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authorArne Jansen <sensille@gmx.net>2011-05-23 14:25:41 +0200
committerArne Jansen <sensille@gmx.net>2011-10-02 08:47:57 +0200
commitab0fff03055d2d1b01a7581badeba18db9c4f55c (patch)
tree3bc6fbbdc7188623783db379eff8fbf23cdcb514
parentbtrfs: add an extra wait mode to read_extent_buffer_pages (diff)
downloadlinux-ab0fff03055d2d1b01a7581badeba18db9c4f55c.tar.xz
linux-ab0fff03055d2d1b01a7581badeba18db9c4f55c.zip
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 <sensille@gmx.net>
-rw-r--r--fs/btrfs/disk-io.c32
-rw-r--r--fs/btrfs/disk-io.h2
-rw-r--r--fs/btrfs/extent_io.h1
3 files changed, 35 insertions, 0 deletions
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