LCOV - code coverage report
Current view: top level - module/bdev/compress - vbdev_compress.c (source / functions) Hit Total Coverage
Test: ut_cov_unit.info Lines: 118 679 17.4 %
Date: 2024-11-05 10:06:02 Functions: 12 63 19.0 %

          Line data    Source code
       1             : /*   SPDX-License-Identifier: BSD-3-Clause
       2             :  *   Copyright (C) 2018 Intel Corporation.
       3             :  *   All rights reserved.
       4             :  *   Copyright (c) 2021, 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
       5             :  */
       6             : 
       7             : #include "vbdev_compress.h"
       8             : 
       9             : #include "spdk/reduce.h"
      10             : #include "spdk/stdinc.h"
      11             : #include "spdk/rpc.h"
      12             : #include "spdk/env.h"
      13             : #include "spdk/endian.h"
      14             : #include "spdk/string.h"
      15             : #include "spdk/thread.h"
      16             : #include "spdk/util.h"
      17             : #include "spdk/bdev_module.h"
      18             : #include "spdk/likely.h"
      19             : #include "spdk/log.h"
      20             : #include "spdk/accel.h"
      21             : 
      22             : #include "spdk/accel_module.h"
      23             : 
      24             : #define CHUNK_SIZE (1024 * 16)
      25             : #define COMP_BDEV_NAME "compress"
      26             : #define BACKING_IO_SZ (4 * 1024)
      27             : 
      28             : /* This namespace UUID was generated using uuid_generate() method. */
      29             : #define BDEV_COMPRESS_NAMESPACE_UUID "c3fad6da-832f-4cc0-9cdc-5c552b225e7b"
      30             : 
      31             : struct vbdev_comp_delete_ctx {
      32             :         spdk_delete_compress_complete   cb_fn;
      33             :         void                            *cb_arg;
      34             :         int                             cb_rc;
      35             :         struct spdk_thread              *orig_thread;
      36             : };
      37             : 
      38             : /* List of virtual bdevs and associated info for each. */
      39             : struct vbdev_compress {
      40             :         struct spdk_bdev                *base_bdev;     /* the thing we're attaching to */
      41             :         struct spdk_bdev_desc           *base_desc;     /* its descriptor we get from open */
      42             :         struct spdk_io_channel          *base_ch;       /* IO channel of base device */
      43             :         struct spdk_bdev                comp_bdev;      /* the compression virtual bdev */
      44             :         struct comp_io_channel          *comp_ch;       /* channel associated with this bdev */
      45             :         struct spdk_io_channel          *accel_channel; /* to communicate with the accel framework */
      46             :         struct spdk_thread              *reduce_thread;
      47             :         pthread_mutex_t                 reduce_lock;
      48             :         uint32_t                        ch_count;
      49             :         TAILQ_HEAD(, spdk_bdev_io)      pending_comp_ios;       /* outstanding operations to a comp library */
      50             :         struct spdk_poller              *poller;        /* completion poller */
      51             :         struct spdk_reduce_vol_params   params;         /* params for the reduce volume */
      52             :         struct spdk_reduce_backing_dev  backing_dev;    /* backing device info for the reduce volume */
      53             :         struct spdk_reduce_vol          *vol;           /* the reduce volume */
      54             :         struct vbdev_comp_delete_ctx    *delete_ctx;
      55             :         bool                            orphaned;       /* base bdev claimed but comp_bdev not registered */
      56             :         int                             reduce_errno;
      57             :         TAILQ_HEAD(, vbdev_comp_op)     queued_comp_ops;
      58             :         TAILQ_ENTRY(vbdev_compress)     link;
      59             :         struct spdk_thread              *thread;        /* thread where base device is opened */
      60             :         enum spdk_accel_comp_algo       comp_algo;      /* compression algorithm for compress bdev */
      61             :         uint32_t                        comp_level;     /* compression algorithm level */
      62             :         bool                            init_failed;    /* compress bdev initialization failed */
      63             : };
      64             : static TAILQ_HEAD(, vbdev_compress) g_vbdev_comp = TAILQ_HEAD_INITIALIZER(g_vbdev_comp);
      65             : 
      66             : /* The comp vbdev channel struct. It is allocated and freed on my behalf by the io channel code.
      67             :  */
      68             : struct comp_io_channel {
      69             :         struct spdk_io_channel_iter     *iter;  /* used with for_each_channel in reset */
      70             : };
      71             : 
      72             : /* Per I/O context for the compression vbdev. */
      73             : struct comp_bdev_io {
      74             :         struct comp_io_channel          *comp_ch;               /* used in completion handling */
      75             :         struct vbdev_compress           *comp_bdev;             /* vbdev associated with this IO */
      76             :         struct spdk_bdev_io_wait_entry  bdev_io_wait;           /* for bdev_io_wait */
      77             :         struct spdk_bdev_io             *orig_io;               /* the original IO */
      78             :         int                             status;                 /* save for completion on orig thread */
      79             : };
      80             : 
      81             : static void vbdev_compress_examine(struct spdk_bdev *bdev);
      82             : static int vbdev_compress_claim(struct vbdev_compress *comp_bdev);
      83             : struct vbdev_compress *_prepare_for_load_init(struct spdk_bdev_desc *bdev_desc, uint32_t lb_size,
      84             :                 uint8_t comp_algo, uint32_t comp_level);
      85             : static void vbdev_compress_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io);
      86             : static void comp_bdev_ch_destroy_cb(void *io_device, void *ctx_buf);
      87             : static void vbdev_compress_delete_done(void *cb_arg, int bdeverrno);
      88             : static void _comp_reduce_resubmit_backing_io(void *_backing_io);
      89             : 
      90             : /* for completing rw requests on the orig IO thread. */
      91             : static void
      92          14 : _reduce_rw_blocks_cb(void *arg)
      93             : {
      94          14 :         struct comp_bdev_io *io_ctx = arg;
      95             : 
      96          14 :         if (spdk_likely(io_ctx->status == 0)) {
      97           7 :                 spdk_bdev_io_complete(io_ctx->orig_io, SPDK_BDEV_IO_STATUS_SUCCESS);
      98           7 :         } else if (io_ctx->status == -ENOMEM) {
      99           0 :                 spdk_bdev_io_complete(io_ctx->orig_io, SPDK_BDEV_IO_STATUS_NOMEM);
     100             :         } else {
     101           7 :                 SPDK_ERRLOG("Failed to execute reduce api. %s\n", spdk_strerror(-io_ctx->status));
     102           7 :                 spdk_bdev_io_complete(io_ctx->orig_io, SPDK_BDEV_IO_STATUS_FAILED);
     103             :         }
     104          14 : }
     105             : 
     106             : /* Completion callback for r/w that were issued via reducelib. */
     107             : static void
     108          14 : reduce_rw_blocks_cb(void *arg, int reduce_errno)
     109             : {
     110          14 :         struct spdk_bdev_io *bdev_io = arg;
     111          14 :         struct comp_bdev_io *io_ctx = (struct comp_bdev_io *)bdev_io->driver_ctx;
     112          14 :         struct spdk_io_channel *ch = spdk_io_channel_from_ctx(io_ctx->comp_ch);
     113             :         struct spdk_thread *orig_thread;
     114             : 
     115             :         /* TODO: need to decide which error codes are bdev_io success vs failure;
     116             :          * example examine calls reading metadata */
     117             : 
     118          14 :         io_ctx->status = reduce_errno;
     119             : 
     120             :         /* Send this request to the orig IO thread. */
     121          14 :         orig_thread = spdk_io_channel_get_thread(ch);
     122             : 
     123          14 :         spdk_thread_exec_msg(orig_thread, _reduce_rw_blocks_cb, io_ctx);
     124          14 : }
     125             : 
     126             : static int
     127           0 : _compress_operation(struct spdk_reduce_backing_dev *backing_dev, struct iovec *src_iovs,
     128             :                     int src_iovcnt, struct iovec *dst_iovs,
     129             :                     int dst_iovcnt, bool compress, void *cb_arg)
     130             : {
     131           0 :         struct spdk_reduce_vol_cb_args *reduce_cb_arg = cb_arg;
     132           0 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(backing_dev, struct vbdev_compress,
     133             :                                            backing_dev);
     134             :         int rc;
     135             : 
     136           0 :         if (compress) {
     137           0 :                 assert(dst_iovcnt == 1);
     138           0 :                 rc = spdk_accel_submit_compress_ext(comp_bdev->accel_channel, dst_iovs[0].iov_base,
     139             :                                                     dst_iovs[0].iov_len, src_iovs, src_iovcnt,
     140             :                                                     comp_bdev->comp_algo, comp_bdev->comp_level,
     141             :                                                     &reduce_cb_arg->output_size, reduce_cb_arg->cb_fn,
     142             :                                                     reduce_cb_arg->cb_arg);
     143             :         } else {
     144           0 :                 rc = spdk_accel_submit_decompress_ext(comp_bdev->accel_channel, dst_iovs, dst_iovcnt,
     145             :                                                       src_iovs, src_iovcnt, comp_bdev->comp_algo,
     146             :                                                       &reduce_cb_arg->output_size, reduce_cb_arg->cb_fn,
     147             :                                                       reduce_cb_arg->cb_arg);
     148             :         }
     149             : 
     150           0 :         return rc;
     151             : }
     152             : 
     153             : /* Entry point for reduce lib to issue a compress operation. */
     154             : static void
     155           0 : _comp_reduce_compress(struct spdk_reduce_backing_dev *dev,
     156             :                       struct iovec *src_iovs, int src_iovcnt,
     157             :                       struct iovec *dst_iovs, int dst_iovcnt,
     158             :                       struct spdk_reduce_vol_cb_args *cb_arg)
     159             : {
     160             :         int rc;
     161             : 
     162           0 :         rc = _compress_operation(dev, src_iovs, src_iovcnt, dst_iovs, dst_iovcnt, true, cb_arg);
     163           0 :         if (rc) {
     164           0 :                 SPDK_ERRLOG("with compress operation code %d (%s)\n", rc, spdk_strerror(-rc));
     165           0 :                 cb_arg->cb_fn(cb_arg->cb_arg, rc);
     166             :         }
     167           0 : }
     168             : 
     169             : /* Entry point for reduce lib to issue a decompress operation. */
     170             : static void
     171           0 : _comp_reduce_decompress(struct spdk_reduce_backing_dev *dev,
     172             :                         struct iovec *src_iovs, int src_iovcnt,
     173             :                         struct iovec *dst_iovs, int dst_iovcnt,
     174             :                         struct spdk_reduce_vol_cb_args *cb_arg)
     175             : {
     176             :         int rc;
     177             : 
     178           0 :         rc = _compress_operation(dev, src_iovs, src_iovcnt, dst_iovs, dst_iovcnt, false, cb_arg);
     179           0 :         if (rc) {
     180           0 :                 SPDK_ERRLOG("with decompress operation code %d (%s)\n", rc, spdk_strerror(-rc));
     181           0 :                 cb_arg->cb_fn(cb_arg->cb_arg, rc);
     182             :         }
     183           0 : }
     184             : 
     185             : static void
     186           2 : _comp_submit_write(void *ctx)
     187             : {
     188           2 :         struct spdk_bdev_io *bdev_io = ctx;
     189           2 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     190             :                                            comp_bdev);
     191             : 
     192           2 :         spdk_reduce_vol_writev(comp_bdev->vol, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
     193             :                                bdev_io->u.bdev.offset_blocks, bdev_io->u.bdev.num_blocks,
     194             :                                reduce_rw_blocks_cb, bdev_io);
     195           2 : }
     196             : 
     197             : static void
     198           2 : _comp_submit_read(void *ctx)
     199             : {
     200           2 :         struct spdk_bdev_io *bdev_io = ctx;
     201           2 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     202             :                                            comp_bdev);
     203             : 
     204           2 :         spdk_reduce_vol_readv(comp_bdev->vol, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
     205             :                               bdev_io->u.bdev.offset_blocks, bdev_io->u.bdev.num_blocks,
     206             :                               reduce_rw_blocks_cb, bdev_io);
     207           2 : }
     208             : 
     209             : 
     210             : /* Callback for getting a buf from the bdev pool in the event that the caller passed
     211             :  * in NULL, we need to own the buffer so it doesn't get freed by another vbdev module
     212             :  * beneath us before we're done with it.
