| /* |
| * CDDL HEADER START |
| * |
| * The contents of this file are subject to the terms of the |
| * Common Development and Distribution License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * |
| * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| * or http://www.opensolaris.org/os/licensing. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * |
| * When distributing Covered Code, include this CDDL HEADER in each |
| * file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| * If applicable, add the following below this CDDL HEADER, with the |
| * fields enclosed by brackets "[]" replaced with your own identifying |
| * information: Portions Copyright [yyyy] [name of copyright owner] |
| * |
| * CDDL HEADER END |
| */ |
| /* |
| * Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC. |
| * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). |
| * Rewritten for Linux by Brian Behlendorf <behlendorf1@llnl.gov>. |
| * LLNL-CODE-403049. |
| * |
| * ZFS volume emulation driver. |
| * |
| * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. |
| * Volumes are accessed through the symbolic links named: |
| * |
| * /dev/<pool_name>/<dataset_name> |
| * |
| * Volumes are persistent through reboot and module load. No user command |
| * needs to be run before opening and using a device. |
| * |
| * Copyright 2014 Nexenta Systems, Inc. All rights reserved. |
| * Copyright (c) 2016 Actifio, Inc. All rights reserved. |
| * Copyright (c) 2012, 2019 by Delphix. All rights reserved. |
| */ |
| |
| /* |
| * Note on locking of zvol state structures. |
| * |
| * These structures are used to maintain internal state used to emulate block |
| * devices on top of zvols. In particular, management of device minor number |
| * operations - create, remove, rename, and set_snapdev - involves access to |
| * these structures. The zvol_state_lock is primarily used to protect the |
| * zvol_state_list. The zv->zv_state_lock is used to protect the contents |
| * of the zvol_state_t structures, as well as to make sure that when the |
| * time comes to remove the structure from the list, it is not in use, and |
| * therefore, it can be taken off zvol_state_list and freed. |
| * |
| * The zv_suspend_lock was introduced to allow for suspending I/O to a zvol, |
| * e.g. for the duration of receive and rollback operations. This lock can be |
| * held for significant periods of time. Given that it is undesirable to hold |
| * mutexes for long periods of time, the following lock ordering applies: |
| * - take zvol_state_lock if necessary, to protect zvol_state_list |
| * - take zv_suspend_lock if necessary, by the code path in question |
| * - take zv_state_lock to protect zvol_state_t |
| * |
| * The minor operations are issued to spa->spa_zvol_taskq queues, that are |
| * single-threaded (to preserve order of minor operations), and are executed |
| * through the zvol_task_cb that dispatches the specific operations. Therefore, |
| * these operations are serialized per pool. Consequently, we can be certain |
| * that for a given zvol, there is only one operation at a time in progress. |
| * That is why one can be sure that first, zvol_state_t for a given zvol is |
| * allocated and placed on zvol_state_list, and then other minor operations |
| * for this zvol are going to proceed in the order of issue. |
| * |
| */ |
| |
| #include <sys/dataset_kstats.h> |
| #include <sys/dbuf.h> |
| #include <sys/dmu_traverse.h> |
| #include <sys/dsl_dataset.h> |
| #include <sys/dsl_prop.h> |
| #include <sys/dsl_dir.h> |
| #include <sys/zap.h> |
| #include <sys/zfeature.h> |
| #include <sys/zil_impl.h> |
| #include <sys/dmu_tx.h> |
| #include <sys/zio.h> |
| #include <sys/zfs_rlock.h> |
| #include <sys/spa_impl.h> |
| #include <sys/zvol.h> |
| #include <sys/zvol_impl.h> |
| |
| unsigned int zvol_inhibit_dev = 0; |
| unsigned int zvol_volmode = ZFS_VOLMODE_GEOM; |
| |
| struct hlist_head *zvol_htable; |
| list_t zvol_state_list; |
| krwlock_t zvol_state_lock; |
| const zvol_platform_ops_t *ops; |
| |
| typedef enum { |
| ZVOL_ASYNC_REMOVE_MINORS, |
| ZVOL_ASYNC_RENAME_MINORS, |
| ZVOL_ASYNC_SET_SNAPDEV, |
| ZVOL_ASYNC_SET_VOLMODE, |
| ZVOL_ASYNC_MAX |
| } zvol_async_op_t; |
| |
| typedef struct { |
| zvol_async_op_t op; |
| char name1[MAXNAMELEN]; |
| char name2[MAXNAMELEN]; |
| uint64_t value; |
| } zvol_task_t; |
| |
| uint64_t |
| zvol_name_hash(const char *name) |
| { |
| int i; |
| uint64_t crc = -1ULL; |
| const uint8_t *p = (const uint8_t *)name; |
| ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY); |
| for (i = 0; i < MAXNAMELEN - 1 && *p; i++, p++) { |
| crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (*p)) & 0xFF]; |
| } |
| return (crc); |
| } |
| |
| /* |
| * Find a zvol_state_t given the name and hash generated by zvol_name_hash. |
| * If found, return with zv_suspend_lock and zv_state_lock taken, otherwise, |
| * return (NULL) without the taking locks. The zv_suspend_lock is always taken |
| * before zv_state_lock. The mode argument indicates the mode (including none) |
| * for zv_suspend_lock to be taken. |
| */ |
| zvol_state_t * |
| zvol_find_by_name_hash(const char *name, uint64_t hash, int mode) |
| { |
| zvol_state_t *zv; |
| struct hlist_node *p = NULL; |
| |
| rw_enter(&zvol_state_lock, RW_READER); |
| hlist_for_each(p, ZVOL_HT_HEAD(hash)) { |
| zv = hlist_entry(p, zvol_state_t, zv_hlink); |
| mutex_enter(&zv->zv_state_lock); |
| if (zv->zv_hash == hash && |
| strncmp(zv->zv_name, name, MAXNAMELEN) == 0) { |
| /* |
| * this is the right zvol, take the locks in the |
| * right order |
| */ |
| if (mode != RW_NONE && |
| !rw_tryenter(&zv->zv_suspend_lock, mode)) { |
| mutex_exit(&zv->zv_state_lock); |
| rw_enter(&zv->zv_suspend_lock, mode); |
| mutex_enter(&zv->zv_state_lock); |
| /* |
| * zvol cannot be renamed as we continue |
| * to hold zvol_state_lock |
| */ |
| ASSERT(zv->zv_hash == hash && |
| strncmp(zv->zv_name, name, MAXNAMELEN) |
| == 0); |
| } |
| rw_exit(&zvol_state_lock); |
| return (zv); |
| } |
| mutex_exit(&zv->zv_state_lock); |
| } |
| rw_exit(&zvol_state_lock); |
| |
| return (NULL); |
| } |
| |
| /* |
| * Find a zvol_state_t given the name. |
