X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fxfs%2Flinux-2.6%2Fxfs_buf.h;h=9e8ef8fef39fff7f5c58d00209b42bdd0d60569e;hb=6ab455eeaff6893cd06da33843e840d888cdc04a;hp=7858703ed84cf42130de0bf5444eac74111c4c82;hpb=02b311bce9fc87987a123adc3e6a2d0a2caa70e2;p=linux-2.6-omap-h63xx.git

diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 7858703ed84..f948ec7ba9a 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -63,14 +63,33 @@ typedef enum {
 
 	/* flags used only internally */
 	_XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache		   */
-	_XBF_KMEM_ALLOC = (1 << 18),/* backed by kmem_alloc()		   */
+	_XBF_PAGES = (1 << 18),	    /* backed by refcounted pages	   */
 	_XBF_RUN_QUEUES = (1 << 19),/* run block device task queue	   */
 	_XBF_DELWRI_Q = (1 << 21),   /* buffer on delwri queue		   */
+
+	/*
+	 * Special flag for supporting metadata blocks smaller than a FSB.
+	 *
+	 * In this case we can have multiple xfs_buf_t on a single page and
+	 * need to lock out concurrent xfs_buf_t readers as they only
+	 * serialise access to the buffer.
+	 *
+	 * If the FSB size >= PAGE_CACHE_SIZE case, we have no serialisation
+	 * between reads of the page. Hence we can have one thread read the
+	 * page and modify it, but then race with another thread that thinks
+	 * the page is not up-to-date and hence reads it again.
+	 *
+	 * The result is that the first modifcation to the page is lost.
+	 * This sort of AGF/AGI reading race can happen when unlinking inodes
+	 * that require truncation and results in the AGI unlinked list
+	 * modifications being lost.
+	 */
+	_XBF_PAGE_LOCKED = (1 << 22),
 } xfs_buf_flags_t;
 
 typedef enum {
-	XBT_FORCE_SLEEP = (0 << 1),
-	XBT_FORCE_FLUSH = (1 << 1),
+	XBT_FORCE_SLEEP = 0,
+	XBT_FORCE_FLUSH = 1,
 } xfs_buftarg_flags_t;
 
 typedef struct xfs_bufhash {
@@ -143,7 +162,6 @@ typedef struct xfs_buf {
 	void			*b_fspriv2;
 	void			*b_fspriv3;
 	unsigned short		b_error;	/* error code on I/O */
-	unsigned short		b_locked;	/* page array is locked */
 	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 */
@@ -298,11 +316,6 @@ extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *);
 #define XFS_BUF_UNWRITE(bp)	((bp)->b_flags &= ~XBF_WRITE)
 #define XFS_BUF_ISWRITE(bp)	((bp)->b_flags & XBF_WRITE)
 
-#define XFS_BUF_ISUNINITIAL(bp)	(0)
-#define XFS_BUF_UNUNINITIAL(bp)	(0)
-
-#define XFS_BUF_BP_ISMAPPED(bp)	(1)
-
 #define XFS_BUF_IODONE_FUNC(bp)			((bp)->b_iodone)
 #define XFS_BUF_SET_IODONE_FUNC(bp, func)	((bp)->b_iodone = (func))
 #define XFS_BUF_CLR_IODONE_FUNC(bp)		((bp)->b_iodone = NULL)
@@ -393,13 +406,15 @@ static inline int XFS_bwrite(xfs_buf_t *bp)
 	return error;
 }
 
-#define XFS_bdwrite(bp)		xfs_buf_iostart(bp, XBF_DELWRI | XBF_ASYNC)
-
-static inline int xfs_bdwrite(void *mp, xfs_buf_t *bp)
+/*
+ * No error can be returned from xfs_buf_iostart for delwri
+ * buffers as they are queued and no I/O is issued.
+ */
+static inline void xfs_bdwrite(void *mp, xfs_buf_t *bp)
 {
 	bp->b_strat = xfs_bdstrat_cb;
 	bp->b_fspriv3 = mp;
-	return xfs_buf_iostart(bp, XBF_DELWRI | XBF_ASYNC);
+	(void)xfs_buf_iostart(bp, XBF_DELWRI | XBF_ASYNC);
 }
 
 #define XFS_bdstrat(bp) xfs_buf_iorequest(bp)
@@ -418,6 +433,9 @@ extern void xfs_free_buftarg(xfs_buftarg_t *, int);
 extern void xfs_wait_buftarg(xfs_buftarg_t *);
 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
+#ifdef CONFIG_KDB_MODULES
+extern struct list_head *xfs_get_buftarg_list(void);
+#endif
 
 #define xfs_getsize_buftarg(buftarg)	block_size((buftarg)->bt_bdev)
 #define xfs_readonly_buftarg(buftarg)	bdev_read_only((buftarg)->bt_bdev)