/* * 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 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * 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/zvol/dsk// * /dev/zvol/rdsk// * * These links are created by the ZFS-specific devfsadm link generator. * Volumes are persistent through reboot. No user command needs to be * run before opening and using a device. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "zfs_namecheck.h" static void *zvol_state; #define ZVOL_DUMPSIZE "dumpsize" /* * This lock protects the zvol_state structure from being modified * while it's being used, e.g. an open that comes in before a create * finishes. It also protects temporary opens of the dataset so that, * e.g., an open doesn't get a spurious EBUSY. */ static kmutex_t zvol_state_lock; static uint32_t zvol_minors; #define NUM_EXTENTS ((SPA_MAXBLOCKSIZE) / sizeof (zvol_extent_t)) typedef struct zvol_extent { dva_t ze_dva; /* dva associated with this extent */ uint64_t ze_stride; /* extent stride */ uint64_t ze_size; /* number of blocks in extent */ } zvol_extent_t; /* * The list of extents associated with the dump device */ typedef struct zvol_ext_list { zvol_extent_t zl_extents[NUM_EXTENTS]; struct zvol_ext_list *zl_next; } zvol_ext_list_t; /* * The in-core state of each volume. */ typedef struct zvol_state { char zv_name[MAXPATHLEN]; /* pool/dd name */ uint64_t zv_volsize; /* amount of space we advertise */ uint64_t zv_volblocksize; /* volume block size */ minor_t zv_minor; /* minor number */ uint8_t zv_min_bs; /* minimum addressable block shift */ uint8_t zv_flags; /* readonly; dumpified */ objset_t *zv_objset; /* objset handle */ uint32_t zv_mode; /* DS_MODE_* flags at open time */ uint32_t zv_open_count[OTYPCNT]; /* open counts */ uint32_t zv_total_opens; /* total open count */ zilog_t *zv_zilog; /* ZIL handle */ zvol_ext_list_t *zv_list; /* List of extents for dump */ uint64_t zv_txg_assign; /* txg to assign during ZIL replay */ znode_t zv_znode; /* for range locking */ } zvol_state_t; /* * zvol specific flags */ #define ZVOL_RDONLY 0x1 #define ZVOL_DUMPIFIED 0x2 #define ZVOL_EXCL 0x4 /* * zvol maximum transfer in one DMU tx. */ int zvol_maxphys = DMU_MAX_ACCESS/2; extern int zfs_set_prop_nvlist(const char *, nvlist_t *); static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); static int zvol_dumpify(zvol_state_t *zv); static int zvol_dump_fini(zvol_state_t *zv); static int zvol_dump_init(zvol_state_t *zv, boolean_t resize); static void zvol_size_changed(zvol_state_t *zv, major_t maj) { dev_t dev = makedevice(maj, zv->zv_minor); VERIFY(ddi_prop_update_int64(dev, zfs_dip, "Size", zv->zv_volsize) == DDI_SUCCESS); VERIFY(ddi_prop_update_int64(dev, zfs_dip, "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); /* Notify specfs to invalidate the cached size */ spec_size_invalidate(dev, VBLK); spec_size_invalidate(dev, VCHR); } int zvol_check_volsize(uint64_t volsize, uint64_t blocksize) { if (volsize == 0) return (EINVAL); if (volsize % blocksize != 0) return (EINVAL); #ifdef _ILP32 if (volsize - 1 > SPEC_MAXOFFSET_T) return (EOVERFLOW); #endif return (0); } int zvol_check_volblocksize(uint64_t volblocksize) { if (volblocksize < SPA_MINBLOCKSIZE || volblocksize > SPA_MAXBLOCKSIZE || !ISP2(volblocksize)) return (EDOM); return (0); } static void zvol_readonly_changed_cb(void *arg, uint64_t newval) { zvol_state_t *zv = arg; if (newval) zv->zv_flags |= ZVOL_RDONLY; else zv->zv_flags &= ~ZVOL_RDONLY; } 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 (error); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 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); } return (error); } /* * Find a free