From 47059d930f0e002ff851beea87d738146804726d Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Thu, 3 Jul 2014 18:22:07 +0800 Subject: [PATCH] Btrfs: make defragment work with nodatacow option Btrfs defragment will utilize COW feature, which means this did not work for nodatacow option, this problem was detected by xfstests generic/018 with nodatacow mount option. Fix this problem by forcing cow for a extent with state @EXTETN_DEFRAG setting. Signed-off-by: Wang Shilong Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/btrfs_inode.h | 6 ++++++ fs/btrfs/inode.c | 39 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 42 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 43527fd78825..fd879418fd42 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -120,6 +120,12 @@ struct btrfs_inode { */ u64 delalloc_bytes; + /* + * total number of bytes pending defrag, used by stat to check whether + * it needs COW. + */ + u64 defrag_bytes; + /* * the size of the file stored in the metadata on disk. data=ordered * means the in-memory i_size might be larger than the size on disk diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e326ffdd5c7b..2370d72972e9 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1445,6 +1445,26 @@ error: return ret; } +static inline int need_force_cow(struct inode *inode, u64 start, u64 end) +{ + + if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && + !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) + return 0; + + /* + * @defrag_bytes is a hint value, no spinlock held here, + * if is not zero, it means the file is defragging. + * Force cow if given extent needs to be defragged. + */ + if (BTRFS_I(inode)->defrag_bytes && + test_range_bit(&BTRFS_I(inode)->io_tree, start, end, + EXTENT_DEFRAG, 0, NULL)) + return 1; + + return 0; +} + /* * extent_io.c call back to do delayed allocation processing */ @@ -1454,11 +1474,12 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page, { int ret; struct btrfs_root *root = BTRFS_I(inode)->root; + int force_cow = need_force_cow(inode, start, end); - if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 1, nr_written); - } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { + } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 0, nr_written); } else if (!btrfs_test_opt(root, COMPRESS) && @@ -1555,6 +1576,8 @@ static void btrfs_set_bit_hook(struct inode *inode, struct extent_state *state, unsigned long *bits) { + if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) + WARN_ON(1); /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC @@ -1577,6 +1600,8 @@ static void btrfs_set_bit_hook(struct inode *inode, root->fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes += len; + if (*bits & EXTENT_DEFRAG) + BTRFS_I(inode)->defrag_bytes += len; if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags)) btrfs_add_delalloc_inodes(root, inode); @@ -1591,6 +1616,13 @@ static void btrfs_clear_bit_hook(struct inode *inode, struct extent_state *state, unsigned long *bits) { + u64 len = state->end + 1 - state->start; + + spin_lock(&BTRFS_I(inode)->lock); + if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) + BTRFS_I(inode)->defrag_bytes -= len; + spin_unlock(&BTRFS_I(inode)->lock); + /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC @@ -1598,7 +1630,6 @@ static void btrfs_clear_bit_hook(struct inode *inode, */ if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; - u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(inode); if (*bits & EXTENT_FIRST_DELALLOC) { @@ -8173,6 +8204,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->last_sub_trans = 0; ei->logged_trans = 0; ei->delalloc_bytes = 0; + ei->defrag_bytes = 0; ei->disk_i_size = 0; ei->flags = 0; ei->csum_bytes = 0; @@ -8231,6 +8263,7 @@ void btrfs_destroy_inode(struct inode *inode) WARN_ON(BTRFS_I(inode)->reserved_extents); WARN_ON(BTRFS_I(inode)->delalloc_bytes); WARN_ON(BTRFS_I(inode)->csum_bytes); + WARN_ON(BTRFS_I(inode)->defrag_bytes); /* * This can happen where we create an inode, but somebody else also -- 2.20.1