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author | Josef Bacik <jbacik@fusionio.com> | 2012-08-01 19:36:24 (GMT) |
---|---|---|
committer | Chris Mason <chris.mason@oracle.com> | 2012-08-28 20:53:33 (GMT) |
commit | 66657b318e0e443ada229fccd40c8be86cfebdbf (patch) | |
tree | bf1334fff93556fbc8d82b26a6d5431fd9e74b5c /fs/btrfs | |
parent | 1fa11e265fa2562fb713171b6a58e72bb7afd276 (diff) | |
download | linux-fsl-qoriq-66657b318e0e443ada229fccd40c8be86cfebdbf.tar.xz |
Btrfs: barrier before waitqueue_active
We need a barrir before calling waitqueue_active otherwise we will miss
wakeups. So in places that do atomic_dec(); then atomic_read() use
atomic_dec_return() which imply a memory barrier (see memory-barriers.txt)
and then add an explicit memory barrier everywhere else that need them.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r-- | fs/btrfs/compression.c | 1 | ||||
-rw-r--r-- | fs/btrfs/delayed-inode.c | 7 | ||||
-rw-r--r-- | fs/btrfs/disk-io.c | 7 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 4 | ||||
-rw-r--r-- | fs/btrfs/volumes.c | 3 |
5 files changed, 10 insertions, 12 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 86eff48..43d1c5a 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -818,6 +818,7 @@ static void free_workspace(int type, struct list_head *workspace) btrfs_compress_op[idx]->free_workspace(workspace); atomic_dec(alloc_workspace); wake: + smp_mb(); if (waitqueue_active(workspace_wait)) wake_up(workspace_wait); } diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 00deed4e..07d5eeb 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -512,8 +512,8 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item) rb_erase(&delayed_item->rb_node, root); delayed_item->delayed_node->count--; - atomic_dec(&delayed_root->items); - if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND && + if (atomic_dec_return(&delayed_root->items) < + BTRFS_DELAYED_BACKGROUND && waitqueue_active(&delayed_root->wait)) wake_up(&delayed_root->wait); } @@ -1056,8 +1056,7 @@ static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node) delayed_node->count--; delayed_root = delayed_node->root->fs_info->delayed_root; - atomic_dec(&delayed_root->items); - if (atomic_read(&delayed_root->items) < + if (atomic_dec_return(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND && waitqueue_active(&delayed_root->wait)) wake_up(&delayed_root->wait); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a7ad8fc..dd86a5d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -754,9 +754,7 @@ static void run_one_async_done(struct btrfs_work *work) limit = btrfs_async_submit_limit(fs_info); limit = limit * 2 / 3; - atomic_dec(&fs_info->nr_async_submits); - - if (atomic_read(&fs_info->nr_async_submits) < limit && + if (atomic_dec_return(&fs_info->nr_async_submits) < limit && waitqueue_active(&fs_info->async_submit_wait)) wake_up(&fs_info->async_submit_wait); @@ -3783,14 +3781,17 @@ int btrfs_cleanup_transaction(struct btrfs_root *root) /* FIXME: cleanup wait for commit */ t->in_commit = 1; t->blocked = 1; + smp_mb(); if (waitqueue_active(&root->fs_info->transaction_blocked_wait)) wake_up(&root->fs_info->transaction_blocked_wait); t->blocked = 0; + smp_mb(); if (waitqueue_active(&root->fs_info->transaction_wait)) wake_up(&root->fs_info->transaction_wait); t->commit_done = 1; + smp_mb(); if (waitqueue_active(&t->commit_wait)) wake_up(&t->commit_wait); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 2d65c52..97baf00 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1007,9 +1007,7 @@ static noinline void async_cow_submit(struct btrfs_work *work) nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; - atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages); - - if (atomic_read(&root->fs_info->async_delalloc_pages) < + if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 5 * 1024 * 1024 && waitqueue_active(&root->fs_info->async_submit_wait)) wake_up(&root->fs_info->async_submit_wait); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 3b39450..0b1e69d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -227,9 +227,8 @@ loop_lock: cur = pending; pending = pending->bi_next; cur->bi_next = NULL; - atomic_dec(&fs_info->nr_async_bios); - if (atomic_read(&fs_info->nr_async_bios) < limit && + if (atomic_dec_return(&fs_info->nr_async_bios) < limit && waitqueue_active(&fs_info->async_submit_wait)) wake_up(&fs_info->async_submit_wait); |