GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-23 07:12:09 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

reiserfs: locking, handle nested locks properly

Browse source 
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>
This commit is contained in:
Jeff Mahoney 2013-08-08 17:34:46 -04:00 • committed by Jeff Mahoney
parent 4c05141df5
commit 278f6679f4
13 changed files with 204 additions and 197 deletions
Download patch file Download diff file Expand all files Collapse all files

26
fs/reiserfs/fix_node.c
View file

@ -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;
}