Patchwork [RESEND] ext3: set i_extra_isize of 11th inode

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Submitter Masayoshi MIZUMA
Date Aug. 23, 2010, 12:50 a.m.
Message ID <20100823095056.ACBA.61FB500B@jp.fujitsu.com>
Download mbox | patch
Permalink /patch/62419/
State New
Headers show

Comments

Masayoshi MIZUMA - Aug. 23, 2010, 12:50 a.m.
In ext3 filesystem, if following conditions 1., 2., 3. and 4. is satisfied,
getfattr can't search the extended attribute (EA) after remount.

Condition:
    1. the inode size is over 128 byte
    2. "lost+found" whose inode number is 11 was removed
    3. the 11th inode is used for a file.
    4. the EA locates in-inode

This happens because of following logic:
    i_extra_isize is set to over 0 by ext3_new_inode() when we create
    a file whose inode number is 11 after removing "lost+found".
    Therefore setfattr creates the EA in-inode.
    After remount, i_extra_isize of 11th inode is set to 0 by ext3_iget()
    when we lookup the file, so getfattr tries to search the EA out-inode.
    However, the EA locates in-inode, so getfattr can't search the EA.

How to reproduce:
    1. mkfs.ext3 -I 256 /dev/sdXX
    2. mount -o acl,user_xattr  /dev/sdXX /TEST
    3. rm -rf /TEST/*
    4. touch /TEST/file (whose inode number is 11)
    5. cd /TEST; setfattr -n user.foo0 -v bar0 file
    6. cd /TEST; getfattr -d file
       -> can see foo0/bar0
    7. umount  /dev/sdXX
    8. mount -o acl,user_xattr /dev/sdXX /TEST
    9. cd /TEST; getfattr -d file
       -> can't see foo0/bar0

Though the 11th inode is used for "lost+found" normally, the other
file can also use it. Therefore, i_extra_isize of 11th inode should be set
to the suitable value by ext3_iget().

CC: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
---
 fs/ext3/inode.c |    8 +-------
 1 files changed, 1 insertions(+), 7 deletions(-)
Jan Kara - Aug. 24, 2010, 1:17 p.m.
On Mon 23-08-10 09:50:56, Masayoshi MIZUMA wrote:
> In ext3 filesystem, if following conditions 1., 2., 3. and 4. is satisfied,
> getfattr can't search the extended attribute (EA) after remount.
> 
> Condition:
>     1. the inode size is over 128 byte
>     2. "lost+found" whose inode number is 11 was removed
>     3. the 11th inode is used for a file.
>     4. the EA locates in-inode
> 
> This happens because of following logic:
>     i_extra_isize is set to over 0 by ext3_new_inode() when we create
>     a file whose inode number is 11 after removing "lost+found".
>     Therefore setfattr creates the EA in-inode.
>     After remount, i_extra_isize of 11th inode is set to 0 by ext3_iget()
>     when we lookup the file, so getfattr tries to search the EA out-inode.
>     However, the EA locates in-inode, so getfattr can't search the EA.
> 
> How to reproduce:
>     1. mkfs.ext3 -I 256 /dev/sdXX
>     2. mount -o acl,user_xattr  /dev/sdXX /TEST
>     3. rm -rf /TEST/*
>     4. touch /TEST/file (whose inode number is 11)
>     5. cd /TEST; setfattr -n user.foo0 -v bar0 file
>     6. cd /TEST; getfattr -d file
>        -> can see foo0/bar0
>     7. umount  /dev/sdXX
>     8. mount -o acl,user_xattr /dev/sdXX /TEST
>     9. cd /TEST; getfattr -d file
>        -> can't see foo0/bar0
> 
> Though the 11th inode is used for "lost+found" normally, the other
> file can also use it. Therefore, i_extra_isize of 11th inode should be set
> to the suitable value by ext3_iget().
  Hmm, with which kernel have you tested that? Because my 2.6.32 kernel
works just fine (and looking into the code, all should be handled well).
Look:
mount -o loop,user_xattr ~jack/fs-images/ext3-image /mnt/
quack:/crypted/home/jack # cd /mnt/
quack:/mnt # touch file
quack:/mnt # ls -i file
11 file
quack:/mnt # setfattr -n user.foo0 -v bar0 file
quack:/mnt # getfattr -d file
# file: file
user.foo0="bar0"

quack:/mnt # cd
quack:~ # umount /mnt
quack:~ # mount -o loop,user_xattr ~jack/fs-images/ext3-image /mnt/
quack:~ # getfattr -d /mnt/file
getfattr: Removing leading '/' from absolute path names
# file: mnt/file
user.foo0="bar0"