minor number. */ static minor_t zvol_minor_alloc(void) { minor_t minor; ASSERT(MUTEX_HELD(&zvol_state_lock)); for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) if (ddi_get_soft_state(zvol_state, minor) == NULL) return (minor); return (0); } static zvol_state_t * zvol_minor_lookup(const char *name) { minor_t minor; zvol_state_t *zv; ASSERT(MUTEX_HELD(&zvol_state_lock)); for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) continue; if (strcmp(zv->zv_name, name) == 0) break; } return (zv); } void zvol_init_extent(zvol_extent_t *ze, blkptr_t *bp) { ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ ze->ze_stride = 0; ze->ze_size = 1; } /* extent mapping arg */ struct maparg { zvol_ext_list_t *ma_list; zvol_extent_t *ma_extent; int ma_gang; }; /*ARGSUSED*/ static int zvol_map_block(traverse_blk_cache_t *bc, spa_t *spa, void *arg) { zbookmark_t *zb = &bc->bc_bookmark; blkptr_t *bp = &bc->bc_blkptr; void *data = bc->bc_data; dnode_phys_t *dnp = bc->bc_dnode; struct maparg *ma = (struct maparg *)arg; uint64_t stride; /* If there is an error, then keep trying to make progress */ if (bc->bc_errno) return (ERESTART); #ifdef ZFS_DEBUG if (zb->zb_level == -1) { ASSERT3U(BP_GET_TYPE(bp), ==, DMU_OT_OBJSET); ASSERT3U(BP_GET_LEVEL(bp), ==, 0); } else { ASSERT3U(BP_GET_TYPE(bp), ==, dnp->dn_type); ASSERT3U(BP_GET_LEVEL(bp), ==, zb->zb_level); } if (zb->zb_level > 0) { uint64_t fill = 0; blkptr_t *bpx, *bpend; for (bpx = data, bpend = bpx + BP_GET_LSIZE(bp) / sizeof (*bpx); bpx < bpend; bpx++) { if (bpx->blk_birth != 0) { fill += bpx->blk_fill; } else { ASSERT(bpx->blk_fill == 0); } } ASSERT3U(fill, ==, bp->blk_fill); } if (zb->zb_level == 0 && dnp->dn_type == DMU_OT_DNODE) { uint64_t fill = 0; dnode_phys_t *dnx, *dnend; for (dnx = data, dnend = dnx + (BP_GET_LSIZE(bp)>>DNODE_SHIFT); dnx < dnend; dnx++) { if (dnx->dn_type != DMU_OT_NONE) fill++; } ASSERT3U(fill, ==, bp->blk_fill); } #endif if (zb->zb_level || dnp->dn_type == DMU_OT_DNODE) return (0); /* Abort immediately if we have encountered gang blocks */ if (BP_IS_GANG(bp)) { ma->ma_gang++; return (EINTR); } /* first time? */ if (ma->ma_extent->ze_size == 0) { zvol_init_extent(ma->ma_extent, bp); return (0); } stride = (DVA_GET_OFFSET(&bp->blk_dva[0])) - ((DVA_GET_OFFSET(&ma->ma_extent->ze_dva)) + (ma->ma_extent->ze_size - 1) * (ma->ma_extent->ze_stride)); if (DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ma->ma_extent->ze_dva)) { if (ma->ma_extent->ze_stride == 0) { /* second block in this extent */ ma->ma_extent->ze_stride = stride; ma->ma_extent->ze_size++; return (0); } else if (ma->ma_extent->ze_stride == stride) { /* * the block we allocated has the same * stride */ ma->ma_extent->ze_size++; return (0); } } /* * dtrace -n 'zfs-dprintf * /stringof(arg0) == "zvol.c"/ * { * printf("%s: %s", stringof(arg1), stringof(arg3)) * } ' */ dprintf("ma_extent 0x%lx mrstride 0x%lx stride %lx\n", ma->ma_extent->ze_size, ma->ma_extent->ze_stride, stride); dprintf_bp(bp, "%s", "next blkptr:"); /* start a new extent */ if (ma->ma_extent == &ma->ma_list->zl_extents[NUM_EXTENTS - 1]) { ma->ma_list->zl_next = kmem_zalloc(sizeof (zvol_ext_list_t), KM_SLEEP); ma->ma_list = ma->ma_list->zl_next; ma->ma_extent = &ma->ma_list->zl_extents[0]; } else { ma->ma_extent++; } zvol_init_extent(ma->ma_extent, bp); return (0); } /* ARGSUSED */ 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); } /* * Replay a TX_WRITE ZIL transaction that didn't get committed * after a system failure */ static int zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) { objset_t *os = zv->zv_objset; char *data = (char *)(lr + 1); /* data follows lr_write_t */ uint64_t off = lr->lr_offset; uint64_t