| * If found, return with zv_suspend_lock and zv_state_lock taken, otherwise, |
| * return (NULL) without the taking locks. The zv_suspend_lock is always taken |
| * before zv_state_lock. The mode argument indicates the mode (including none) |
| * for zv_suspend_lock to be taken. |
| */ |
| static zvol_state_t * |
| zvol_find_by_name(const char *name, int mode) |
| { |
| return (zvol_find_by_name_hash(name, zvol_name_hash(name), mode)); |
| } |
| |
| /* |
| * ZFS_IOC_CREATE callback handles dmu zvol and zap object creation. |
| */ |
| void |
| zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx) |
| { |
| zfs_creat_t *zct = arg; |
| nvlist_t *nvprops = zct->zct_props; |
| int error; |
| uint64_t volblocksize, volsize; |
| |
| VERIFY(nvlist_lookup_uint64(nvprops, |
| zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); |
| if (nvlist_lookup_uint64(nvprops, |
| zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) |
| volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); |
| |
| /* |
| * These properties must be removed from the list so the generic |
| * property setting step won't apply to them. |
| */ |
| VERIFY(nvlist_remove_all(nvprops, |
| zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); |
| (void) nvlist_remove_all(nvprops, |
| zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); |
| |
| error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, |
| DMU_OT_NONE, 0, tx); |
| ASSERT(error == 0); |
| |
| error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, |
| DMU_OT_NONE, 0, tx); |
| ASSERT(error == 0); |
| |
| error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); |
| ASSERT(error == 0); |
| } |
| |
| /* |
| * ZFS_IOC_OBJSET_STATS entry point. |
| */ |
| int |
| zvol_get_stats(objset_t *os, nvlist_t *nv) |
| { |
| int error; |
| dmu_object_info_t *doi; |
| uint64_t val; |
| |
| error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); |
| if (error) |
| return (SET_ERROR(error)); |
| |
| dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); |
| doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP); |
| error = dmu_object_info(os, ZVOL_OBJ, doi); |
| |
| if (error == 0) { |
| dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, |
| doi->doi_data_block_size); |
| } |
| |
| kmem_free(doi, sizeof (dmu_object_info_t)); |
| |
| return (SET_ERROR(error)); |
| } |
| |
| /* |
| * Sanity check volume size. |
| */ |
| int |
| zvol_check_volsize(uint64_t volsize, uint64_t blocksize) |
| { |
| if (volsize == 0) |
| return (SET_ERROR(EINVAL)); |
| |
| if (volsize % blocksize != 0) |
| return (SET_ERROR(EINVAL)); |
| |
| #ifdef _ILP32 |
| if (volsize - 1 > SPEC_MAXOFFSET_T) |
| return (SET_ERROR(EOVERFLOW)); |
| #endif |
| return (0); |
| } |
| |
| /* |
| * Ensure the zap is flushed then inform the VFS of the capacity change. |
| */ |
| static int |
| zvol_update_volsize(uint64_t volsize, objset_t *os) |
| { |
| dmu_tx_t *tx; |
| int error; |
| uint64_t txg; |
| |
| tx = dmu_tx_create(os); |
| dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); |
| dmu_tx_mark_netfree(tx); |
| error = dmu_tx_assign(tx, TXG_WAIT); |
| if (error) { |
| dmu_tx_abort(tx); |
| return (SET_ERROR(error)); |
| } |
| txg = dmu_tx_get_txg(tx); |
| |
| error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, |
| &volsize, tx); |
| dmu_tx_commit(tx); |
| |
| txg_wait_synced(dmu_objset_pool(os), txg); |
| |
| if (error == 0) |
| error = dmu_free_long_range(os, |
| ZVOL_OBJ, volsize, DMU_OBJECT_END); |
| |
| return (error); |
| } |
| |
| /* |
| * Set ZFS_PROP_VOLSIZE set entry point. Note that modifying the volume |
| * size will result in a udev "change" event being generated. |
| */ |
| int |
| zvol_set_volsize(const char *name, uint64_t volsize) |
| { |
| objset_t *os = NULL; |
| uint64_t readonly; |
| int error; |
| boolean_t owned = B_FALSE; |
| |
| error = dsl_prop_get_integer(name, |
| zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL); |
| if (error != 0) |
| return (SET_ERROR(error)); |
| if (readonly) |
| return (SET_ERROR(EROFS)); |
| |
| zvol_state_t *zv = zvol_find_by_name(name, RW_READER); |
| |
| ASSERT(zv == NULL || (MUTEX_HELD(&zv->zv_state_lock) && |
| RW_READ_HELD(&zv->zv_suspend_lock))); |
| |
| if (zv == NULL || zv->zv_objset == NULL) { |
| if (zv != NULL) |
| rw_exit(&zv->zv_suspend_lock); |
| if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE, B_TRUE, |
| FTAG, &os)) != 0) { |
| if (zv != NULL) |
| mutex_exit(&zv->zv_state_lock); |
| return (SET_ERROR(error)); |
| } |
| owned = B_TRUE; |
| if (zv != NULL) |
| zv->zv_objset = os; |
| } else { |
| os = zv->zv_objset; |
| } |
| |
| dmu_object_info_t *doi = kmem_alloc(sizeof (*doi), KM_SLEEP); |
| |
| if ((error = dmu_object_info(os, ZVOL_OBJ, doi)) || |
| (error = zvol_check_volsize(volsize, doi->doi_data_block_size))) |
| goto out; |
| |
| error = zvol_update_volsize(volsize, os); |
| if (error == 0 && zv != NULL) { |
| zv->zv_volsize = volsize; |
| zv->zv_changed = 1; |
| } |
| out: |
| kmem_free(doi, sizeof (dmu_object_info_t)); |
| |
| if (owned) { |
| dmu_objset_disown(os, B_TRUE, FTAG); |
| if (zv != NULL) |
| zv->zv_objset = NULL; |
| } else { |
| rw_exit(&zv->zv_suspend_lock); |
| } |
| |
| if (zv != NULL) |
| mutex_exit(&zv->zv_state_lock); |
| |
| if (error == 0 && zv != NULL) |
| ops->zv_update_volsize(zv, volsize); |
| |
| return (SET_ERROR(error)); |
| } |
| |
| /* |
| * Sanity check volume block size. |
| */ |
| int |
| zvol_check_volblocksize(const char *name, uint64_t volblocksize) |
| { |
| /* Record sizes above 128k need the feature to be enabled */ |
| if (volblocksize > SPA_OLD_MAXBLOCKSIZE) { |
| spa_t *spa; |
| int error; |
| |
| if ((error = spa_open(name, &spa, FTAG)) != 0) |
| return (error); |
| |
| if (!spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) { |
| spa_close(spa, FTAG); |
| return (SET_ERROR(ENOTSUP)); |
| } |
| |
| /* |
| * We don't allow setting the property above 1MB, |
| * unless the tunable has been changed. |
| */ |
| if (volblocksize > zfs_max_recordsize) |
| return (SET_ERROR(EDOM)); |
| |
| spa_close(spa, FTAG); |
| } |
| |
| if (volblocksize < SPA_MINBLOCKSIZE || |
| volblocksize > SPA_MAXBLOCKSIZE || |
| !ISP2(volblocksize)) |
