail early in that case. This fixes occasional generic/219 failure due to lockdep complaint. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reported-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201015110330.28716-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 901c1c938276..f997fc95cc31 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6225,6 +6225,11 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
/* Quotafile not on the same filesystem? */
if (path->dentry->d_sb != sb)
return -EXDEV;
+
+ /* Quota already enabled for this file? */
+ if (IS_NOQUOTA(d_inode(path->dentry)))
+ return -EBUSY;
+
/* Journaling quota? */
if (EXT4_SB(sb)->s_qf_names[type]) {
/* Quotafile not in fs root? */