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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-05-08 14:53:52 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-09-14 07:18:20 +0200 |
| commit | d6f5b0aa08078c3dabe377d5b1a6077e9c9352d3 (patch) | |
| tree | b5d6bd99e007c57a6cd4953368202d99a41141cd /fs/reiserfs | |
| parent | 09eb47a7c52ad535aafca889e0b936c445c375ce (diff) | |
| download | linux-d6f5b0aa08078c3dabe377d5b1a6077e9c9352d3.tar.bz2 | |
kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end()
reiserfs_write_end() is a hot path in reiserfs.
We have two wasteful write lock lock/release inside that can be gathered
without changing the code logic.
This patch factorizes them out in a single protected section, reducing the
number of contentions inside.
[ Impact: reduce lock contention in a reiserfs hotpath ]
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'fs/reiserfs')
| -rw-r--r-- | fs/reiserfs/inode.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 6114050f342e..853f4f6fe920 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -2681,6 +2681,8 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, int update_sd = 0; struct reiserfs_transaction_handle *th; unsigned start; + int lock_depth = 0; + bool locked = false; if ((unsigned long)fsdata & AOP_FLAG_CONT_EXPAND) pos ++; @@ -2707,9 +2709,11 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, ** to do the i_size updates here. */ pos += copied; + if (pos > inode->i_size) { struct reiserfs_transaction_handle myth; - reiserfs_write_lock(inode->i_sb); + lock_depth = reiserfs_write_lock_once(inode->i_sb); + locked = true; /* If the file have grown beyond the border where it can have a tail, unmark it as needing a tail packing */ @@ -2720,10 +2724,9 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask; ret = journal_begin(&myth, inode->i_sb, 1); - if (ret) { - reiserfs_write_unlock(inode->i_sb); + if (ret) goto journal_error; - } + reiserfs_update_inode_transaction(inode); inode->i_size = pos; /* @@ -2735,34 +2738,36 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, reiserfs_update_sd(&myth, inode); update_sd = 1; ret = journal_end(&myth, inode->i_sb, 1); - reiserfs_write_unlock(inode->i_sb); if (ret) goto journal_error; } if (th) { - reiserfs_write_lock(inode->i_sb); + if (!locked) { + lock_depth = reiserfs_write_lock_once(inode->i_sb); + locked = true; + } if (!update_sd) mark_inode_dirty(inode); ret = reiserfs_end_persistent_transaction(th); - reiserfs_write_unlock(inode->i_sb); if (ret) goto out; } out: + if (locked) + reiserfs_write_unlock_once(inode->i_sb, lock_depth); unlock_page(page); page_cache_release(page); return ret == 0 ? copied : ret; journal_error: + reiserfs_write_unlock_once(inode->i_sb, lock_depth); + locked = false; if (th) { - reiserfs_write_lock(inode->i_sb); if (!update_sd) reiserfs_update_sd(th, inode); ret = reiserfs_end_persistent_transaction(th); - reiserfs_write_unlock(inode->i_sb); } - goto out; } |