[PATCH 7/9] xfs: use discontiguous xfs_buf support in dabuf wrappers

Dave Chinner
2012-06-22T08:50:34Z

First step in converting the directory code to use native
discontiguous buffers and replacing the dabuf construct.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_da_btree.c | 538 ++++++++++++++++++++++---------------------------
fs/xfs/xfs_da_btree.h | 6 +-
2 files changed, 239 insertions(+), 305 deletions(-)

diff --git a/fs/xfs/xfs_da_btree.c b/fs/xfs/xfs_da_btree.c
index 015b946..76e5dba 100644
--- a/fs/xfs/xfs_da_btree.c
+++ b/fs/xfs/xfs_da_btree.c
@@ -85,7 +85,7 @@ STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
*/
STATIC uint xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
STATIC int xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
-STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps);
+STATIC xfs_dabuf_t *xfs_da_buf_make(xfs_buf_t *bp);
STATIC int xfs_da_blk_unlink(xfs_da_state_t *state,
xfs_da_state_blk_t *drop_blk,
xfs_da_state_blk_t *save_blk);
@@ -1967,35 +1967,75 @@ xfs_da_map_covers_blocks(
}

/*
- * Make a dabuf.
- * Used for get_buf, read_buf, read_bufr, and reada_buf.
+ * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
+ *
+ * For the single map case, it is assumed that the caller has provided a pointer
+ * to a valid xfs_buf_map. For the multiple map case, this function will
+ * allocate the xfs_buf_map to hold all the maps and replace the caller's single
+ * map pointer with the allocated map.
*/
-STATIC int
-xfs_da_do_buf(
- xfs_trans_t *trans,
- xfs_inode_t *dp,
- xfs_dablk_t bno,
- xfs_daddr_t *mappedbnop,
- xfs_dabuf_t **bpp,
- int whichfork,
- int caller)
+static int
+xfs_buf_map_from_irec(
+ struct xfs_mount *mp,
+ struct xfs_buf_map **mapp,
+ unsigned int *nmaps,
+ struct xfs_bmbt_irec *irecs,
+ unsigned int nirecs)
{
- xfs_buf_t *bp = NULL;
- xfs_buf_t **bplist;
- int error=0;
- int i;
- xfs_bmbt_irec_t map;
- xfs_bmbt_irec_t *mapp;
- xfs_daddr_t mappedbno;
- xfs_mount_t *mp;
- int nbplist=0;
- int nfsb;
- int nmap;
- xfs_dabuf_t *rbp;
+ struct xfs_buf_map *map;
+ int i;
+
+ ASSERT(*nmaps == 1);
+ ASSERT(nirecs >= 1);
+
+ if (nirecs > 1) {
+ map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_SLEEP);
+ if (!map)
+ return ENOMEM;
+ *mapp = map;
+ }
+
+ *nmaps = nirecs;
+ map = *mapp;
+ for (i = 0; i < *nmaps; i++) {
+ ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
+ irecs[i].br_startblock != HOLESTARTBLOCK);
+ map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
+ map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
+ }
+ return 0;
+}
+
+/*
+ * Map the block we are given ready for reading. There are three possible return
+ * values:
+ * -1 - will be returned if we land in a hole and mappedbno == -2 so the
+ * caller knows not to execute a subsequent read.
+ * 0 - if we mapped the block successfully
+ * >0 - positive error number if there was an error.
+ */
+static int
+xfs_dabuf_map(
+ struct xfs_trans *trans,
+ struct xfs_inode *dp,
+ xfs_dablk_t bno,
+ xfs_daddr_t mappedbno,
+ int whichfork,
+ struct xfs_buf_map **map,
+ int *nmaps)
+{
+ struct xfs_mount *mp = dp->i_mount;
+ int nfsb;
+ int error = 0;
+ struct xfs_bmbt_irec irec;
+ struct xfs_bmbt_irec *irecs = &irec;
+ int nirecs;
+
+ ASSERT(map && *map);
+ ASSERT(*nmaps == 1);

