From 7014cdb49305eda0767d2ae6136f8c191ea8fd81 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 30 Aug 2012 20:06:49 -0400 Subject: [PATCH] Btrfs: btrfs_drop_extent_cache should never fail I noticed this when I was doing the fsync stuff, we allocate split extents if we drop an extent range that is in the middle of an existing extent. This BUG()'s if we fail to allocate memory, but the fact is this is just a cache, we will just regenerate the cache if we need it, the important part is that we free the range we are given. This can be done without allocations, so if we fail to allocate splits just skip the splitting stage and free our em and look for more extents to drop. This also makes btrfs_drop_extent_cache a void since nobody was checking the return value anyway. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/ctree.h | 4 ++-- fs/btrfs/file.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 88adfe63840..b7cd3adb5a5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3316,8 +3316,8 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, struct inode *inode); int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info); int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync); -int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, - int skip_pinned); +void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, + int skip_pinned); int btrfs_replace_extent_cache(struct inode *inode, struct extent_map *replace, u64 start, u64 end, int skip_pinned, int modified); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 57026a6e9c9..a50e98733e2 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -459,8 +459,8 @@ int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode, * this drops all the extents in the cache that intersect the range * [start, end]. Existing extents are split as required. */ -int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, - int skip_pinned) +void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, + int skip_pinned) { struct extent_map *em; struct extent_map *split = NULL; @@ -479,11 +479,14 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, testend = 0; } while (1) { + int no_splits = 0; + if (!split) split = alloc_extent_map(); if (!split2) split2 = alloc_extent_map(); - BUG_ON(!split || !split2); /* -ENOMEM */ + if (!split || !split2) + no_splits = 1; write_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, len); @@ -509,6 +512,8 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); clear_bit(EXTENT_FLAG_PINNED, &em->flags); remove_extent_mapping(em_tree, em); + if (no_splits) + goto next; if (em->block_start < EXTENT_MAP_LAST_BYTE && em->start < start) { @@ -559,6 +564,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, free_extent_map(split); split = NULL; } +next: write_unlock(&em_tree->lock); /* once for us */ @@ -570,7 +576,6 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, free_extent_map(split); if (split2) free_extent_map(split2); - return 0; } /* -- 2.41.0