linux/fs/9p
Al Viro 4ad7862844 9p: ->evict_inode() should kick out ->i_data, not ->i_mapping
For block devices the pagecache is associated with the inode
on bdevfs, not with the aliasing ones on the mountable filesystems.
The latter have its own ->i_data empty and ->i_mapping pointing
to the (unique per major/minor) bdevfs inode.  That guarantees
cache coherence between all block device inodes with the same
device number.

Eviction of an alias inode has no business trying to evict the
pages belonging to bdevfs one; moreover, ->i_mapping is only
safe to access when the thing is opened.  At the time of
->evict_inode() the victim is definitely *not* opened.  We are
about to kill the address space embedded into struct inode
(inode->i_data) and that's what we need to empty of any pages.

9p instance tries to empty inode->i_mapping instead, which is
both unsafe and bogus - if we have several device nodes with
the same device number in different places, closing one of them
should not try to empty the (shared) page cache.

Fortunately, other instances in the tree are OK; they are
evicting from &inode->i_data instead, as 9p one should.

Cc: stable@vger.kernel.org # v2.6.32+, ones prior to 2.6.36 need only half of that
Reported-by: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
Tested-by: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 14:51:16 -05:00
..
acl.c 9p: xattr simplifications 2015-11-13 20:34:33 -05:00
acl.h
cache.c
cache.h fs: 9p: cache.h: Add #define of include guard 2015-11-11 02:19:50 -05:00
fid.c
fid.h
Kconfig
Makefile 9p: xattr simplifications 2015-11-13 20:34:33 -05:00
v9fs_vfs.h
v9fs.c 9p: remove unused option Opt_trans 2015-08-23 14:21:16 -05:00
v9fs.h 9p: don't bother with __getname() in ->follow_link() 2015-05-10 22:18:19 -04:00
vfs_addr.c
vfs_dentry.c
vfs_dir.c fs/9p: fix readdir() 2015-04-24 15:45:03 -04:00
vfs_file.c Merge branch 'akpm' (patches from Andrew) 2015-11-05 23:10:54 -08:00
vfs_inode_dotl.c fs/9p: remove unnecessary new_valid_dev() checks 2015-11-09 15:11:24 -08:00
vfs_inode.c 9p: ->evict_inode() should kick out ->i_data, not ->i_mapping 2015-12-08 14:51:16 -05:00
vfs_super.c v9fs: fix error handling in v9fs_session_init() 2015-06-08 09:05:06 -06:00
xattr.c 9p: xattr simplifications 2015-11-13 20:34:33 -05:00
xattr.h 9p: xattr simplifications 2015-11-13 20:34:33 -05:00