     213             :  */
     214             : static void
     215           2 : comp_read_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
     216             : {
     217           2 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     218             :                                            comp_bdev);
     219             : 
     220           2 :         if (spdk_unlikely(!success)) {
     221           0 :                 SPDK_ERRLOG("Failed to get data buffer\n");
     222           0 :                 reduce_rw_blocks_cb(bdev_io, -ENOMEM);
     223           0 :                 return;
     224             :         }
     225             : 
     226           2 :         spdk_thread_exec_msg(comp_bdev->reduce_thread, _comp_submit_read, bdev_io);
     227             : }
     228             : 
     229             : struct partial_chunk_info {
     230             :         uint64_t chunk_idx;
     231             :         uint64_t block_offset;
     232             :         uint64_t block_length;
     233             : };
     234             : 
     235             : /*
     236             :  * It's a structure used to hold information needed during the execution of an unmap operation.
     237             :  */
     238             : struct compress_unmap_split_ctx {
     239             :         struct spdk_bdev_io *bdev_io;
     240             :         int32_t status;
     241             :         uint32_t logical_blocks_per_chunk;
     242             :         /* The first chunk that can be fully covered by the unmap bdevio interval */
     243             :         uint64_t full_chunk_idx_b;
     244             :         /* The last chunk that can be fully covered by the unmap bdevio interval */
     245             :         uint64_t full_chunk_idx_e;
     246             :         uint64_t num_full_chunks;
     247             :         uint64_t num_full_chunks_consumed;
     248             :         uint32_t num_partial_chunks;
     249             :         uint32_t num_partial_chunks_consumed;
     250             :         /* Used to hold the partial chunk information. There will only be less than or equal to two,
     251             :         because chunks that cannot be fully covered will only appear at the beginning or end or both two. */
     252             :         struct partial_chunk_info partial_chunk_info[2];
     253             : };
     254             : 
     255             : static void _comp_unmap_subcmd_done_cb(void *ctx, int error);
     256             : 
     257             : /*
     258             :  * This function processes the unmap operation for both full and partial chunks in a
     259             :  * compressed block device. It iteratively submits unmap requests until all the chunks
     260             :  * have been unmapped or an error occurs.
     261             :  */
     262             : static void
     263          20 : _comp_submit_unmap_split(void *ctx)
     264             : {
     265          20 :         struct compress_unmap_split_ctx *split_ctx = ctx;
     266          20 :         struct spdk_bdev_io *bdev_io = split_ctx->bdev_io;
     267          20 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     268             :                                            comp_bdev);
     269          20 :         struct partial_chunk_info *partial_chunk = NULL;
     270          20 :         uint64_t chunk_idx = 0;
     271          20 :         uint64_t block_offset = 0;
     272          20 :         uint64_t block_length = 0;
     273             : 
     274          20 :         if (split_ctx->status != 0 ||
     275          15 :             (split_ctx->num_full_chunks_consumed == split_ctx->num_full_chunks &&
     276          13 :              split_ctx->num_partial_chunks_consumed == split_ctx->num_partial_chunks)) {
     277          10 :                 reduce_rw_blocks_cb(bdev_io, split_ctx->status);
     278          10 :                 free(split_ctx);
     279          10 :                 return;
     280             :         }
     281             : 
     282          10 :         if (split_ctx->num_full_chunks_consumed < split_ctx->num_full_chunks) {
     283           2 :                 chunk_idx = split_ctx->full_chunk_idx_b + split_ctx->num_full_chunks_consumed;
     284           2 :                 block_offset = chunk_idx * split_ctx->logical_blocks_per_chunk;
     285           2 :                 block_length = split_ctx->logical_blocks_per_chunk;
     286             : 
     287           2 :                 split_ctx->num_full_chunks_consumed++;
     288           2 :                 spdk_reduce_vol_unmap(comp_bdev->vol,
     289             :                                       block_offset, block_length,
     290             :                                       _comp_unmap_subcmd_done_cb, split_ctx);
     291           8 :         } else if (split_ctx->num_partial_chunks_consumed < split_ctx->num_partial_chunks) {
     292           8 :                 partial_chunk = &split_ctx->partial_chunk_info[split_ctx->num_partial_chunks_consumed];
     293           8 :                 block_offset = partial_chunk->chunk_idx * split_ctx->logical_blocks_per_chunk +
     294           8 :                                partial_chunk->block_offset;
     295           8 :                 block_length = partial_chunk->block_length;
     296             : 
     297           8 :                 split_ctx->num_partial_chunks_consumed++;
     298           8 :                 spdk_reduce_vol_unmap(comp_bdev->vol,
     299             :                                       block_offset, block_length,
     300             :                                       _comp_unmap_subcmd_done_cb, split_ctx);
     301             :         } else {
     302           0 :                 assert(false);
     303             :         }
     304             : }
     305             : 
     306             : /*
     307             :  * When mkfs or fstrim, large unmap requests may be generated.
     308             :  * Large request will be split into multiple subcmds and processed recursively.
     309             :  * Run too many subcmds recursively may cause stack overflow or monopolize the thread,
     310             :  * delaying other tasks. To avoid this, next subcmd need to be processed asynchronously
     311             :  * by 'spdk_thread_send_msg'.
     312             :  */
     313             : static void
     314          10 : _comp_unmap_subcmd_done_cb(void *ctx, int error)
     315             : {
     316          10 :         struct compress_unmap_split_ctx *split_ctx = ctx;
     317             : 
     318          10 :         split_ctx->status = error;
     319          10 :         spdk_thread_send_msg(spdk_get_thread(), _comp_submit_unmap_split, split_ctx);
     320          10 : }
     321             : 
     322             : /*
     323             :  * This function splits the unmap operation into full and partial chunks based on the
     324             :  * block range specified in the 'spdk_bdev_io' structure. It calculates the start and end
     325             :  * chunks, as well as any partial chunks at the beginning or end of the range, and prepares
     326             :  * a context (compress_unmap_split_ctx) to handle these chunks. The unmap operation is
     327             :  * then submitted for processing through '_comp_submit_unmap_split'.
