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Diffstat (limited to 'include/sys/zio_impl.h')
| -rw-r--r-- | include/sys/zio_impl.h | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/include/sys/zio_impl.h b/include/sys/zio_impl.h new file mode 100644 index 000000000000..4c998571653a --- /dev/null +++ b/include/sys/zio_impl.h @@ -0,0 +1,270 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2009 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +/* + * Copyright (c) 2012, 2015 by Delphix. All rights reserved. + */ + +#ifndef _ZIO_IMPL_H +#define _ZIO_IMPL_H + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * XXX -- Describe ZFS I/O pipeline here. Fill in as needed. + * + * The ZFS I/O pipeline is comprised of various stages which are defined + * in the zio_stage enum below. The individual stages are used to construct + * these basic I/O operations: Read, Write, Free, Claim, and Ioctl. + * + * I/O operations: (XXX - provide detail for each of the operations) + * + * Read: + * Write: + * Free: + * Claim: + * Ioctl: + * + * Although the most common pipeline are used by the basic I/O operations + * above, there are some helper pipelines (one could consider them + * sub-pipelines) which are used internally by the ZIO module and are + * explained below: + * + * Interlock Pipeline: + * The interlock pipeline is the most basic pipeline and is used by all + * of the I/O operations. The interlock pipeline does not perform any I/O + * and is used to coordinate the dependencies between I/Os that are being + * issued (i.e. the parent/child relationship). + * + * Vdev child Pipeline: + * The vdev child pipeline is responsible for performing the physical I/O. + * It is in this pipeline where the I/O are queued and possibly cached. + * + * In addition to performing I/O, the pipeline is also responsible for + * data transformations. The transformations performed are based on the + * specific properties that user may have selected and modify the + * behavior of the pipeline. Examples of supported transformations are + * compression, dedup, and nop writes. Transformations will either modify + * the data or the pipeline. This list below further describes each of + * the supported transformations: + * + * Compression: + * ZFS supports five different flavors of compression -- gzip, lzjb, lz4, zle, + * and zstd. Compression occurs as part of the write pipeline and is + * performed in the ZIO_STAGE_WRITE_BP_INIT stage. + * + * Dedup: + * Dedup reads are handled by the ZIO_STAGE_DDT_READ_START and + * ZIO_STAGE_DDT_READ_DONE stages. These stages are added to an existing + * read pipeline if the dedup bit is set on the block pointer. + * Writing a dedup block is performed by the ZIO_STAGE_DDT_WRITE stage + * and added to a write pipeline if a user has enabled dedup on that + * particular dataset. + * + * NOP Write: + * The NOP write feature is performed by the ZIO_STAGE_NOP_WRITE stage + * and is added to an existing write pipeline if a cryptographically + * secure checksum (i.e. SHA256) is enabled and compression is turned on. + * The NOP write stage will compare the checksums of the current data + * on-disk (level-0 blocks only) and the data that is currently being written. + * If the checksum values are identical then the pipeline is converted to + * an interlock pipeline skipping block allocation and bypassing the + * physical I/O. The nop write feature can handle writes in either + * syncing or open context (i.e. zil writes) and as a result is mutually + * exclusive with dedup. + * + * Encryption: + * Encryption and authentication is handled by the ZIO_STAGE_ENCRYPT stage. + * This stage determines how the encryption metadata is stored in the bp. + * Decryption and MAC verification is performed during zio_decrypt() as a + * transform callback. Encryption is mutually exclusive with nopwrite, because + * blocks with the same plaintext will be encrypted with different salts and + * IV's (if dedup is off), and therefore have different ciphertexts. For dedup + * blocks we deterministically generate the IV and salt by performing an HMAC + * of the plaintext, which