From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Separate the disk dquot read and allocation functionality into
two helper functions, then refactor dqread to call them directly.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/xfs_dquot.c | 261 ++++++++++++++++++++--------------------------------
1 file changed, 99 insertions(+), 162 deletions(-)
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 7154909..ef4cd56 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -288,49 +288,44 @@ xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
}
/*
- * Allocate a block and fill it with dquots.
- * This is called when the bmapi finds a hole.
+ * Ensure that the given in-core dquot has a buffer on disk backing it, and
+ * return the buffer. This is called when the bmapi finds a hole.
*/
STATIC int
-xfs_qm_dqalloc(
- xfs_trans_t **tpp,
- xfs_mount_t *mp,
- xfs_dquot_t *dqp,
- xfs_inode_t *quotip,
- xfs_fileoff_t offset_fsb,
- xfs_buf_t **O_bpp)
+xfs_qm_dqalloc_ondisk(
+ struct xfs_trans **tpp,
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
{
- xfs_fsblock_t firstblock;
- struct xfs_defer_ops dfops;
- xfs_bmbt_irec_t map;
- int nmaps, error;
- xfs_buf_t *bp;
- xfs_trans_t *tp = *tpp;
-
- ASSERT(tp != NULL);
+ struct xfs_bmbt_irec map;
+ struct xfs_defer_ops dfops;
+ struct xfs_mount *mp = (*tpp)->t_mountp;
+ struct xfs_buf *bp;
+ struct xfs_inode *quotip;
+ xfs_fsblock_t firstblock;
+ int nmaps = 1;
+ int error;
trace_xfs_dqalloc(dqp);
- /*
- * Initialize the bmap freelist prior to calling bmapi code.
- */
+ quotip = xfs_quota_inode(mp, dqp->dq_flags);
xfs_defer_init(&dfops, &firstblock);
xfs_ilock(quotip, XFS_ILOCK_EXCL);
- /*
- * Return if this type of quotas is turned off while we didn't
- * have an inode lock
- */
if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
+ /*
+ * Return if this type of quotas is turned off while we didn't
+ * have an inode lock
+ */
xfs_iunlock(quotip, XFS_ILOCK_EXCL);
return -ESRCH;
}
- xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
- nmaps = 1;
- error = xfs_bmapi_write(tp, quotip, offset_fsb,
- XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
- &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
- &map, &nmaps, &dfops);
+ /* Create the block mapping. */
+ xfs_trans_ijoin(*tpp, quotip, XFS_ILOCK_EXCL);
+ error = xfs_bmapi_write(*tpp, quotip, dqp->q_fileoffset,
+ XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
+ &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
+ &map, &nmaps, &dfops);
if (error)
goto error0;
ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
@@ -344,10 +339,8 @@ xfs_qm_dqalloc(
dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
/* now we can just get the buffer (there's nothing to read yet) */
- bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
- dqp->q_blkno,
- mp->m_quotainfo->qi_dqchunklen,
- 0);
+ bp = xfs_trans_get_buf(*tpp, mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, 0);
if (!bp) {
error = -ENOMEM;
goto error1;
@@ -358,37 +351,22 @@ xfs_qm_dqalloc(
* Make a chunk of dquots out of this buffer and log
* the entire thing.
*/
- xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
+ xfs_qm_init_dquot_blk(*tpp, mp, be32_to_cpu(dqp->q_core.d_id),
dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
+ xfs_buf_set_ref(bp, XFS_DQUOT_REF);
/*
- * xfs_defer_finish() may commit the current transaction and
- * start a second transaction if the freelist is not empty.
- *
- * Since we still want to modify this buffer, we need to
- * ensure that the buffer is not released on commit of
- * the first transaction and ensure the buffer is added to the
- * second transaction.
- *
- * If there is only one transaction then don't stop the buffer
- * from being released when it commits later on.
+ * Hold the buffer and join it to the dfops so that we'll still own
+ * the buffer when we return to the caller.