- mp = dp->i_mount;
nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
- mappedbno = *mappedbnop;
+
/*
* Caller doesn't have a mapping. -2 means don't complain
* if we land in a hole.
@@ -2004,112 +2044,152 @@ xfs_da_do_buf(
/*
* Optimize the one-block case.
*/
- if (nfsb == 1)
- mapp = &map;
- else
- mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
+ if (nfsb != 1)
+ irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP);

- nmap = nfsb;
- error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, mapp,
- &nmap, xfs_bmapi_aflag(whichfork));
+ nirecs = nfsb;
+ error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
+ &nirecs, xfs_bmapi_aflag(whichfork));
if (error)
- goto exit0;
+ goto out;
} else {
- map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
- map.br_startoff = (xfs_fileoff_t)bno;
- map.br_blockcount = nfsb;
- mapp = &map;
- nmap = 1;
+ irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
+ irecs->br_startoff = (xfs_fileoff_t)bno;
+ irecs->br_blockcount = nfsb;
+ irecs->br_state = 0;
+ nirecs = 1;
}
- if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
- error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
+
+ if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
+ error = mappedbno == -2 ? -1 : XFS_ERROR(EFSCORRUPTED);
if (unlikely(error == EFSCORRUPTED)) {
if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
+ int i;
xfs_alert(mp, "%s: bno %lld dir: inode %lld",
__func__, (long long)bno,
(long long)dp->i_ino);
- for (i = 0; i < nmap; i++) {
+ for (i = 0; i < *nmaps; i++) {
xfs_alert(mp,
"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
i,
- (long long)mapp[i].br_startoff,
- (long long)mapp[i].br_startblock,
- (long long)mapp[i].br_blockcount,
- mapp[i].br_state);
+ (long long)irecs[i].br_startoff,
+ (long long)irecs[i].br_startblock,
+ (long long)irecs[i].br_blockcount,
+ irecs[i].br_state);
}
}
XFS_ERROR_REPORT("xfs_da_do_buf(1)",
XFS_ERRLEVEL_LOW, mp);
}
- goto exit0;
+ goto out;
}
- if (caller != 3 && nmap > 1) {
- bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
- nbplist = 0;
- } else
- bplist = NULL;
- /*
- * Turn the mapping(s) into buffer(s).
- */
- for (i = 0; i < nmap; i++) {
- int nmapped;
-
- mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
- if (i == 0)
- *mappedbnop = mappedbno;
- nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
- switch (caller) {
- case 0:
- bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
- mappedbno, nmapped, 0);
- error = bp ? bp->b_error : XFS_ERROR(EIO);
- break;
- case 1:
- case 2:
- bp = NULL;
- error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
- mappedbno, nmapped, 0, &bp);
- break;
- case 3:
- xfs_buf_readahead(mp->m_ddev_targp, mappedbno, nmapped);
+ error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
+out:
+ if (irecs != &irec)
+ kmem_free(irecs);
+ return error;
+}
+
+/*
+ * Get a buffer for the dir/attr block.
+ */
+int
+xfs_da_get_buf(
+ struct xfs_trans *trans,
+ struct xfs_inode *dp,
+ xfs_dablk_t bno,
+ xfs_daddr_t mappedbno,
+ xfs_dabuf_t **bpp,
+ int whichfork)
+{
+ struct xfs_buf *bp;
+ struct xfs_buf_map map;
+ struct xfs_buf_map *mapp;
+ int nmap;
+ int error;
+
+ *bpp = NULL;
+ mapp = &map;
+ nmap = 1;
+ error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
+ &mapp, &nmap);
+ if (error) {
+ /* mapping a hole is not an error, but we don't continue */
+ if (error == -1)
error = 0;
- bp = NULL;
- break;
- }
- if (error) {
- if (bp)
- xfs_trans_brelse(trans, bp);
- goto exit1;
- }
- if (!bp)
- continue;
- if (caller == 1) {
- if (whichfork == XFS_ATTR_FORK)
- xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
- else
- xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
- }
- if (bplist) {
- bplist[nbplist++] = bp;
- }
+ goto out_free;
}
- /*
- * Build a dabuf structure.
- */
- if (bplist) {
- rbp = xfs_da_buf_make(nbplist, bplist);
- } else if (bp)
- rbp = xfs_da_buf_make(1, &bp);
+
+ bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
+ mapp, nmap, 0);
+ error = bp ? bp->b_error : XFS_ERROR(EIO);
+ if (error) {
+ xfs_trans_brelse(trans, bp);
+ goto out_free;
+ }
+
+ *bpp = xfs_da_buf_make(bp);
+
+out_free:
+ if (mapp != &map)
+ kmem_free(mapp);
+
+ return error;
+}
+
+/*
+ * Get a buffer for the dir/attr block, fill in the contents.
+ */
+int
+xfs_da_read_buf(
+ struct xfs_trans *trans,
+ struct xfs_inode *dp,
+ xfs_dablk_t bno,
+ xfs_daddr_t mappedbno,
+ xfs_dabuf_t **bpp,
+ int whichfork)
+{
+ struct xfs_buf *bp;
+ struct xfs_buf_map map;
+ struct xfs_buf_map *mapp;
+ int nmap;
+ int error;
+
+ *bpp = NULL;
+ mapp = &map;
+ nmap = 1;
+ error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
+ &mapp, &nmap);
+ if (error) {
+ /* mapping a hole is not an error, but we don't continue */
+ if (error == -1)
+ error = 0;
+ goto out_free;
+ }
+
+ error = xfs_trans_read_buf_map(dp->i_mount, trans,
+ dp->i_mount->m_ddev_targp,
+ mapp, nmap, 0, &bp);
+ if (error)
+ goto out_free;
+
+ if (whichfork == XFS_ATTR_FORK)
+ xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
else
- rbp = NULL;
+ xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
+
+ *bpp = xfs_da_buf_make(bp);
+
/*
- * For read_buf, check the magic number.
+ * This verification code will be moved to a CRC verification callback
+ * function so just leave it here unchanged until then.
*/
- if (caller == 1) {
- xfs_dir2_data_hdr_t *hdr = rbp->data;
- xfs_dir2_free_t *free = rbp->data;
- xfs_da_blkinfo_t *info = rbp->data;
+ {
+ xfs_dir2_data_hdr_t *hdr = (*bpp)->data;
+ xfs_dir2_free_t *free = (*bpp)->data;
+ xfs_da_blkinfo_t *info = (*bpp)->data;
uint magic, magic1;
+ struct xfs_mount *mp = dp->i_mount;