| return (SET_ERROR(EDOM)); |
| |
| return (0); |
| } |
| |
| /* |
| * Set ZFS_PROP_VOLBLOCKSIZE set entry point. |
| */ |
| int |
| zvol_set_volblocksize(const char *name, uint64_t volblocksize) |
| { |
| zvol_state_t *zv; |
| dmu_tx_t *tx; |
| int error; |
| |
| zv = zvol_find_by_name(name, RW_READER); |
| |
| if (zv == NULL) |
| return (SET_ERROR(ENXIO)); |
| |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock)); |
| ASSERT(RW_READ_HELD(&zv->zv_suspend_lock)); |
| |
| if (zv->zv_flags & ZVOL_RDONLY) { |
| mutex_exit(&zv->zv_state_lock); |
| rw_exit(&zv->zv_suspend_lock); |
| return (SET_ERROR(EROFS)); |
| } |
| |
| tx = dmu_tx_create(zv->zv_objset); |
| dmu_tx_hold_bonus(tx, ZVOL_OBJ); |
| error = dmu_tx_assign(tx, TXG_WAIT); |
| if (error) { |
| dmu_tx_abort(tx); |
| } else { |
| error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, |
| volblocksize, 0, tx); |
| if (error == ENOTSUP) |
| error = SET_ERROR(EBUSY); |
| dmu_tx_commit(tx); |
| if (error == 0) |
| zv->zv_volblocksize = volblocksize; |
| } |
| |
| mutex_exit(&zv->zv_state_lock); |
| rw_exit(&zv->zv_suspend_lock); |
| |
| return (SET_ERROR(error)); |
| } |
| |
| /* |
| * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we |
| * implement DKIOCFREE/free-long-range. |
| */ |
| static int |
| zvol_replay_truncate(void *arg1, void *arg2, boolean_t byteswap) |
| { |
| zvol_state_t *zv = arg1; |
| lr_truncate_t *lr = arg2; |
| uint64_t offset, length; |
| |
| if (byteswap) |
| byteswap_uint64_array(lr, sizeof (*lr)); |
| |
| offset = lr->lr_offset; |
| length = lr->lr_length; |
| |
| dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); |
| dmu_tx_mark_netfree(tx); |
| int error = dmu_tx_assign(tx, TXG_WAIT); |
| if (error != 0) { |
| dmu_tx_abort(tx); |
| } else { |
| zil_replaying(zv->zv_zilog, tx); |
| dmu_tx_commit(tx); |
| error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, |
| length); |
| } |
| |
| return (error); |
| } |
| |
| /* |
| * Replay a TX_WRITE ZIL transaction that didn't get committed |
| * after a system failure |
| */ |
| static int |
| zvol_replay_write(void *arg1, void *arg2, boolean_t byteswap) |
| { |
| zvol_state_t *zv = arg1; |
| lr_write_t *lr = arg2; |
| objset_t *os = zv->zv_objset; |
| char *data = (char *)(lr + 1); /* data follows lr_write_t */ |
| uint64_t offset, length; |
| dmu_tx_t *tx; |
| int error; |
| |
| if (byteswap) |
| byteswap_uint64_array(lr, sizeof (*lr)); |
| |
| offset = lr->lr_offset; |
| length = lr->lr_length; |
| |
| /* If it's a dmu_sync() block, write the whole block */ |
| if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) { |
| uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr); |
| if (length < blocksize) { |
| offset -= offset % blocksize; |
| length = blocksize; |
| } |
| } |
| |
| tx = dmu_tx_create(os); |
| dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length); |
| error = dmu_tx_assign(tx, TXG_WAIT); |
| if (error) { |
| dmu_tx_abort(tx); |
| } else { |
| dmu_write(os, ZVOL_OBJ, offset, length, data, tx); |
| zil_replaying(zv->zv_zilog, tx); |
| dmu_tx_commit(tx); |
| } |
| |
| return (error); |
| } |
| |
| static int |
| zvol_replay_err(void *arg1, void *arg2, boolean_t byteswap) |
| { |
| return (SET_ERROR(ENOTSUP)); |
| } |
| |
| /* |
| * Callback vectors for replaying records. |
| * Only TX_WRITE and TX_TRUNCATE are needed for zvol. |
| */ |
| zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { |
| zvol_replay_err, /* no such transaction type */ |
| zvol_replay_err, /* TX_CREATE */ |
| zvol_replay_err, /* TX_MKDIR */ |
| zvol_replay_err, /* TX_MKXATTR */ |
| zvol_replay_err, /* TX_SYMLINK */ |
| zvol_replay_err, /* TX_REMOVE */ |
| zvol_replay_err, /* TX_RMDIR */ |
| zvol_replay_err, /* TX_LINK */ |
| zvol_replay_err, /* TX_RENAME */ |
| zvol_replay_write, /* TX_WRITE */ |
| zvol_replay_truncate, /* TX_TRUNCATE */ |
| zvol_replay_err, /* TX_SETATTR */ |
| zvol_replay_err, /* TX_ACL */ |
| zvol_replay_err, /* TX_CREATE_ATTR */ |
| zvol_replay_err, /* TX_CREATE_ACL_ATTR */ |
| zvol_replay_err, /* TX_MKDIR_ACL */ |
| zvol_replay_err, /* TX_MKDIR_ATTR */ |
| zvol_replay_err, /* TX_MKDIR_ACL_ATTR */ |
| zvol_replay_err, /* TX_WRITE2 */ |
| }; |
| |
| /* |
| * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. |
| * |
| * We store data in the log buffers if it's small enough. |
| * Otherwise we will later flush the data out via dmu_sync(). |
| */ |
| ssize_t zvol_immediate_write_sz = 32768; |
| |
| void |
| zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset, |
| uint64_t size, int sync) |
| { |
| uint32_t blocksize = zv->zv_volblocksize; |
| zilog_t *zilog = zv->zv_zilog; |
| itx_wr_state_t write_state; |
| uint64_t sz = size; |
| |
| if (zil_replaying(zilog, tx)) |
| return; |
| |
| if (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT) |
| write_state = WR_INDIRECT; |
| else if (!spa_has_slogs(zilog->zl_spa) && |
| size >= blocksize && blocksize > zvol_immediate_write_sz) |
| write_state = WR_INDIRECT; |
| else if (sync) |
| write_state = WR_COPIED; |
| else |
| write_state = WR_NEED_COPY; |
| |
| while (size) { |
| itx_t *itx; |
| lr_write_t *lr; |
| itx_wr_state_t wr_state = write_state; |
| ssize_t len = size; |
| |
| if (wr_state == WR_COPIED && size > zil_max_copied_data(zilog)) |
| wr_state = WR_NEED_COPY; |
| else if (wr_state == WR_INDIRECT) |
| len = MIN(blocksize - P2PHASE(offset, blocksize), size); |
| |
| itx = zil_itx_create(TX_WRITE, sizeof (*lr) + |
| (wr_state == WR_COPIED ? len : 0)); |
| lr = (lr_write_t *)&itx->itx_lr; |
| if (wr_state == WR_COPIED && dmu_read_by_dnode(zv->zv_dn, |
| offset, len, lr+1, DMU_READ_NO_PREFETCH) != 0) { |
| zil_itx_destroy(itx); |
| itx = zil_itx_create(TX_WRITE, sizeof (*lr)); |
| lr = (lr_write_t *)&itx->itx_lr; |
| wr_state = WR_NEED_COPY; |
| } |
| |
| itx->itx_wr_state = wr_state; |
| lr->lr_foid = ZVOL_OBJ; |
| lr->lr_offset = offset; |
| lr->lr_length = len; |
| lr->lr_blkoff = 0; |
| BP_ZERO(&lr->lr_blkptr); |
| |
| itx->itx_private = zv; |
| itx->itx_sync = sync; |
| |
| (void) zil_itx_assign(zilog, itx, tx); |
| |
| offset += len; |
| size -= len; |
| } |
| |
| if (write_state == WR_COPIED || write_state == WR_NEED_COPY) { |
