diff options
Diffstat (limited to 'fs/xfs/xfs_buf_item.c')
| -rw-r--r-- | fs/xfs/xfs_buf_item.c | 345 |
1 files changed, 246 insertions, 99 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index d9e451115f9..a8d0ed91119 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -153,33 +153,25 @@ STATIC void xfs_buf_do_callbacks(struct xfs_buf *bp); * If the XFS_BLI_STALE flag has been set, then log nothing. */ STATIC uint -xfs_buf_item_size( - struct xfs_log_item *lip) +xfs_buf_item_size_segment( + struct xfs_buf_log_item *bip, + struct xfs_buf_log_format *blfp) { - struct xfs_buf_log_item *bip = BUF_ITEM(lip); struct xfs_buf *bp = bip->bli_buf; uint nvecs; int next_bit; int last_bit; - ASSERT(atomic_read(&bip->bli_refcount) > 0); - if (bip->bli_flags & XFS_BLI_STALE) { - /* - * The buffer is stale, so all we need to log - * is the buf log format structure with the - * cancel flag in it. - */ - trace_xfs_buf_item_size_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); - return 1; - } + last_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0); + if (last_bit == -1) + return 0; + + /* + * initial count for a dirty buffer is 2 vectors - the format structure + * and the first dirty region. + */ + nvecs = 2; - ASSERT(bip->bli_flags & XFS_BLI_LOGGED); - nvecs = 1; - last_bit = xfs_next_bit(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size, 0); - ASSERT(last_bit != -1); - nvecs++; while (last_bit != -1) { /* * This takes the bit number to start looking from and @@ -187,16 +179,15 @@ xfs_buf_item_size( * if there are no more bits set or the start bit is * beyond the end of the bitmap. */ - next_bit = xfs_next_bit(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size, - last_bit + 1); + next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, + last_bit + 1); /* * If we run out of bits, leave the loop, * else if we find a new set of bits bump the number of vecs, * else keep scanning the current set of bits. */ if (next_bit == -1) { - last_bit = -1; + break; } else if (next_bit != last_bit + 1) { last_bit = next_bit; nvecs++; @@ -210,22 +201,73 @@ xfs_buf_item_size( } } - trace_xfs_buf_item_size(bip); return nvecs; } /* - * This is called to fill in the vector of log iovecs for the - * given log buf item. It fills the first entry with a buf log - * format structure, and the rest point to contiguous chunks - * within the buffer. + * This returns the number of log iovecs needed to log the given buf log item. + * + * It calculates this as 1 iovec for the buf log format structure and 1 for each + * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged + * in a single iovec. + * + * Discontiguous buffers need a format structure per region that that is being + * logged. This makes the changes in the buffer appear to log recovery as though + * they came from separate buffers, just like would occur if multiple buffers + * were used instead of a single discontiguous buffer. This enables + * discontiguous buffers to be in-memory constructs, completely transparent to + * what ends up on disk. + * + * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log + * format structures. */ -STATIC void -xfs_buf_item_format( - struct xfs_log_item *lip, - struct xfs_log_iovec *vecp) +STATIC uint +xfs_buf_item_size( + struct xfs_log_item *lip) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); + uint nvecs; + int i; + + ASSERT(atomic_read(&bip->bli_refcount) > 0); + if (bip->bli_flags & XFS_BLI_STALE) { + /* + * The buffer is stale, so all we need to log + * is the buf log format structure with the + * cancel flag in it. + */ + trace_xfs_buf_item_size_stale(bip); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); + return