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authorJoel Becker <joel.becker@oracle.com>2008-11-14 01:49:20 +0300
committerMark Fasheh <mfasheh@suse.com>2009-01-05 19:36:54 +0300
commita8549fb5abb2b372e46d5de0d23ff8b24f4a61af (patch)
treeb35c565519fec6827b4bd76938dcfd39e762caf4 /fs/ocfs2/extent_map.h
parent970e4936d7d15f35d00fd15a14f5343ba78b2fc8 (diff)
downloadlinux-a8549fb5abb2b372e46d5de0d23ff8b24f4a61af.tar.xz
ocfs2: Wrap virtual block reads in ocfs2_read_virt_blocks()
The ocfs2_read_dir_block() function really maps an inode's virtual blocks to physical ones before calling ocfs2_read_blocks(). Let's extract that to common code, because other places might want to do that. Other than the block number being virtual, ocfs2_read_virt_blocks() takes the same arguments as ocfs2_read_blocks(). It converts those virtual block numbers to physical before calling ocfs2_read_blocks() directly. If the blocks asked for are discontiguous, this can mean multiple calls to ocfs2_read_blocks(), but this is mostly hidden from the caller. Like ocfs2_read_blocks(), the caller can pass in an existing buffer_head. This is usually done to pick up some readahead I/O. ocfs2_read_virt_blocks() checks the buffer_head's block number against the extent map - it must match. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Diffstat (limited to 'fs/ocfs2/extent_map.h')
-rw-r--r--fs/ocfs2/extent_map.h24
1 files changed, 24 insertions, 0 deletions
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 1c4aa8b06f34..b7dd9731b462 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -57,4 +57,28 @@ int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
u32 *p_cluster, u32 *num_clusters,
struct ocfs2_extent_list *el);
+int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
+ struct buffer_head *bhs[], int flags,
+ int (*validate)(struct super_block *sb,
+ struct buffer_head *bh));
+static inline int ocfs2_read_virt_block(struct inode *inode, u64 v_block,
+ struct buffer_head **bh,
+ int (*validate)(struct super_block *sb,
+ struct buffer_head *bh))
+{
+ int status = 0;
+
+ if (bh == NULL) {
+ printk("ocfs2: bh == NULL\n");
+ status = -EINVAL;
+ goto bail;
+ }
+
+ status = ocfs2_read_virt_blocks(inode, v_block, 1, bh, 0, validate);
+
+bail:
+ return status;
+}
+
+
#endif /* _EXTENT_MAP_H */