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author | Jeff Mahoney <jeffm@suse.com> | 2013-08-08 21:34:46 (GMT) |
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committer | Jeff Mahoney <jeffm@suse.de> | 2013-08-08 21:34:46 (GMT) |
commit | 278f6679f454bf185a07d9a4ca355b153482d17a (patch) | |
tree | ffead073e67cfdc1ddfc3949ebc93c06dcaaab8f /fs/reiserfs/resize.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/resize.c')
-rw-r--r-- | fs/reiserfs/resize.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c index 3ce02cf..a4ef5cd 100644 --- a/fs/reiserfs/resize.c +++ b/fs/reiserfs/resize.c @@ -34,6 +34,7 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new) unsigned long int block_count, free_blocks; int i; int copy_size; + int depth; sb = SB_DISK_SUPER_BLOCK(s); @@ -43,7 +44,9 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new) } /* check the device size */ + depth = reiserfs_write_unlock_nested(s); bh = sb_bread(s, block_count_new - 1); + reiserfs_write_lock_nested(s, depth); if (!bh) { printk("reiserfs_resize: can\'t read last block\n"); return -EINVAL; @@ -125,9 +128,12 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new) * transaction begins, and the new bitmaps don't matter if the * transaction fails. */ for (i = bmap_nr; i < bmap_nr_new; i++) { + int depth; /* don't use read_bitmap_block since it will cache * the uninitialized bitmap */ + depth = reiserfs_write_unlock_nested(s); bh = sb_bread(s, i * s->s_blocksize * 8); + reiserfs_write_lock_nested(s, depth); if (!bh) { vfree(bitmap); return -EIO; @@ -138,9 +144,9 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new) set_buffer_uptodate(bh); mark_buffer_dirty(bh); - reiserfs_write_unlock(s); + depth = reiserfs_write_unlock_nested(s); sync_dirty_buffer(bh); - reiserfs_write_lock(s); + reiserfs_write_lock_nested(s, depth); // update bitmap_info stuff bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; brelse(bh); |