bip->bli_format_count; + } + + ASSERT(bip->bli_flags & XFS_BLI_LOGGED); + + /* + * the vector count is based on the number of buffer vectors we have + * dirty bits in. This will only be greater than one when we have a + * compound buffer with more than one segment dirty. Hence for compound + * buffers we need to track which segment the dirty bits correspond to, + * and when we move from one segment to the next increment the vector + * count for the extra buf log format structure that will need to be + * written. + */ + nvecs = 0; + for (i = 0; i < bip->bli_format_count; i++) { + nvecs += xfs_buf_item_size_segment(bip, &bip->bli_formats[i]); + } + + trace_xfs_buf_item_size(bip); + return nvecs; +} + +static struct xfs_log_iovec * +xfs_buf_item_format_segment( + struct xfs_buf_log_item *bip, + struct xfs_log_iovec *vecp, + uint offset, + struct xfs_buf_log_format *blfp) +{ struct xfs_buf *bp = bip->bli_buf; uint base_size; uint nvecs; @@ -235,40 +277,22 @@ xfs_buf_item_format( uint nbits; uint buffer_offset; - ASSERT(atomic_read(&bip->bli_refcount) > 0); - ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || - (bip->bli_flags & XFS_BLI_STALE)); + /* copy the flags across from the base format item */ + blfp->blf_flags = bip->bli_format.blf_flags; /* - * The size of the base structure is the size of the - * declared structure plus the space for the extra words - * of the bitmap. We subtract one from the map size, because - * the first element of the bitmap is accounted for in the - * size of the base structure. + * Base size is the actual size of the ondisk structure - it reflects + * the actual size of the dirty bitmap rather than the size of the in + * memory structure. */ - base_size = - (uint)(sizeof(xfs_buf_log_format_t) + - ((bip->bli_format.blf_map_size - 1) * sizeof(uint))); - vecp->i_addr = &bip->bli_format; + base_size = offsetof(struct xfs_buf_log_format, blf_data_map) + + (blfp->blf_map_size * sizeof(blfp->blf_data_map[0])); + vecp->i_addr = blfp; vecp->i_len = base_size; vecp->i_type = XLOG_REG_TYPE_BFORMAT; vecp++; nvecs = 1; - /* - * If it is an inode buffer, transfer the in-memory state to the - * format flags and clear the in-memory state. We do not transfer - * this state if the inode buffer allocation has not yet been committed - * to the log as setting the XFS_BLI_INODE_BUF flag will prevent - * correct replay of the inode allocation. - */ - if (bip->bli_flags & XFS_BLI_INODE_BUF) { - if (!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && - xfs_log_item_in_current_chkpt(lip))) - bip->bli_format.blf_flags |= XFS_BLF_INODE_BUF; - bip->bli_flags &= ~XFS_BLI_INODE_BUF; - } - if (bip->bli_flags & XFS_BLI_STALE) { /* * The buffer is stale, so all we need to log @@ -276,16 +300,15 @@ xfs_buf_item_format( * cancel flag in it. */ trace_xfs_buf_item_format_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); - bip->bli_format.blf_size = nvecs; - return; + ASSERT(blfp->blf_flags & XFS_BLF_CANCEL); + blfp->blf_size = nvecs; + return vecp; } /* * Fill in an iovec for each set of contiguous chunks. */ - first_bit = xfs_next_bit(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size, 0); + first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0); ASSERT(first_bit != -1); last_bit = first_bit; nbits = 1; @@ -296,9 +319,8 @@ xfs_buf_item_format( * if there are no more bits set or the start bit is * beyond the end of the bitmap. */ - next_bit = xfs_next_bit(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size, - (uint)last_bit + 1); + next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, + (uint)last_bit + 1); /* * If