From 5b21f2ed3f2947b5195b65c9fdbdd9e52904cc03 Mon Sep 17 00:00:00 2001 From: Zheng Yan Date: Fri, 26 Sep 2008 10:05:38 -0400 Subject: Btrfs: extent_map and data=ordered fixes for space balancing * Add an EXTENT_BOUNDARY state bit to keep the writepage code from merging data extents that are in the process of being relocated. This allows us to do accounting for them properly. * The balancing code relocates data extents indepdent of the underlying inode. The extent_map code was modified to properly account for things moving around (invalidating extent_map caches in the inode). * Don't take the drop_mutex in the create_subvol ioctl. It isn't required. * Fix walking of the ordered extent list to avoid races with sys_unlink * Change the lock ordering rules. Transaction start goes outside the drop_mutex. This allows btrfs_commit_transaction to directly drop the relocation trees. Signed-off-by: Chris Mason --- fs/btrfs/file.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'fs/btrfs/file.c') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 8856570..1b7e51a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -294,7 +294,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans, last_pos_in_file, 0, 0, hole_size, 0); btrfs_drop_extent_cache(inode, last_pos_in_file, - last_pos_in_file + hole_size -1); + last_pos_in_file + hole_size - 1, 0); mutex_unlock(&BTRFS_I(inode)->extent_mutex); btrfs_check_file(root, inode); } @@ -337,7 +337,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans, inline_size -= start_pos; err = insert_inline_extent(trans, root, inode, start_pos, inline_size, pages, 0, num_pages); - btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1); + btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1, 0); BUG_ON(err); mutex_unlock(&BTRFS_I(inode)->extent_mutex); @@ -362,7 +362,8 @@ out_unlock: return err; } -int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) +int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, + int skip_pinned) { struct extent_map *em; struct extent_map *split = NULL; @@ -371,6 +372,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) u64 len = end - start + 1; int ret; int testend = 1; + unsigned long flags; WARN_ON(end < start); if (end == (u64)-1) { @@ -389,6 +391,23 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) spin_unlock(&em_tree->lock); break; } + flags = em->flags; + if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { + spin_unlock(&em_tree->lock); + if (em->start <= start && + (!testend || em->start + em->len >= start + len)) { + free_extent_map(em); + break; + } + if (start < em->start) { + len = em->start - start; + } else { + len = start + len - (em->start + em->len); + start = em->start + em->len; + } + free_extent_map(em); + continue; + } clear_bit(EXTENT_FLAG_PINNED, &em->flags); remove_extent_mapping(em_tree, em); @@ -398,7 +417,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) split->len = start - em->start; split->block_start = em->block_start; split->bdev = em->bdev; - split->flags = em->flags; + split->flags = flags; ret = add_extent_mapping(em_tree, split); BUG_ON(ret); free_extent_map(split); @@ -412,7 +431,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) split->start = start + len; split->len = em->start + em->len - (start + len); split->bdev = em->bdev; - split->flags = em->flags; + split->flags = flags; split->block_start = em->block_start + diff; @@ -541,7 +560,7 @@ int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans, int recow; int ret; - btrfs_drop_extent_cache(inode, start, end - 1); + btrfs_drop_extent_cache(inode, start, end - 1, 0); path = btrfs_alloc_path(); if (!path) -- cgit v1.1