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authorFrederic Weisbecker <fweisbec@gmail.com>2009-05-08 14:53:52 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2009-09-14 07:18:20 +0200
commitd6f5b0aa08078c3dabe377d5b1a6077e9c9352d3 (patch)
treeb5d6bd99e007c57a6cd4953368202d99a41141cd /fs/reiserfs/inode.c
parent09eb47a7c52ad535aafca889e0b936c445c375ce (diff)
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/inode.c')
-rw-r--r--fs/reiserfs/inode.c25
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;
}