From de1cbee46269a3b707eb99b37f33afdd4cfaaea4 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Apr 2012 15:58:50 +1000 Subject: [PATCH] xfs: kill b_file_offset Seeing as we pass block numbers around everywhere in the buffer cache now, it makes no sense to index everything by byte offset. Replace all the byte offset indexing with block number based indexing, and replace all uses of the byte offset with direct conversion from the block index. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- fs/xfs/xfs_buf.c | 17 +++++++---------- fs/xfs/xfs_buf.h | 5 +---- 2 files changed, 8 insertions(+), 14 deletions(-) diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index d3a1974c91d5..854b27a8e776 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -196,7 +196,7 @@ xfs_buf_alloc( sema_init(&bp->b_sema, 0); /* held, no waiters */ XB_SET_OWNER(bp); bp->b_target = target; - bp->b_file_offset = blkno << BBSHIFT; + /* * Set buffer_length and count_desired to the same value initially. * I/O routines should use count_desired, which will be the same in @@ -337,8 +337,8 @@ xfs_buf_allocate_memory( } use_alloc_page: - end = bp->b_file_offset + bp->b_buffer_length; - page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); + end = BBTOB(bp->b_bn) + bp->b_buffer_length; + page_count = xfs_buf_btoc(end) - xfs_buf_btoct(BBTOB(bp->b_bn)); error = _xfs_buf_get_pages(bp, page_count, flags); if (unlikely(error)) return error; @@ -439,19 +439,17 @@ _xfs_buf_find( xfs_buf_flags_t flags, xfs_buf_t *new_bp) { - xfs_off_t offset; size_t numbytes; struct xfs_perag *pag; struct rb_node **rbp; struct rb_node *parent; xfs_buf_t *bp; - offset = BBTOB(blkno); numbytes = BBTOB(numblks); /* Check for IOs smaller than the sector size / not sector aligned */ ASSERT(!(numbytes < (1 << btp->bt_sshift))); - ASSERT(!(offset & (xfs_off_t)btp->bt_smask)); + ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask)); /* get tree root */ pag = xfs_perag_get(btp->bt_mount, @@ -466,13 +464,13 @@ _xfs_buf_find( parent = *rbp; bp = rb_entry(parent, struct xfs_buf, b_rbnode); - if (offset < bp->b_file_offset) + if (blkno < bp->b_bn) rbp = &(*rbp)->rb_left; - else if (offset > bp->b_file_offset) + else if (blkno > bp->b_bn) rbp = &(*rbp)->rb_right; else { /* - * found a block offset match. If the range doesn't + * found a block number match. If the range doesn't * match, the only way this is allowed is if the buffer * in the cache is stale and the transaction that made * it stale has not yet committed. i.e. we are @@ -718,7 +716,6 @@ xfs_buf_set_empty( bp->b_pages = NULL; bp->b_page_count = 0; bp->b_addr = NULL; - bp->b_file_offset = 0; bp->b_buffer_length = bp->b_count_desired = numblks << BBSHIFT; bp->b_bn = XFS_BUF_DADDR_NULL; bp->b_flags &= ~XBF_MAPPED; diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index ffd6da045d22..4d472e5ded7a 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -116,7 +116,7 @@ typedef struct xfs_buf { * fast-path on locking. */ struct rb_node b_rbnode; /* rbtree node */ - xfs_off_t b_file_offset; /* offset in file */ + xfs_daddr_t b_bn; /* block number for I/O */ size_t b_buffer_length;/* size of buffer in bytes */ atomic_t b_hold; /* reference count */ atomic_t b_lru_ref; /* lru reclaim ref count */ @@ -128,7 +128,6 @@ typedef struct xfs_buf { struct list_head b_list; struct xfs_perag *b_pag; /* contains rbtree root */ xfs_buftarg_t *b_target; /* buffer target (device) */ - xfs_daddr_t b_bn; /* block number for I/O */ size_t b_count_desired;/* desired transfer size */ void *b_addr; /* virtual address of buffer */ struct work_struct b_iodone_work; @@ -245,8 +244,6 @@ void xfs_buf_stale(struct xfs_buf *bp); #define XFS_BUF_ADDR(bp) ((bp)->b_bn) #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno)) -#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset) -#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off)) #define XFS_BUF_COUNT(bp) ((bp)->b_count_desired) #define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt)) #define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length) -- 2.30.2