diff options
Diffstat (limited to 'usr/src/uts/common/fs/zfs/sys/dnode.h')
| -rw-r--r-- | usr/src/uts/common/fs/zfs/sys/dnode.h | 246 |
1 files changed, 232 insertions, 14 deletions
diff --git a/usr/src/uts/common/fs/zfs/sys/dnode.h b/usr/src/uts/common/fs/zfs/sys/dnode.h index 89a7b2ef60..68872a8e9e 100644 --- a/usr/src/uts/common/fs/zfs/sys/dnode.h +++ b/usr/src/uts/common/fs/zfs/sys/dnode.h @@ -86,12 +86,26 @@ extern "C" { /* * Derived constants. */ -#define DNODE_SIZE (1 << DNODE_SHIFT) -#define DN_MAX_NBLKPTR ((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT) -#define DN_MAX_BONUSLEN (DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT)) -#define DN_MAX_OBJECT (1ULL << DN_MAX_OBJECT_SHIFT) -#define DN_ZERO_BONUSLEN (DN_MAX_BONUSLEN + 1) -#define DN_KILL_SPILLBLK (1) +#define DNODE_MIN_SIZE (1 << DNODE_SHIFT) +#define DNODE_MAX_SIZE (1 << DNODE_BLOCK_SHIFT) +#define DNODE_BLOCK_SIZE (1 << DNODE_BLOCK_SHIFT) +#define DNODE_MIN_SLOTS (DNODE_MIN_SIZE >> DNODE_SHIFT) +#define DNODE_MAX_SLOTS (DNODE_MAX_SIZE >> DNODE_SHIFT) +#define DN_BONUS_SIZE(dnsize) ((dnsize) - DNODE_CORE_SIZE - \ + (1 << SPA_BLKPTRSHIFT)) +#define DN_SLOTS_TO_BONUSLEN(slots) DN_BONUS_SIZE((slots) << DNODE_SHIFT) +#define DN_OLD_MAX_BONUSLEN (DN_BONUS_SIZE(DNODE_MIN_SIZE)) +#define DN_MAX_NBLKPTR ((DNODE_MIN_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT) +#define DN_MAX_OBJECT (1ULL << DN_MAX_OBJECT_SHIFT) +#define DN_ZERO_BONUSLEN (DN_BONUS_SIZE(DNODE_MAX_SIZE) + 1) +#define DN_KILL_SPILLBLK (1) + +#define DN_SLOT_UNINIT ((void *)NULL) /* Uninitialized */ +#define DN_SLOT_FREE ((void *)1UL) /* Free slot */ +#define DN_SLOT_ALLOCATED ((void *)2UL) /* Allocated slot */ +#define DN_SLOT_INTERIOR ((void *)3UL) /* Interior allocated slot */ +#define DN_SLOT_IS_PTR(dn) ((void *)dn > DN_SLOT_INTERIOR) +#define DN_SLOT_IS_VALID(dn) ((void *)dn != NULL) #define DNODES_PER_BLOCK_SHIFT (DNODE_BLOCK_SHIFT - DNODE_SHIFT) #define DNODES_PER_BLOCK (1ULL << DNODES_PER_BLOCK_SHIFT) @@ -109,6 +123,10 @@ extern "C" { #define DN_BONUS(dnp) ((void*)((dnp)->dn_bonus + \ (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t)))) +#define DN_MAX_BONUS_LEN(dnp) \ + ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) ? \ + (uint8_t *)DN_SPILL_BLKPTR(dnp) - (uint8_t *)DN_BONUS(dnp) : \ + (uint8_t *)(dnp + (dnp->dn_extra_slots + 1)) - (uint8_t *)DN_BONUS(dnp)) #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \ (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT) @@ -132,6 +150,57 @@ enum dnode_dirtycontext { /* Does dnode have a SA spill blkptr in bonus? */ #define DNODE_FLAG_SPILL_BLKPTR (1<<2) +/* + * VARIABLE-LENGTH (LARGE) DNODES + * + * The motivation for variable-length dnodes is to eliminate the overhead + * associated with using spill blocks. Spill blocks are used to store + * system attribute data (i.e. file metadata) that does not fit in the + * dnode's bonus buffer. By allowing a larger bonus buffer area the use of + * a spill block can be avoided. Spill blocks potentially incur an + * additional read I/O for every dnode in a dnode block. As a worst case + * example, reading 32 dnodes from a 16k dnode block and all of the spill + * blocks could issue 33 separate reads. Now suppose those dnodes have size + * 1024 and therefore don't need spill blocks. Then the worst case number + * of blocks read is reduced to from 33 to two--one per dnode block. + * + * ZFS-on-Linux systems that make heavy use of extended attributes benefit + * from this feature. In particular, ZFS-on-Linux supports the xattr=sa + * dataset property which allows file extended attribute data to be stored + * in the dnode bonus buffer as an alternative to the traditional + * directory-based format. Workloads such as SELinux and the Lustre + * distributed filesystem often store enough xattr data to force spill + * blocks when xattr=sa is in effect. Large dnodes may therefore provide a + * performance benefit to such systems. Other use cases that benefit from + * this feature include files with large ACLs and symbolic links with long + * target names. + * + * The size of a dnode may be a multiple of 512 bytes up to the size of a + * dnode block (currently 16384 bytes). The dn_extra_slots field of the + * on-disk dnode_phys_t structure describes the size of the physical dnode + * on disk. The field represents how many "extra" dnode_phys_t slots a + * dnode consumes in its dnode block. This convention results in a value of + * 0 for 512 byte dnodes which preserves on-disk format compatibility with + * older software which doesn't support large dnodes. + * + * Similarly, the in-memory dnode_t structure has a dn_num_slots field + * to represent the total number of dnode_phys_t slots consumed on disk. + * Thus dn->dn_num_slots is 1 greater than the corresponding + * dnp->dn_extra_slots. This difference in convention was adopted + * because, unlike on-disk structures, backward compatibility is not a + * concern for in-memory objects, so we used a more natural way to + * represent size for a dnode_t. + * + * The default size for newly created dnodes is determined by the value of + * the "dnodesize" dataset property. By default the property is set to + * "legacy" which is compatible with older software. Setting the property + * to "auto" will allow the filesystem to choose the most suitable dnode + * size. Currently this just sets the default dnode size to 1k, but future + * code improvements could dynamically choose a size based on observed + * workload patterns. Dnodes of varying sizes can coexist within the same + * dataset and even within the same dnode block. + */ + typedef struct dnode_phys { uint8_t dn_type; /* dmu_object_type_t */ uint8_t dn_indblkshift; /* ln2(indirect block size) */ @@ -143,19 +212,32 @@ typedef struct dnode_phys { uint8_t dn_flags; /* DNODE_FLAG_* */ uint16_t dn_datablkszsec; /* data block size in 512b sectors */ uint16_t dn_bonuslen; /* length of dn_bonus */ - uint8_t dn_pad2[4]; + uint8_t dn_extra_slots; /* # of subsequent slots consumed */ + uint8_t dn_pad2[3]; /* accounting is protected by dn_dirty_mtx */ uint64_t dn_maxblkid; /* largest allocated block ID */ uint64_t dn_used; /* bytes (or sectors) of disk space */ uint64_t dn_pad3[4]; - - blkptr_t dn_blkptr[1]; - uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)]; - blkptr_t dn_spill; + union { + blkptr_t dn_blkptr[1+DN_OLD_MAX_BONUSLEN/sizeof (blkptr_t)]; + struct { + blkptr_t __dn_ignore1; + uint8_t dn_bonus[DN_OLD_MAX_BONUSLEN]; + }; + struct { + blkptr_t __dn_ignore2; + uint8_t __dn_ignore3[DN_OLD_MAX_BONUSLEN - + sizeof (blkptr_t)]; + blkptr_t dn_spill; + }; + }; } dnode_phys_t; +#define DN_SPILL_BLKPTR(dnp) (blkptr_t *)((char *)(dnp) + \ + (((dnp)->dn_extra_slots + 1) << DNODE_SHIFT) - (1 << SPA_BLKPTRSHIFT)) + struct dnode { /* * Protects the structure of the dnode, including the number of levels @@ -192,6 +274,7 @@ struct dnode { uint32_t dn_datablksz; /* in bytes */ uint64_t dn_maxblkid; uint8_t dn_next_type[TXG_SIZE]; + uint8_t dn_num_slots; /* metadnode slots consumed on disk */ uint8_t dn_next_nblkptr[TXG_SIZE]; uint8_t dn_next_nlevels[TXG_SIZE]; uint8_t dn_next_indblkshift[TXG_SIZE]; @@ -287,7 +370,7 @@ void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx); int dnode_hold(struct objset *dd, uint64_t object, void *ref, dnode_t **dnp); -int dnode_hold_impl(struct objset *dd, uint64_t object, int flag, +int dnode_hold_impl(struct objset *dd, uint64_t object, int flag, int dn_slots, void *ref, dnode_t **dnp); boolean_t dnode_add_ref(dnode_t *dn, void *ref); void dnode_rele(dnode_t *dn, void *ref); @@ -295,9 +378,9 @@ void dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting); void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx); void dnode_sync(dnode_t *dn, dmu_tx_t *tx); void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, - dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); + dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx); void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, - dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); + dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx); void dnode_free(dnode_t *dn, dmu_tx_t *tx); void dnode_byteswap(dnode_phys_t *dnp); void dnode_buf_byteswap(void *buf, size_t size); @@ -313,6 +396,7 @@ int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off, int minlvl, uint64_t blkfill, uint64_t txg); void dnode_evict_dbufs(dnode_t *dn); void dnode_evict_bonus(dnode_t *dn); +void dnode_free_interior_slots(dnode_t *dn); boolean_t dnode_needs_remap(const dnode_t *dn); #define DNODE_IS_CACHEABLE(_dn) \ @@ -324,6 +408,140 @@ boolean_t dnode_needs_remap(const dnode_t *dn); ((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL || \ (_dn)->dn_objset->os_primary_cache == ZFS_CACHE_METADATA) +/* + * Used for dnodestats kstat. + */ +typedef struct dnode_stats { + /* + * Number of failed attempts to hold a meta dnode dbuf. + */ + kstat_named_t dnode_hold_dbuf_hold; + /* + * Number of failed attempts to read a meta dnode dbuf. + */ + kstat_named_t dnode_hold_dbuf_read; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) was able + * to hold the requested object number which was allocated. This is + * the common case when looking up any allocated object number. + */ + kstat_named_t dnode_hold_alloc_hits; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) was not + * able to hold the request object number because it was not allocated. + */ + kstat_named_t dnode_hold_alloc_misses; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) was not + * able to hold the request object number because the object number + * refers to an interior large dnode slot. + */ + kstat_named_t dnode_hold_alloc_interior; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) needed + * to retry acquiring slot zrl locks due to contention. + */ + kstat_named_t dnode_hold_alloc_lock_retry; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) did not + * need to create the dnode because another thread did so after + * dropping the read lock but before acquiring the write lock. + */ + kstat_named_t dnode_hold_alloc_lock_misses; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_ALLOCATED) found + * a free dnode instantiated by dnode_create() but not yet allocated + * by dnode_allocate(). + */ + kstat_named_t dnode_hold_alloc_type_none; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) was able + * to hold the requested range of free dnode slots. + */ + kstat_named_t dnode_hold_free_hits; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) was not + * able to hold the requested range of free dnode slots because + * at least one slot was allocated. + */ + kstat_named_t dnode_hold_free_misses; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) was not + * able to hold the requested range of free dnode slots because + * after acquiring the zrl lock at least one slot was allocated. + */ + kstat_named_t dnode_hold_free_lock_misses; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) needed + * to retry acquiring slot zrl locks due to contention. + */ + kstat_named_t dnode_hold_free_lock_retry; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) requested + * a range of dnode slots which were held by another thread. + */ + kstat_named_t dnode_hold_free_refcount; + /* + * Number of times dnode_hold(..., DNODE_MUST_BE_FREE) requested + * a range of dnode slots which would overflow the dnode_phys_t. + */ + kstat_named_t dnode_hold_free_overflow; + /* + * Number of times a dnode_hold(...) was attempted on a dnode + * which had already been unlinked in an earlier txg. + */ + kstat_named_t dnode_hold_free_txg; + /* + * Number of times dnode_free_interior_slots() needed to retry + * acquiring a slot zrl lock due to contention. + */ + kstat_named_t dnode_free_interior_lock_retry; + /* + * Number of new dnodes allocated by dnode_allocate(). + */ + kstat_named_t dnode_allocate; + /* + * Number of dnodes re-allocated by dnode_reallocate(). + */ + kstat_named_t dnode_reallocate; + /* + * Number of meta dnode dbufs evicted. + */ + kstat_named_t dnode_buf_evict; + /* + * Number of times dmu_object_alloc*() reached the end of the existing + * object ID chunk and advanced to a new one. + */ + kstat_named_t dnode_alloc_next_chunk; + /* + * Number of times multiple threads attempted to allocate a dnode + * from the same block of free dnodes. + */ + kstat_named_t dnode_alloc_race; + /* + * Number of times dmu_object_alloc*() was forced to advance to the + * next meta dnode dbuf due to an error from dmu_object_next(). + */ + kstat_named_t dnode_alloc_next_block; + /* + * Statistics for tracking dnodes which have been moved. + */ + kstat_named_t dnode_move_invalid; + kstat_named_t dnode_move_recheck1; + kstat_named_t dnode_move_recheck2; + kstat_named_t dnode_move_special; + kstat_named_t dnode_move_handle; + kstat_named_t dnode_move_rwlock; + kstat_named_t dnode_move_active; +} dnode_stats_t; + +extern dnode_stats_t dnode_stats; + +#define DNODE_STAT_INCR(stat, val) \ + atomic_add_64(&dnode_stats.stat.value.ui64, (val)); +#define DNODE_STAT_BUMP(stat) \ + DNODE_STAT_INCR(stat, 1); + #ifdef ZFS_DEBUG /* |