ext4: Clarify the locking details in mballoc
We don't need to take the alloc_sem lock when we are adding new
groups, since mballoc won't see the new group added until we bump
sbi->s_groups_count.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 68b0351..3cfc343 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -746,7 +746,6 @@
struct inode *inode = NULL;
handle_t *handle;
int gdb_off, gdb_num;
- int num_grp_locked = 0;
int err, err2;
gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
@@ -856,7 +855,6 @@
* using the new disk blocks.
*/
- num_grp_locked = ext4_mb_get_buddy_cache_lock(sb, input->group);
/* Update group descriptor block for new group */
gdp = (struct ext4_group_desc *)((char *)primary->b_data +
gdb_off * EXT4_DESC_SIZE(sb));
@@ -875,10 +873,8 @@
* descriptor
*/
err = ext4_mb_add_groupinfo(sb, input->group, gdp);
- if (err) {
- ext4_mb_put_buddy_cache_lock(sb, input->group, num_grp_locked);
+ if (err)
goto exit_journal;
- }
/*
* Make the new blocks and inodes valid next. We do this before
@@ -920,7 +916,6 @@
/* Update the global fs size fields */
sbi->s_groups_count++;
- ext4_mb_put_buddy_cache_lock(sb, input->group, num_grp_locked);
ext4_handle_dirty_metadata(handle, NULL, primary);