magic = be16_to_cpu(info->magic);
magic1 = be32_to_cpu(hdr->magic);
@@ -2123,66 +2203,20 @@ xfs_da_do_buf(
(free->hdr.magic != cpu_to_be32(XFS_DIR2_FREE_MAGIC)),
mp, XFS_ERRTAG_DA_READ_BUF,
XFS_RANDOM_DA_READ_BUF))) {
- trace_xfs_da_btree_corrupt(rbp->bps[0], _RET_IP_);
+ trace_xfs_da_btree_corrupt(bp, _RET_IP_);
XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
XFS_ERRLEVEL_LOW, mp, info);
error = XFS_ERROR(EFSCORRUPTED);
- xfs_da_brelse(trans, rbp);
- nbplist = 0;
- goto exit1;
+ xfs_da_brelse(trans, *bpp);
+ goto out_free;
}
}
- if (bplist) {
- kmem_free(bplist);
- }
- if (mapp != &map) {
- kmem_free(mapp);
- }
- if (bpp)
- *bpp = rbp;
- return 0;
-exit1:
- if (bplist) {
- for (i = 0; i < nbplist; i++)
- xfs_trans_brelse(trans, bplist[i]);
- kmem_free(bplist);
- }
-exit0:
+
+out_free:
if (mapp != &map)
kmem_free(mapp);
- if (bpp)
- *bpp = NULL;
- return error;
-}
-
-/*
- * Get a buffer for the dir/attr block.
- */
-int
-xfs_da_get_buf(
- xfs_trans_t *trans,
- xfs_inode_t *dp,
- xfs_dablk_t bno,
- xfs_daddr_t mappedbno,
- xfs_dabuf_t **bpp,
- int whichfork)
-{
- return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0);
-}

