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Diffstat (limited to 'fs/xfs/linux-2.6/xfs_buf.h')
-rw-r--r--fs/xfs/linux-2.6/xfs_buf.h30
1 files changed, 19 insertions, 11 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index c79882ecb513..161333785f69 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -162,33 +162,41 @@ typedef int (*xfs_buf_bdstrat_t)(struct xfs_buf *);
#define XB_PAGES 2
typedef struct xfs_buf {
+ /*
+ * first cacheline holds all the fields needed for an uncontended cache
+ * hit to be fully processed. The semaphore straddles the cacheline
+ * boundary, but the counter and lock sits on the first cacheline,
+ * which is the only bit that is touched if we hit the semaphore
+ * fast-path on locking.
+ */
+ struct rb_node b_rbnode; /* rbtree node */
+ xfs_off_t b_file_offset; /* offset in file */
+ size_t b_buffer_length;/* size of buffer in bytes */
+ atomic_t b_hold; /* reference count */
+ xfs_buf_flags_t b_flags; /* status flags */
struct semaphore b_sema; /* semaphore for lockables */
- unsigned long b_queuetime; /* time buffer was queued */
- atomic_t b_pin_count; /* pin count */
+
wait_queue_head_t b_waiters; /* unpin waiters */
struct list_head b_list;
- xfs_buf_flags_t b_flags; /* status flags */
- struct rb_node b_rbnode; /* rbtree node */
struct xfs_perag *b_pag; /* contains rbtree root */
xfs_buftarg_t *b_target; /* buffer target (device) */
- atomic_t b_hold; /* reference count */
xfs_daddr_t b_bn; /* block number for I/O */
- xfs_off_t b_file_offset; /* offset in file */
- size_t b_buffer_length;/* size of buffer in bytes */
size_t b_count_desired;/* desired transfer size */
void *b_addr; /* virtual address of buffer */
struct work_struct b_iodone_work;
- atomic_t b_io_remaining; /* #outstanding I/O requests */
xfs_buf_iodone_t b_iodone; /* I/O completion function */
xfs_buf_relse_t b_relse; /* releasing function */
struct completion b_iowait; /* queue for I/O waiters */
void *b_fspriv;
void *b_fspriv2;
- unsigned short b_error; /* error code on I/O */
- unsigned int b_page_count; /* size of page array */
- unsigned int b_offset; /* page offset in first page */
struct page **b_pages; /* array of page pointers */
struct page *b_page_array[XB_PAGES]; /* inline pages */
+ unsigned long b_queuetime; /* time buffer was queued */
+ atomic_t b_pin_count; /* pin count */
+ atomic_t b_io_remaining; /* #outstanding I/O requests */
+ unsigned int b_page_count; /* size of page array */
+ unsigned int b_offset; /* page offset in first page */
+ unsigned short b_error; /* error code on I/O */
#ifdef XFS_BUF_LOCK_TRACKING
int b_last_holder;
#endif