     328             :  * some cases to handle:
     329             :  * 1. start and end chunks are different
     330             :  * 1.1 start and end chunks are full
     331             :  * 1.2 start and end chunks are partial
     332             :  * 1.3 start or  end chunk  is full and the other is partial
     333             :  * 2. start and end chunks are the same
     334             :  * 2.1 full
     335             :  * 2.2 partial
     336             :  */
     337             : static void
     338          10 : _comp_submit_unmap(void *ctx)
     339             : {
     340          10 :         struct spdk_bdev_io *bdev_io = ctx;
     341          10 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     342             :                                            comp_bdev);
     343          10 :         const struct spdk_reduce_vol_params *vol_params = spdk_reduce_vol_get_params(comp_bdev->vol);
     344             :         struct compress_unmap_split_ctx *split_ctx;
     345             :         struct partial_chunk_info *partial_chunk;
     346             :         uint32_t logical_blocks_per_chunk;
     347             :         uint64_t start_chunk, end_chunk, start_offset, end_tail;
     348             : 
     349          10 :         logical_blocks_per_chunk = vol_params->chunk_size / vol_params->logical_block_size;
     350          10 :         start_chunk = bdev_io->u.bdev.offset_blocks / logical_blocks_per_chunk;
     351          10 :         end_chunk = (bdev_io->u.bdev.offset_blocks + bdev_io->u.bdev.num_blocks - 1) /
     352             :                     logical_blocks_per_chunk;
     353          10 :         start_offset = bdev_io->u.bdev.offset_blocks % logical_blocks_per_chunk;
     354          10 :         end_tail = (bdev_io->u.bdev.offset_blocks + bdev_io->u.bdev.num_blocks) %
     355             :                    logical_blocks_per_chunk;
     356             : 
     357          10 :         split_ctx = calloc(1, sizeof(struct compress_unmap_split_ctx));
     358          10 :         if (split_ctx == NULL) {
     359           0 :                 reduce_rw_blocks_cb(bdev_io, -ENOMEM);
     360           0 :                 return;
     361             :         }
     362          10 :         partial_chunk = split_ctx->partial_chunk_info;
     363          10 :         split_ctx->bdev_io = bdev_io;
     364          10 :         split_ctx->logical_blocks_per_chunk = logical_blocks_per_chunk;
     365             : 
     366          10 :         if (start_chunk < end_chunk) {
     367           0 :                 if (start_offset != 0) {
     368           0 :                         partial_chunk[split_ctx->num_partial_chunks].chunk_idx = start_chunk;
     369           0 :                         partial_chunk[split_ctx->num_partial_chunks].block_offset = start_offset;
     370           0 :                         partial_chunk[split_ctx->num_partial_chunks].block_length = logical_blocks_per_chunk
     371           0 :                                         - start_offset;
     372           0 :                         split_ctx->num_partial_chunks++;
     373           0 :                         split_ctx->full_chunk_idx_b = start_chunk + 1;
     374             :                 } else {
     375           0 :                         split_ctx->full_chunk_idx_b = start_chunk;
     376             :                 }
     377             : 
     378           0 :                 if (end_tail != 0) {
     379           0 :                         partial_chunk[split_ctx->num_partial_chunks].chunk_idx = end_chunk;
     380           0 :                         partial_chunk[split_ctx->num_partial_chunks].block_offset = 0;
     381           0 :                         partial_chunk[split_ctx->num_partial_chunks].block_length = end_tail;
     382           0 :                         split_ctx->num_partial_chunks++;
     383           0 :                         split_ctx->full_chunk_idx_e = end_chunk - 1;
     384             :                 } else {
     385           0 :                         split_ctx->full_chunk_idx_e = end_chunk;
     386             :                 }
     387             : 
     388           0 :                 split_ctx->num_full_chunks = end_chunk - start_chunk + 1 - split_ctx->num_partial_chunks;
     389             : 
     390           0 :                 if (split_ctx->num_full_chunks) {
     391           0 :                         assert(split_ctx->full_chunk_idx_b != UINT64_MAX && split_ctx->full_chunk_idx_e != UINT64_MAX);
     392           0 :                         assert(split_ctx->full_chunk_idx_e - split_ctx->full_chunk_idx_b + 1 == split_ctx->num_full_chunks);
     393             :                 } else {
     394           0 :                         assert(split_ctx->full_chunk_idx_b - split_ctx->full_chunk_idx_e == 1);
     395             :                 }
     396          10 :         } else if (start_offset != 0 || end_tail != 0) {
     397           8 :                 partial_chunk[0].chunk_idx = start_chunk;
     398           8 :                 partial_chunk[0].block_offset = start_offset;
     399           8 :                 partial_chunk[0].block_length =
     400           8 :                         bdev_io->u.bdev.num_blocks;
     401           8 :                 split_ctx->num_partial_chunks = 1;
     402             :         } else {
     403           2 :                 split_ctx->full_chunk_idx_b = start_chunk;
     404           2 :                 split_ctx->full_chunk_idx_e = end_chunk;
     405           2 :                 split_ctx->num_full_chunks = 1;
     406             :         }
     407          10 :         assert(split_ctx->num_partial_chunks <= SPDK_COUNTOF(split_ctx->partial_chunk_info));
     408             : 
     409          10 :         _comp_submit_unmap_split(split_ctx);
     410             : }
     411             : 
     412             : /* Called when someone above submits IO to this vbdev. */
     413             : static void
     414          14 : vbdev_compress_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
     415             : {
     416          14 :         struct comp_bdev_io *io_ctx = (struct comp_bdev_io *)bdev_io->driver_ctx;
     417          14 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_compress,
     418             :                                            comp_bdev);
     419          14 :         struct comp_io_channel *comp_ch = spdk_io_channel_get_ctx(ch);
     420             : 
     421          14 :         memset(io_ctx, 0, sizeof(struct comp_bdev_io));
     422          14 :         io_ctx->comp_bdev = comp_bdev;
     423          14 :         io_ctx->comp_ch = comp_ch;
     424          14 :         io_ctx->orig_io = bdev_io;
     425             : 
     426          14 :         switch (bdev_io->type) {
     427           2 :         case SPDK_BDEV_IO_TYPE_READ:
     428           2 :                 spdk_bdev_io_get_buf(bdev_io, comp_read_get_buf_cb,
     429           2 :                                      bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
     430           2 :                 return;
     431           2 :         case SPDK_BDEV_IO_TYPE_WRITE:
     432           2 :                 spdk_thread_exec_msg(comp_bdev->reduce_thread, _comp_submit_write, bdev_io);
     433           2 :                 return;
     434          10 :         case SPDK_BDEV_IO_TYPE_UNMAP:
     435          10 :                 spdk_thread_exec_msg(comp_bdev->reduce_thread, _comp_submit_unmap, bdev_io);
     436          10 :                 return;
     437             :         /* TODO support RESET in future patch in the series */
     438           0 :         case SPDK_BDEV_IO_TYPE_RESET:
     439             :         case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
     440             :         case SPDK_BDEV_IO_TYPE_FLUSH:
     441             :         default:
     442           0 :                 SPDK_ERRLOG("Unknown I/O type %d\n", bdev_io->type);
     443           0 :                 spdk_bdev_io_complete(io_ctx->orig_io, SPDK_BDEV_IO_STATUS_FAILED);
     444           0 :                 break;
     445             :         }
     446             : }
     447             : 
     448             : static bool
     449          12 : vbdev_compress_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
     450             : {
     451          12 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     452             : 
     453          12 :         switch (io_type) {
     454           4 :         case SPDK_BDEV_IO_TYPE_READ:
     455             :         case SPDK_BDEV_IO_TYPE_WRITE:
     456           4 :                 return spdk_bdev_io_type_supported(comp_bdev->base_bdev, io_type);
     457           2 :         case SPDK_BDEV_IO_TYPE_UNMAP:
     458           2 :                 return true;
     459           6 :         case SPDK_BDEV_IO_TYPE_RESET:
     460             :         case SPDK_BDEV_IO_TYPE_FLUSH:
     461             :         case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
     462             :         default:
     463           6 :                 return false;
     464             :         }
     465             : }
     466             : 
     467             : /* Callback for unregistering the IO device. */
     468             : static void
     469           0 : _device_unregister_cb(void *io_device)
     470             : {
     471           0 :         struct vbdev_compress *comp_bdev = io_device;
     472             : 
     473             :         /* Done with this comp_bdev. */
     474           0 :         pthread_mutex_destroy(&comp_bdev->reduce_lock);
     475           0 :         free(comp_bdev->comp_bdev.name);
     476           0 :         free(comp_bdev);
     477           0 : }
     478             : 
     479             : static void
     480           0 : _vbdev_compress_destruct_cb(void *ctx)
     481             : {
     482           0 :         struct vbdev_compress *comp_bdev = ctx;
     483             : 
     484             :         /* Close the underlying bdev on its same opened thread. */
     485           0 :         spdk_bdev_close(comp_bdev->base_desc);
     486           0 :         comp_bdev->vol = NULL;
     487           0 :         if (comp_bdev->init_failed) {
     488           0 :                 free(comp_bdev);
     489           0 :                 return;
     490             :         }
     491             : 
     492           0 :         TAILQ_REMOVE(&g_vbdev_comp, comp_bdev, link);
     493           0 :         spdk_bdev_module_release_bdev(comp_bdev->base_bdev);
     494             : 
     495           0 :         if (comp_bdev->orphaned == false) {
     496           0 :                 spdk_io_device_unregister(comp_bdev, _device_unregister_cb);
     497             :         } else {
     498           0 :                 vbdev_compress_delete_done(comp_bdev->delete_ctx, 0);
     499           0 :                 _device_unregister_cb(comp_bdev);
     500             :         }
     501             : }
     502             : 
     503             : static void
     504           0 : vbdev_compress_destruct_cb(void *cb_arg, int reduce_errno)
     505             : {
     506           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)cb_arg;
     507             : 
     508           0 :         if (reduce_errno) {
     509           0 :                 SPDK_ERRLOG("number %d\n", reduce_errno);
     510             :         } else {
     511           0 :                 if (comp_bdev->thread && comp_bdev->thread != spdk_get_thread()) {
     512           0 :                         spdk_thread_send_msg(comp_bdev->thread,
     513             :                                              _vbdev_compress_destruct_cb, comp_bdev);
     514             :                 } else {
     515           0 :                         _vbdev_compress_destruct_cb(comp_bdev);
     516             :                 }
     517             :         }
     518           0 : }
     519             : 
     520             : static void
     521           0 : _reduce_destroy_cb(void *ctx, int reduce_errno)
     522             : {
     523           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     524             : 
     525           0 :         if (reduce_errno) {
     526           0 :                 SPDK_ERRLOG("number %d\n", reduce_errno);
     527             :         }
     528             : 
     529           0 :         comp_bdev->vol = NULL;
     530           0 :         spdk_put_io_channel(comp_bdev->base_ch);
     531           0 :         if (comp_bdev->init_failed || comp_bdev->orphaned) {
     532           0 :                 vbdev_compress_destruct_cb((void *)comp_bdev, 0);
     533             :         } else {
     534           0 :                 spdk_bdev_unregister(&comp_bdev->comp_bdev, vbdev_compress_delete_done,
     535           0 :                                      comp_bdev->delete_ctx);
     536             :         }
     537             : 
     538           0 : }
     539             : 
     540             : static void
     541           0 : _delete_vol_unload_cb(void *ctx)
     542             : {
     543           0 :         struct vbdev_compress *comp_bdev = ctx;
     544             : 
     545             :         /* FIXME: Assert if these conditions are not satisfied for now. */
     546           0 :         assert(!comp_bdev->reduce_thread ||
     547             :                comp_bdev->reduce_thread == spdk_get_thread());
     548             : 
     549             :         /* reducelib needs a channel to comm with the backing device */
     550           0 :         comp_bdev->base_ch = spdk_bdev_get_io_channel(comp_bdev->base_desc);
     551             : 
     552             :         /* Clean the device before we free our resources. */
     553           0 :         spdk_reduce_vol_destroy(&comp_bdev->backing_dev, _reduce_destroy_cb, comp_bdev);
     554           0 : }
     555             : 
     556             : /* Called by reduceLib after performing unload vol actions */
     557             : static void
     558           0 : delete_vol_unload_cb(void *cb_arg, int reduce_errno)
     559             : {
     560           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)cb_arg;
     561             : 
     562           0 :         if (reduce_errno) {
     563           0 :                 SPDK_ERRLOG("Failed to unload vol, error %s\n", spdk_strerror(-reduce_errno));
     564           0 :                 vbdev_compress_delete_done(comp_bdev->delete_ctx, reduce_errno);
     565           0 :                 return;
     566             :         }
     567             : 
     568           0 :         pthread_mutex_lock(&comp_bdev->reduce_lock);
     569           0 :         if (comp_bdev->reduce_thread && comp_bdev->reduce_thread != spdk_get_thread()) {
     570           0 :                 spdk_thread_send_msg(comp_bdev->reduce_thread,
     571             :                                      _delete_vol_unload_cb, comp_bdev);
     572           0 :                 pthread_mutex_unlock(&comp_bdev->reduce_lock);
     573             :         } else {
     574           0 :                 pthread_mutex_unlock(&comp_bdev->reduce_lock);
     575             : 
     576           0 :                 _delete_vol_unload_cb(comp_bdev);
     577             :         }
     578             : }
     579             : 
     580             : const char *
     581           0 : compress_get_name(const struct vbdev_compress *comp_bdev)
     582             : {
     583           0 :         return comp_bdev->comp_bdev.name;
     584             : }
     585             : 
     586             : struct vbdev_compress *
     587           0 : compress_bdev_first(void)
     588             : {
     589             :         struct vbdev_compress *comp_bdev;
     590             : 
     591           0 :         comp_bdev = TAILQ_FIRST(&g_vbdev_comp);
     592             : 
     593           0 :         return comp_bdev;
     594             : }
     595             : 
     596             : struct vbdev_compress *
     597           0 : compress_bdev_next(struct vbdev_compress *prev)
     598             : {
     599             :         struct vbdev_compress *comp_bdev;
     600             : 
     601           0 :         comp_bdev = TAILQ_NEXT(prev, link);
     602             : 
     603           0 :         return comp_bdev;
     604             : }
     605             : 
     606             : bool
     607           0 : compress_has_orphan(const char *name)
     608             : {
     609             :         struct vbdev_compress *comp_bdev;
     610             : 
     611           0 :         TAILQ_FOREACH(comp_bdev, &g_vbdev_comp, link) {
     612           0 :                 if (comp_bdev->orphaned && strcmp(name, comp_bdev->comp_bdev.name) == 0) {
     613           0 :                         return true;
     614             :                 }
     615             :         }
     616           0 :         return false;
     617             : }
     618             : 
     619             : /* Called after we've unregistered following a hot remove callback.
