From d63192c8904727fced1644f0dd0f7aa26b5f7dc4 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 4 May 2018 15:30:23 -0700 Subject: xfs: refactor xfs_qm_dqtobp and xfs_qm_dqalloc 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 Reviewed-by: Brian Foster --- fs/xfs/xfs_dquot.c | 270 ++++++++++++++++++++++++----------------------------- 1 file changed, 122 insertions(+), 148 deletions(-) (limited to 'fs/xfs/xfs_dquot.c') diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c index 434137eb07a4..22bb52ee82c8 100644 --- a/fs/xfs/xfs_dquot.c +++ b/fs/xfs/xfs_dquot.c @@ -288,49 +288,43 @@ 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_dquot_disk_alloc( + 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_quota_inode(mp, dqp->dq_flags); + xfs_fsblock_t firstblock; + int nmaps = 1; + int error; trace_xfs_dqalloc(dqp); - /* - * Initialize the bmap freelist prior to calling bmapi code. - */ 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 +338,8 @@ 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; @@ -358,8 +350,9 @@ 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); /* * Hold the buffer and join it to the dfops so that we'll still own @@ -379,7 +372,7 @@ xfs_qm_dqalloc( * transaction, so we must _buf_relse it. * * If everything succeeds, the caller of this function is returned a - * buffer that is locked and joined to the transaction. The caller + * buffer that is locked and held to the transaction. The caller * is responsible for unlocking any buffer passed back, either * manually or by committing the transaction. */ @@ -395,8 +388,7 @@ xfs_qm_dqalloc( xfs_buf_relse(bp); goto error1; } - xfs_trans_bhold_release(*tpp, bp); - *O_bpp = bp; + *bpp = bp; return 0; error1: @@ -406,32 +398,24 @@ error0: } /* - * 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_dquot_disk_read( + 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); + struct xfs_inode *quotip = xfs_quota_inode(mp, dqp->dq_flags); uint lock_mode; - - quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags); - dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; + int nmaps = 1; + int error; 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. @@ -444,57 +428,36 @@ 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; } @@ -516,6 +479,12 @@ xfs_dquot_alloc( 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 @@ -554,8 +523,10 @@ xfs_dquot_alloc( STATIC void xfs_dquot_from_disk( 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)); @@ -571,6 +542,44 @@ xfs_dquot_from_disk( xfs_dquot_set_prealloc_limits(dqp); } +/* Allocate and initialize the dquot buffer for this in-core dquot. */ +static int +xfs_qm_dqread_alloc( + struct xfs_mount *mp, + struct xfs_dquot *dqp, + struct xfs_buf **bpp) +{ + struct xfs_trans *tp; + struct xfs_buf *bp; + int error; + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, + XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); + if (error) + goto err; + + error = xfs_dquot_disk_alloc(&tp, dqp, &bp); + if (error) + goto err_cancel; + + error = xfs_trans_commit(tp); + if (error) { + /* + * Buffer was held to the transaction, so we have to unlock it + * manually here because we're not passing it back. + */ + xfs_buf_relse(bp); + goto err; + } + *bpp = bp; + return 0; + +err_cancel: + xfs_trans_cancel(tp); +err: + return error; +} + /* * Read in the ondisk dquot using dqtobp() then copy it to an incore version, * and release the buffer immediately. @@ -583,74 +592,39 @@ 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; int error; dqp = xfs_dquot_alloc(mp, id, type); trace_xfs_dqread(dqp); - if (flags & XFS_QMOPT_DQALLOC) { - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, - XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); - if (error) - goto error0; - } - - /* - * 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; - } - - xfs_dquot_from_disk(dqp, ddqp); - - /* Mark the buf so that this will stay incore a little longer */ - xfs_buf_set_ref(bp, XFS_DQUOT_REF); + /* Try to read the buffer, allocating if necessary. */ + error = xfs_dquot_disk_read(mp, dqp, &bp); + if (error == -ENOENT && (flags & XFS_QMOPT_DQALLOC)) + error = xfs_qm_dqread_alloc(mp, dqp, &bp); + if (error) + goto err; /* - * 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. Copy the data + * to the incore dquot and release the buffer since the incore dquot + * has its own 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; - } + xfs_dquot_from_disk(dqp, bp); - *O_dqpp = dqp; + xfs_buf_relse(bp); + *dqpp = dqp; return error; -error1: - if (tp) - xfs_trans_cancel(tp); -error0: +err: + trace_xfs_dqread_fail(dqp); xfs_qm_dqdestroy(dqp); - *O_dqpp = NULL; + *dqpp = NULL; return error; } -- cgit v1.2.3