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Diffstat (limited to 'fs/xfs/xfs_buf.h')
-rw-r--r--fs/xfs/xfs_buf.h168
1 files changed, 133 insertions, 35 deletions
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 79344c48008..433a12ed7b1 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -38,26 +38,28 @@ typedef enum {
XBRW_ZERO = 3, /* Zero target memory */
} xfs_buf_rw_t;
-#define XBF_READ (1 << 0) /* buffer intended for reading from device */
-#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
-#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
-#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
-#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
-#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
+#define XBF_READ (1 << 0) /* buffer intended for reading from device */
+#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
+#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
+#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
+#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
+#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
/* I/O hints for the BIO layer */
-#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
-#define XBF_FUA (1 << 11)/* force cache write through mode */
-#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
+#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
+#define XBF_FUA (1 << 11)/* force cache write through mode */
+#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
/* flags used only as arguments to access routines */
-#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
-#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
+#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
+#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
/* flags used only internally */
-#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
-#define _XBF_KMEM (1 << 21)/* backed by heap memory */
-#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
+#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
+#define _XBF_KMEM (1 << 21)/* backed by heap memory */
+#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
+#define _XBF_COMPOUND (1 << 23)/* compound buffer */
+#define _XBF_LRU_DISPOSE (1 << 24)/* buffer being discarded */
typedef unsigned int xfs_buf_flags_t;
@@ -71,11 +73,13 @@ typedef unsigned int xfs_buf_flags_t;
{ XBF_SYNCIO, "SYNCIO" }, \
{ XBF_FUA, "FUA" }, \
{ XBF_FLUSH, "FLUSH" }, \
- { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
+ { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
{ XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_KMEM, "KMEM" }, \
- { _XBF_DELWRI_Q, "DELWRI_Q" }
+ { _XBF_DELWRI_Q, "DELWRI_Q" }, \
+ { _XBF_COMPOUND, "COMPOUND" }, \
+ { _XBF_LRU_DISPOSE, "LRU_DISPOSE" }
typedef struct xfs_buftarg {
dev_t bt_dev;
@@ -96,8 +100,22 @@ typedef struct xfs_buftarg {
struct xfs_buf;
typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
+
#define XB_PAGES 2
+struct xfs_buf_map {
+ xfs_daddr_t bm_bn; /* block number for I/O */
+ int bm_len; /* size of I/O */
+};
+
+#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
+ struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
+
+struct xfs_buf_ops {
+ void (*verify_read)(struct xfs_buf *);
+ void (*verify_write)(struct xfs_buf *);
+};
+
typedef struct xfs_buf {
/*
* first cacheline holds all the fields needed for an uncontended cache
@@ -107,14 +125,19 @@ typedef struct xfs_buf {
* fast-path on locking.
*/
struct rb_node b_rbnode; /* rbtree node */
- xfs_daddr_t b_bn; /* block number for I/O */
+ xfs_daddr_t b_bn; /* block number of buffer */
int b_length; /* size of buffer in BBs */
atomic_t b_hold; /* reference count */
atomic_t b_lru_ref; /* lru reclaim ref count */
xfs_buf_flags_t b_flags; /* status flags */
struct semaphore b_sema; /* semaphore for lockables */
+ /*
+ * concurrent access to b_lru and b_lru_flags are protected by
+ * bt_lru_lock and not by b_sema
+ */
struct list_head b_lru; /* lru list */
+ xfs_buf_flags_t b_lru_flags; /* internal lru status flags */
wait_queue_head_t b_waiters; /* unpin waiters */
struct list_head b_list;
struct xfs_perag *b_pag; /* contains rbtree root */
@@ -127,42 +150,107 @@ typedef struct xfs_buf {
struct xfs_trans *b_transp;
struct page **b_pages; /* array of page pointers */
struct page *b_page_array[XB_PAGES]; /* inline pages */
+ struct xfs_buf_map *b_maps; /* compound buffer map */
+ struct xfs_buf_map __b_map; /* inline compound buffer map */
+ int b_map_count;
int b_io_length; /* IO size in BBs */
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 */
+ const struct xfs_buf_ops *b_ops;
+
#ifdef XFS_BUF_LOCK_TRACKING
int b_last_holder;
#endif
} xfs_buf_t;
-
/* Finding and Reading Buffers */
-struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target, xfs_daddr_t blkno,
- size_t numblks, xfs_buf_flags_t flags,
- struct xfs_buf *new_bp);
-#define xfs_incore(buftarg,blkno,len,lockit) \
- _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
-
-struct xfs_buf *xfs_buf_get(struct xfs_buftarg *target, xfs_daddr_t blkno,
- size_t numblks, xfs_buf_flags_t flags);
-struct xfs_buf *xfs_buf_read(struct xfs_buftarg *target, xfs_daddr_t blkno,
- size_t numblks, xfs_buf_flags_t flags);
-void xfs_buf_readahead(struct xfs_buftarg *target, xfs_daddr_t blkno,
- size_t numblks);
+struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags, struct xfs_buf *new_bp);
+
+static inline struct xfs_buf *
+xfs_incore(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return _xfs_buf_find(target, &map, 1, flags, NULL);
+}
+
+struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags);
+
+static inline struct xfs_buf *
+xfs_buf_alloc(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return _xfs_buf_alloc(target, &map, 1, flags);
+}
+
+struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags);
+struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags,
+ const struct xfs_buf_ops *ops);
+void xfs_buf_readahead_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ const struct xfs_buf_ops *ops);
+
+static inline struct xfs_buf *
+xfs_buf_get(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_get_map(target, &map, 1, flags);
+}
+
+static inline struct xfs_buf *
+xfs_buf_read(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags,
+ const struct xfs_buf_ops *ops)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_read_map(target, &map, 1, flags, ops);
+}
+
+static inline void
+xfs_buf_readahead(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ const struct xfs_buf_ops *ops)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_readahead_map(target, &map, 1, ops);
+}
struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
-struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *target, xfs_daddr_t blkno,
- size_t numblks, xfs_buf_flags_t flags);
void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks);
int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
int flags);
struct xfs_buf *xfs_buf_read_uncached(struct xfs_buftarg *target,
- xfs_daddr_t daddr, size_t numblks, int flags);
+ xfs_daddr_t daddr, size_t numblks, int flags,
+ const struct xfs_buf_ops *ops);
void xfs_buf_hold(struct xfs_buf *bp);
/* Releasing Buffers */
@@ -232,8 +320,18 @@ void xfs_buf_stale(struct xfs_buf *bp);
#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
-#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
-#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
+/*
+ * These macros use the IO block map rather than b_bn. b_bn is now really
+ * just for the buffer cache index for cached buffers. As IO does not use b_bn
+ * anymore, uncached buffers do not use b_bn at all and hence must modify the IO
+ * map directly. Uncached buffers are not allowed to be discontiguous, so this
+ * is safe to do.
+ *
+ * In future, uncached buffers will pass the block number directly to the io
+ * request function and hence these macros will go away at that point.
+ */
+#define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn)
+#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
{