     620             :  * Our finish entry point will be called next.
     621             :  */
     622             : static int
     623           0 : vbdev_compress_destruct(void *ctx)
     624             : {
     625           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     626             : 
     627           0 :         if (comp_bdev->vol != NULL) {
     628             :                 /* Tell reducelib that we're done with this volume. */
     629           0 :                 spdk_reduce_vol_unload(comp_bdev->vol, vbdev_compress_destruct_cb, comp_bdev);
     630             :         } else {
     631           0 :                 vbdev_compress_destruct_cb(comp_bdev, 0);
     632             :         }
     633             : 
     634           0 :         return 0;
     635             : }
     636             : 
     637             : /* We supplied this as an entry point for upper layers who want to communicate to this
     638             :  * bdev.  This is how they get a channel.
     639             :  */
     640             : static struct spdk_io_channel *
     641           0 : vbdev_compress_get_io_channel(void *ctx)
     642             : {
     643           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     644             : 
     645             :         /* The IO channel code will allocate a channel for us which consists of
     646             :          * the SPDK channel structure plus the size of our comp_io_channel struct
     647             :          * that we passed in when we registered our IO device. It will then call
     648             :          * our channel create callback to populate any elements that we need to
     649             :          * update.
     650             :          */
     651           0 :         return spdk_get_io_channel(comp_bdev);
     652             : }
     653             : 
     654             : /* This is the output for bdev_get_bdevs() for this vbdev */
     655             : static int
     656           0 : vbdev_compress_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
     657             : {
     658           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     659             :         const struct spdk_reduce_vol_info *vol_info;
     660           0 :         char *comp_algo = NULL;
     661             : 
     662           0 :         if (comp_bdev->params.comp_algo == SPDK_ACCEL_COMP_ALGO_LZ4) {
     663           0 :                 comp_algo = "lz4";
     664           0 :         } else if (comp_bdev->params.comp_algo == SPDK_ACCEL_COMP_ALGO_DEFLATE) {
     665           0 :                 comp_algo = "deflate";
     666             :         } else {
     667           0 :                 assert(false);
     668             :         }
     669             : 
     670           0 :         spdk_json_write_name(w, "compress");
     671           0 :         spdk_json_write_object_begin(w);
     672           0 :         spdk_json_write_named_string(w, "name", spdk_bdev_get_name(&comp_bdev->comp_bdev));
     673           0 :         spdk_json_write_named_string(w, "base_bdev_name", spdk_bdev_get_name(comp_bdev->base_bdev));
     674           0 :         spdk_json_write_named_string(w, "pm_path", spdk_reduce_vol_get_pm_path(comp_bdev->vol));
     675           0 :         spdk_json_write_named_string(w, "comp_algo", comp_algo);
     676           0 :         spdk_json_write_named_uint32(w, "comp_level", comp_bdev->params.comp_level);
     677           0 :         spdk_json_write_named_uint32(w, "chunk_size", comp_bdev->params.chunk_size);
     678           0 :         spdk_json_write_named_uint32(w, "backing_io_unit_size", comp_bdev->params.backing_io_unit_size);
     679           0 :         vol_info = spdk_reduce_vol_get_info(comp_bdev->vol);
     680           0 :         spdk_json_write_named_uint64(w, "allocated_io_units", vol_info->allocated_io_units);
     681           0 :         spdk_json_write_object_end(w);
     682             : 
     683           0 :         return 0;
     684             : }
     685             : 
     686             : static int
     687           0 : vbdev_compress_config_json(struct spdk_json_write_ctx *w)
     688             : {
     689             :         /* Nothing to dump as compress bdev configuration is saved on physical device. */
     690           0 :         return 0;
     691             : }
     692             : 
     693             : struct vbdev_init_reduce_ctx {
     694             :         struct vbdev_compress   *comp_bdev;
     695             :         int                     status;
     696             :         bdev_compress_create_cb cb_fn;
     697             :         void                    *cb_ctx;
     698             : };
     699             : 
     700             : static void
     701           0 : _cleanup_vol_unload_cb(void *ctx)
     702             : {
     703           0 :         struct vbdev_compress *comp_bdev = ctx;
     704             : 
     705           0 :         assert(!comp_bdev->reduce_thread ||
     706             :                comp_bdev->reduce_thread == spdk_get_thread());
     707             : 
     708           0 :         comp_bdev->base_ch = spdk_bdev_get_io_channel(comp_bdev->base_desc);
     709             : 
     710           0 :         spdk_reduce_vol_destroy(&comp_bdev->backing_dev, _reduce_destroy_cb, comp_bdev);
     711           0 : }
     712             : 
     713             : static void
     714           0 : init_vol_unload_cb(void *ctx, int reduce_errno)
     715             : {
     716           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)ctx;
     717             : 
     718           0 :         if (reduce_errno) {
     719           0 :                 SPDK_ERRLOG("Failed to unload vol, error %s\n", spdk_strerror(-reduce_errno));
     720             :         }
     721             : 
     722           0 :         pthread_mutex_lock(&comp_bdev->reduce_lock);
     723           0 :         if (comp_bdev->reduce_thread && comp_bdev->reduce_thread != spdk_get_thread()) {
     724           0 :                 spdk_thread_send_msg(comp_bdev->reduce_thread,
     725             :                                      _cleanup_vol_unload_cb, comp_bdev);
     726           0 :                 pthread_mutex_unlock(&comp_bdev->reduce_lock);
     727             :         } else {
     728           0 :                 pthread_mutex_unlock(&comp_bdev->reduce_lock);
     729             : 
     730           0 :                 _cleanup_vol_unload_cb(comp_bdev);
     731             :         }
     732           0 : }
     733             : 
     734             : static void
     735           0 : _vbdev_reduce_init_cb(void *ctx)
     736             : {
     737           0 :         struct vbdev_init_reduce_ctx *init_ctx = ctx;
     738           0 :         struct vbdev_compress *comp_bdev = init_ctx->comp_bdev;
     739           0 :         int rc = init_ctx->status;
     740             : 
     741           0 :         assert(comp_bdev->base_desc != NULL);
     742             : 
     743             :         /* We're done with metadata operations */
     744           0 :         spdk_put_io_channel(comp_bdev->base_ch);
     745             : 
     746           0 :         if (rc != 0) {
     747           0 :                 goto err;
     748             :         }
     749             : 
     750           0 :         assert(comp_bdev->vol != NULL);
     751             : 
     752           0 :         rc = vbdev_compress_claim(comp_bdev);
     753           0 :         if (rc != 0) {
     754           0 :                 comp_bdev->init_failed = true;
     755           0 :                 spdk_reduce_vol_unload(comp_bdev->vol, init_vol_unload_cb, comp_bdev);
     756             :         }
     757             : 
     758           0 :         init_ctx->cb_fn(init_ctx->cb_ctx, rc);
     759           0 :         free(init_ctx);
     760           0 :         return;
     761             : 
     762           0 : err:
     763           0 :         init_ctx->cb_fn(init_ctx->cb_ctx, rc);
     764             :         /* Close the underlying bdev on its same opened thread. */
     765           0 :         spdk_bdev_close(comp_bdev->base_desc);
     766           0 :         free(comp_bdev);
     767           0 :         free(init_ctx);
     768             : }
     769             : 
     770             : /* Callback from reduce for when init is complete. We'll pass the vbdev_comp struct
     771             :  * used for initial metadata operations to claim where it will be further filled out
     772             :  * and added to the global list.
