commit 4ad78628445d26e5e9487b2e8f23274ad7b0f5d3 upstream.

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.

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>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>

commit 0a73d0a204a4a04a1e110539c5a524ae51f91d6d upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Zefan Li <lizefan@huawei.com>

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4:
 - adjust context
 - need one more name change in debugfs]

Pull 9p changes for the 3.4 merge window from Eric Van Hensbergen.

* tag 'for-linus-3.4-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: statfs should not override server f_type
  net/9p: handle flushed Tclunk/Tremove
  net/9p: don't allow Tflush to be interrupted

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Allow a 9p2000.L server to supply the statfs f_type value rather than
hardwiring V9FS_MAGIC.  It is desirable to give the server this option
in some applications, e.g. I/O forwarding.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  fs/9p: iattr_valid flags are kernel internal flags map them to 9p values.
  fs/9p: We should not allocate a new inode when creating hardlines.
  fs/9p: v9fs_stat2inode should update suid/sgid bits.
  9p: Reduce object size with CONFIG_NET_9P_DEBUG
  fs/9p: check schedule_timeout_interruptible return value

Fix up trivial conflicts in fs/9p/{vfs_inode.c,vfs_inode_dotl.c} due to
debug messages having changed to use p9_debug() on one hand, and the
changes for umode_t on the other.

Kernel internal values can change, add protocol values for these constant
and use them.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

Don't do new_inode_from fid in case of hardlink creation. This ensures
that link count for hardlink files get updated properly. Earlier link count
was not updated on removing a hardlink with cache mode enabled.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>