Messages in this thread Patch in this message | | | From | André Almeida <> | Subject | [PATCH 2/3] ext4: Prevent dangling dentries on casefold directories | Date | Sun, 28 Mar 2021 11:43:55 -0300 |
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Before making a folder a case-insensitive one, this folder could have been used before and created some negative dentries (given that the folder needs to be empty before making it case-insensitive, all detries there are negative ones). During a new file creation, if a d_hash() collision happens and the name matches a negative dentry, the new file might have a name different than the specified by user.
To prevent this from happening, remove all negative dentries in a directory before making it a case-folded one.
Fixes: b886ee3e778e ("ext4: Support case-insensitive file name lookups") Signed-off-by: André Almeida <andrealmeid@collabora.com> --- fs/ext4/ioctl.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a2cf35066f46..0eede4c93c22 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -381,6 +381,9 @@ static int ext4_ioctl_setflags(struct inode *inode, err = -ENOTEMPTY; goto flags_out; } + + if (!(oldflags & EXT4_CASEFOLD_FL) && (flags & EXT4_CASEFOLD_FL)) + d_clear_dir_neg_dentries(inode); } /* -- 2.31.0
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