     773             :  */
     774             : static void
     775           0 : vbdev_reduce_init_cb(void *cb_arg, struct spdk_reduce_vol *vol, int reduce_errno)
     776             : {
     777           0 :         struct vbdev_init_reduce_ctx *init_ctx = cb_arg;
     778           0 :         struct vbdev_compress *comp_bdev = init_ctx->comp_bdev;
     779             : 
     780           0 :         if (reduce_errno == 0) {
     781           0 :                 comp_bdev->vol = vol;
     782             :         } else {
     783           0 :                 SPDK_ERRLOG("for vol %s, error %s\n",
     784             :                             spdk_bdev_get_name(comp_bdev->base_bdev), spdk_strerror(-reduce_errno));
     785             :         }
     786             : 
     787           0 :         init_ctx->status = reduce_errno;
     788             : 
     789           0 :         if (comp_bdev->thread && comp_bdev->thread != spdk_get_thread()) {
     790           0 :                 spdk_thread_send_msg(comp_bdev->thread, _vbdev_reduce_init_cb, init_ctx);
     791             :         } else {
     792           0 :                 _vbdev_reduce_init_cb(init_ctx);
     793             :         }
     794           0 : }
     795             : 
     796             : /* Callback for the function used by reduceLib to perform IO to/from the backing device. We just
     797             :  * call the callback provided by reduceLib when it called the read/write/unmap function and
     798             :  * free the bdev_io.
     799             :  */
     800             : static void
     801           0 : comp_reduce_io_cb(struct spdk_bdev_io *bdev_io, bool success, void *arg)
     802             : {
     803           0 :         struct spdk_reduce_vol_cb_args *cb_args = arg;
     804             :         int reduce_errno;
     805             : 
     806           0 :         if (success) {
     807           0 :                 reduce_errno = 0;
     808             :         } else {
     809           0 :                 reduce_errno = -EIO;
     810             :         }
     811           0 :         spdk_bdev_free_io(bdev_io);
     812           0 :         cb_args->cb_fn(cb_args->cb_arg, reduce_errno);
     813           0 : }
     814             : 
     815             : static void
     816           0 : _comp_backing_bdev_queue_io_wait(struct vbdev_compress *comp_bdev,
     817             :                                  struct spdk_reduce_backing_io *backing_io)
     818             : {
     819             :         struct spdk_bdev_io_wait_entry *waitq_entry;
     820             :         int rc;
     821             : 
     822           0 :         waitq_entry = (struct spdk_bdev_io_wait_entry *) &backing_io->user_ctx;
     823           0 :         waitq_entry->bdev = spdk_bdev_desc_get_bdev(comp_bdev->base_desc);
     824           0 :         waitq_entry->cb_fn = _comp_reduce_resubmit_backing_io;
     825           0 :         waitq_entry->cb_arg = backing_io;
     826             : 
     827           0 :         rc = spdk_bdev_queue_io_wait(waitq_entry->bdev, comp_bdev->base_ch, waitq_entry);
     828           0 :         if (rc) {
     829           0 :                 SPDK_ERRLOG("Queue io failed in _comp_backing_bdev_queue_io_wait, rc=%d.\n", rc);
     830           0 :                 assert(false);
     831             :                 backing_io->backing_cb_args->cb_fn(backing_io->backing_cb_args->cb_arg, rc);
     832             :         }
     833           0 : }
     834             : 
     835             : static void
     836           0 : _comp_backing_bdev_read(struct spdk_reduce_backing_io *backing_io)
     837             : {
     838           0 :         struct spdk_reduce_vol_cb_args *backing_cb_args = backing_io->backing_cb_args;
     839           0 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(backing_io->dev, struct vbdev_compress,
     840             :                                            backing_dev);
     841             :         int rc;
     842             : 
     843           0 :         rc = spdk_bdev_readv_blocks(comp_bdev->base_desc, comp_bdev->base_ch,
     844           0 :                                     backing_io->iov, backing_io->iovcnt,
     845           0 :                                     backing_io->lba, backing_io->lba_count,
     846             :                                     comp_reduce_io_cb,
     847             :                                     backing_cb_args);
     848             : 
     849           0 :         if (rc) {
     850           0 :                 if (rc == -ENOMEM) {
     851           0 :                         _comp_backing_bdev_queue_io_wait(comp_bdev, backing_io);
     852           0 :                         return;
     853             :                 } else {
     854           0 :                         SPDK_ERRLOG("submitting readv request, rc=%d\n", rc);
     855             :                 }
     856           0 :                 backing_cb_args->cb_fn(backing_cb_args->cb_arg, rc);
     857             :         }
     858             : }
     859             : 
     860             : static void
     861           0 : _comp_backing_bdev_write(struct spdk_reduce_backing_io  *backing_io)
     862             : {
     863           0 :         struct spdk_reduce_vol_cb_args *backing_cb_args = backing_io->backing_cb_args;
     864           0 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(backing_io->dev, struct vbdev_compress,
     865             :                                            backing_dev);
     866             :         int rc;
     867             : 
     868           0 :         rc = spdk_bdev_writev_blocks(comp_bdev->base_desc, comp_bdev->base_ch,
     869           0 :                                      backing_io->iov, backing_io->iovcnt,
     870           0 :                                      backing_io->lba, backing_io->lba_count,
     871             :                                      comp_reduce_io_cb,
     872             :                                      backing_cb_args);
     873             : 
     874           0 :         if (rc) {
     875           0 :                 if (rc == -ENOMEM) {
     876           0 :                         _comp_backing_bdev_queue_io_wait(comp_bdev, backing_io);
     877           0 :                         return;
     878             :                 } else {
     879           0 :                         SPDK_ERRLOG("error submitting writev request, rc=%d\n", rc);
     880             :                 }
     881           0 :                 backing_cb_args->cb_fn(backing_cb_args->cb_arg, rc);
     882             :         }
     883             : }
     884             : 
     885             : static void
     886           0 : _comp_backing_bdev_unmap(struct spdk_reduce_backing_io *backing_io)
     887             : {
     888           0 :         struct spdk_reduce_vol_cb_args *backing_cb_args = backing_io->backing_cb_args;
     889           0 :         struct vbdev_compress *comp_bdev = SPDK_CONTAINEROF(backing_io->dev, struct vbdev_compress,
     890             :                                            backing_dev);
     891             :         int rc;
     892             : 
     893           0 :         rc = spdk_bdev_unmap_blocks(comp_bdev->base_desc, comp_bdev->base_ch,
     894           0 :                                     backing_io->lba, backing_io->lba_count,
     895             :                                     comp_reduce_io_cb,
     896             :                                     backing_cb_args);
     897             : 
     898           0 :         if (rc) {
     899           0 :                 if (rc == -ENOMEM) {
     900           0 :                         _comp_backing_bdev_queue_io_wait(comp_bdev, backing_io);
     901           0 :                         return;
     902             :                 } else {
     903           0 :                         SPDK_ERRLOG("submitting unmap request, rc=%d\n", rc);
     904             :                 }
     905           0 :                 backing_cb_args->cb_fn(backing_cb_args->cb_arg, rc);
     906             :         }
     907             : }
     908             : 
     909             : /* This is the function provided to the reduceLib for sending reads/writes/unmaps
     910             :  * directly to the backing device.
     911             :  */
     912             : static void
     913           0 : _comp_reduce_submit_backing_io(struct spdk_reduce_backing_io *backing_io)
     914             : {
     915           0 :         switch (backing_io->backing_io_type) {
     916           0 :         case SPDK_REDUCE_BACKING_IO_WRITE:
     917           0 :                 _comp_backing_bdev_write(backing_io);
     918           0 :                 break;
     919           0 :         case SPDK_REDUCE_BACKING_IO_READ:
     920           0 :                 _comp_backing_bdev_read(backing_io);
     921           0 :                 break;
     922           0 :         case SPDK_REDUCE_BACKING_IO_UNMAP:
     923           0 :                 _comp_backing_bdev_unmap(backing_io);
     924           0 :                 break;
     925           0 :         default:
     926           0 :                 SPDK_ERRLOG("Unknown I/O type %d\n", backing_io->backing_io_type);
     927           0 :                 backing_io->backing_cb_args->cb_fn(backing_io->backing_cb_args->cb_arg, -EINVAL);
     928           0 :                 break;
     929             :         }
     930           0 : }
     931             : 
     932             : static void
     933           0 : _comp_reduce_resubmit_backing_io(void *_backing_io)
     934             : {
     935           0 :         struct spdk_reduce_backing_io *backing_io = _backing_io;
     936             : 
     937           0 :         _comp_reduce_submit_backing_io(backing_io);
     938           0 : }
     939             : 
     940             : /* Called by reduceLib after performing unload vol actions following base bdev hotremove */
     941             : static void
     942           0 : bdev_hotremove_vol_unload_cb(void *cb_arg, int reduce_errno)
     943             : {
     944           0 :         struct vbdev_compress *comp_bdev = (struct vbdev_compress *)cb_arg;
     945             : 
     946           0 :         if (reduce_errno) {
     947           0 :                 SPDK_ERRLOG("number %d\n", reduce_errno);
     948             :         }
     949             : 
     950           0 :         comp_bdev->vol = NULL;
     951           0 :         spdk_bdev_unregister(&comp_bdev->comp_bdev, NULL, NULL);
     952           0 : }
     953             : 
     954             : static void
     955           0 : vbdev_compress_base_bdev_hotremove_cb(struct spdk_bdev *bdev_find)
     956             : {
     957             :         struct vbdev_compress *comp_bdev, *tmp;
     958             : 
     959           0 :         TAILQ_FOREACH_SAFE(comp_bdev, &g_vbdev_comp, link, tmp) {
     960           0 :                 if (bdev_find == comp_bdev->base_bdev) {
     961             :                         /* Tell reduceLib that we're done with this volume. */
     962           0 :                         spdk_reduce_vol_unload(comp_bdev->vol, bdev_hotremove_vol_unload_cb, comp_bdev);
     963             :                 }
     964             :         }
     965           0 : }
     966             : 
     967             : /* Called when the underlying base bdev triggers asynchronous event such as bdev removal. */
     968             : static void
     969           0 : vbdev_compress_base_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
     970             :                                   void *event_ctx)
     971             : {
     972           0 :         switch (type) {
     973           0 :         case SPDK_BDEV_EVENT_REMOVE:
     974           0 :                 vbdev_compress_base_bdev_hotremove_cb(bdev);
     975           0 :                 break;
     976           0 :         default:
     977           0 :                 SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);
     978           0 :                 break;
     979             :         }
     980           0 : }
     981             : 
     982             : /* TODO: determine which parms we want user configurable, HC for now
     983             :  * params.vol_size
     984             :  * params.chunk_size
     985             :  * compression PMD, algorithm, window size, comp level, etc.