len = lr->lr_length; dmu_tx_t *tx; int error; if (byteswap) byteswap_uint64_array(lr, sizeof (*lr)); tx = dmu_tx_create(os); dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); error = dmu_tx_assign(tx, zv->zv_txg_assign); if (error) { dmu_tx_abort(tx); } else { dmu_write(os, ZVOL_OBJ, off, len, data, tx); dmu_tx_commit(tx); } return (error); } /* ARGSUSED */ static int zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) { return (ENOTSUP); } /* * Callback vectors for replaying records. * Only TX_WRITE is needed for zvol. */ zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { zvol_replay_err, /* 0 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_err, /* TX_TRUNCATE */ zvol_replay_err, /* TX_SETATTR */ zvol_replay_err, /* TX_ACL */ }; /* * reconstruct dva that gets us to the desired offset (offset * is in bytes) */ int zvol_get_dva(zvol_state_t *zv, uint64_t offset, dva_t *dva) { zvol_ext_list_t *zl; zvol_extent_t *ze; int idx; uint64_t tmp; if ((zl = zv->zv_list) == NULL) return (EIO); idx = 0; ze = &zl->zl_extents[0]; while (offset >= ze->ze_size * zv->zv_volblocksize) { offset -= ze->ze_size * zv->zv_volblocksize; if (idx == NUM_EXTENTS - 1) { /* we've reached the end of this array */ ASSERT(zl->zl_next != NULL); if (zl->zl_next == NULL) return (-1); zl = zl->zl_next; ze = &zl->zl_extents[0]; idx = 0; } else { ze++; idx++; } } DVA_SET_VDEV(dva, DVA_GET_VDEV(&ze->ze_dva)); tmp = DVA_GET_OFFSET((&ze->ze_dva)); tmp += (ze->ze_stride * (offset / zv->zv_volblocksize)); DVA_SET_OFFSET(dva, tmp); return (0); } static void zvol_free_extents(zvol_state_t *zv) { zvol_ext_list_t *zl; zvol_ext_list_t *tmp; if (zv->zv_list != NULL) { zl = zv->zv_list; while (zl != NULL) { tmp = zl->zl_next; kmem_free(zl, sizeof (zvol_ext_list_t)); zl = tmp; } zv->zv_list = NULL; } } int zvol_get_lbas(zvol_state_t *zv) { struct maparg ma; zvol_ext_list_t *zl; zvol_extent_t *ze; uint64_t blocks = 0; int err; ma.ma_list = zl = kmem_zalloc(sizeof (zvol_ext_list_t), KM_SLEEP); ma.ma_extent = &ma.ma_list->zl_extents[0]; ma.ma_gang = 0; zv->zv_list = ma.ma_list; err = traverse_zvol(zv->zv_objset, ADVANCE_PRE, zvol_map_block, &ma); if (err == EINTR && ma.ma_gang) { /* * We currently don't support dump devices when the pool * is so fragmented that our allocation has resulted in * gang blocks. */ zvol_free_extents(zv); return (EFRAGS); } ASSERT3U(err, ==, 0); ze = &zl->zl_extents[0]; while (ze) { blocks += ze->ze_size; if (ze == &zl->zl_extents[NUM_EXTENTS - 1]) { zl = zl->zl_next; ze = &zl->zl_extents[0]; } else { ze++; } } if (blocks != (zv->zv_volsize / zv->zv_volblocksize)) { zvol_free_extents(zv); return (EIO); } return (0); } /* * Create a minor node (plus a whole lot more) for the specified volume. */ int zvol_create_minor(const char *name, major_t maj) { zvol_state_t *zv; objset_t *os; dmu_object_info_t doi; uint64_t volsize; minor_t minor = 0; struct pathname linkpath; int ds_mode = DS_MODE_OWNER; vnode_t *vp = NULL; char *devpath; size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + strlen(name) + 1; char chrbuf[30], blkbuf[30]; int error; mutex_enter(&zvol_state_lock); if ((zv = zvol_minor_lookup(name)) != NULL) { mutex_exit(&zvol_state_lock); return (EEXIST); } if (strchr(name, '@') != 0) ds_mode |= DS_MODE_READONLY; error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); if (error) { mutex_exit(&zvol_state_lock); return (error); } error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); if (error) { dmu_objset_close(os); mutex_exit(&zvol_state_lock); return (error); } /* * If there's an existing /dev/zvol symlink, try to use the * same minor number we used last time. */ devpath = kmem_alloc(devpathlen, KM_SLEEP); (void) sprintf(devpath, "%s%s", ZVOL_FULL_DEV_DIR, name); error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); kmem_free(devpath, devpathlen); if (error == 0 && vp->v_type != VLNK) error = EINVAL; if (error == 0) { pn_alloc(&linkpath); error = pn_getsymlink(vp, &linkpath, kcred); if (error == 0) { char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); if (ms != NULL) { ms += strlen(ZVOL_PSEUDO_DEV); minor = stoi(&ms); } } pn_free(&linkpath); } if (vp != NULL) VN_RELE(vp); /* * If we found a minor but it's already in use, we must pick a new one. */ if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) minor = 0; if (minor == 0) minor = zvol_minor_alloc(); if (minor == 0) { dmu_objset_close(os); mutex_exit(&zvol_state_lock); return (ENXIO); } if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { dmu_objset_close(os); mutex_exit(&zvol_state_lock); return (EAGAIN); } (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, (char *)name); (void) sprintf(chrbuf, "%uc,raw", minor); if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, minor, DDI_PSEUDO, 0) == DDI_FAILURE) { ddi_soft_state_free(zvol_state, minor); dmu_objset_close(os); mutex_exit(&zvol_state_lock); return (EAGAIN); } (void) sprintf(blkbuf, "%uc", minor); if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, minor, DDI_PSEUDO, 0) == DDI_FAILURE) { ddi_remove_minor_node(zfs_dip, chrbuf); ddi_soft_state_free(zvol_state, minor); dmu_objset_close(os); mutex_exit(&zvol_state_lock); return (EAGAIN); } zv = ddi_get_soft_state(zvol_state, minor); (void) strcpy(zv->zv_name, name); zv->zv_min_bs = DEV_BSHIFT; zv->zv_minor = minor; zv->zv_volsize = volsize; zv->zv_objset = os; zv->zv_mode = ds_mode; zv->zv_zilog = zil_open(os, zvol_get_data); mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, sizeof (rl_t), offsetof(rl_t, r_node)); /* get and cache the blocksize */ error = dmu_object_info(os, ZVOL_OBJ, &doi); ASSERT(error == 0); zv->zv_volblocksize = doi.doi_data_block_size; zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector, NULL); zvol_size_changed(zv, maj); /* XXX this should handle the possible i/o error */ VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), "readonly", zvol_readonly_changed_cb, zv) == 0); zvol_minors++; mutex_exit(&zvol_state_lock); return (0); } /* * Remove minor node for the specified volume. */ int zvol_remove_minor(const char *name) { zvol_state_t *zv; char namebuf[30]; mutex_enter(&zvol_state_lock); if ((zv = zvol_minor_lookup(name)) == NULL) { mutex_exit(&zvol_state_lock); return (ENXIO); } if (zv->zv_total_opens != 0) { mutex_exit(&zvol_state_lock); return (EBUSY); } (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); ddi_remove_minor_node(zfs_dip, namebuf); (void) sprintf(namebuf, "%uc", zv->zv_minor); ddi_remove_minor_node(zfs_dip, namebuf); VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), "readonly", zvol_readonly_changed_cb, zv) == 0); zil_close(zv->zv_zilog); zv->zv_zilog = NULL; dmu_objset_close(zv->zv_objset); zv->zv_objset = NULL; avl_destroy(&zv->zv_znode.z_range_avl); mutex_destroy(&zv->zv_znode.z_range_lock); ddi_soft_state_free(zvol_state, zv->zv_minor); zvol_minors--; mutex_exit(&zvol_state_lock); return (0); } int zvol_prealloc(zvol_state_t *zv) { objset_t *os = zv->zv_objset; dmu_tx_t *tx; void *data; uint64_t refd, avail, usedobjs, availobjs; uint64_t resid = zv->zv_volsize; uint64_t off = 0; /* Check the space usage before attempting to allocate the space */ dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs); if (avail < zv->zv_volsize) return (ENOSPC); /* Free old extents if they exist */ zvol_free_extents(zv); /* allocate the blocks by writing each