| dsl_pool_wrlog_count(zilog->zl_dmu_pool, sz, tx->tx_txg); |
| } |
| } |
| |
| /* |
| * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE. |
| */ |
| void |
| zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len, |
| boolean_t sync) |
| { |
| itx_t *itx; |
| lr_truncate_t *lr; |
| zilog_t *zilog = zv->zv_zilog; |
| |
| if (zil_replaying(zilog, tx)) |
| return; |
| |
| itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr)); |
| lr = (lr_truncate_t *)&itx->itx_lr; |
| lr->lr_foid = ZVOL_OBJ; |
| lr->lr_offset = off; |
| lr->lr_length = len; |
| |
| itx->itx_sync = sync; |
| zil_itx_assign(zilog, itx, tx); |
| } |
| |
| |
| /* ARGSUSED */ |
| static void |
| zvol_get_done(zgd_t *zgd, int error) |
| { |
| if (zgd->zgd_db) |
| dmu_buf_rele(zgd->zgd_db, zgd); |
| |
| zfs_rangelock_exit(zgd->zgd_lr); |
| |
| kmem_free(zgd, sizeof (zgd_t)); |
| } |
| |
| /* |
| * Get data to generate a TX_WRITE intent log record. |
| */ |
| int |
| zvol_get_data(void *arg, uint64_t arg2, lr_write_t *lr, char *buf, |
| struct lwb *lwb, zio_t *zio) |
| { |
| zvol_state_t *zv = arg; |
| uint64_t offset = lr->lr_offset; |
| uint64_t size = lr->lr_length; |
| dmu_buf_t *db; |
| zgd_t *zgd; |
| int error; |
| |
| ASSERT3P(lwb, !=, NULL); |
| ASSERT3P(zio, !=, NULL); |
| ASSERT3U(size, !=, 0); |
| |
| zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP); |
| zgd->zgd_lwb = lwb; |
| |
| /* |
| * Write records come in two flavors: immediate and indirect. |
| * For small writes it's cheaper to store the data with the |
| * log record (immediate); for large writes it's cheaper to |
| * sync the data and get a pointer to it (indirect) so that |
| * we don't have to write the data twice. |
| */ |
| if (buf != NULL) { /* immediate write */ |
| zgd->zgd_lr = zfs_rangelock_enter(&zv->zv_rangelock, offset, |
| size, RL_READER); |
| error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf, |
| DMU_READ_NO_PREFETCH); |
| } else { /* indirect write */ |
| /* |
| * Have to lock the whole block to ensure when it's written out |
| * and its checksum is being calculated that no one can change |
| * the data. Contrarily to zfs_get_data we need not re-check |
| * blocksize after we get the lock because it cannot be changed. |
| */ |
| size = zv->zv_volblocksize; |
| offset = P2ALIGN_TYPED(offset, size, uint64_t); |
| zgd->zgd_lr = zfs_rangelock_enter(&zv->zv_rangelock, offset, |
| size, RL_READER); |
| error = dmu_buf_hold_by_dnode(zv->zv_dn, offset, zgd, &db, |
| DMU_READ_NO_PREFETCH); |
| if (error == 0) { |
| blkptr_t *bp = &lr->lr_blkptr; |
| |
| zgd->zgd_db = db; |
| zgd->zgd_bp = bp; |
| |
| ASSERT(db != NULL); |
| ASSERT(db->db_offset == offset); |
| ASSERT(db->db_size == size); |
| |
| error = dmu_sync(zio, lr->lr_common.lrc_txg, |
| zvol_get_done, zgd); |
| |
| if (error == 0) |
| return (0); |
| } |
| } |
| |
| zvol_get_done(zgd, error); |
| |
| return (SET_ERROR(error)); |
| } |
| |
| /* |
| * The zvol_state_t's are inserted into zvol_state_list and zvol_htable. |
| */ |
| |
| void |
| zvol_insert(zvol_state_t *zv) |
| { |
| ASSERT(RW_WRITE_HELD(&zvol_state_lock)); |
| list_insert_head(&zvol_state_list, zv); |
| hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash)); |
| } |
| |
| /* |
| * Simply remove the zvol from to list of zvols. |
| */ |
| static void |
| zvol_remove(zvol_state_t *zv) |
| { |
| ASSERT(RW_WRITE_HELD(&zvol_state_lock)); |
| list_remove(&zvol_state_list, zv); |
| hlist_del(&zv->zv_hlink); |
| } |
| |
| /* |
| * Setup zv after we just own the zv->objset |
| */ |
| static int |
| zvol_setup_zv(zvol_state_t *zv) |
| { |
| uint64_t volsize; |
| int error; |
| uint64_t ro; |
| objset_t *os = zv->zv_objset; |
| |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock)); |
| ASSERT(RW_LOCK_HELD(&zv->zv_suspend_lock)); |
| |
| zv->zv_zilog = NULL; |
| zv->zv_flags &= ~ZVOL_WRITTEN_TO; |
| |
| error = dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL); |
| if (error) |
| return (SET_ERROR(error)); |
| |
| error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); |
| if (error) |
| return (SET_ERROR(error)); |
| |
| error = dnode_hold(os, ZVOL_OBJ, zv, &zv->zv_dn); |
| if (error) |
| return (SET_ERROR(error)); |
| |
| ops->zv_set_capacity(zv, volsize >> 9); |
| zv->zv_volsize = volsize; |
| |
| if (ro || dmu_objset_is_snapshot(os) || |
| !spa_writeable(dmu_objset_spa(os))) { |
| ops->zv_set_disk_ro(zv, 1); |
| zv->zv_flags |= ZVOL_RDONLY; |
| } else { |
| ops->zv_set_disk_ro(zv, 0); |
| zv->zv_flags &= ~ZVOL_RDONLY; |
| } |
| return (0); |
| } |
| |
| /* |
| * Shutdown every zv_objset related stuff except zv_objset itself. |
| * The is the reverse of zvol_setup_zv. |
| */ |
| static void |
| zvol_shutdown_zv(zvol_state_t *zv) |
| { |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock) && |
| RW_LOCK_HELD(&zv->zv_suspend_lock)); |
| |
| if (zv->zv_flags & ZVOL_WRITTEN_TO) { |
| ASSERT(zv->zv_zilog != NULL); |
| zil_close(zv->zv_zilog); |
| } |
| |
| zv->zv_zilog = NULL; |
| |
| dnode_rele(zv->zv_dn, zv); |
| zv->zv_dn = NULL; |
| |
| /* |
| * Evict cached data. We must write out any dirty data before |
| * disowning the dataset. |
| */ |
| if (zv->zv_flags & ZVOL_WRITTEN_TO) |
| txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0); |
| (void) dmu_objset_evict_dbufs(zv->zv_objset); |
| } |
| |
| /* |
| * return the proper tag for rollback and recv |
| */ |
| void * |
| zvol_tag(zvol_state_t *zv) |
| { |
| ASSERT(RW_WRITE_HELD(&zv->zv_suspend_lock)); |
| return (zv->zv_open_count > 0 ? zv : NULL); |
| } |
| |
| /* |
| * Suspend the zvol for recv and rollback. |
| */ |
| zvol_state_t * |
| zvol_suspend(const char *name) |
| { |
| zvol_state_t *zv; |
| |
| zv = zvol_find_by_name(name, RW_WRITER); |
| |
| if (zv == NULL) |
| return (NULL); |
| |
| /* block all I/O, release in zvol_resume. */ |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock)); |
| ASSERT(RW_WRITE_HELD(&zv->zv_suspend_lock)); |
| |
| atomic_inc(&zv->zv_suspend_ref); |
| |
| if (zv->zv_open_count > 0) |
| zvol_shutdown_zv(zv); |
| |
| /* |
| * do not hold zv_state_lock across suspend/resume to |
| * avoid locking up zvol lookups |
| */ |
| mutex_exit(&zv->zv_state_lock); |
| |
| /* zv_suspend_lock is released in zvol_resume() */ |