*/
-
- xfs_trans_bhold(tp, bp);
-
+ xfs_trans_bhold(*tpp, bp);
+ error = xfs_defer_bjoin(&dfops, bp);
+ if (error)
+ goto error1;
error = xfs_defer_finish(tpp, &dfops);
if (error)
goto error1;
-
- /* Transaction was committed? */
- if (*tpp != tp) {
- tp = *tpp;
- xfs_trans_bjoin(tp, bp);
- } else {
- xfs_trans_bhold_release(tp, bp);
- }
-
- *O_bpp = bp;
+ *bpp = bp;
return 0;
error1:
@@ -398,32 +376,25 @@ xfs_qm_dqalloc(
}
/*
- * Maps a dquot to the buffer containing its on-disk version.
- * This returns a ptr to the buffer containing the on-disk dquot
- * in the bpp param, and a ptr to the on-disk dquot within that buffer
+ * Read in the in-core dquot's on-disk metadata and return the buffer.
+ * Returns ENOENT to signal a hole.
*/
STATIC int
-xfs_qm_dqtobp(
- xfs_trans_t **tpp,
- xfs_dquot_t *dqp,
- xfs_disk_dquot_t **O_ddpp,
- xfs_buf_t **O_bpp,
- uint flags)
+xfs_qm_dqread_ondisk(
+ struct xfs_mount *mp,
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
{
struct xfs_bmbt_irec map;
- int nmaps = 1, error;
struct xfs_buf *bp;
struct xfs_inode *quotip;
- struct xfs_mount *mp = dqp->q_mount;
- xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id);
- struct xfs_trans *tp = (tpp ? *tpp : NULL);
uint lock_mode;
+ int nmaps = 1;
+ int error;
- quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags);
- dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
-
+ quotip = xfs_quota_inode(mp, dqp->dq_flags);
lock_mode = xfs_ilock_data_map_shared(quotip);
- if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
+ if (!xfs_this_quota_on(mp, dqp->dq_flags)) {
/*
* Return if this type of quotas is turned off while we
* didn't have the quota inode lock.
@@ -436,57 +407,36 @@ xfs_qm_dqtobp(
* Find the block map; no allocations yet
*/
error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
- XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
-
+ XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
xfs_iunlock(quotip, lock_mode);
if (error)
return error;
ASSERT(nmaps == 1);
- ASSERT(map.br_blockcount == 1);
+ ASSERT(map.br_blockcount >= 1);
+ ASSERT(map.br_startblock != DELAYSTARTBLOCK);
+ if (map.br_startblock == HOLESTARTBLOCK)
+ return -ENOENT;
+
+ trace_xfs_dqtobp_read(dqp);
/*
- * Offset of dquot in the (fixed sized) dquot chunk.
+ * store the blkno etc so that we don't have to do the
+ * mapping all the time
*/
- dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
- sizeof(xfs_dqblk_t);
-
- ASSERT(map.br_startblock != DELAYSTARTBLOCK);
- if (map.br_startblock == HOLESTARTBLOCK) {
- /*
- * We don't allocate unless we're asked to
- */
- if (!(flags & XFS_QMOPT_DQALLOC))
- return -ENOENT;
-
- ASSERT(tp);
- error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
- dqp->q_fileoffset, &bp);
- if (error)
- return error;
- tp = *tpp;
- } else {
- trace_xfs_dqtobp_read(dqp);
+ dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
- /*
- * store the blkno etc so that we don't have to do the
- * mapping all the time
- */
- dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
-
- error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
- dqp->q_blkno,
- mp->m_quotainfo->qi_dqchunklen,
- 0, &bp, &xfs_dquot_buf_ops);
- if (error) {
- ASSERT(bp == NULL);
- return error;
- }
+ error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, 0, &bp,
+ &xfs_dquot_buf_ops);
+ if (error) {
+ ASSERT(bp == NULL);
+ return error;
}
ASSERT(xfs_buf_islocked(bp));
- *O_bpp = bp;
- *O_ddpp = bp->b_addr + dqp->q_bufoffset;
+ xfs_buf_set_ref(bp, XFS_DQUOT_REF);
+ *bpp = bp;
return 0;
}
@@ -508,6 +458,12 @@ xfs_qm_dqinit_once(
INIT_LIST_HEAD(&dqp->q_lru);
mutex_init(&dqp->q_qlock);
init_waitqueue_head(&dqp->q_pinwait);
+ dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
+ /*
+ * Offset of dquot in the (fixed sized) dquot chunk.
