Messages in this thread | | | Date | Tue, 16 Jan 2007 17:01:04 -0500 | From | Peter Staubach <> | Subject | Re: [PATCH] return ENOENT from ext3_link when racing with unlink |
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Eric Sandeen wrote: > An update from the earlier thread, [PATCH] [RFC] remove ext3 inode > from orphan list when link and unlink race > > I think this is better than the original idea of trying to handle the > race; > I've seen that the orphan inode list can get corrupted, but there may > well > be other implications of the race which haven't yet been exposed. I > think > it's safer to simply return -ENOENT in this race window, and avoid other > potential problems. Anything wrong with this? > > Thanks for the comments suggesting this approach in the prior thread. > > Thanks, > > -Eric > > --- > > Return -ENOENT from ext[34]_link if we've raced with unlink and > i_nlink is 0. Doing otherwise has the potential to corrupt the > orphan inode list, because we'd wind up with an inode with a > non-zero link count on the list, and it will never get properly > cleaned up & removed from the orphan list before it is freed. > > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > > Index: linux-2.6.19/fs/ext3/namei.c > =================================================================== > --- linux-2.6.19.orig/fs/ext3/namei.c > +++ linux-2.6.19/fs/ext3/namei.c > @@ -2191,6 +2191,8 @@ static int ext3_link (struct dentry * ol > > if (inode->i_nlink >= EXT3_LINK_MAX) > return -EMLINK; > + if (inode->i_nlink == 0) > + return -ENOENT; > > retry: > handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) + > Index: linux-2.6.19/fs/ext4/namei.c > =================================================================== > --- linux-2.6.19.orig/fs/ext4/namei.c > +++ linux-2.6.19/fs/ext4/namei.c > @@ -2189,6 +2189,8 @@ static int ext4_link (struct dentry * ol > > if (inode->i_nlink >= EXT4_LINK_MAX) > return -EMLINK; > + if (inode->i_nlink == 0) > + return -ENOENT; > > retry: > handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + >
Just out of curosity, what keeps i_nlink from going to 0 immediately after the new test is executed?
Thanx...
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