we run out of bits fill in the last iovec and get * out of the loop. @@ -309,14 +331,14 @@ xfs_buf_item_format( * keep counting and scanning. */ if (next_bit == -1) { - buffer_offset = first_bit * XFS_BLF_CHUNK; + buffer_offset = offset + first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; nvecs++; break; } else if (next_bit != last_bit + 1) { - buffer_offset = first_bit * XFS_BLF_CHUNK; + buffer_offset = offset + first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; @@ -325,14 +347,17 @@ xfs_buf_item_format( first_bit = next_bit; last_bit = next_bit; nbits = 1; - } else if (xfs_buf_offset(bp, next_bit << XFS_BLF_SHIFT) != - (xfs_buf_offset(bp, last_bit << XFS_BLF_SHIFT) + + } else if (xfs_buf_offset(bp, offset + + (next_bit << XFS_BLF_SHIFT)) != + (xfs_buf_offset(bp, offset + + (last_bit << XFS_BLF_SHIFT)) + XFS_BLF_CHUNK)) { - buffer_offset = first_bit * XFS_BLF_CHUNK; + buffer_offset = offset + first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; -/* You would think we need to bump the nvecs here too, but we do not +/* + * You would think we need to bump the nvecs here too, but we do not * this number is used by recovery, and it gets confused by the boundary * split here * nvecs++; @@ -347,6 +372,48 @@ xfs_buf_item_format( } } bip->bli_format.blf_size = nvecs; + return vecp; +} + +/* + * This is called to fill in the vector of log iovecs for the + * given log buf item. It fills the first entry with a buf log + * format structure, and the rest point to contiguous chunks + * within the buffer. + */ +STATIC void +xfs_buf_item_format( + struct xfs_log_item *lip, + struct xfs_log_iovec *vecp) +{ + struct xfs_buf_log_item *bip = BUF_ITEM(lip); + struct xfs_buf *bp = bip->bli_buf; + uint offset = 0; + int i; + + ASSERT(atomic_read(&bip->bli_refcount) > 0); + ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || + (bip->bli_flags & XFS_BLI_STALE)); + + /* + * If it is an inode buffer, transfer the in-memory state to the + * format flags and clear the in-memory state. We do not transfer + * this state if the inode buffer allocation has not yet been committed + * to the log as setting the XFS_BLI_INODE_BUF flag will prevent + * correct replay of the inode allocation. + */ + if (bip->bli_flags & XFS_BLI_INODE_BUF) { + if (!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && + xfs_log_item_in_current_chkpt(lip))) + bip->bli_format.blf_flags |= XFS_BLF_INODE_BUF; + bip->bli_flags &= ~XFS_BLI_INODE_BUF; + } + + for (i = 0; i < bip->bli_format_count; i++) { + vecp = xfs_buf_item_format_segment(bip, vecp, offset, + &bip->bli_formats[i]); + offset += bp->b_maps[i].bm_len; + } /* * Check to make sure everything is consistent. @@ -622,6 +689,35 @@ static const struct xfs_item_ops xfs_buf_item_ops = { .iop_committing = xfs_buf_item_committing }; +STATIC int +xfs_buf_item_get_format( + struct xfs_buf_log_item *bip, + int count) +{ + ASSERT(bip->bli_formats == NULL); + bip->bli_format_count = count; + + if (count == 1) { + bip->bli_formats = &bip->bli_format; + return 0; + } + + bip->bli_formats = kmem_zalloc(count * sizeof(struct xfs_buf_log_format), + KM_SLEEP); + if (!bip->bli_formats) + return ENOMEM; + return 0; +} + +STATIC void +xfs_buf_item_free_format( + struct xfs_buf_log_item *bip) +{ + if (bip->bli_formats != &bip->bli_format) { + kmem_free(bip->bli_formats); + bip->bli_formats = NULL; + } +} /* * Allocate a new buf log item to go with the given buffer. @@ -639,6 +735,8 @@ xfs_buf_item_init( xfs_buf_log_item_t *bip; int chunks; int map_size; + int error; + int i; /* * Check to see if there is already a buf log item for @@ -650,25 +748,33 @@ xfs_buf_item_init( if (lip != NULL && lip->li_type == XFS_LI_BUF) return; - /* - * chunks is the number of XFS_BLF_CHUNK size pieces - * the buffer can be divided into. Make sure not to - * truncate any pieces. map_size is the size of the - * bitmap needed to describe the chunks of the buffer. - */ - chunks = (int)((BBTOB(bp->b_length) + (XFS_BLF_CHUNK - 1)) >> - XFS_BLF_SHIFT); - map_size = (int)((chunks + NBWORD) >> BIT_TO_WORD_SHIFT); - - bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone, - KM_SLEEP); + bip = kmem_zone_zalloc(xfs_buf_item_zone, KM_SLEEP); xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops); bip->bli_buf = bp; xfs_buf_hold(bp); - bip->bli_format.blf_type = XFS_LI_BUF; - bip->bli_format.blf_blkno = (__int64_t)XFS_BUF_ADDR(bp); - bip->bli_format.blf_len = (ushort)bp->b_length; - bip->bli_format.blf_map_size = map_size; + + /* + * chunks is the number of XFS_BLF_CHUNK size pieces the buffer + * can be divided into. Make sure not to truncate any pieces. + * map_size is the size of the bitmap needed to describe the + * chunks of the buffer. + * + * Discontiguous buffer support follows the layout of the underlying + * buffer. This makes the implementation as simple as possible. + */ + error = xfs_buf_item_get_format(bip, bp->b_map_count); + ASSERT(error == 0); + + for (i = 0; i < bip->bli_format_count; i++) { + chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len), + XFS_BLF_CHUNK); + map_size = DIV_ROUND_UP(chunks, NBWORD); + + bip->bli_formats[i].blf_type = XFS_LI_BUF; + bip->bli_formats[i].blf_blkno = bp->b_maps[i].bm_bn; + bip->bli_formats[i].blf_len = bp->b_maps[i].bm_len; + bip->bli_formats[i].blf_map_size = map_size; + } #ifdef XFS_TRANS_DEBUG /* @@ -699,10 +805,11 @@ xfs_buf_item_init( * item's bitmap. */ void -xfs_buf_item_log( - xfs_buf_log_item_t *bip, +xfs_buf_item_log_segment( + struct xfs_buf_log_item *bip, uint first, - uint last) + uint last, + uint *map) { uint first_bit; uint last_bit; @@ -715,12 +822,6 @@ xfs_buf_item_log( uint mask; /* - * Mark the item as having some dirty data for - * quick reference in xfs_buf_item_dirty. - */ - bip->bli_flags |= XFS_BLI_DIRTY; - - /* * Convert byte offsets to bit numbers. */ first_bit = first >> XFS_BLF_SHIFT; @@ -736,7 +837,7 @@ xfs_buf_item_log( * to set a bit in. */ word_num = first_bit >> BIT_TO_WORD_SHIFT; - wordp = &(bip->bli_format.blf_data_map[word_num]); + wordp = &map[word_num]; /* * Calculate the starting bit in the first word. @@ -783,6 +884,51 @@ xfs_buf_item_log( xfs_buf_item_log_debug(bip, first, last); } +/* + * Mark bytes first through last inclusive as dirty in the buf + * item's bitmap. + */ +void +xfs_buf_item_log( + xfs_buf_log_item_t *bip, + uint first, + uint last) +{ + int i; + uint start; + uint end; + struct xfs_buf *bp = bip->bli_buf; + + /* + * Mark the item as having some dirty data for + * quick reference in xfs_buf_item_dirty. + */ + bip->bli_flags |= XFS_BLI_DIRTY; + + /* + * walk each buffer segment and mark them dirty appropriately. + */ + start = 0; + for (i = 0; i < bip->bli_format_count; i++) { + if (start > last) + break; + end = start + BBTOB(bp->b_maps[i].bm_len); + if (first > end) { + start += BBTOB(bp->b_maps[i].bm_len); + continue; + } + if (first < start) + first = start; + if (end > last) + end = last; + + xfs_buf_item_log_segment(bip, first, end, + &bip->bli_formats[i].blf_data_map[0]); + + start += bp->b_maps[i].bm_len; + } +} + /* * Return 1 if the buffer has some data that has been logged (at any @@ -804,6 +950,7 @@ xfs_buf_item_free( kmem_free(bip->bli_logged); #endif /* XFS_TRANS_DEBUG */ + xfs_buf_item_free_format(bip); kmem_zone_free(xfs_buf_item_zone, bip); } |