one */ data = kmem_zalloc(SPA_MAXBLOCKSIZE, KM_SLEEP); while (resid != 0) { int error; uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE); tx = dmu_tx_create(os); dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); kmem_free(data, SPA_MAXBLOCKSIZE); (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); return (error); } dmu_write(os, ZVOL_OBJ, off, bytes, data, tx); dmu_tx_commit(tx); off += bytes; resid -= bytes; } kmem_free(data, SPA_MAXBLOCKSIZE); txg_wait_synced(dmu_objset_pool(os), 0); return (0); } int zvol_update_volsize(zvol_state_t *zv, major_t maj, uint64_t volsize) { dmu_tx_t *tx; int error; ASSERT(MUTEX_HELD(&zvol_state_lock)); tx = dmu_tx_create(zv->zv_objset); dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); return (error); } error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); dmu_tx_commit(tx); if (error == 0) error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, volsize, DMU_OBJECT_END); /* * If we are using a faked-up state (zv_minor == 0) then don't * try to update the in-core zvol state. */ if (error == 0 && zv->zv_minor) { zv->zv_volsize = volsize; zvol_size_changed(zv, maj); } return (error); } int zvol_set_volsize(const char *name, major_t maj, uint64_t volsize) { zvol_state_t *zv; int error; dmu_object_info_t doi; uint64_t old_volsize = 0ULL; zvol_state_t state = { 0 }; mutex_enter(&zvol_state_lock); if ((zv = zvol_minor_lookup(name)) == NULL) { /* * If we are doing a "zfs clone -o volsize=", then the * minor node won't exist yet. */ error = dmu_objset_open(name, DMU_OST_ZVOL, DS_MODE_OWNER, &state.zv_objset); if (error != 0) goto out; zv = &state; } old_volsize = zv->zv_volsize; if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0) goto out; if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) { error = EROFS; goto out; } error = zvol_update_volsize(zv, maj, volsize); /* * Reinitialize the dump area to the new size. If we * failed to resize the dump area then restore the it back to * it's original size. */ if (error == 0 && zv->zv_flags & ZVOL_DUMPIFIED) { if ((error = zvol_dumpify(zv)) != 0 || (error = dumpvp_resize()) != 0) { (void) zvol_update_volsize(zv, maj, old_volsize); error = zvol_dumpify(zv); } } out: if (state.zv_objset) dmu_objset_close(state.zv_objset); mutex_exit(&zvol_state_lock); return (error); } int zvol_set_volblocksize(const char *name, uint64_t volblocksize) { zvol_state_t *zv; dmu_tx_t *tx; int error; mutex_enter(&zvol_state_lock); if ((zv = zvol_minor_lookup(name)) == NULL) { mutex_exit(&zvol_state_lock); return (ENXIO); } if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) { mutex_exit(&zvol_state_lock); return (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 = EBUSY; dmu_tx_commit(tx); } mutex_exit(&zvol_state_lock); return (error); } /*ARGSUSED*/ int zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) { minor_t minor = getminor(*devp); zvol_state_t *zv; if (minor == 0) /* This is the control device */ return (0); mutex_enter(&zvol_state_lock); zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) { mutex_exit(&zvol_state_lock); return (ENXIO); } ASSERT(zv->zv_objset != NULL); if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY))) { mutex_exit(&zvol_state_lock); return (EROFS); } if (zv->zv_flags & ZVOL_EXCL) { mutex_exit(&zvol_state_lock); return (EBUSY); } if (flag & FEXCL) { if (zv->zv_total_opens != 0) { mutex_exit(&zvol_state_lock); return (EBUSY); } zv->zv_flags |= ZVOL_EXCL; } if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { zv->zv_open_count[otyp]++; zv->zv_total_opens++; } mutex_exit(&zvol_state_lock); return (0); } /*ARGSUSED*/ int zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) { minor_t