-/*
- * Get a buffer for the dir/attr block, fill in the contents.
- */
-int
-xfs_da_read_buf(
- xfs_trans_t *trans,
- xfs_inode_t *dp,
- xfs_dablk_t bno,
- xfs_daddr_t mappedbno,
- xfs_dabuf_t **bpp,
- int whichfork)
-{
- return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1);
+ return error;
}

/*
@@ -2190,18 +2224,38 @@ xfs_da_read_buf(
*/
xfs_daddr_t
xfs_da_reada_buf(
- xfs_trans_t *trans,
- xfs_inode_t *dp,
- xfs_dablk_t bno,
- int whichfork)
+ struct xfs_trans *trans,
+ struct xfs_inode *dp,
+ xfs_dablk_t bno,
+ int whichfork)
{
- xfs_daddr_t rval;
+ xfs_daddr_t mappedbno = -1;
+ struct xfs_buf_map map;
+ struct xfs_buf_map *mapp;
+ int nmap;
+ int error;
+
+ mapp = &map;
+ nmap = 1;
+ error = xfs_dabuf_map(trans, dp, bno, -1, whichfork,
+ &mapp, &nmap);
+ if (error) {
+ /* mapping a hole is not an error, but we don't continue */
+ if (error == -1)
+ error = 0;
+ goto out_free;
+ }

- rval = -1;
- if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3))
+ mappedbno = mapp[0].bm_bn;
+ xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap);
+
+out_free:
+ if (mapp != &map)
+ kmem_free(mapp);
+
+ if (error)
return -1;
- else
- return rval;
+ return mappedbno;
}

kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
@@ -2261,78 +2315,25 @@ xfs_da_state_free(xfs_da_state_t *state)
*/
/* ARGSUSED */
STATIC xfs_dabuf_t *
-xfs_da_buf_make(int nbuf, xfs_buf_t **bps)
+xfs_da_buf_make(xfs_buf_t *bp)
{
- xfs_buf_t *bp;
xfs_dabuf_t *dabuf;
- int i;
- int off;

- if (nbuf == 1)
- dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_NOFS);
- else
- dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_NOFS);
- dabuf->dirty = 0;
- if (nbuf == 1) {
- dabuf->nbuf = 1;
- bp = bps[0];
- dabuf->bbcount = bp->b_length;
- dabuf->data = bp->b_addr;
- dabuf->bps[0] = bp;
- } else {
- dabuf->nbuf = nbuf;
- for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
- dabuf->bps[i] = bp = bps[i];
- dabuf->bbcount += bp->b_length;
- }
- dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
- for (i = off = 0; i < nbuf; i++, off += BBTOB(bp->b_length)) {
- bp = bps[i];
- memcpy((char *)dabuf->data + off, bp->b_addr,
- BBTOB(bp->b_length));
- }
- }
+ dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_NOFS);
+ dabuf->bbcount = bp->b_length;
+ dabuf->data = bp->b_addr;
+ dabuf->bp = bp;
return dabuf;
}

/*
- * Un-dirty a dabuf.
- */
-STATIC void
-xfs_da_buf_clean(xfs_dabuf_t *dabuf)
-{
- xfs_buf_t *bp;
- int i;
- int off;
-
- if (dabuf->dirty) {
- ASSERT(dabuf->nbuf > 1);
- dabuf->dirty = 0;
- for (i = off = 0; i < dabuf->nbuf;
- i++, off += BBTOB(bp->b_length)) {
- bp = dabuf->bps[i];
- memcpy(bp->b_addr, dabuf->data + off,
- BBTOB(bp->b_length));
- }
- }
-}
-
-/*
* Release a dabuf.
*/
void
xfs_da_buf_done(xfs_dabuf_t *dabuf)
{
- ASSERT(dabuf);
- ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
- if (dabuf->dirty)
- xfs_da_buf_clean(dabuf);
- if (dabuf->nbuf > 1) {
- kmem_free(dabuf->data);
- kmem_free(dabuf);
- } else {
- kmem_zone_free(xfs_dabuf_zone, dabuf);
- }
+ ASSERT(dabuf->data && dabuf->bbcount && dabuf->bp);
+ kmem_zone_free(xfs_dabuf_zone, dabuf);
}

