diff options
author | Jeff Mahoney <jeffm@suse.com> | 2013-08-08 21:34:46 (GMT) |
---|---|---|
committer | Jeff Mahoney <jeffm@suse.de> | 2013-08-08 21:34:46 (GMT) |
commit | 278f6679f454bf185a07d9a4ca355b153482d17a (patch) | |
tree | ffead073e67cfdc1ddfc3949ebc93c06dcaaab8f /fs/reiserfs/fix_node.c | |
parent | 4c05141df57f4ffc1a9a28f1925434924179bfe4 (diff) | |
download | linux-278f6679f454bf185a07d9a4ca355b153482d17a.tar.xz |
reiserfs: locking, handle nested locks properly
The reiserfs write lock replaced the BKL and uses similar semantics.
Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.
The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.
This patch implements that and adds a number of places where the lock
should be dropped.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Diffstat (limited to 'fs/reiserfs/fix_node.c')
-rw-r--r-- | fs/reiserfs/fix_node.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/fs/reiserfs/fix_node.c b/fs/reiserfs/fix_node.c index 430e065..dc4d415 100644 --- a/fs/reiserfs/fix_node.c +++ b/fs/reiserfs/fix_node.c @@ -1022,9 +1022,9 @@ static int get_far_parent(struct tree_balance *tb, if (buffer_locked(*pcom_father)) { /* Release the write lock while the buffer is busy */ - reiserfs_write_unlock(tb->tb_sb); + int depth = reiserfs_write_unlock_nested(tb->tb_sb); __wait_on_buffer(*pcom_father); - reiserfs_write_lock(tb->tb_sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (FILESYSTEM_CHANGED_TB(tb)) { brelse(*pcom_father); return REPEAT_SEARCH; @@ -1929,9 +1929,9 @@ static int get_direct_parent(struct tree_balance *tb, int h) return REPEAT_SEARCH; if (buffer_locked(bh)) { - reiserfs_write_unlock(tb->tb_sb); + int depth = reiserfs_write_unlock_nested(tb->tb_sb); __wait_on_buffer(bh); - reiserfs_write_lock(tb->tb_sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (FILESYSTEM_CHANGED_TB(tb)) return REPEAT_SEARCH; } @@ -1952,6 +1952,7 @@ static int get_neighbors(struct tree_balance *tb, int h) unsigned long son_number; struct super_block *sb = tb->tb_sb; struct buffer_head *bh; + int depth; PROC_INFO_INC(sb, get_neighbors[h]); @@ -1969,9 +1970,9 @@ static int get_neighbors(struct tree_balance *tb, int h) tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb-> FL[h]); son_number = B_N_CHILD_NUM(tb->FL[h], child_position); - reiserfs_write_unlock(sb); + depth = reiserfs_write_unlock_nested(tb->tb_sb); bh = sb_bread(sb, son_number); - reiserfs_write_lock(sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (!bh) return IO_ERROR; if (FILESYSTEM_CHANGED_TB(tb)) { @@ -2009,9 +2010,9 @@ static int get_neighbors(struct tree_balance *tb, int h) child_position = (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0; son_number = B_N_CHILD_NUM(tb->FR[h], child_position); - reiserfs_write_unlock(sb); + depth = reiserfs_write_unlock_nested(tb->tb_sb); bh = sb_bread(sb, son_number); - reiserfs_write_lock(sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (!bh) return IO_ERROR; if (FILESYSTEM_CHANGED_TB(tb)) { @@ -2272,6 +2273,7 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) } if (locked) { + int depth; #ifdef CONFIG_REISERFS_CHECK repeat_counter++; if ((repeat_counter % 10000) == 0) { @@ -2286,9 +2288,9 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) REPEAT_SEARCH : CARRY_ON; } #endif - reiserfs_write_unlock(tb->tb_sb); + depth = reiserfs_write_unlock_nested(tb->tb_sb); __wait_on_buffer(locked); - reiserfs_write_lock(tb->tb_sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (FILESYSTEM_CHANGED_TB(tb)) return REPEAT_SEARCH; } @@ -2359,9 +2361,9 @@ int fix_nodes(int op_mode, struct tree_balance *tb, /* if it possible in indirect_to_direct conversion */ if (buffer_locked(tbS0)) { - reiserfs_write_unlock(tb->tb_sb); + int depth = reiserfs_write_unlock_nested(tb->tb_sb); __wait_on_buffer(tbS0); - reiserfs_write_lock(tb->tb_sb); + reiserfs_write_lock_nested(tb->tb_sb, depth); if (FILESYSTEM_CHANGED_TB(tb)) return REPEAT_SEARCH; } |