From ab0fff03055d2d1b01a7581badeba18db9c4f55c Mon Sep 17 00:00:00 2001 From: Arne Jansen Date: Mon, 23 May 2011 14:25:41 +0200 Subject: [PATCH] btrfs: add READAHEAD extent buffer flag Add a READAHEAD extent buffer flag. Add a function to trigger a read with this flag set. Changes v2: - use extent buffer flags instead of extent state flags Changes v5: - adapt to changed read_extent_buffer_pages interface - don't return eb from reada_tree_block_flagged if it has CORRUPT flag set Signed-off-by: Arne Jansen --- fs/btrfs/disk-io.c | 32 ++++++++++++++++++++++++++++++++ fs/btrfs/disk-io.h | 2 ++ fs/btrfs/extent_io.h | 1 + 3 files changed, 35 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e6170e142cad..1220d04072c8 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -980,6 +980,38 @@ int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, return ret; } +int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize, + int mirror_num, struct extent_buffer **eb) +{ + struct extent_buffer *buf = NULL; + struct inode *btree_inode = root->fs_info->btree_inode; + struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree; + int ret; + + buf = btrfs_find_create_tree_block(root, bytenr, blocksize); + if (!buf) + return 0; + + set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags); + + ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK, + btree_get_extent, mirror_num); + if (ret) { + free_extent_buffer(buf); + return ret; + } + + if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) { + free_extent_buffer(buf); + return -EIO; + } else if (extent_buffer_uptodate(io_tree, buf, NULL)) { + *eb = buf; + } else { + free_extent_buffer(buf); + } + return 0; +} + struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize) { diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index bec3ea4bd67f..b3bdb5c1390f 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -40,6 +40,8 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 parent_transid); int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 parent_transid); +int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize, + int mirror_num, struct extent_buffer **eb); struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize); int clean_tree_block(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 6d74c6b34691..fcaf49bcb880 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -32,6 +32,7 @@ #define EXTENT_BUFFER_BLOCKING 1 #define EXTENT_BUFFER_DIRTY 2 #define EXTENT_BUFFER_CORRUPT 3 +#define EXTENT_BUFFER_READAHEAD 4 /* this got triggered by readahead */ /* these are flags for extent_clear_unlock_delalloc */ #define EXTENT_CLEAR_UNLOCK_PAGE 0x1 -- 2.20.1