summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMichael Halcrow <mhalcrow@us.ibm.com>2006-12-22 01:08:43 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-22 08:55:48 -0800
commitba3ff12fca318225cb978c6181b83d38dcbc5b09 (patch)
treefe1ae914a197aa6e74a7c1281bf38888e2eac3d5
parentef8142a525c58dec325e8dd9a7bf92fb240d05c7 (diff)
downloadlinux-sh-ba3ff12fca318225cb978c6181b83d38dcbc5b09.tar.gz
[PATCH] fsstack: Remove inode copy
Trevor found a file size problem in eCryptfs in recent kernels, and he tracked it down to an fsstack change. This was the eCryptfs copy_attr_all: > -void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src) > -{ > - dest->i_mode = src->i_mode; > - dest->i_nlink = src->i_nlink; > - dest->i_uid = src->i_uid; > - dest->i_gid = src->i_gid; > - dest->i_rdev = src->i_rdev; > - dest->i_atime = src->i_atime; > - dest->i_mtime = src->i_mtime; > - dest->i_ctime = src->i_ctime; > - dest->i_blkbits = src->i_blkbits; > - dest->i_flags = src->i_flags; > -} This is the fsstack copy_attr_all: > +void fsstack_copy_attr_all(struct inode *dest, const struct inode *src, > + int (*get_nlinks)(struct inode *)) > +{ > + if (!get_nlinks) > + dest->i_nlink = src->i_nlink; > + else > + dest->i_nlink = (*get_nlinks)(dest); > + > + dest->i_mode = src->i_mode; > + dest->i_uid = src->i_uid; > + dest->i_gid = src->i_gid; > + dest->i_rdev = src->i_rdev; > + dest->i_atime = src->i_atime; > + dest->i_mtime = src->i_mtime; > + dest->i_ctime = src->i_ctime; > + dest->i_blkbits = src->i_blkbits; > + dest->i_flags = src->i_flags; > + > + fsstack_copy_inode_size(dest, src); > +} The addition of copy_inode_size breaks eCryptfs, since eCryptfs needs to interpolate the file sizes (eCryptfs has extra space in the lower file for the header). The setting of the upper inode size occurs elsewhere in eCryptfs, and the new copy_attr_all now undoes what eCryptfs was doing right beforehand. I see three ways of going forward from here. (1) Something like this patch needs to go in (assuming it jives with Unionfs), (2) we need to make a change to the fsstack API for more fine-grained control over copying attributes (e.g., by also including a callback function for calculating the right file size, which will require some more work on both eCryptfs and Unionfs), or (3) the fsstack patch on eCryptfs (commit 0cc72dc7f050188d8d7344b1dd688cbc68d3cd30 made on Fri Dec 8 02:36:31 2006 -0800) needs to be yanked in 2.6.20. I think the simplest solution, from eCryptfs' perspective, is to just remove the inode size copy. Remove inode size copy in general fsstack attr copy code. Stacked filesystems may need to interpolate the inode size, since the file size in the lower file may be different than the file size in the stacked layer. Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com> Acked-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/stack.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/fs/stack.c b/fs/stack.c
index 5ddbc34535f9..8ffb880d2f46 100644
--- a/fs/stack.c
+++ b/fs/stack.c
@@ -34,7 +34,5 @@ void fsstack_copy_attr_all(struct inode *dest, const struct inode *src,
dest->i_ctime = src->i_ctime;
dest->i_blkbits = src->i_blkbits;
dest->i_flags = src->i_flags;
-
- fsstack_copy_inode_size(dest, src);
}
EXPORT_SYMBOL_GPL(fsstack_copy_attr_all);