/*
@@ -2341,41 +2342,9 @@ xfs_da_buf_done(xfs_dabuf_t *dabuf)
void
xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
{
- xfs_buf_t *bp;
- uint f;
- int i;
- uint l;
- int off;
-
- ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
- if (dabuf->nbuf == 1) {
- ASSERT(dabuf->data == dabuf->bps[0]->b_addr);
- xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
- return;
- }
- dabuf->dirty = 1;
- ASSERT(first <= last);
- for (i = off = 0; i < dabuf->nbuf; i++, off += BBTOB(bp->b_length)) {
- bp = dabuf->bps[i];
- f = off;
- l = f + BBTOB(bp->b_length) - 1;
- if (f < first)
- f = first;
- if (l > last)
- l = last;
- if (f <= l)
- xfs_trans_log_buf(tp, bp, f - off, l - off);
- /*
- * B_DONE is set by xfs_trans_log buf.
- * If we don't set it on a new buffer (get not read)
- * then if we don't put anything in the buffer it won't
- * be set, and at commit it it released into the cache,
- * and then a read will fail.
- */
- else if (!(XFS_BUF_ISDONE(bp)))
- XFS_BUF_DONE(bp);
- }
- ASSERT(last < off);
+ ASSERT(dabuf->data && dabuf->bbcount && dabuf->bp);
+ ASSERT(dabuf->data == dabuf->bp->b_addr);
+ xfs_trans_log_buf(tp, dabuf->bp, first, last);
}

/*
@@ -2386,24 +2355,9 @@ xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
void
xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
{
- xfs_buf_t *bp;
- xfs_buf_t **bplist;
- int i;
- int nbuf;
-
- ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
- if ((nbuf = dabuf->nbuf) == 1) {
- bplist = &bp;
- bp = dabuf->bps[0];
- } else {
- bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
- memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
- }
+ ASSERT(dabuf->data && dabuf->bbcount && dabuf->bp);
+ xfs_trans_brelse(tp, dabuf->bp);
xfs_da_buf_done(dabuf);
- for (i = 0; i < nbuf; i++)
- xfs_trans_brelse(tp, bplist[i]);
- if (bplist != &bp)
- kmem_free(bplist);
}

/*
@@ -2412,24 +2366,9 @@ xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
void
xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
{
- xfs_buf_t *bp;
- xfs_buf_t **bplist;
- int i;
- int nbuf;
-
- ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
- if ((nbuf = dabuf->nbuf) == 1) {
- bplist = &bp;
- bp = dabuf->bps[0];
- } else {
- bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
- memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
- }
+ ASSERT(dabuf->data && dabuf->bbcount && dabuf->bp);
xfs_da_buf_done(dabuf);
- for (i = 0; i < nbuf; i++)
- xfs_trans_binval(tp, bplist[i]);
- if (bplist != &bp)
- kmem_free(bplist);
+ xfs_trans_binval(tp, dabuf->bp);
}

/*
@@ -2438,7 +2377,6 @@ xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
xfs_daddr_t
xfs_da_blkno(xfs_dabuf_t *dabuf)
{
- ASSERT(dabuf->nbuf);
ASSERT(dabuf->data);
- return XFS_BUF_ADDR(dabuf->bps[0]);
+ return XFS_BUF_ADDR(dabuf->bp);
}
diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h
index dbf7c07..0b64c4a 100644
--- a/fs/xfs/xfs_da_btree.h
+++ b/fs/xfs/xfs_da_btree.h
@@ -141,14 +141,10 @@ typedef struct xfs_da_args {
* same place as the b_addr field for the buffer, else to kmem_alloced memory.
*/
typedef struct xfs_dabuf {
- int nbuf; /* number of buffer pointers present */
- short dirty; /* data needs to be copied back */
short bbcount; /* how large is data in bbs */
void *data; /* pointer for buffers' data */
- struct xfs_buf *bps[1]; /* actually nbuf of these */
+ struct xfs_buf *bp; /* actually nbuf of these */
} xfs_dabuf_t;
-#define XFS_DA_BUF_SIZE(n) \
- (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))

/*
* Storage for holding state during Btree searches and split/join ops.