     986             :  * DEV_MD_PATH
     987             :  */
     988             : 
     989             : /* Common function for init and load to allocate and populate the minimal
     990             :  * information for reducelib to init or load.
     991             :  */
     992             : struct vbdev_compress *
     993           0 : _prepare_for_load_init(struct spdk_bdev_desc *bdev_desc, uint32_t lb_size, uint8_t comp_algo,
     994             :                        uint32_t comp_level)
     995             : {
     996             :         struct vbdev_compress *comp_bdev;
     997             :         struct spdk_bdev *bdev;
     998             : 
     999           0 :         comp_bdev = calloc(1, sizeof(struct vbdev_compress));
    1000           0 :         if (comp_bdev == NULL) {
    1001           0 :                 SPDK_ERRLOG("failed to alloc comp_bdev\n");
    1002           0 :                 return NULL;
    1003             :         }
    1004             : 
    1005           0 :         comp_bdev->backing_dev.submit_backing_io = _comp_reduce_submit_backing_io;
    1006           0 :         comp_bdev->backing_dev.compress = _comp_reduce_compress;
    1007           0 :         comp_bdev->backing_dev.decompress = _comp_reduce_decompress;
    1008             : 
    1009           0 :         comp_bdev->base_desc = bdev_desc;
    1010           0 :         bdev = spdk_bdev_desc_get_bdev(bdev_desc);
    1011           0 :         comp_bdev->base_bdev = bdev;
    1012             : 
    1013           0 :         comp_bdev->backing_dev.blocklen = bdev->blocklen;
    1014           0 :         comp_bdev->backing_dev.blockcnt = bdev->blockcnt;
    1015             : 
    1016           0 :         comp_bdev->backing_dev.user_ctx_size = sizeof(struct spdk_bdev_io_wait_entry);
    1017             : 
    1018           0 :         comp_bdev->comp_algo = comp_algo;
    1019           0 :         comp_bdev->comp_level = comp_level;
    1020           0 :         comp_bdev->params.comp_algo = comp_algo;
    1021           0 :         comp_bdev->params.comp_level = comp_level;
    1022           0 :         comp_bdev->params.chunk_size = CHUNK_SIZE;
    1023           0 :         if (lb_size == 0) {
    1024           0 :                 comp_bdev->params.logical_block_size = bdev->blocklen;
    1025             :         } else {
    1026           0 :                 comp_bdev->params.logical_block_size = lb_size;
    1027             :         }
    1028             : 
    1029           0 :         comp_bdev->params.backing_io_unit_size = BACKING_IO_SZ;
    1030           0 :         return comp_bdev;
    1031             : }
    1032             : 
    1033             : /* Call reducelib to initialize a new volume */
    1034             : static int
    1035           0 : vbdev_init_reduce(const char *bdev_name, const char *pm_path, uint32_t lb_size, uint8_t comp_algo,
    1036             :                   uint32_t comp_level, bdev_compress_create_cb cb_fn, void *cb_arg)
    1037             : {
    1038           0 :         struct spdk_bdev_desc *bdev_desc = NULL;
    1039             :         struct vbdev_init_reduce_ctx *init_ctx;
    1040             :         struct vbdev_compress *comp_bdev;
    1041             :         int rc;
    1042             : 
    1043           0 :         init_ctx = calloc(1, sizeof(*init_ctx));
    1044           0 :         if (init_ctx == NULL) {
    1045           0 :                 SPDK_ERRLOG("failed to alloc init contexts\n");
    1046           0 :                 return - ENOMEM;
    1047             :         }
    1048             : 
    1049           0 :         init_ctx->cb_fn = cb_fn;
    1050           0 :         init_ctx->cb_ctx = cb_arg;
    1051             : 
    1052           0 :         rc = spdk_bdev_open_ext(bdev_name, true, vbdev_compress_base_bdev_event_cb,
    1053             :                                 NULL, &bdev_desc);
    1054           0 :         if (rc) {
    1055           0 :                 SPDK_ERRLOG("could not open bdev %s, error %s\n", bdev_name, spdk_strerror(-rc));
    1056           0 :                 free(init_ctx);
    1057           0 :                 return rc;
    1058             :         }
    1059             : 
    1060           0 :         comp_bdev = _prepare_for_load_init(bdev_desc, lb_size, comp_algo, comp_level);
    1061           0 :         if (comp_bdev == NULL) {
    1062           0 :                 free(init_ctx);
    1063           0 :                 spdk_bdev_close(bdev_desc);
    1064           0 :                 return -EINVAL;
    1065             :         }
    1066             : 
    1067           0 :         init_ctx->comp_bdev = comp_bdev;
    1068             : 
    1069             :         /* Save the thread where the base device is opened */
    1070           0 :         comp_bdev->thread = spdk_get_thread();
    1071             : 
    1072           0 :         comp_bdev->base_ch = spdk_bdev_get_io_channel(comp_bdev->base_desc);
    1073             : 
    1074           0 :         spdk_reduce_vol_init(&comp_bdev->params, &comp_bdev->backing_dev,
    1075             :                              pm_path,
    1076             :                              vbdev_reduce_init_cb,
    1077             :                              init_ctx);
    1078           0 :         return 0;
    1079             : }
    1080             : 
    1081             : /* We provide this callback for the SPDK channel code to create a channel using
    1082             :  * the channel struct we provided in our module get_io_channel() entry point. Here
    1083             :  * we get and save off an underlying base channel of the device below us so that
    1084             :  * we can communicate with the base bdev on a per channel basis.  If we needed
    1085             :  * our own poller for this vbdev, we'd register it here.
    1086             :  */
    1087             : static int
    1088           0 : comp_bdev_ch_create_cb(void *io_device, void *ctx_buf)
    1089             : {
    1090           0 :         struct vbdev_compress *comp_bdev = io_device;
    1091             : 
    1092             :         /* Now set the reduce channel if it's not already set. */
    1093           0 :         pthread_mutex_lock(&comp_bdev->reduce_lock);
    1094           0 :         if (comp_bdev->ch_count == 0) {
    1095             :                 /* We use this queue to track outstanding IO in our layer. */
    1096           0 :                 TAILQ_INIT(&comp_bdev->pending_comp_ios);
    1097             : 
    1098             :                 /* We use this to queue up compression operations as needed. */
    1099           0 :                 TAILQ_INIT(&comp_bdev->queued_comp_ops);
    1100             : 
    1101           0 :                 comp_bdev->base_ch = spdk_bdev_get_io_channel(comp_bdev->base_desc);
    1102           0 :                 comp_bdev->reduce_thread = spdk_get_thread();
    1103           0 :                 comp_bdev->accel_channel = spdk_accel_get_io_channel();
    1104             :         }
    1105           0 :         comp_bdev->ch_count++;
    1106           0 :         pthread_mutex_unlock(&comp_bdev->reduce_lock);
    1107             : 
    1108           0 :         return 0;
    1109             : }
    1110             : 
    1111             : static void
    1112           0 : _channel_cleanup(struct vbdev_compress *comp_bdev)
    1113             : {
    1114           0 :         spdk_put_io_channel(comp_bdev->base_ch);
    1115           0 :         spdk_put_io_channel(comp_bdev->accel_channel);
    1116           0 :         comp_bdev->reduce_thread = NULL;
    1117           0 : }
    1118             : 
    1119             : /* Used to reroute destroy_ch to the correct thread */
    1120             : static void
    1121           0 : _comp_bdev_ch_destroy_cb(void *arg)
    1122             : {
    1123           0 :         struct vbdev_compress *comp_bdev = arg;
    1124             : 
    1125           0 :         pthread_mutex_lock(&comp_bdev->reduce_lock);
    1126           0 :         _channel_cleanup(comp_bdev);
    1127           0 :         pthread_mutex_unlock(&comp_bdev->reduce_lock);
    1128           0 : }
    1129             : 
    1130             : /* We provide this callback for the SPDK channel code to destroy a channel
    1131             :  * created with our create callback. We just need to undo anything we did
    1132             :  * when we created. If this bdev used its own poller, we'd unregister it here.
    1133             :  */
    1134             : static void
    1135           0 : comp_bdev_ch_destroy_cb(void *io_device, void *ctx_buf)
    1136             : {
    1137           0 :         struct vbdev_compress *comp_bdev = io_device;
    1138             : 
    1139           0 :         pthread_mutex_lock(&comp_bdev->reduce_lock);
    1140           0 :         comp_bdev->ch_count--;
    1141           0 :         if (comp_bdev->ch_count == 0) {
    1142             :                 /* Send this request to the thread where the channel was created. */
    1143           0 :                 if (comp_bdev->reduce_thread != spdk_get_thread()) {
    1144           0 :                         spdk_thread_send_msg(comp_bdev->reduce_thread,
    1145             :                                              _comp_bdev_ch_destroy_cb, comp_bdev);
    1146             :                 } else {
    1147           0 :                         _channel_cleanup(comp_bdev);
    1148             :                 }
    1149             :         }
    1150           0 :         pthread_mutex_unlock(&comp_bdev->reduce_lock);
    1151           0 : }
    1152             : 
    1153             : static int
    1154           0 : _check_compress_bdev_comp_algo(enum spdk_accel_comp_algo algo, uint32_t comp_level)
    1155             : {
    1156           0 :         uint32_t min_level, max_level;
    1157             :         int rc;
    1158             : 
    1159           0 :         rc = spdk_accel_get_compress_level_range(algo, &min_level, &max_level);
    1160           0 :         if (rc != 0) {
    1161           0 :                 return rc;
    1162             :         }
    1163             : 
    1164             :         /* If both min_level and max_level are 0, the compression level can be ignored.
    1165             :          * The back-end implementation hardcodes the compression level.