is computationally expensive, but allows us to keep + * support for encrypted dedup. See the block comment in zio_crypt.c for + * details. + */ + +/* + * zio pipeline stage definitions + */ +enum zio_stage { + ZIO_STAGE_OPEN = 1 << 0, /* RWFCI */ + + ZIO_STAGE_READ_BP_INIT = 1 << 1, /* R---- */ + ZIO_STAGE_WRITE_BP_INIT = 1 << 2, /* -W--- */ + ZIO_STAGE_FREE_BP_INIT = 1 << 3, /* --F-- */ + ZIO_STAGE_ISSUE_ASYNC = 1 << 4, /* RWF-- */ + ZIO_STAGE_WRITE_COMPRESS = 1 << 5, /* -W--- */ + + ZIO_STAGE_ENCRYPT = 1 << 6, /* -W--- */ + ZIO_STAGE_CHECKSUM_GENERATE = 1 << 7, /* -W--- */ + + ZIO_STAGE_NOP_WRITE = 1 << 8, /* -W--- */ + + ZIO_STAGE_DDT_READ_START = 1 << 9, /* R---- */ + ZIO_STAGE_DDT_READ_DONE = 1 << 10, /* R---- */ + ZIO_STAGE_DDT_WRITE = 1 << 11, /* -W--- */ + ZIO_STAGE_DDT_FREE = 1 << 12, /* --F-- */ + + ZIO_STAGE_GANG_ASSEMBLE = 1 << 13, /* RWFC- */ + ZIO_STAGE_GANG_ISSUE = 1 << 14, /* RWFC- */ + + ZIO_STAGE_DVA_THROTTLE = 1 << 15, /* -W--- */ + ZIO_STAGE_DVA_ALLOCATE = 1 << 16, /* -W--- */ + ZIO_STAGE_DVA_FREE = 1 << 17, /* --F-- */ + ZIO_STAGE_DVA_CLAIM = 1 << 18, /* ---C- */ + + ZIO_STAGE_READY = 1 << 19, /* RWFCI */ + + ZIO_STAGE_VDEV_IO_START = 1 << 20, /* RW--I */ + ZIO_STAGE_VDEV_IO_DONE = 1 << 21, /* RW--I */ + ZIO_STAGE_VDEV_IO_ASSESS = 1 << 22, /* RW--I */ + + ZIO_STAGE_CHECKSUM_VERIFY = 1 << 23, /* R---- */ + + ZIO_STAGE_DONE = 1 << 24 /* RWFCI */ +}; + +#define ZIO_INTERLOCK_STAGES \ + (ZIO_STAGE_READY | \ + ZIO_STAGE_DONE) + +#define ZIO_INTERLOCK_PIPELINE \ + ZIO_INTERLOCK_STAGES + +#define ZIO_VDEV_IO_STAGES \ + (ZIO_STAGE_VDEV_IO_START | \ + ZIO_STAGE_VDEV_IO_DONE | \ + ZIO_STAGE_VDEV_IO_ASSESS) + +#define ZIO_VDEV_CHILD_PIPELINE \ + (ZIO_VDEV_IO_STAGES | \ + ZIO_STAGE_DONE) + +#define ZIO_READ_COMMON_STAGES \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_VDEV_IO_STAGES | \ + ZIO_STAGE_CHECKSUM_VERIFY) + +#define ZIO_READ_PHYS_PIPELINE \ + ZIO_READ_COMMON_STAGES + +#define ZIO_READ_PIPELINE \ + (ZIO_READ_COMMON_STAGES | \ + ZIO_STAGE_READ_BP_INIT) + +#define ZIO_DDT_CHILD_READ_PIPELINE \ + ZIO_READ_COMMON_STAGES + +#define ZIO_DDT_READ_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_READ_BP_INIT | \ + ZIO_STAGE_DDT_READ_START | \ + ZIO_STAGE_DDT_READ_DONE) + +#define ZIO_WRITE_COMMON_STAGES \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_VDEV_IO_STAGES | \ + ZIO_STAGE_ISSUE_ASYNC | \ + ZIO_STAGE_CHECKSUM_GENERATE) + +#define ZIO_WRITE_PHYS_PIPELINE \ + ZIO_WRITE_COMMON_STAGES + +#define ZIO_REWRITE_PIPELINE \ + (ZIO_WRITE_COMMON_STAGES | \ + ZIO_STAGE_WRITE_COMPRESS | \ + ZIO_STAGE_ENCRYPT | \ + ZIO_STAGE_WRITE_BP_INIT) + +#define ZIO_WRITE_PIPELINE \ + (ZIO_WRITE_COMMON_STAGES | \ + ZIO_STAGE_WRITE_BP_INIT | \ + ZIO_STAGE_WRITE_COMPRESS | \ + ZIO_STAGE_ENCRYPT | \ + ZIO_STAGE_DVA_THROTTLE | \ + ZIO_STAGE_DVA_ALLOCATE) + +#define ZIO_DDT_CHILD_WRITE_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_VDEV_IO_STAGES | \ + ZIO_STAGE_DVA_THROTTLE | \ + ZIO_STAGE_DVA_ALLOCATE) + +#define ZIO_DDT_WRITE_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_WRITE_BP_INIT | \ + ZIO_STAGE_ISSUE_ASYNC | \ + ZIO_STAGE_WRITE_COMPRESS | \ + ZIO_STAGE_ENCRYPT | \ + ZIO_STAGE_CHECKSUM_GENERATE | \ + ZIO_STAGE_DDT_WRITE) + +#define ZIO_GANG_STAGES \ + (ZIO_STAGE_GANG_ASSEMBLE | \ + ZIO_STAGE_GANG_ISSUE) + +#define ZIO_FREE_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_FREE_BP_INIT | \ + ZIO_STAGE_DVA_FREE) + +#define ZIO_DDT_FREE_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_FREE_BP_INIT | \ + ZIO_STAGE_ISSUE_ASYNC | \ + ZIO_STAGE_DDT_FREE) + +#define ZIO_CLAIM_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_DVA_CLAIM) + +#define ZIO_IOCTL_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_VDEV_IO_START | \ + ZIO_STAGE_VDEV_IO_ASSESS) + +#define ZIO_TRIM_PIPELINE \ + (ZIO_INTERLOCK_STAGES | \ + ZIO_STAGE_ISSUE_ASYNC | \ + ZIO_VDEV_IO_STAGES) + +#define ZIO_BLOCKING_STAGES \ + (ZIO_STAGE_DVA_ALLOCATE | \ + ZIO_STAGE_DVA_CLAIM | \ + ZIO_STAGE_VDEV_IO_START) + +extern void zio_inject_init(void); +extern void zio_inject_fini(void); + +#ifdef __cplusplus +} +#endif + +#endif /* _ZIO_IMPL_H */ |