+ */
+ dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
+ sizeof(xfs_dqblk_t);
/*
* Because we want to use a counting completion, complete
@@ -544,8 +500,10 @@ xfs_qm_dqinit_once(
STATIC void
xfs_qm_dqinit_from_buf(
struct xfs_dquot *dqp,
- struct xfs_disk_dquot *ddqp)
+ struct xfs_buf *bp)
{
+ struct xfs_disk_dquot *ddqp = bp->b_addr + dqp->q_bufoffset;
+
/* copy everything from disk dquot to the incore dquot */
memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
xfs_qm_dquot_logitem_init(dqp);
@@ -574,74 +532,53 @@ xfs_qm_dqread(
xfs_dqid_t id,
uint type,
uint flags,
- struct xfs_dquot **O_dqpp)
+ struct xfs_dquot **dqpp)
{
struct xfs_dquot *dqp;
- struct xfs_disk_dquot *ddqp;
struct xfs_buf *bp;
- struct xfs_trans *tp = NULL;
+ struct xfs_trans *tp;
int error;
dqp = xfs_qm_dqinit_once(mp, id, type);
trace_xfs_dqread(dqp);
- if (flags & XFS_QMOPT_DQALLOC) {
+ /* Try to read the buffer... */
+ error = xfs_qm_dqread_ondisk(mp, dqp, &bp);
+ if (error == -ENOENT && (flags & XFS_QMOPT_DQALLOC)) {
+ /* ...or allocate a new block and buffer. */
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc,
XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp);
if (error)
- goto error0;
- }
+ goto err;
- /*
- * get a pointer to the on-disk dquot and the buffer containing it
- * dqp already knows its own type (GROUP/USER).
- */
- error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
- if (error) {
- /*
- * This can happen if quotas got turned off (ESRCH),
- * or if the dquot didn't exist on disk and we ask to
- * allocate (ENOENT).
- */
- trace_xfs_dqread_fail(dqp);
- goto error1;
- }
+ error = xfs_qm_dqalloc_ondisk(&tp, dqp, &bp);
+ if (error)
+ goto err_cancel;
- xfs_qm_dqinit_from_buf(dqp, ddqp);
+ error = xfs_trans_commit(tp);
+ }
+ ASSERT(xfs_buf_islocked(bp));
+ if (error)
+ goto err;
- /* Mark the buf so that this will stay incore a little longer */
- xfs_buf_set_ref(bp, XFS_DQUOT_REF);
+ xfs_qm_dqinit_from_buf(dqp, bp);
/*
- * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
- * So we need to release with xfs_trans_brelse().
- * The strategy here is identical to that of inodes; we lock
- * the dquot in xfs_qm_dqget() before making it accessible to
- * others. This is because dquots, like inodes, need a good level of
- * concurrency, and we don't want to take locks on the entire buffers
- * for dquot accesses.
- * Note also that the dquot buffer may even be dirty at this point, if
- * this particular dquot was repaired. We still aren't afraid to
- * brelse it because we have the changes incore.
+ * At this point we should have a clean locked buffer. Release the
+ * buffer since the incore dquot has its own copy and locking
+ * protocol so we needn't tie up the buffer any further.
*/
ASSERT(xfs_buf_islocked(bp));
- xfs_trans_brelse(tp, bp);
-
- if (tp) {
- error = xfs_trans_commit(tp);
- if (error)
- goto error0;
- }
-
- *O_dqpp = dqp;
+ xfs_buf_relse(bp);
+ *dqpp = dqp;
return error;
-error1:
- if (tp)
- xfs_trans_cancel(tp);
-error0:
+err_cancel:
+ xfs_trans_cancel(tp);
+err:
+ trace_xfs_dqread_fail(dqp);
xfs_qm_dqdestroy(dqp);
- *O_dqpp = NULL;
+ *dqpp = NULL;
return error;
}
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