| return (zv); |
| } |
| |
| int |
| zvol_resume(zvol_state_t *zv) |
| { |
| int error = 0; |
| |
| ASSERT(RW_WRITE_HELD(&zv->zv_suspend_lock)); |
| |
| mutex_enter(&zv->zv_state_lock); |
| |
| if (zv->zv_open_count > 0) { |
| VERIFY0(dmu_objset_hold(zv->zv_name, zv, &zv->zv_objset)); |
| VERIFY3P(zv->zv_objset->os_dsl_dataset->ds_owner, ==, zv); |
| VERIFY(dsl_dataset_long_held(zv->zv_objset->os_dsl_dataset)); |
| dmu_objset_rele(zv->zv_objset, zv); |
| |
| error = zvol_setup_zv(zv); |
| } |
| |
| mutex_exit(&zv->zv_state_lock); |
| |
| rw_exit(&zv->zv_suspend_lock); |
| /* |
| * We need this because we don't hold zvol_state_lock while releasing |
| * zv_suspend_lock. zvol_remove_minors_impl thus cannot check |
| * zv_suspend_lock to determine it is safe to free because rwlock is |
| * not inherent atomic. |
| */ |
| atomic_dec(&zv->zv_suspend_ref); |
| |
| return (SET_ERROR(error)); |
| } |
| |
| int |
| zvol_first_open(zvol_state_t *zv, boolean_t readonly) |
| { |
| objset_t *os; |
| int error; |
| |
| ASSERT(RW_READ_HELD(&zv->zv_suspend_lock)); |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock)); |
| ASSERT(mutex_owned(&spa_namespace_lock)); |
| |
| boolean_t ro = (readonly || (strchr(zv->zv_name, '@') != NULL)); |
| error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, ro, B_TRUE, zv, &os); |
| if (error) |
| return (SET_ERROR(error)); |
| |
| zv->zv_objset = os; |
| |
| error = zvol_setup_zv(zv); |
| if (error) { |
| dmu_objset_disown(os, 1, zv); |
| zv->zv_objset = NULL; |
| } |
| |
| return (error); |
| } |
| |
| void |
| zvol_last_close(zvol_state_t *zv) |
| { |
| ASSERT(RW_READ_HELD(&zv->zv_suspend_lock)); |
| ASSERT(MUTEX_HELD(&zv->zv_state_lock)); |
| |
| zvol_shutdown_zv(zv); |
| |
| dmu_objset_disown(zv->zv_objset, 1, zv); |
| zv->zv_objset = NULL; |
| } |
| |
| typedef struct minors_job { |
| list_t *list; |
| list_node_t link; |
| /* input */ |
| char *name; |
| /* output */ |
| int error; |
| } minors_job_t; |
| |
| /* |
| * Prefetch zvol dnodes for the minors_job |
| */ |
| static void |
| zvol_prefetch_minors_impl(void *arg) |
| { |
| minors_job_t *job = arg; |
| char *dsname = job->name; |
| objset_t *os = NULL; |
| |
| job->error = dmu_objset_own(dsname, DMU_OST_ZVOL, B_TRUE, B_TRUE, |
| FTAG, &os); |
| if (job->error == 0) { |
| dmu_prefetch(os, ZVOL_OBJ, 0, 0, 0, ZIO_PRIORITY_SYNC_READ); |
| dmu_objset_disown(os, B_TRUE, FTAG); |
| } |
| } |
| |
| /* |
| * Mask errors to continue dmu_objset_find() traversal |
| */ |
| static int |
| zvol_create_snap_minor_cb(const char *dsname, void *arg) |
| { |
| minors_job_t *j = arg; |
| list_t *minors_list = j->list; |
| const char *name = j->name; |
| |
| ASSERT0(MUTEX_HELD(&spa_namespace_lock)); |
| |
| /* skip the designated dataset */ |
| if (name && strcmp(dsname, name) == 0) |
| return (0); |
| |
| /* at this point, the dsname should name a snapshot */ |
| if (strchr(dsname, '@') == 0) { |
| dprintf("zvol_create_snap_minor_cb(): " |
| "%s is not a snapshot name\n", dsname); |
| } else { |
| minors_job_t *job; |
| char *n = kmem_strdup(dsname); |
| if (n == NULL) |
| return (0); |
| |
| job = kmem_alloc(sizeof (minors_job_t), KM_SLEEP); |
| job->name = n; |
| job->list = minors_list; |
| job->error = 0; |
| list_insert_tail(minors_list, job); |
| /* don't care if dispatch fails, because job->error is 0 */ |
| taskq_dispatch(system_taskq, zvol_prefetch_minors_impl, job, |
| TQ_SLEEP); |
| } |
| |
| return (0); |
| } |
| |
| /* |
| * If spa_keystore_load_wkey() is called for an encrypted zvol, |
| * we need to look for any clones also using the key. This function |
| * is "best effort" - so we just skip over it if there are failures. |
| */ |
| static void |
| zvol_add_clones(const char *dsname, list_t *minors_list) |
| { |
| /* Also check if it has clones */ |
| dsl_dir_t *dd = NULL; |
| dsl_pool_t *dp = NULL; |
| |
| if (dsl_pool_hold(dsname, FTAG, &dp) != 0) |
| return; |
| |
| if (!spa_feature_is_enabled(dp->dp_spa, |
| SPA_FEATURE_ENCRYPTION)) |
| goto out; |
| |
| if (dsl_dir_hold(dp, dsname, FTAG, &dd, NULL) != 0) |
| goto out; |
| |
| if (dsl_dir_phys(dd)->dd_clones == 0) |
| goto out; |
| |
| zap_cursor_t *zc = kmem_alloc(sizeof (zap_cursor_t), KM_SLEEP); |
| zap_attribute_t *za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); |
| objset_t *mos = dd->dd_pool->dp_meta_objset; |
| |
| for (zap_cursor_init(zc, mos, dsl_dir_phys(dd)->dd_clones); |
| zap_cursor_retrieve(zc, za) == 0; |
| zap_cursor_advance(zc)) { |
| dsl_dataset_t *clone; |
| minors_job_t *job; |
| |
| if (dsl_dataset_hold_obj(dd->dd_pool, |
| za->za_first_integer, FTAG, &clone) == 0) { |
| |
| char name[ZFS_MAX_DATASET_NAME_LEN]; |
| dsl_dataset_name(clone, name); |
| |
| char *n = kmem_strdup(name); |
| job = kmem_alloc(sizeof (minors_job_t), KM_SLEEP); |
| job->name = n; |
| job->list = minors_list; |
| job->error = 0; |
| list_insert_tail(minors_list, job); |
| |
| dsl_dataset_rele(clone, FTAG); |
| } |
| } |
| zap_cursor_fini(zc); |
| kmem_free(za, sizeof (zap_attribute_t)); |
| kmem_free(zc, sizeof (zap_cursor_t)); |
| |
| out: |
| if (dd != NULL) |
| dsl_dir_rele(dd, FTAG); |
| if (dp != NULL) |
| dsl_pool_rele(dp, FTAG); |
| } |
| |
| /* |
| * Mask errors to continue dmu_objset_find() traversal |
| */ |
| static int |
| zvol_create_minors_cb(const char *dsname, void *arg) |
| { |
| uint64_t snapdev; |
| int error; |
| list_t *minors_list = arg; |
| |
| ASSERT0(MUTEX_HELD(&spa_namespace_lock)); |
| |
| error = dsl_prop_get_integer(dsname, "snapdev", &snapdev, NULL); |
| if (error) |
| return (0); |
| |
| /* |
| * Given the name and the 'snapdev' property, create device minor nodes |
| * with the linkages to zvols/snapshots as needed. |
| * If the name represents a zvol, create a minor node for the zvol, then |
| * check if its snapshots are 'visible', and if so, iterate over the |
| * snapshots and create device minor nodes for those. |
| */ |
| if (strchr(dsname, '@') == 0) { |
| minors_job_t *job; |
| char *n = kmem_strdup(dsname); |
| if (n == NULL) |
| return (0); |
| |
| job = kmem_alloc(sizeof (minors_job_t), KM_SLEEP); |
| job->name = n; |
| job->list = minors_list; |
| job->error = 0; |