    1166             :          */
    1167           0 :         if (min_level == 0 && max_level == 0) {
    1168           0 :                 return 0;
    1169             :         }
    1170             : 
    1171           0 :         if (comp_level > max_level || comp_level < min_level) {
    1172           0 :                 return -EINVAL;
    1173             :         }
    1174             : 
    1175           0 :         return 0;
    1176             : }
    1177             : 
    1178             : /* RPC entry point for compression vbdev creation. */
    1179             : int
    1180           0 : create_compress_bdev(const char *bdev_name, const char *pm_path, uint32_t lb_size,
    1181             :                      uint8_t comp_algo, uint32_t comp_level,
    1182             :                      bdev_compress_create_cb cb_fn, void *cb_arg)
    1183             : {
    1184           0 :         struct vbdev_compress *comp_bdev = NULL;
    1185           0 :         struct stat info;
    1186             :         int rc;
    1187             : 
    1188           0 :         if (stat(pm_path, &info) != 0) {
    1189           0 :                 SPDK_ERRLOG("PM path %s does not exist.\n", pm_path);
    1190           0 :                 return -EINVAL;
    1191           0 :         } else if (!S_ISDIR(info.st_mode)) {
    1192           0 :                 SPDK_ERRLOG("PM path %s is not a directory.\n", pm_path);
    1193           0 :                 return -EINVAL;
    1194             :         }
    1195             : 
    1196           0 :         if ((lb_size != 0) && (lb_size != LB_SIZE_4K) && (lb_size != LB_SIZE_512B)) {
    1197           0 :                 SPDK_ERRLOG("Logical block size must be 512 or 4096\n");
    1198           0 :                 return -EINVAL;
    1199             :         }
    1200             : 
    1201           0 :         rc = _check_compress_bdev_comp_algo(comp_algo, comp_level);
    1202           0 :         if (rc != 0) {
    1203           0 :                 SPDK_ERRLOG("Compress bdev doesn't support compression algo(%u) or level(%u)\n",
    1204             :                             comp_algo, comp_level);
    1205           0 :                 return rc;
    1206             :         }
    1207             : 
    1208           0 :         TAILQ_FOREACH(comp_bdev, &g_vbdev_comp, link) {
    1209           0 :                 if (strcmp(bdev_name, comp_bdev->base_bdev->name) == 0) {
    1210           0 :                         SPDK_ERRLOG("Bass bdev %s already being used for a compress bdev\n", bdev_name);
    1211           0 :                         return -EBUSY;
    1212             :                 }
    1213             :         }
    1214           0 :         return vbdev_init_reduce(bdev_name, pm_path, lb_size, comp_algo, comp_level, cb_fn, cb_arg);
    1215             : }
    1216             : 
    1217             : static int
    1218           0 : vbdev_compress_init(void)
    1219             : {
    1220           0 :         return 0;
    1221             : }
    1222             : 
    1223             : /* Called when the entire module is being torn down. */
    1224             : static void
    1225           0 : vbdev_compress_finish(void)
    1226             : {
    1227             :         /* TODO: unload vol in a future patch */
    1228           0 : }
    1229             : 
    1230             : /* During init we'll be asked how much memory we'd like passed to us
    1231             :  * in bev_io structures as context. Here's where we specify how
    1232             :  * much context we want per IO.
    1233             :  */
    1234             : static int
    1235           0 : vbdev_compress_get_ctx_size(void)
    1236             : {
    1237           0 :         return sizeof(struct comp_bdev_io);
    1238             : }
    1239             : 
    1240             : /* When we register our bdev this is how we specify our entry points. */
    1241             : static const struct spdk_bdev_fn_table vbdev_compress_fn_table = {
    1242             :         .destruct               = vbdev_compress_destruct,
    1243             :         .submit_request         = vbdev_compress_submit_request,
    1244             :         .io_type_supported      = vbdev_compress_io_type_supported,
    1245             :         .get_io_channel         = vbdev_compress_get_io_channel,
    1246             :         .dump_info_json         = vbdev_compress_dump_info_json,
    1247             :         .write_config_json      = NULL,
    1248             : };
    1249             : 
    1250             : static struct spdk_bdev_module compress_if = {
    1251             :         .name = "compress",
    1252             :         .module_init = vbdev_compress_init,
    1253             :         .get_ctx_size = vbdev_compress_get_ctx_size,
    1254             :         .examine_disk = vbdev_compress_examine,
    1255             :         .module_fini = vbdev_compress_finish,
    1256             :         .config_json = vbdev_compress_config_json
    1257             : };
    1258             : 
    1259           1 : SPDK_BDEV_MODULE_REGISTER(compress, &compress_if)
    1260             : 
    1261           0 : static int _set_compbdev_name(struct vbdev_compress *comp_bdev)
    1262             : {
    1263             :         struct spdk_bdev_alias *aliases;
    1264             : 
    1265           0 :         if (!TAILQ_EMPTY(spdk_bdev_get_aliases(comp_bdev->base_bdev))) {
    1266           0 :                 aliases = TAILQ_FIRST(spdk_bdev_get_aliases(comp_bdev->base_bdev));
    1267           0 :                 comp_bdev->comp_bdev.name = spdk_sprintf_alloc("COMP_%s", aliases->alias.name);
    1268           0 :                 if (!comp_bdev->comp_bdev.name) {
    1269           0 :                         SPDK_ERRLOG("could not allocate comp_bdev name for alias\n");
    1270           0 :                         return -ENOMEM;
    1271             :                 }
    1272             :         } else {
    1273           0 :                 comp_bdev->comp_bdev.name = spdk_sprintf_alloc("COMP_%s", comp_bdev->base_bdev->name);
    1274           0 :                 if (!comp_bdev->comp_bdev.name) {
    1275           0 :                         SPDK_ERRLOG("could not allocate comp_bdev name for unique name\n");
    1276           0 :                         return -ENOMEM;
    1277             :                 }
    1278             :         }
    1279           0 :         return 0;
    1280             : }
    1281             : 
    1282             : static int
    1283           0 : vbdev_compress_claim(struct vbdev_compress *comp_bdev)
    1284             : {
    1285           0 :         struct spdk_uuid ns_uuid;
    1286             :         int rc;
    1287             : 
    1288           0 :         if (_set_compbdev_name(comp_bdev)) {
    1289           0 :                 return -EINVAL;
    1290             :         }
    1291             : 
    1292             :         /* Note: some of the fields below will change in the future - for example,
    1293             :          * blockcnt specifically will not match (the compressed volume size will
    1294             :          * be slightly less than the base bdev size)
    1295             :          */
    1296           0 :         comp_bdev->comp_bdev.product_name = COMP_BDEV_NAME;
    1297           0 :         comp_bdev->comp_bdev.write_cache = comp_bdev->base_bdev->write_cache;
    1298             : 
    1299           0 :         comp_bdev->comp_bdev.optimal_io_boundary =
    1300           0 :                 comp_bdev->params.chunk_size / comp_bdev->params.logical_block_size;
    1301             : 
    1302           0 :         comp_bdev->comp_bdev.split_on_optimal_io_boundary = true;
    1303             : 
    1304           0 :         comp_bdev->comp_bdev.blocklen = comp_bdev->params.logical_block_size;
    1305           0 :         comp_bdev->comp_bdev.blockcnt = comp_bdev->params.vol_size / comp_bdev->comp_bdev.blocklen;
    1306           0 :         assert(comp_bdev->comp_bdev.blockcnt > 0);
    1307             : 
    1308             :         /* This is the context that is passed to us when the bdev
    1309             :          * layer calls in so we'll save our comp_bdev node here.
