BMC/Intel-BMC/linux.git/fs/btrfs/free-space-cache.c, branch dev

Btrfs: fix mutex unlock without prior lock on space cache truncation

2015-06-03T02:34:34+00:00

If the call to btrfs_truncate_inode_items() failed and we don't have a block group, we were unlocking the cache_write_mutex without having locked it (we do it only if we have a block group). Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout outside critical section in commit") Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: Chris Mason

Btrfs: fix crash after inode cache writeback failure

2015-05-11T14:59:10+00:00

If the writeback of an inode cache failed we were unnecessarilly attempting to release again the delalloc metadata that we previously reserved. However attempting to do this a second time triggers an assertion at drop_outstanding_extent() because we have no more outstanding extents for our inode cache's inode. If we were able to start writeback of the cache the reserved metadata space is released at btrfs_finished_ordered_io(), even if an error happens during writeback. So make sure we don't repeat the metadata space release if writeback started for our inode cache. This issue was trivial to reproduce by running the fstest btrfs/088 with "-o inode_cache", which triggered the assertion leading to a BUG() call and requiring a reboot in order to run the remaining fstests. Trace produced by btrfs/088: [255289.385904] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5276 [255289.388094] ------------[ cut here ]------------ [255289.389184] kernel BUG at fs/btrfs/ctree.h:4057! [255289.390125] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [255289.392068] Call Trace: [255289.392068] [] drop_outstanding_extent+0x3d/0x6d [btrfs] [255289.392068] [] btrfs_delalloc_release_metadata+0x54/0xe3 [btrfs] [255289.392068] [] btrfs_write_out_ino_cache+0x95/0xad [btrfs] [255289.392068] [] btrfs_save_ino_cache+0x275/0x2dc [btrfs] [255289.392068] [] commit_fs_roots.isra.12+0xaa/0x137 [btrfs] [255289.392068] [] ? trace_hardirqs_on+0xd/0xf [255289.392068] [] ? btrfs_commit_transaction+0x4b1/0x9c9 [btrfs] [255289.392068] [] ? _raw_spin_unlock+0x32/0x46 [255289.392068] [] btrfs_commit_transaction+0x4c0/0x9c9 [btrfs] (...) Signed-off-by: Filipe Manana Signed-off-by: Chris Mason

Btrfs: fix wrong mapping flags for free space inode

2015-05-07T00:06:13+00:00

We were passing a flags value that differed from the intention in commit 2b108268006e ("Btrfs: don't use highmem for free space cache pages"). This caused problems in a ARM machine, leaving btrfs unusable there. Reported-by: Merlijn Wajer Tested-by: Merlijn Wajer Signed-off-by: Filipe Manana Signed-off-by: Chris Mason

btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache

2015-04-26T13:27:01+00:00

If io_ctl_prepare_pages fails, the pages in io_ctl.pages are not valid. When we try to access them later, things will blow up in various ways. Also fix the comment about the return value, which is an errno on error, not -1, and update the cases where it was not. Reviewed-by: Liu Bo Signed-off-by: Omar Sandoval Signed-off-by: Chris Mason

Btrfs: prevent list corruption during free space cache processing

2015-04-24T18:52:25+00:00

__btrfs_write_out_cache is holding the ctl->tree_lock while it prepares a list of bitmaps to record in the free space cache. It was dropping the lock while it worked on other components, which made a window for free_bitmap() to free the bitmap struct without removing it from the list. This changes things to hold the lock the whole time, and also makes sure we hold the lock during enospc cleanup. Reported-by: Filipe Manana Signed-off-by: Chris Mason

Btrfs: fix inode cache writeout

2015-04-24T00:47:34+00:00

The code to fix stalls during free spache cache IO wasn't using the correct root when waiting on the IO for inode caches. This is only a problem when the inode cache is enabled with mount -o inode_cache This fixes the inode cache writeout to preserve any error values and makes sure not to override the root when inode cache writeout is done. Reported-by: Filipe Manana Signed-off-by: Chris Mason

Btrfs: allow block group cache writeout outside critical section in commit

2015-04-10T21:07:22+00:00

We loop through all of the dirty block groups during commit and write the free space cache. In order to make sure the cache is currect, we do this while no other writers are allowed in the commit. If a large number of block groups are dirty, this can introduce long stalls during the final stages of the commit, which can block new procs trying to change the filesystem. This commit changes the block group cache writeout to take appropriate locks and allow it to run earlier in the commit. We'll still have to redo some of the block groups, but it means we can get most of the work out of the way without blocking the entire FS. Signed-off-by: Chris Mason

Btrfs: don't use highmem for free space cache pages

2015-04-10T21:07:18+00:00

In order to create the free space cache concurrently with FS modifications, we need to take a few block group locks. The cache code also does kmap, which would schedule with the locks held. Instead of going through kmap_atomic, lets just use lowmem for the cache pages. Signed-off-by: Chris Mason

Btrfs: two stage dirty block group writeout

2015-04-10T21:07:11+00:00

Block group cache writeout is currently waiting on the pages for each block group cache before moving on to writing the next one. This commit switches things around to send down all the caches and then wait on them in batches. The end result is much faster, since we're keeping the disk pipeline full. Signed-off-by: Chris Mason

btrfs: move struct io_ctl into ctree.h and rename it

2015-04-10T21:07:04+00:00

We'll need to put the io_ctl into the block_group cache struct, so name it struct btrfs_io_ctl and move it into ctree.h Signed-off-by: Chris Mason