| list_insert_tail(minors_list, job); |
| /* don't care if dispatch fails, because job->error is 0 */ |
| taskq_dispatch(system_taskq, zvol_prefetch_minors_impl, job, |
| TQ_SLEEP); |
| |
| zvol_add_clones(dsname, minors_list); |
| |
| if (snapdev == ZFS_SNAPDEV_VISIBLE) { |
| /* |
| * traverse snapshots only, do not traverse children, |
| * and skip the 'dsname' |
| */ |
| error = dmu_objset_find(dsname, |
| zvol_create_snap_minor_cb, (void *)job, |
| DS_FIND_SNAPSHOTS); |
| } |
| } else { |
| dprintf("zvol_create_minors_cb(): %s is not a zvol name\n", |
| dsname); |
| } |
| |
| return (0); |
| } |
| |
| /* |
| * Create minors for the specified dataset, including children and snapshots. |
| * Pay attention to the 'snapdev' property and iterate over the snapshots |
| * only if they are 'visible'. This approach allows one to assure that the |
| * snapshot metadata is read from disk only if it is needed. |
| * |
| * The name can represent a dataset to be recursively scanned for zvols and |
| * their snapshots, or a single zvol snapshot. If the name represents a |
| * dataset, the scan is performed in two nested stages: |
| * - scan the dataset for zvols, and |
| * - for each zvol, create a minor node, then check if the zvol's snapshots |
| * are 'visible', and only then iterate over the snapshots if needed |
| * |
| * If the name represents a snapshot, a check is performed if the snapshot is |
| * 'visible' (which also verifies that the parent is a zvol), and if so, |
| * a minor node for that snapshot is created. |
| */ |
| void |
| zvol_create_minors_recursive(const char *name) |
| { |
| list_t minors_list; |
| minors_job_t *job; |
| |
| if (zvol_inhibit_dev) |
| return; |
| |
| /* |
| * This is the list for prefetch jobs. Whenever we found a match |
| * during dmu_objset_find, we insert a minors_job to the list and do |
| * taskq_dispatch to parallel prefetch zvol dnodes. Note we don't need |
| * any lock because all list operation is done on the current thread. |
| * |
| * We will use this list to do zvol_create_minor_impl after prefetch |
| * so we don't have to traverse using dmu_objset_find again. |
| */ |
| list_create(&minors_list, sizeof (minors_job_t), |
| offsetof(minors_job_t, link)); |
| |
| |
| if (strchr(name, '@') != NULL) { |
| uint64_t snapdev; |
| |
| int error = dsl_prop_get_integer(name, "snapdev", |
| &snapdev, NULL); |
| |
| if (error == 0 && snapdev == ZFS_SNAPDEV_VISIBLE) |
| (void) ops->zv_create_minor(name); |
| } else { |
| fstrans_cookie_t cookie = spl_fstrans_mark(); |
| (void) dmu_objset_find(name, zvol_create_minors_cb, |
| &minors_list, DS_FIND_CHILDREN); |
| spl_fstrans_unmark(cookie); |
| } |
| |
| taskq_wait_outstanding(system_taskq, 0); |
| |
| /* |
| * Prefetch is completed, we can do zvol_create_minor_impl |
| * sequentially. |
| */ |
| while ((job = list_head(&minors_list)) != NULL) { |
| list_remove(&minors_list, job); |
| if (!job->error) |
| (void) ops->zv_create_minor(job->name); |
| kmem_strfree(job->name); |
| kmem_free(job, sizeof (minors_job_t)); |
| } |
| |
| list_destroy(&minors_list); |
| } |
| |
| void |
| zvol_create_minor(const char *name) |
| { |
| /* |
| * Note: the dsl_pool_config_lock must not be held. |
| * Minor node creation needs to obtain the zvol_state_lock. |
| * zvol_open() obtains the zvol_state_lock and then the dsl pool |
| * config lock. Therefore, we can't have the config lock now if |
| * we are going to wait for the zvol_state_lock, because it |
| * would be a lock order inversion which could lead to deadlock. |
| */ |
| |
| if (zvol_inhibit_dev) |
| return; |
| |
| if (strchr(name, '@') != NULL) { |
| uint64_t snapdev; |
| |
| int error = dsl_prop_get_integer(name, |
| "snapdev", &snapdev, NULL); |
| |
| if (error == 0 && snapdev == ZFS_SNAPDEV_VISIBLE) |
| (void) ops->zv_create_minor(name); |
| } else { |
| (void) ops->zv_create_minor(name); |
| } |
| } |
| |
| /* |
| * Remove minors for specified dataset including children and snapshots. |
| */ |
| |
| static void |
| zvol_free_task(void *arg) |
| { |
| ops->zv_free(arg); |
| } |
| |
| void |
| zvol_remove_minors_impl(const char *name) |
| { |
| zvol_state_t *zv, *zv_next; |
| int namelen = ((name) ? strlen(name) : 0); |
| taskqid_t t; |
| list_t free_list; |
| |
| if (zvol_inhibit_dev) |
| return; |
| |
| list_create(&free_list, sizeof (zvol_state_t), |
| offsetof(zvol_state_t, zv_next)); |
| |
| rw_enter(&zvol_state_lock, RW_WRITER); |
| |
| for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) { |
| zv_next = list_next(&zvol_state_list, zv); |
| |
| mutex_enter(&zv->zv_state_lock); |
| if (name == NULL || strcmp(zv->zv_name, name) == 0 || |
| (strncmp(zv->zv_name, name, namelen) == 0 && |
| (zv->zv_name[namelen] == '/' || |
| zv->zv_name[namelen] == '@'))) { |
| /* |
| * By holding zv_state_lock here, we guarantee that no |
| * one is currently using this zv |
| */ |
| |
| /* If in use, leave alone */ |
| if (zv->zv_open_count > 0 || |
| atomic_read(&zv->zv_suspend_ref)) { |
| mutex_exit(&zv->zv_state_lock); |
| continue; |
| } |
| |
| zvol_remove(zv); |
| |
| /* |
| * Cleared while holding zvol_state_lock as a writer |
| * which will prevent zvol_open() from opening it. |
| */ |
| ops->zv_clear_private(zv); |
| |
| /* Drop zv_state_lock before zvol_free() */ |
| mutex_exit(&zv->zv_state_lock); |
| |
| /* Try parallel zv_free, if failed do it in place */ |
| t = taskq_dispatch(system_taskq, zvol_free_task, zv, |
| TQ_SLEEP); |
| if (t == TASKQID_INVALID) |
| list_insert_head(&free_list, zv); |
| } else { |
| mutex_exit(&zv->zv_state_lock); |
| } |
| } |
| rw_exit(&zvol_state_lock); |
| |
| /* Drop zvol_state_lock before calling zvol_free() */ |
| while ((zv = list_head(&free_list)) != NULL) { |
| list_remove(&free_list, zv); |
| ops->zv_free(zv); |
| } |
| } |
| |
| /* Remove minor for this specific volume only */ |
| static void |
| zvol_remove_minor_impl(const char *name) |
| { |
| zvol_state_t *zv = NULL, *zv_next; |
| |
| if (zvol_inhibit_dev) |
| return; |
| |
| rw_enter(&zvol_state_lock, RW_WRITER); |
| |
| for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) { |
| zv_next = list_next(&zvol_state_list, zv); |
| |
| mutex_enter(&zv->zv_state_lock); |
