diff options
| -rw-r--r-- | fs/xfs/xfs_dquot.c | 112 |
1 files changed, 78 insertions, 34 deletions
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c index 8d2a3becc4f4..299d4ce90ded 100644 --- a/fs/xfs/xfs_dquot.c +++ b/fs/xfs/xfs_dquot.c @@ -687,6 +687,81 @@ xfs_dq_get_next_id( } /* + * Look up the dquot in the in-core cache. If found, the dquot is returned + * locked and ready to go. + */ +static struct xfs_dquot * +xfs_qm_dqget_cache_lookup( + struct xfs_mount *mp, + struct xfs_quotainfo *qi, + struct radix_tree_root *tree, + xfs_dqid_t id) +{ + struct xfs_dquot *dqp; + +restart: + mutex_lock(&qi->qi_tree_lock); + dqp = radix_tree_lookup(tree, id); + if (!dqp) { + mutex_unlock(&qi->qi_tree_lock); + XFS_STATS_INC(mp, xs_qm_dqcachemisses); + return NULL; + } + + xfs_dqlock(dqp); + if (dqp->dq_flags & XFS_DQ_FREEING) { + xfs_dqunlock(dqp); + mutex_unlock(&qi->qi_tree_lock); + trace_xfs_dqget_freeing(dqp); + delay(1); + goto restart; + } + + dqp->q_nrefs++; + mutex_unlock(&qi->qi_tree_lock); + + trace_xfs_dqget_hit(dqp); + XFS_STATS_INC(mp, xs_qm_dqcachehits); + return dqp; +} + +/* + * Try to insert a new dquot into the in-core cache. If an error occurs the + * caller should throw away the dquot and start over. Otherwise, the dquot + * is returned locked (and held by the cache) as if there had been a cache + * hit. + */ +static int +xfs_qm_dqget_cache_insert( + struct xfs_mount *mp, + struct xfs_quotainfo *qi, + struct radix_tree_root *tree, + xfs_dqid_t id, + struct xfs_dquot *dqp) +{ + int error; + + mutex_lock(&qi->qi_tree_lock); + error = radix_tree_insert(tree, id, dqp); + if (unlikely(error)) { + /* Duplicate found! Caller must try again. */ + WARN_ON(error != -EEXIST); + mutex_unlock(&qi->qi_tree_lock); + trace_xfs_dqget_dup(dqp); + return error; + } + + /* Return a locked dquot to the caller, with a reference taken. */ + xfs_dqlock(dqp); + dqp->q_nrefs = 1; + + qi->qi_dquots++; + mutex_unlock(&qi->qi_tree_lock); + + return 0; +} + +/* * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a * a locked dquot, doing an allocation (if requested) as needed. * When both an inode and an id are given, the inode's id takes precedence. @@ -724,28 +799,11 @@ xfs_qm_dqget( } restart: - mutex_lock(&qi->qi_tree_lock); - dqp = radix_tree_lookup(tree, id); + dqp = xfs_qm_dqget_cache_lookup(mp, qi, tree, id); if (dqp) { - xfs_dqlock(dqp); - if (dqp->dq_flags & XFS_DQ_FREEING) { - xfs_dqunlock(dqp); - mutex_unlock(&qi->qi_tree_lock); - trace_xfs_dqget_freeing(dqp); - delay(1); - goto restart; - } - - dqp->q_nrefs++; - mutex_unlock(&qi->qi_tree_lock); - - trace_xfs_dqget_hit(dqp); - XFS_STATS_INC(mp, xs_qm_dqcachehits); *O_dqpp = dqp; return 0; } - mutex_unlock(&qi->qi_tree_lock); - XFS_STATS_INC(mp, xs_qm_dqcachemisses); /* * Dquot cache miss. We don't want to keep the inode lock across @@ -787,31 +845,17 @@ restart: } } - mutex_lock(&qi->qi_tree_lock); - error = radix_tree_insert(tree, id, dqp); - if (unlikely(error)) { - WARN_ON(error != -EEXIST); - + error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp); + if (error) { /* * Duplicate found. Just throw away the new dquot and start * over. */ - mutex_unlock(&qi->qi_tree_lock); - trace_xfs_dqget_dup(dqp); xfs_qm_dqdestroy(dqp); XFS_STATS_INC(mp, xs_qm_dquot_dups); goto restart; } - /* - * We return a locked dquot to the caller, with a reference taken - */ - xfs_dqlock(dqp); - dqp->q_nrefs = 1; - - qi->qi_dquots++; - mutex_unlock(&qi->qi_tree_lock); - dqret: ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL)); trace_xfs_dqget_miss(dqp); |