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author | Chris Mason <chris.mason@oracle.com> | 2007-11-27 01:34:41 +0100 |
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committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 17:03:58 +0200 |
commit | 793955bca66c99defdffc857ae6eb7e8431d6bbe (patch) | |
tree | 2f8376247033fced7289038b8d82e10a6cc55f22 | |
parent | Btrfs: Handle writeback under high memory pressure better (diff) | |
download | linux-793955bca66c99defdffc857ae6eb7e8431d6bbe.tar.xz linux-793955bca66c99defdffc857ae6eb7e8431d6bbe.zip |
Btrfs: Limit btree writeback to prevent seeks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r-- | fs/btrfs/disk-io.c | 9 | ||||
-rw-r--r-- | fs/btrfs/extent_map.c | 39 | ||||
-rw-r--r-- | fs/btrfs/extent_map.h | 3 |
3 files changed, 51 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 3e16cca72b49..28e9ef8a3253 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -210,6 +210,15 @@ static int btree_writepages(struct address_space *mapping, { struct extent_map_tree *tree; tree = &BTRFS_I(mapping->host)->extent_tree; + if (wbc->sync_mode == WB_SYNC_NONE) { + u64 num_dirty; + u64 start = 0; + unsigned long thresh = 96 * 1024 * 1024; + num_dirty = count_range_bits(tree, &start, thresh, EXTENT_DIRTY); + if (num_dirty < thresh) { + return 0; + } + } return extent_writepages(tree, mapping, btree_get_extent, wbc); } diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 55f272c335c6..b6a4974ecc23 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1106,6 +1106,45 @@ out: return found; } +u64 count_range_bits(struct extent_map_tree *tree, + u64 *start, u64 max_bytes, unsigned long bits) +{ + struct rb_node *node; + struct extent_state *state; + u64 cur_start = *start; + u64 total_bytes = 0; + int found = 0; + + write_lock_irq(&tree->lock); + /* + * this search will find all the extents that end after + * our range starts. + */ + node = tree_search(&tree->state, cur_start); + if (!node || IS_ERR(node)) { + goto out; + } + + while(1) { + state = rb_entry(node, struct extent_state, rb_node); + if ((state->state & bits)) { + total_bytes += state->end - state->start + 1; + if (total_bytes >= max_bytes) + break; + if (!found) { + *start = state->start; + found = 1; + } + } + node = rb_next(node); + if (!node) + break; + } +out: + write_unlock_irq(&tree->lock); + return total_bytes; +} + /* * helper function to lock both pages and extents in the tree. * pages must be locked first. diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index 24ddc8c93461..13c562f7cb6f 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -113,6 +113,9 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page, int __init extent_map_init(void); void __exit extent_map_exit(void); +u64 count_range_bits(struct extent_map_tree *tree, + u64 *start, u64 max_bytes, unsigned long bits); + int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, int filled); int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, |