| if (strcmp(zv->zv_name, name) == 0) { |
| /* |
| * By holding zv_state_lock here, we guarantee that no |
| * one is currently using this zv |
| */ |
| |
| /* If in use, leave alone */ |
| if (zv->zv_open_count > 0 || |
| atomic_read(&zv->zv_suspend_ref)) { |
| mutex_exit(&zv->zv_state_lock); |
| continue; |
| } |
| zvol_remove(zv); |
| |
| ops->zv_clear_private(zv); |
| mutex_exit(&zv->zv_state_lock); |
| break; |
| } else { |
| mutex_exit(&zv->zv_state_lock); |
| } |
| } |
| |
| /* Drop zvol_state_lock before calling zvol_free() */ |
| rw_exit(&zvol_state_lock); |
| |
| if (zv != NULL) |
| ops->zv_free(zv); |
| } |
| |
| /* |
| * Rename minors for specified dataset including children and snapshots. |
| */ |
| static void |
| zvol_rename_minors_impl(const char *oldname, const char *newname) |
| { |
| zvol_state_t *zv, *zv_next; |
| int oldnamelen; |
| |
| if (zvol_inhibit_dev) |
| return; |
| |
| oldnamelen = strlen(oldname); |
| |
| rw_enter(&zvol_state_lock, RW_READER); |
| |
| for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) { |
| zv_next = list_next(&zvol_state_list, zv); |
| |
| mutex_enter(&zv->zv_state_lock); |
| |
| if (strcmp(zv->zv_name, oldname) == 0) { |
| ops->zv_rename_minor(zv, newname); |
| } else if (strncmp(zv->zv_name, oldname, oldnamelen) == 0 && |
| (zv->zv_name[oldnamelen] == '/' || |
| zv->zv_name[oldnamelen] == '@')) { |
| char *name = kmem_asprintf("%s%c%s", newname, |
| zv->zv_name[oldnamelen], |
| zv->zv_name + oldnamelen + 1); |
| ops->zv_rename_minor(zv, name); |
| kmem_strfree(name); |
| } |
| |
| mutex_exit(&zv->zv_state_lock); |
| } |
| |
| rw_exit(&zvol_state_lock); |
| } |
| |
| typedef struct zvol_snapdev_cb_arg { |
| uint64_t snapdev; |
| } zvol_snapdev_cb_arg_t; |
| |
| static int |
| zvol_set_snapdev_cb(const char *dsname, void *param) |
| { |
| zvol_snapdev_cb_arg_t *arg = param; |
| |
| if (strchr(dsname, '@') == NULL) |
| return (0); |
| |
| switch (arg->snapdev) { |
| case ZFS_SNAPDEV_VISIBLE: |
| (void) ops->zv_create_minor(dsname); |
| break; |
| case ZFS_SNAPDEV_HIDDEN: |
| (void) zvol_remove_minor_impl(dsname); |
| break; |
| } |
| |
| return (0); |
| } |
| |
| static void |
| zvol_set_snapdev_impl(char *name, uint64_t snapdev) |
| { |
| zvol_snapdev_cb_arg_t arg = {snapdev}; |
| fstrans_cookie_t cookie = spl_fstrans_mark(); |
| /* |
| * The zvol_set_snapdev_sync() sets snapdev appropriately |
| * in the dataset hierarchy. Here, we only scan snapshots. |
| */ |
| dmu_objset_find(name, zvol_set_snapdev_cb, &arg, DS_FIND_SNAPSHOTS); |
| spl_fstrans_unmark(cookie); |
| } |
| |
| typedef struct zvol_volmode_cb_arg { |
| uint64_t volmode; |
| } zvol_volmode_cb_arg_t; |
| |
| static void |
| zvol_set_volmode_impl(char *name, uint64_t volmode) |
| { |
| fstrans_cookie_t cookie; |
| uint64_t old_volmode; |
| zvol_state_t *zv; |
| |
| if (strchr(name, '@') != NULL) |
| return; |
| |
| /* |
| * It's unfortunate we need to remove minors before we create new ones: |
| * this is necessary because our backing gendisk (zvol_state->zv_disk) |
| * could be different when we set, for instance, volmode from "geom" |
| * to "dev" (or vice versa). |
| */ |
| zv = zvol_find_by_name(name, RW_NONE); |
| if (zv == NULL && volmode == ZFS_VOLMODE_NONE) |
| return; |
| if (zv != NULL) { |
| old_volmode = zv->zv_volmode; |
| mutex_exit(&zv->zv_state_lock); |
| if (old_volmode == volmode) |
| return; |
| zvol_wait_close(zv); |
| } |
| cookie = spl_fstrans_mark(); |
| switch (volmode) { |
| case ZFS_VOLMODE_NONE: |
| (void) zvol_remove_minor_impl(name); |
| break; |
| case ZFS_VOLMODE_GEOM: |
| case ZFS_VOLMODE_DEV: |
| (void) zvol_remove_minor_impl(name); |
| (void) ops->zv_create_minor(name); |
| break; |
| case ZFS_VOLMODE_DEFAULT: |
| (void) zvol_remove_minor_impl(name); |
| if (zvol_volmode == ZFS_VOLMODE_NONE) |
| break; |
| else /* if zvol_volmode is invalid defaults to "geom" */ |
| (void) ops->zv_create_minor(name); |
| break; |
| } |
| spl_fstrans_unmark(cookie); |
| } |
| |
| static zvol_task_t * |
| zvol_task_alloc(zvol_async_op_t op, const char *name1, const char *name2, |
| uint64_t value) |
| { |
| zvol_task_t *task; |
| |
| /* Never allow tasks on hidden names. */ |
| if (name1[0] == '$') |
| return (NULL); |
| |
| task = kmem_zalloc(sizeof (zvol_task_t), KM_SLEEP); |
| task->op = op; |
| task->value = value; |
| |
| strlcpy(task->name1, name1, MAXNAMELEN); |
| if (name2 != NULL) |
| strlcpy(task->name2, name2, MAXNAMELEN); |
| |
| return (task); |
| } |
| |
| static void |
| zvol_task_free(zvol_task_t *task) |
| { |
| kmem_free(task, sizeof (zvol_task_t)); |
| } |
| |
| /* |
| * The worker thread function performed asynchronously. |
| */ |
| static void |
| zvol_task_cb(void *arg) |
| { |
| zvol_task_t *task = arg; |
| |
| switch (task->op) { |
| case ZVOL_ASYNC_REMOVE_MINORS: |
| zvol_remove_minors_impl(task->name1); |
| break; |
| case ZVOL_ASYNC_RENAME_MINORS: |
| zvol_rename_minors_impl(task->name1, task->name2); |
| break; |
| case ZVOL_ASYNC_SET_SNAPDEV: |
| zvol_set_snapdev_impl(task->name1, task->value); |
| break; |
| case ZVOL_ASYNC_SET_VOLMODE: |
| zvol_set_volmode_impl(task->name1, task->value); |
| break; |
| default: |
| VERIFY(0); |
| break; |
| } |
| |
| zvol_task_free(task); |
| } |
| |
| typedef struct zvol_set_prop_int_arg { |
| const char *zsda_name; |
| uint64_t zsda_value; |
| zprop_source_t zsda_source; |
| dmu_tx_t *zsda_tx; |
| } zvol_set_prop_int_arg_t; |
| |
| /* |
| * Sanity check the dataset for safe use by the sync task. No additional |
| * conditions are imposed. |
| */ |
| static int |
| zvol_set_snapdev_check(void *arg, dmu_tx_t *tx) |
| { |
| zvol_set_prop_int_arg_t *zsda = arg; |
| dsl_pool_t *dp = dmu_tx_pool(tx); |
| dsl_dir_t *dd; |
| int error; |
| |
| error = dsl_dir_hold(dp, zsda->zsda_name, FTAG, &dd, NULL); |
| if (error != 0) |
| return (error); |
| |
| dsl_dir_rele(dd, FTAG); |
| |
| return (error); |
| } |
| |
| /* ARGSUSED */ |
| static int |
| zvol_set_snapdev_sync_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg) |
| { |
| char dsname[MAXNAMELEN]; |
| zvol_task_t *task; |
| uint64_t snapdev; |
| |
| dsl_dataset_name(ds, dsname); |
| if (dsl_prop_get_int_ds(ds, "snapdev", &snapdev) != 0) |
