linux/fs/btrfs
NeilBrown 743162013d sched: Remove proliferation of wait_on_bit() action functions
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:39 +02:00
..
tests Btrfs: fix qgroups sanity test crash or hang 2014-06-13 09:52:24 -07:00
acl.c btrfs: remove useless ACL check 2014-06-09 17:20:42 -07:00
async-thread.c
async-thread.h
backref.c Btrfs: fix scrub_print_warning to handle skinny metadata extents 2014-06-09 17:21:17 -07:00
backref.h Btrfs: fix scrub_print_warning to handle skinny metadata extents 2014-06-09 17:21:17 -07:00
btrfs_inode.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-06-11 09:22:21 -07:00
check-integrity.c btrfs: check_int: propagate out-of-memory error upwards 2014-06-09 17:20:21 -07:00
check-integrity.h
compression.c btrfs compression: reuse recently used workspace 2014-06-28 13:48:46 -07:00
compression.h
ctree.c Btrfs: fix leaf corruption after __btrfs_drop_extents 2014-06-09 17:21:10 -07:00
ctree.h Btrfs: fix broken free space cache after the system crashed 2014-06-19 14:20:54 -07:00
delayed-inode.c btrfs: free delayed node outside of root->inode_lock 2014-06-09 17:21:08 -07:00
delayed-inode.h
delayed-ref.c Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
delayed-ref.h Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
dev-replace.c btrfs: dev replace should replace the sysfs entry 2014-06-28 13:48:44 -07:00
dev-replace.h
dir-item.c
disk-io.c Btrfs: fix race between balance recovery and root deletion 2014-07-03 07:04:04 -07:00
disk-io.h Btrfs: add sanity tests for new qgroup accounting code 2014-06-09 17:20:49 -07:00
export.c
export.h
extent_io.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
extent_io.h Btrfs: remove unused wait queue in struct extent_buffer 2014-06-19 14:20:28 -07:00
extent_map.c Btrfs: fix NULL pointer crash when running balance and scrub concurrently 2014-06-19 14:20:55 -07:00
extent_map.h Btrfs: fix NULL pointer crash when running balance and scrub concurrently 2014-06-19 14:20:55 -07:00
extent-tree.c Btrfs: fix race of using total_bytes_pinned 2014-07-03 07:04:15 -07:00
file-item.c Btrfs: make fsync work after cloning into a file 2014-06-09 17:21:16 -07:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
free-space-cache.c Btrfs: fix broken free space cache after the system crashed 2014-06-19 14:20:54 -07:00
free-space-cache.h
hash.c
hash.h
inode-item.c
inode-map.c btrfs: remove newline from inode cache kthread name 2014-06-09 17:20:53 -07:00
inode-map.h
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-06-21 14:21:43 -10:00
ioctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-07-04 08:53:53 -07:00
Kconfig
locking.c Btrfs: fix deadlocks with trylock on tree nodes 2014-06-19 14:19:55 -07:00
locking.h
lzo.c btrfs: return errno instead of -1 from compression 2014-06-09 17:20:21 -07:00
Makefile Btrfs: add sanity tests for new qgroup accounting code 2014-06-09 17:20:49 -07:00
math.h
ordered-data.c btrfs: remove stale newlines from log messages 2014-06-09 17:20:53 -07:00
ordered-data.h
orphan.c
print-tree.c Btrfs: fix btrfs_print_leaf for skinny metadata 2014-07-03 07:04:16 -07:00
print-tree.h
props.c
props.h
qgroup.c btrfs: free ulist in qgroup_shared_accounting() error path 2014-06-13 09:52:26 -07:00
qgroup.h Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
raid56.c Btrfs: fix crash when mounting raid5 btrfs with missing disks 2014-06-28 13:48:45 -07:00
raid56.h
rcu-string.h
reada.c Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting 2014-06-13 09:52:21 -07:00
relocation.c btrfs: remove stale newlines from log messages 2014-06-09 17:20:53 -07:00
root-tree.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
scrub.c btrfs: Skip scrubbing removed chunks to avoid -ENOENT. 2014-06-19 14:20:54 -07:00
send.c Btrfs: send, use the right limits for xattr names and values 2014-06-09 17:21:00 -07:00
send.h
struct-funcs.c
super.c btrfs: fix null pointer dereference in btrfs_show_devname when name is null 2014-07-03 07:04:09 -07:00
sysfs.c btrfs: dev add should add its sysfs entry 2014-06-28 13:48:43 -07:00
sysfs.h btrfs: dev add should add its sysfs entry 2014-06-28 13:48:43 -07:00
transaction.c Btrfs: fix crash when starting transaction 2014-07-03 07:04:18 -07:00
transaction.h Btrfs: add sanity tests for new qgroup accounting code 2014-06-09 17:20:49 -07:00
tree-defrag.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
tree-log.c Btrfs: use helpers for last_trans_log_full_commit instead of opencode 2014-06-09 17:20:45 -07:00
tree-log.h Btrfs: use helpers for last_trans_log_full_commit instead of opencode 2014-06-09 17:20:45 -07:00
ulist.c
ulist.h
uuid-tree.c
volumes.c btrfs: fix null pointer dereference in clone_fs_devices when name is null 2014-07-03 07:04:07 -07:00
volumes.h Btrfs: fix deadlock when mounting a degraded fs 2014-06-19 14:20:56 -07:00
xattr.c
xattr.h
zlib.c btrfs: use E2BIG instead of EIO if compression does not help 2014-07-03 07:04:13 -07:00