								Honza
Masayoshi MIZUMA - Aug. 25, 2010, 12:05 a.m.
On Tue, 24 Aug 2010 15:17:36 +0200
Jan Kara <jack@suse.cz> wrote:

> On Mon 23-08-10 09:50:56, Masayoshi MIZUMA wrote:
> > In ext3 filesystem, if following conditions 1., 2., 3. and 4. is satisfied,
> > getfattr can't search the extended attribute (EA) after remount.
> > 
> > Condition:
> >     1. the inode size is over 128 byte
> >     2. "lost+found" whose inode number is 11 was removed
> >     3. the 11th inode is used for a file.
> >     4. the EA locates in-inode
> > 
> > This happens because of following logic:
> >     i_extra_isize is set to over 0 by ext3_new_inode() when we create
> >     a file whose inode number is 11 after removing "lost+found".
> >     Therefore setfattr creates the EA in-inode.
> >     After remount, i_extra_isize of 11th inode is set to 0 by ext3_iget()
> >     when we lookup the file, so getfattr tries to search the EA out-inode.
> >     However, the EA locates in-inode, so getfattr can't search the EA.
> > 
> > How to reproduce:
> >     1. mkfs.ext3 -I 256 /dev/sdXX
> >     2. mount -o acl,user_xattr  /dev/sdXX /TEST
> >     3. rm -rf /TEST/*
> >     4. touch /TEST/file (whose inode number is 11)
> >     5. cd /TEST; setfattr -n user.foo0 -v bar0 file
> >     6. cd /TEST; getfattr -d file
> >        -> can see foo0/bar0
> >     7. umount  /dev/sdXX
> >     8. mount -o acl,user_xattr /dev/sdXX /TEST
> >     9. cd /TEST; getfattr -d file
> >        -> can't see foo0/bar0
> > 
> > Though the 11th inode is used for "lost+found" normally, the other
> > file can also use it. Therefore, i_extra_isize of 11th inode should be set
> > to the suitable value by ext3_iget().
>   Hmm, with which kernel have you tested that? Because my 2.6.32 kernel
> works just fine (and looking into the code, all should be handled well).
I tested at 2.6.35.

> Look:
> mount -o loop,user_xattr ~jack/fs-images/ext3-image /mnt/
> quack:/crypted/home/jack # cd /mnt/
> quack:/mnt # touch file
> quack:/mnt # ls -i file
> 11 file
> quack:/mnt # setfattr -n user.foo0 -v bar0 file
> quack:/mnt # getfattr -d file
> # file: file
> user.foo0="bar0"
> 
> quack:/mnt # cd
> quack:~ # umount /mnt
> quack:~ # mount -o loop,user_xattr ~jack/fs-images/ext3-image /mnt/
> quack:~ # getfattr -d /mnt/file
> getfattr: Removing leading '/' from absolute path names
> # file: mnt/file
> user.foo0="bar0"
What size is the inode ? This problem happens if the size is larger than 128 byte.
(I tested at 256 byte inode.)

Thanks,
Masayoshi

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Patch

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 5e0faf4..69c3d47 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -2914,13 +2914,7 @@  struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
 		atomic_set(&ei->i_datasync_tid, tid);
 	}
 
-	if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
-	    EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
-		/*
-		 * When mke2fs creates big inodes it does not zero out
-		 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
-		 * so ignore those first few inodes.
-		 */
+	if (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
 		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
 		if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
 		    EXT3_INODE_SIZE(inode->i_sb)) {