minor = getminor(dev); zvol_state_t *zv; if (minor == 0) /* This is the control device */ return (0); mutex_enter(&zvol_state_lock); zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) { mutex_exit(&zvol_state_lock); return (ENXIO); } if (zv->zv_flags & ZVOL_EXCL) { ASSERT(zv->zv_total_opens == 1); zv->zv_flags &= ~ZVOL_EXCL; } /* * If the open count is zero, this is a spurious close. * That indicates a bug in the kernel / DDI framework. */ ASSERT(zv->zv_open_count[otyp] != 0); ASSERT(zv->zv_total_opens != 0); /* * You may get multiple opens, but only one close. */ zv->zv_open_count[otyp]--; zv->zv_total_opens--; mutex_exit(&zvol_state_lock); return (0); } static void zvol_get_done(dmu_buf_t *db, void *vzgd) { zgd_t *zgd = (zgd_t *)vzgd; rl_t *rl = zgd->zgd_rl; dmu_buf_rele(db, vzgd); zfs_range_unlock(rl); zil_add_block(zgd->zgd_zilog, zgd->zgd_bp); kmem_free(zgd, sizeof (zgd_t)); } /* * Get data to generate a TX_WRITE intent log record. */ static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) { zvol_state_t *zv = arg; objset_t *os = zv->zv_objset; dmu_buf_t *db; rl_t *rl; zgd_t *zgd; uint64_t boff; /* block starting offset */ int dlen = lr->lr_length; /* length of user data */ int error; ASSERT(zio); ASSERT(dlen != 0); /* * 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 */ return (dmu_read(os, ZVOL_OBJ, lr->lr_offset, dlen, buf)); zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP); zgd->zgd_zilog = zv->zv_zilog; zgd->zgd_bp = &lr->lr_blkptr; /* * Lock the range of the block to ensure that when the data is * written out and its checksum is being calculated that no other * thread can change the block. */ boff = P2ALIGN_TYPED(lr->lr_offset, zv->zv_volblocksize, uint64_t); rl = zfs_range_lock(&zv->zv_znode, boff, zv->zv_volblocksize, RL_READER); zgd->zgd_rl = rl; VERIFY(0 == dmu_buf_hold(os, ZVOL_OBJ, lr->lr_offset, zgd, &db)); error = dmu_sync(zio, db, &lr->lr_blkptr, lr->lr_common.lrc_txg, zvol_get_done, zgd); if (error == 0) zil_add_block(zv->zv_zilog, &lr->lr_blkptr); /* * If we get EINPROGRESS, then we need to wait for a * write IO initiated by dmu_sync() to complete before * we can release this dbuf. We will finish everything * up in the zvol_get_done() callback. */ if (error == EINPROGRESS) return (0); dmu_buf_rele(db, zgd); zfs_range_unlock(rl); kmem_free(zgd, sizeof (zgd_t)); return (error); } /* * 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; static void zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len) { uint32_t blocksize = zv->zv_volblocksize; lr_write_t *lr; while (len) { ssize_t nbytes = MIN(len, blocksize - P2PHASE(off, blocksize)); itx_t *itx = zil_itx_create(TX_WRITE, sizeof (*lr)); itx->itx_wr_state = len > zvol_immediate_write_sz ? WR_INDIRECT : WR_NEED_COPY; itx->itx_private = zv; lr = (lr_write_t *)&itx->itx_lr; lr->lr_foid = ZVOL_OBJ; lr->lr_offset = off; lr->lr_length = nbytes; lr->lr_blkoff = off - P2ALIGN_TYPED(off, blocksize, uint64_t); BP_ZERO(&lr->lr_blkptr); (void) zil_itx_assign(zv->zv_zilog, itx, tx); len -= nbytes; off += nbytes; } } int zvol_dumpio(vdev_t *vd, uint64_t size, uint64_t offset, void *addr, int bflags, int isdump) { vdev_disk_t *dvd; int direction; int c; int numerrors = 0; for (c = 0; c < vd->vdev_children; c++) { if (zvol_dumpio(vd->vdev_child[c], size, offset, addr, bflags, isdump) != 0) { numerrors++; } else if (bflags & B_READ) { break; } } if (!vd->vdev_ops->vdev_op_leaf) return (numerrors < vd->vdev_children ? 0 : EIO); if (!vdev_writeable(vd)) return (EIO); dvd = vd->vdev_tsd; ASSERT3P(dvd, !