diff options
Diffstat (limited to 'module')
| -rw-r--r-- | module/zfs/vdev_indirect.c | 111 |
1 files changed, 91 insertions, 20 deletions
diff --git a/module/zfs/vdev_indirect.c b/module/zfs/vdev_indirect.c index 7f172e297..70bf3bf15 100644 --- a/module/zfs/vdev_indirect.c +++ b/module/zfs/vdev_indirect.c @@ -14,7 +14,7 @@ */ /* - * Copyright (c) 2014, 2015 by Delphix. All rights reserved. + * Copyright (c) 2014, 2017 by Delphix. All rights reserved. */ #include <sys/zfs_context.h> @@ -945,6 +945,57 @@ rs_alloc(vdev_t *vd, uint64_t offset, uint64_t asize, uint64_t split_offset) } /* + * Given an indirect vdev and an extent on that vdev, it duplicates the + * physical entries of the indirect mapping that correspond to the extent + * to a new array and returns a pointer to it. In addition, copied_entries + * is populated with the number of mapping entries that were duplicated. + * + * Note that the function assumes that the caller holds vdev_indirect_rwlock. + * This ensures that the mapping won't change due to condensing as we + * copy over its contents. + * + * Finally, since we are doing an allocation, it is up to the caller to + * free the array allocated in this function. + */ +vdev_indirect_mapping_entry_phys_t * +vdev_indirect_mapping_duplicate_adjacent_entries(vdev_t *vd, uint64_t offset, + uint64_t asize, uint64_t *copied_entries) +{ + vdev_indirect_mapping_entry_phys_t *duplicate_mappings = NULL; + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + uint64_t entries = 0; + + ASSERT(RW_READ_HELD(&vd->vdev_indirect_rwlock)); + + vdev_indirect_mapping_entry_phys_t *first_mapping = + vdev_indirect_mapping_entry_for_offset(vim, offset); + ASSERT3P(first_mapping, !=, NULL); + + vdev_indirect_mapping_entry_phys_t *m = first_mapping; + while (asize > 0) { + uint64_t size = DVA_GET_ASIZE(&m->vimep_dst); + + ASSERT3U(offset, >=, DVA_MAPPING_GET_SRC_OFFSET(m)); + ASSERT3U(offset, <, DVA_MAPPING_GET_SRC_OFFSET(m) + size); + + uint64_t inner_offset = offset - DVA_MAPPING_GET_SRC_OFFSET(m); + uint64_t inner_size = MIN(asize, size - inner_offset); + + offset += inner_size; + asize -= inner_size; + entries++; + m++; + } + + size_t copy_length = entries * sizeof (*first_mapping); + duplicate_mappings = kmem_alloc(copy_length, KM_SLEEP); + bcopy(first_mapping, duplicate_mappings, copy_length); + *copied_entries = entries; + + return (duplicate_mappings); +} + +/* * Goes through the relevant indirect mappings until it hits a concrete vdev * and issues the callback. On the way to the concrete vdev, if any other * indirect vdevs are encountered, then the callback will also be called on @@ -984,24 +1035,41 @@ vdev_indirect_remap(vdev_t *vd, uint64_t offset, uint64_t asize, for (remap_segment_t *rs = rs_alloc(vd, offset, asize, 0); rs != NULL; rs = list_remove_head(&stack)) { vdev_t *v = rs->rs_vd; + uint64_t num_entries = 0; + + ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); + ASSERT(rs->rs_asize > 0); /* - * Note: this can be called from open context - * (eg. zio_read()), so we need the rwlock to prevent - * the mapping from being changed by condensing. + * Note: As this function can be called from open context + * (e.g. zio_read()), we need the following rwlock to + * prevent the mapping from being changed by condensing. + * + * So we grab the lock and we make a copy of the entries + * that are relevant to the extent that we are working on. + * Once that is done, we drop the lock and iterate over + * our copy of the mapping. Once we are done with the with + * the remap segment and we free it, we also free our copy + * of the indirect mapping entries that are relevant to it. + * + * This way we don't need to wait until the function is + * finished with a segment, to condense it. In addition, we + * don't need a recursive rwlock for the case that a call to + * vdev_indirect_remap() needs to call itself (through the + * codepath of its callback) for the same vdev in the middle + * of its execution. */ rw_enter(&v->vdev_indirect_rwlock, RW_READER); - vdev_indirect_mapping_t *vim = v->vdev_indirect_mapping; - ASSERT3P(vim, !=, NULL); - - ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); - ASSERT(rs->rs_asize > 0); + ASSERT3P(v->vdev_indirect_mapping, !=, NULL); vdev_indirect_mapping_entry_phys_t *mapping = - vdev_indirect_mapping_entry_for_offset(vim, rs->rs_offset); + vdev_indirect_mapping_duplicate_adjacent_entries(v, + rs->rs_offset, rs->rs_asize, &num_entries); ASSERT3P(mapping, !=, NULL); + ASSERT3U(num_entries, >, 0); + rw_exit(&v->vdev_indirect_rwlock); - while (rs->rs_asize > 0) { + for (uint64_t i = 0; i < num_entries; i++) { /* * Note: the vdev_indirect_mapping can not change * while we are running. It only changes while the @@ -1010,20 +1078,23 @@ vdev_indirect_remap(vdev_t *vd, uint64_t offset, uint64_t asize, * function is only called for frees, which also only * happen from syncing context. */ + vdev_indirect_mapping_entry_phys_t *m = &mapping[i]; + + ASSERT3P(m, !=, NULL); + ASSERT3U(rs->rs_asize, >, 0); - uint64_t size = DVA_GET_ASIZE(&mapping->vimep_dst); - uint64_t dst_offset = - DVA_GET_OFFSET(&mapping->vimep_dst); - uint64_t dst_vdev = DVA_GET_VDEV(&mapping->vimep_dst); + uint64_t size = DVA_GET_ASIZE(&m->vimep_dst); + uint64_t dst_offset = DVA_GET_OFFSET(&m->vimep_dst); + uint64_t dst_vdev = DVA_GET_VDEV(&m->vimep_dst); ASSERT3U(rs->rs_offset, >=, - DVA_MAPPING_GET_SRC_OFFSET(mapping)); + DVA_MAPPING_GET_SRC_OFFSET(m)); ASSERT3U(rs->rs_offset, <, - DVA_MAPPING_GET_SRC_OFFSET(mapping) + size); + DVA_MAPPING_GET_SRC_OFFSET(m) + size); ASSERT3U(dst_vdev, !=, v->vdev_id); uint64_t inner_offset = rs->rs_offset - - DVA_MAPPING_GET_SRC_OFFSET(mapping); + DVA_MAPPING_GET_SRC_OFFSET(m); uint64_t inner_size = MIN(rs->rs_asize, size - inner_offset); @@ -1064,10 +1135,10 @@ vdev_indirect_remap(vdev_t *vd, uint64_t offset, uint64_t asize, rs->rs_offset += inner_size; rs->rs_asize -= inner_size; rs->rs_split_offset += inner_size; - mapping++; } + VERIFY0(rs->rs_asize); - rw_exit(&v->vdev_indirect_rwlock); + kmem_free(mapping, num_entries * sizeof (*mapping)); kmem_free(rs, sizeof (remap_segment_t)); } list_destroy(&stack); |