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| author | Miao Xie <miaox@cn.fujitsu.com> | 2013-01-10 05:47:57 (GMT) |
|---|---|---|
| committer | Fengguang Wu <fengguang.wu@intel.com> | 2013-01-12 02:47:43 (GMT) |
| commit | 10ee27a06cc8eb57f83342a8eabcb75deb872d52 (patch) | |
| tree | d14f69011b7aa1896f1aef37cb2b64f868bce459 /fs/btrfs/extent-tree.c | |
| parent | 9931faca02c604c22335f5a935a501bb2ace6e20 (diff) | |
| download | linux-10ee27a06cc8eb57f83342a8eabcb75deb872d52.tar.xz | |
vfs: re-implement writeback_inodes_sb(_nr)_if_idle() and rename them
writeback_inodes_sb(_nr)_if_idle() is re-implemented by replacing down_read()
with down_read_trylock() because
- If ->s_umount is write locked, then the sb is not idle. That is
writeback_inodes_sb(_nr)_if_idle() needn't wait for the lock.
- writeback_inodes_sb(_nr)_if_idle() grabs s_umount lock when it want to start
writeback, it may bring us deadlock problem when doing umount. In order to
fix the problem, ext4 and btrfs implemented their own writeback functions
instead of writeback_inodes_sb(_nr)_if_idle(), but it introduced the redundant
code, it is better to implement a new writeback_inodes_sb(_nr)_if_idle().
The name of these two functions is cumbersome, so rename them to
try_to_writeback_inodes_sb(_nr).
This idea came from Christoph Hellwig.
Some code is from the patch of Kamal Mostafa.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 20 |
1 files changed, 3 insertions, 17 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 521e9d4..f31abb1 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3689,20 +3689,6 @@ static int can_overcommit(struct btrfs_root *root, return 0; } -static int writeback_inodes_sb_nr_if_idle_safe(struct super_block *sb, - unsigned long nr_pages, - enum wb_reason reason) -{ - if (!writeback_in_progress(sb->s_bdi) && - down_read_trylock(&sb->s_umount)) { - writeback_inodes_sb_nr(sb, nr_pages, reason); - up_read(&sb->s_umount); - return 1; - } - - return 0; -} - /* * shrink metadata reservation for delalloc */ @@ -3735,9 +3721,9 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, while (delalloc_bytes && loops < 3) { max_reclaim = min(delalloc_bytes, to_reclaim); nr_pages = max_reclaim >> PAGE_CACHE_SHIFT; - writeback_inodes_sb_nr_if_idle_safe(root->fs_info->sb, - nr_pages, - WB_REASON_FS_FREE_SPACE); + try_to_writeback_inodes_sb_nr(root->fs_info->sb, + nr_pages, + WB_REASON_FS_FREE_SPACE); /* * We need to wait for the async pages to actually start before |