| return (0); |
| task = zvol_task_alloc(ZVOL_ASYNC_SET_SNAPDEV, dsname, NULL, snapdev); |
| if (task == NULL) |
| return (0); |
| |
| (void) taskq_dispatch(dp->dp_spa->spa_zvol_taskq, zvol_task_cb, |
| task, TQ_SLEEP); |
| return (0); |
| } |
| |
| /* |
| * Traverse all child datasets and apply snapdev appropriately. |
| * We call dsl_prop_set_sync_impl() here to set the value only on the toplevel |
| * dataset and read the effective "snapdev" on every child in the callback |
| * function: this is because the value is not guaranteed to be the same in the |
| * whole dataset hierarchy. |
| */ |
| static void |
| zvol_set_snapdev_sync(void *arg, dmu_tx_t *tx) |
| { |
| zvol_set_prop_int_arg_t *zsda = arg; |
| dsl_pool_t *dp = dmu_tx_pool(tx); |
| dsl_dir_t *dd; |
| dsl_dataset_t *ds; |
| int error; |
| |
| VERIFY0(dsl_dir_hold(dp, zsda->zsda_name, FTAG, &dd, NULL)); |
| zsda->zsda_tx = tx; |
| |
| error = dsl_dataset_hold(dp, zsda->zsda_name, FTAG, &ds); |
| if (error == 0) { |
| dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_SNAPDEV), |
| zsda->zsda_source, sizeof (zsda->zsda_value), 1, |
| &zsda->zsda_value, zsda->zsda_tx); |
| dsl_dataset_rele(ds, FTAG); |
| } |
| dmu_objset_find_dp(dp, dd->dd_object, zvol_set_snapdev_sync_cb, |
| zsda, DS_FIND_CHILDREN); |
| |
| dsl_dir_rele(dd, FTAG); |
| } |
| |
| int |
| zvol_set_snapdev(const char *ddname, zprop_source_t source, uint64_t snapdev) |
| { |
| zvol_set_prop_int_arg_t zsda; |
| |
| zsda.zsda_name = ddname; |
| zsda.zsda_source = source; |
| zsda.zsda_value = snapdev; |
| |
| return (dsl_sync_task(ddname, zvol_set_snapdev_check, |
| zvol_set_snapdev_sync, &zsda, 0, ZFS_SPACE_CHECK_NONE)); |
| } |
| |
| /* |
| * Sanity check the dataset for safe use by the sync task. No additional |
| * conditions are imposed. |
| */ |
| static int |
| zvol_set_volmode_check(void *arg, dmu_tx_t *tx) |
| { |
| zvol_set_prop_int_arg_t *zsda = arg; |
| dsl_pool_t *dp = dmu_tx_pool(tx); |
| dsl_dir_t *dd; |
| int error; |
| |
| error = dsl_dir_hold(dp, zsda->zsda_name, FTAG, &dd, NULL); |
| if (error != 0) |
| return (error); |
| |
| dsl_dir_rele(dd, FTAG); |
| |
| return (error); |
| } |
| |
| /* ARGSUSED */ |
| static int |
| zvol_set_volmode_sync_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg) |
| { |
| char dsname[MAXNAMELEN]; |
| zvol_task_t *task; |
| uint64_t volmode; |
| |
| dsl_dataset_name(ds, dsname); |
| if (dsl_prop_get_int_ds(ds, "volmode", &volmode) != 0) |
| return (0); |
| task = zvol_task_alloc(ZVOL_ASYNC_SET_VOLMODE, dsname, NULL, volmode); |
| if (task == NULL) |
| return (0); |
| |
| (void) taskq_dispatch(dp->dp_spa->spa_zvol_taskq, zvol_task_cb, |
| task, TQ_SLEEP); |
| return (0); |
| } |
| |
| /* |
| * Traverse all child datasets and apply volmode appropriately. |
| * We call dsl_prop_set_sync_impl() here to set the value only on the toplevel |
| * dataset and read the effective "volmode" on every child in the callback |
| * function: this is because the value is not guaranteed to be the same in the |
| * whole dataset hierarchy. |
| */ |
| static void |
| zvol_set_volmode_sync(void *arg, dmu_tx_t *tx) |
| { |
| zvol_set_prop_int_arg_t *zsda = arg; |
| dsl_pool_t *dp = dmu_tx_pool(tx); |
| dsl_dir_t *dd; |
| dsl_dataset_t *ds; |
| int error; |
| |
| VERIFY0(dsl_dir_hold(dp, zsda->zsda_name, FTAG, &dd, NULL)); |
| zsda->zsda_tx = tx; |
| |
| error = dsl_dataset_hold(dp, zsda->zsda_name, FTAG, &ds); |
| if (error == 0) { |
| dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_VOLMODE), |
| zsda->zsda_source, sizeof (zsda->zsda_value), 1, |
| &zsda->zsda_value, zsda->zsda_tx); |
| dsl_dataset_rele(ds, FTAG); |
| } |
| |
| dmu_objset_find_dp(dp, dd->dd_object, zvol_set_volmode_sync_cb, |
| zsda, DS_FIND_CHILDREN); |
| |
| dsl_dir_rele(dd, FTAG); |
| } |
| |
| int |
| zvol_set_volmode(const char *ddname, zprop_source_t source, uint64_t volmode) |
| { |
| zvol_set_prop_int_arg_t zsda; |
| |
| zsda.zsda_name = ddname; |
| zsda.zsda_source = source; |
| zsda.zsda_value = volmode; |
| |
| return (dsl_sync_task(ddname, zvol_set_volmode_check, |
| zvol_set_volmode_sync, &zsda, 0, ZFS_SPACE_CHECK_NONE)); |
| } |
| |
| void |
| zvol_remove_minors(spa_t *spa, const char *name, boolean_t async) |
| { |
| zvol_task_t *task; |
| taskqid_t id; |
| |
| task = zvol_task_alloc(ZVOL_ASYNC_REMOVE_MINORS, name, NULL, ~0ULL); |
| if (task == NULL) |
| return; |
| |
| id = taskq_dispatch(spa->spa_zvol_taskq, zvol_task_cb, task, TQ_SLEEP); |
| if ((async == B_FALSE) && (id != TASKQID_INVALID)) |
| taskq_wait_id(spa->spa_zvol_taskq, id); |
| } |
| |
| void |
| zvol_rename_minors(spa_t *spa, const char *name1, const char *name2, |
| boolean_t async) |
| { |
| zvol_task_t *task; |
| taskqid_t id; |
| |
| task = zvol_task_alloc(ZVOL_ASYNC_RENAME_MINORS, name1, name2, ~0ULL); |
| if (task == NULL) |
| return; |
| |
| id = taskq_dispatch(spa->spa_zvol_taskq, zvol_task_cb, task, TQ_SLEEP); |
| if ((async == B_FALSE) && (id != TASKQID_INVALID)) |
| taskq_wait_id(spa->spa_zvol_taskq, id); |
| } |
| |
| boolean_t |
| zvol_is_zvol(const char *name) |
| { |
| |
| return (ops->zv_is_zvol(name)); |
| } |
| |
| void |
| zvol_register_ops(const zvol_platform_ops_t *zvol_ops) |
| { |
| ops = zvol_ops; |
| } |
| |
| int |
| zvol_init_impl(void) |
| { |
| int i; |
| |
| list_create(&zvol_state_list, sizeof (zvol_state_t), |
| offsetof(zvol_state_t, zv_next)); |
| rw_init(&zvol_state_lock, NULL, RW_DEFAULT, NULL); |
| |
| zvol_htable = kmem_alloc(ZVOL_HT_SIZE * sizeof (struct hlist_head), |
| KM_SLEEP); |
| for (i = 0; i < ZVOL_HT_SIZE; i++) |
| INIT_HLIST_HEAD(&zvol_htable[i]); |
| |
| return (0); |
| } |
| |
| void |
| zvol_fini_impl(void) |
| { |
| zvol_remove_minors_impl(NULL); |
| |
| /* |
| * The call to "zvol_remove_minors_impl" may dispatch entries to |
| * the system_taskq, but it doesn't wait for those entries to |
| * complete before it returns. Thus, we must wait for all of the |
| * removals to finish, before we can continue. |
| */ |
| taskq_wait_outstanding(system_taskq, 0); |
| |
| kmem_free(zvol_htable, ZVOL_HT_SIZE * sizeof (struct hlist_head)); |
| list_destroy(&zvol_state_list); |
| rw_destroy(&zvol_state_lock); |
| } |