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author | Chris Mason <chris.mason@oracle.com> | 2008-07-22 11:18:08 -0400 |
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committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:05 -0400 |
commit | a61e6f29dc7c9d56a776a518eed92bbc61848263 (patch) | |
tree | 6856ad3e5822eacfc2ac94693b6023ef81567fd2 /fs | |
parent | 6af118ce51b52ceda357c671550c79628b9c4a65 (diff) | |
download | kernel_samsung_smdk4412-a61e6f29dc7c9d56a776a518eed92bbc61848263.zip kernel_samsung_smdk4412-a61e6f29dc7c9d56a776a518eed92bbc61848263.tar.gz kernel_samsung_smdk4412-a61e6f29dc7c9d56a776a518eed92bbc61848263.tar.bz2 |
Btrfs: Use a mutex in the extent buffer for tree block locking
This replaces the use of the page cache lock bit for locking, which wasn't
suitable for block size < page size and couldn't be used recursively.
The mutexes alone don't fix either problem, but they are the first step.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/extent-tree.c | 7 | ||||
-rw-r--r-- | fs/btrfs/extent_io.c | 9 | ||||
-rw-r--r-- | fs/btrfs/extent_io.h | 1 | ||||
-rw-r--r-- | fs/btrfs/locking.c | 13 |
4 files changed, 17 insertions, 13 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index ccd4932..c51cd11 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1451,7 +1451,7 @@ static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes, struct extent_buffer *buf; buf = btrfs_find_tree_block(root, bytenr, num_bytes); if (buf) { - if (!btrfs_try_tree_lock(buf) && + if (btrfs_try_tree_lock(buf) && btrfs_buffer_uptodate(buf, 0)) { u64 transid = root->fs_info->running_transaction->transid; @@ -3345,11 +3345,6 @@ int btrfs_read_block_groups(struct btrfs_root *root) set_state_private(block_group_cache, found_key.objectid, (unsigned long)cache); - /* hack for now */ - if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) { - cache_block_group(root->fs_info->extent_root, - cache); - } if (key.objectid >= btrfs_super_total_bytes(&info->super_copy)) break; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 32bb4ed..7380449 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2690,6 +2690,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, eb = kmem_cache_zalloc(extent_buffer_cache, mask); eb->start = start; eb->len = len; + mutex_init(&eb->mutex); spin_lock_irqsave(&leak_lock, flags); list_add(&eb->leak_list, &buffers); spin_unlock_irqrestore(&leak_lock, flags); @@ -2837,6 +2838,7 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, for (i = 0; i < num_pages; i++) { page = extent_buffer_page(eb, i); + lock_page(page); if (i == 0) set_page_extent_head(page, eb->len); else @@ -2854,6 +2856,7 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, end = start + PAGE_CACHE_SIZE - 1; if (test_range_bit(tree, start, end, EXTENT_DIRTY, 0)) { + unlock_page(page); continue; } } @@ -2865,6 +2868,7 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, PAGECACHE_TAG_DIRTY); } read_unlock_irq(&page->mapping->tree_lock); + unlock_page(page); } return 0; } @@ -2893,12 +2897,17 @@ int set_extent_buffer_dirty(struct extent_io_tree *tree, * on us if the page isn't already dirty. */ if (i == 0) { + lock_page(page); set_page_extent_head(page, eb->len); } else if (PagePrivate(page) && page->private != EXTENT_PAGE_PRIVATE) { + lock_page(page); set_page_extent_mapped(page); + unlock_page(page); } __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); + if (i == 0) + unlock_page(page); } return set_extent_dirty(tree, eb->start, eb->start + eb->len - 1, GFP_NOFS); diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index dd36761..6c03e6a 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -90,6 +90,7 @@ struct extent_buffer { int flags; struct list_head leak_list; struct rb_node rb_node; + struct mutex mutex; }; struct extent_map_tree; diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 058a506..01a9ac2 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -29,32 +29,31 @@ int btrfs_tree_lock(struct extent_buffer *eb) { int i; - if (!TestSetPageLocked(eb->first_page)) + if (mutex_trylock(&eb->mutex)) return 0; for (i = 0; i < 512; i++) { cpu_relax(); - if (!TestSetPageLocked(eb->first_page)) + if (mutex_trylock(&eb->mutex)) return 0; } cpu_relax(); - lock_page(eb->first_page); + mutex_lock(&eb->mutex); return 0; } int btrfs_try_tree_lock(struct extent_buffer *eb) { - return TestSetPageLocked(eb->first_page); + return mutex_trylock(&eb->mutex); } int btrfs_tree_unlock(struct extent_buffer *eb) { - WARN_ON(!PageLocked(eb->first_page)); - unlock_page(eb->first_page); + mutex_unlock(&eb->mutex); return 0; } int btrfs_tree_locked(struct extent_buffer *eb) { - return PageLocked(eb->first_page); + return mutex_is_locked(&eb->mutex); } |