Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next

Pull fs-cache fixes from David Howells:

Can you pull these commits to fix an issue with NFS whereby caching can be
enabled on a file that is open for writing by subsequently opening it for
reading.  This can be made to crash by opening it for writing again if you're
quick enough.

The gist of the patchset is that the cookie should be acquired at inode
creation only and subsequently enabled and disabled as appropriate (which
dispenses with the backing objects when they're not needed).

The extra synchronisation that NFS does can then be dispensed with as it is
thenceforth managed by FS-Cache.

Could you send these on to Linus?

This likely will need fixing also in CIFS and 9P also once the FS-Cache
changes are upstream.  AFS and Ceph are probably safe.

* 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()
  FS-Cache: Provide the ability to enable/disable cookies
  FS-Cache: Add use/unuse/wake cookie wrappers

4 files changed, 5 insertions, 4 deletions

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 3c090b7555ea..ca0a3cf93791 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -179,7 +179,7 @@ struct afs_cell *afs_cell_create(const char *name, unsigned namesz,
 	/* put it up for caching (this never returns an error) */
 	cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index,
 					     &afs_cell_cache_index_def,
-					     cell);
+					     cell, true);
 #endif
 
 	/* add to the cell lists */
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 789bc253b5f6..ce25d755b7aa 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -259,7 +259,7 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 #ifdef CONFIG_AFS_FSCACHE
 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
 					      &afs_vnode_cache_index_def,
-					      vnode);
+					      vnode, true);
 #endif
 
 	ret = afs_inode_map_status(vnode, key);
diff --git a/fs/afs/vlocation.c b/fs/afs/vlocation.c
index 57bcb1596530..b6df2e83809f 100644
--- a/fs/afs/vlocation.c
+++ b/fs/afs/vlocation.c
@@ -308,7 +308,8 @@ static int afs_vlocation_fill_in_record(struct afs_vlocation *vl,
 	/* see if we have an in-cache copy (will set vl->valid if there is) */
 #ifdef CONFIG_AFS_FSCACHE
 	vl->cache = fscache_acquire_cookie(vl->cell->cache,
-					   &afs_vlocation_cache_index_def, vl);
+					   &afs_vlocation_cache_index_def, vl,
+					   true);
 #endif
 
 	if (vl->valid) {
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 401eeb21869f..2b607257820c 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -131,7 +131,7 @@ struct afs_volume *afs_volume_lookup(struct afs_mount_params *params)
 #ifdef CONFIG_AFS_FSCACHE
 	volume->cache = fscache_acquire_cookie(vlocation->cache,
 					       &afs_volume_cache_index_def,
-					       volume);
+					       volume, true);
 #endif
 	afs_get_vlocation(vlocation);
 	volume->vlocation = vlocation;