    1310             :          */
    1311           0 :         comp_bdev->comp_bdev.ctxt = comp_bdev;
    1312           0 :         comp_bdev->comp_bdev.fn_table = &vbdev_compress_fn_table;
    1313           0 :         comp_bdev->comp_bdev.module = &compress_if;
    1314             : 
    1315             :         /* Generate UUID based on namespace UUID + base bdev UUID. */
    1316           0 :         spdk_uuid_parse(&ns_uuid, BDEV_COMPRESS_NAMESPACE_UUID);
    1317           0 :         rc = spdk_uuid_generate_sha1(&comp_bdev->comp_bdev.uuid, &ns_uuid,
    1318           0 :                                      (const char *)&comp_bdev->base_bdev->uuid, sizeof(struct spdk_uuid));
    1319           0 :         if (rc) {
    1320           0 :                 SPDK_ERRLOG("Unable to generate new UUID for compress bdev, error %s\n", spdk_strerror(-rc));
    1321           0 :                 return -EINVAL;
    1322             :         }
    1323             : 
    1324           0 :         pthread_mutex_init(&comp_bdev->reduce_lock, NULL);
    1325             : 
    1326             :         /* Save the thread where the base device is opened */
    1327           0 :         comp_bdev->thread = spdk_get_thread();
    1328             : 
    1329           0 :         spdk_io_device_register(comp_bdev, comp_bdev_ch_create_cb, comp_bdev_ch_destroy_cb,
    1330             :                                 sizeof(struct comp_io_channel),
    1331           0 :                                 comp_bdev->comp_bdev.name);
    1332             : 
    1333           0 :         rc = spdk_bdev_module_claim_bdev(comp_bdev->base_bdev, comp_bdev->base_desc,
    1334             :                                          comp_bdev->comp_bdev.module);
    1335           0 :         if (rc) {
    1336           0 :                 SPDK_ERRLOG("could not claim bdev %s, error %s\n", spdk_bdev_get_name(comp_bdev->base_bdev),
    1337             :                             spdk_strerror(-rc));
    1338           0 :                 goto error_claim;
    1339             :         }
    1340             : 
    1341           0 :         rc = spdk_bdev_register(&comp_bdev->comp_bdev);
    1342           0 :         if (rc < 0) {
    1343           0 :                 SPDK_ERRLOG("trying to register bdev, error %s\n", spdk_strerror(-rc));
    1344           0 :                 goto error_bdev_register;
    1345             :         }
    1346             : 
    1347           0 :         TAILQ_INSERT_TAIL(&g_vbdev_comp, comp_bdev, link);
    1348             : 
    1349           0 :         SPDK_NOTICELOG("registered io_device and virtual bdev for: %s\n", comp_bdev->comp_bdev.name);
    1350             : 
    1351           0 :         return 0;
    1352             : 
    1353             :         /* Error cleanup paths. */
    1354           0 : error_bdev_register:
    1355           0 :         spdk_bdev_module_release_bdev(comp_bdev->base_bdev);
    1356           0 : error_claim:
    1357           0 :         spdk_io_device_unregister(comp_bdev, NULL);
    1358           0 :         free(comp_bdev->comp_bdev.name);
    1359           0 :         return rc;
    1360             : }
    1361             : 
    1362             : static void
    1363           0 : _vbdev_compress_delete_done(void *_ctx)
    1364             : {
    1365           0 :         struct vbdev_comp_delete_ctx *ctx = _ctx;
    1366             : 
    1367           0 :         ctx->cb_fn(ctx->cb_arg, ctx->cb_rc);
    1368             : 
    1369           0 :         free(ctx);
    1370           0 : }
    1371             : 
    1372             : static void
    1373           0 : vbdev_compress_delete_done(void *cb_arg, int bdeverrno)
    1374             : {
    1375           0 :         struct vbdev_comp_delete_ctx *ctx = cb_arg;
    1376             : 
    1377           0 :         ctx->cb_rc = bdeverrno;
    1378             : 
    1379           0 :         if (ctx->orig_thread != spdk_get_thread()) {
    1380           0 :                 spdk_thread_send_msg(ctx->orig_thread, _vbdev_compress_delete_done, ctx);
    1381             :         } else {
    1382           0 :                 _vbdev_compress_delete_done(ctx);
    1383             :         }
    1384           0 : }
    1385             : 
    1386             : void
    1387           0 : bdev_compress_delete(const char *name, spdk_delete_compress_complete cb_fn, void *cb_arg)
    1388             : {
    1389           0 :         struct vbdev_compress *comp_bdev = NULL;
    1390             :         struct vbdev_comp_delete_ctx *ctx;
    1391             : 
    1392           0 :         TAILQ_FOREACH(comp_bdev, &g_vbdev_comp, link) {
    1393           0 :                 if (strcmp(name, comp_bdev->comp_bdev.name) == 0) {
    1394           0 :                         break;
    1395             :                 }
    1396             :         }
    1397             : 
    1398           0 :         if (comp_bdev == NULL) {
    1399           0 :                 cb_fn(cb_arg, -ENODEV);
    1400           0 :                 return;
    1401             :         }
    1402             : 
    1403           0 :         ctx = calloc(1, sizeof(*ctx));
    1404           0 :         if (ctx == NULL) {
    1405           0 :                 SPDK_ERRLOG("Failed to allocate delete context\n");
    1406           0 :                 cb_fn(cb_arg, -ENOMEM);
    1407           0 :                 return;
    1408             :         }
    1409             : 
    1410             :         /* Save these for after the vol is destroyed. */
    1411           0 :         ctx->cb_fn = cb_fn;
    1412           0 :         ctx->cb_arg = cb_arg;
    1413           0 :         ctx->orig_thread = spdk_get_thread();
    1414             : 
    1415           0 :         comp_bdev->delete_ctx = ctx;
    1416             : 
    1417             :         /* Tell reducelib that we're done with this volume. */
    1418           0 :         if (comp_bdev->orphaned == false) {
    1419           0 :                 spdk_reduce_vol_unload(comp_bdev->vol, delete_vol_unload_cb, comp_bdev);
    1420             :         } else {
    1421           0 :                 delete_vol_unload_cb(comp_bdev, 0);
    1422             :         }
    1423             : }
    1424             : 
    1425             : static void
    1426           0 : _vbdev_reduce_load_unload_cb(void *ctx, int reduce_errno)
    1427             : {
    1428           0 : }
    1429             : 
    1430             : static void
    1431           0 : _vbdev_reduce_load_cb(void *ctx)
    1432             : {
    1433           0 :         struct vbdev_compress *comp_bdev = ctx;
    1434             :         int rc;
    1435             : 
    1436           0 :         assert(comp_bdev->base_desc != NULL);
    1437             : 
    1438             :         /* Done with metadata operations */
    1439           0 :         spdk_put_io_channel(comp_bdev->base_ch);
    1440             : 
    1441           0 :         if (comp_bdev->reduce_errno == 0) {
    1442           0 :                 rc = vbdev_compress_claim(comp_bdev);
    1443           0 :                 if (rc != 0) {
    1444           0 :                         spdk_reduce_vol_unload(comp_bdev->vol, _vbdev_reduce_load_unload_cb, NULL);
    1445           0 :                         goto err;
    1446             :                 }
    1447           0 :         } else if (comp_bdev->reduce_errno == -ENOENT) {
    1448           0 :                 if (_set_compbdev_name(comp_bdev)) {
    1449           0 :                         goto err;
    1450             :                 }
    1451             : 
    1452             :                 /* Save the thread where the base device is opened */
    1453           0 :                 comp_bdev->thread = spdk_get_thread();
    1454             : 
    1455           0 :                 comp_bdev->comp_bdev.module = &compress_if;
    1456           0 :                 pthread_mutex_init(&comp_bdev->reduce_lock, NULL);
    1457           0 :                 rc = spdk_bdev_module_claim_bdev(comp_bdev->base_bdev, comp_bdev->base_desc,
    1458             :                                                  comp_bdev->comp_bdev.module);
    1459           0 :                 if (rc) {
    1460           0 :                         SPDK_ERRLOG("could not claim bdev %s, error %s\n", spdk_bdev_get_name(comp_bdev->base_bdev),
    1461             :                                     spdk_strerror(-rc));
    1462           0 :                         free(comp_bdev->comp_bdev.name);
    1463           0 :                         goto err;
    1464             :                 }
    1465             : 
    1466           0 :                 comp_bdev->orphaned = true;
    1467           0 :                 TAILQ_INSERT_TAIL(&g_vbdev_comp, comp_bdev, link);
    1468             :         } else {
    1469           0 :                 if (comp_bdev->reduce_errno != -EILSEQ) {
    1470           0 :                         SPDK_ERRLOG("for vol %s, error %s\n", spdk_bdev_get_name(comp_bdev->base_bdev),
    1471             :                                     spdk_strerror(-comp_bdev->reduce_errno));
    1472             :                 }
    1473           0 :                 goto err;
    1474             :         }
    1475             : 
    1476           0 :         spdk_bdev_module_examine_done(&compress_if);
    1477           0 :         return;
    1478             : 
    1479           0 : err:
    1480             :         /* Close the underlying bdev on its same opened thread. */
    1481           0 :         spdk_bdev_close(comp_bdev->base_desc);
    1482           0 :         free(comp_bdev);
    1483           0 :         spdk_bdev_module_examine_done(&compress_if);
    1484             : }
    1485             : 
    1486             : /* Callback from reduce for then load is complete. We'll pass the vbdev_comp struct
    1487             :  * used for initial metadata operations to claim where it will be further filled out
    1488             :  * and added to the global list.
    1489             :  */
    1490             : static void
    1491           0 : vbdev_reduce_load_cb(void *cb_arg, struct spdk_reduce_vol *vol, int reduce_errno)
    1492             : {
    1493           0 :         struct vbdev_compress *comp_bdev = cb_arg;
    1494             : 
    1495           0 :         if (reduce_errno == 0) {
    1496             :                 /* Update information following volume load. */
    1497           0 :                 comp_bdev->vol = vol;
    1498           0 :                 memcpy(&comp_bdev->params, spdk_reduce_vol_get_params(vol),
    1499             :                        sizeof(struct spdk_reduce_vol_params));
    1500           0 :                 comp_bdev->comp_algo = comp_bdev->params.comp_algo;
    1501           0 :                 comp_bdev->comp_level = comp_bdev->params.comp_level;
    1502             :         }
    1503             : 
    1504           0 :         comp_bdev->reduce_errno = reduce_errno;
    1505             : 
    1506           0 :         if (comp_bdev->thread && comp_bdev->thread != spdk_get_thread()) {
    1507           0 :                 spdk_thread_send_msg(comp_bdev->thread, _vbdev_reduce_load_cb, comp_bdev);
    1508             :         } else {
    1509           0 :                 _vbdev_reduce_load_cb(comp_bdev);
    1510             :         }
    1511             : 
    1512           0 : }
    1513             : 
    1514             : /* Examine_disk entry point: will do a metadata load to see if this is ours,
    1515             :  * and if so will go ahead and claim it.
    1516             :  */
    1517             : static void
    1518           0 : vbdev_compress_examine(struct spdk_bdev *bdev)
    1519             : {
    1520           0 :         struct spdk_bdev_desc *bdev_desc = NULL;
    1521             :         struct vbdev_compress *comp_bdev;
    1522             :         int rc;
    1523             : 
    1524           0 :         if (strcmp(bdev->product_name, COMP_BDEV_NAME) == 0) {
    1525           0 :                 spdk_bdev_module_examine_done(&compress_if);
    1526           0 :                 return;
    1527             :         }
    1528             : 
    1529           0 :         rc = spdk_bdev_open_ext(spdk_bdev_get_name(bdev), false,
    1530             :                                 vbdev_compress_base_bdev_event_cb, NULL, &bdev_desc);
    1531           0 :         if (rc) {
    1532           0 :                 SPDK_ERRLOG("could not open bdev %s, error %s\n", spdk_bdev_get_name(bdev),
    1533             :                             spdk_strerror(-rc));
    1534           0 :                 spdk_bdev_module_examine_done(&compress_if);
    1535           0 :                 return;
    1536             :         }
    1537             : 
    1538           0 :         comp_bdev = _prepare_for_load_init(bdev_desc, 0, SPDK_ACCEL_COMP_ALGO_DEFLATE, 1);
    1539           0 :         if (comp_bdev == NULL) {
    1540           0 :                 spdk_bdev_close(bdev_desc);
    1541           0 :                 spdk_bdev_module_examine_done(&compress_if);
    1542           0 :                 return;
    1543             :         }
    1544             : 
    1545             :         /* Save the thread where the base device is opened */
    1546           0 :         comp_bdev->thread = spdk_get_thread();
    1547             : 
    1548           0 :         comp_bdev->base_ch = spdk_bdev_get_io_channel(comp_bdev->base_desc);
    1549           0 :         spdk_reduce_vol_load(&comp_bdev->backing_dev, vbdev_reduce_load_cb, comp_bdev);
    1550             : }
    1551             : 
    1552           1 : SPDK_LOG_REGISTER_COMPONENT(vbdev_compress)

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