=, NULL); direction = bflags & (B_WRITE | B_READ); ASSERT(ISP2(direction)); offset += VDEV_LABEL_START_SIZE; if (ddi_in_panic() || isdump) { if (direction & B_READ) return (EIO); return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), lbtodb(size))); } else { return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, direction)); } } int zvol_physio(zvol_state_t *zv, int bflags, uint64_t off, uint64_t size, void *addr, int isdump) { dva_t dva; vdev_t *vd; int error; spa_t *spa = dmu_objset_spa(zv->zv_objset); ASSERT(size <= zv->zv_volblocksize); /* restrict requests to multiples of the system block size */ if (P2PHASE(off, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE)) return (EINVAL); if (zvol_get_dva(zv, off, &dva) != 0) return (EIO); spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva)); error = zvol_dumpio(vd, size, DVA_GET_OFFSET(&dva) + (off % zv->zv_volblocksize), addr, bflags & (B_READ | B_WRITE | B_PHYS), isdump); spa_config_exit(spa, SCL_STATE, FTAG); return (error); } int zvol_strategy(buf_t *bp) { zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); uint64_t off, volsize; size_t size, resid; char *addr; objset_t *os; rl_t *rl; int error = 0; boolean_t reading, is_dump = zv->zv_flags & ZVOL_DUMPIFIED; if (zv == NULL) { bioerror(bp, ENXIO); biodone(bp); return (0); } if (getminor(bp->b_edev) == 0) { bioerror(bp, EINVAL); biodone(bp); return (0); } if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY || zv->zv_mode & DS_MODE_READONLY)) { bioerror(bp, EROFS); biodone(bp); return (0); } off = ldbtob(bp->b_blkno); volsize = zv->zv_volsize; os = zv->zv_objset; ASSERT(os != NULL); bp_mapin(bp); addr = bp->b_un.b_addr; resid = bp->b_bcount; if (resid > 0 && (off < 0 || off >= volsize)) return (EIO); /* * There must be no buffer changes when doing a dmu_sync() because * we can't change the data whilst calculating the checksum. */ reading = bp->b_flags & B_READ; rl = zfs_range_lock(&zv->zv_znode, off, resid, reading ? RL_READER : RL_WRITER); if (resid > volsize - off) /* don't write past the end */ resid = volsize - off; while (resid != 0 && off < volsize) { size = MIN(resid, zvol_maxphys); if (is_dump) { /* can't straddle a block boundary */ size = MIN(size, P2END(off, zv->zv_volblocksize) - off); error = zvol_physio(zv, bp->b_flags, off, size, addr, 0); } else if (reading) { error = dmu_read(os, ZVOL_OBJ, off, size, addr); } else { dmu_tx_t *tx = dmu_tx_create(os); dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); } else { dmu_write(os, ZVOL_OBJ, off, size, addr, tx); zvol_log_write(zv, tx, off, size); dmu_tx_commit(tx); } } if (error) { /* convert checksum errors into IO errors */ if (error == ECKSUM) error = EIO; break; } off += size; addr += size; resid -= size; } zfs_range_unlock(rl); if ((bp->b_resid = resid) == bp->b_bcount) bioerror(bp, off > volsize ? EINVAL : error); if (!(bp->b_flags & B_ASYNC) && !reading && !zil_disable && !is_dump) zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); biodone(bp); return (0); } /* * Set the buffer count to the zvol maximum transfer. * Using our own routine instead of the default minphys() * means that for larger writes we write bigger buffers on X86 * (128K instead of 56K) and flush the disk write cache less often * (every zvol_maxphys - currently 1MB) instead of minphys (currently * 56K on X86 and 128K on sparc). */ void zvol_minphys(struct buf *bp) { if (bp->b_bcount > zvol_maxphys) bp->b_bcount = zvol_maxphys; } int zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks) { minor_t minor = getminor(dev); zvol_state_t *zv; int error = 0; uint64_t size; uint64_t boff; uint64_t resid; if (minor == 0) /* This is the control device */ return (ENXIO); zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) return (ENXIO); boff = ldbtob(blkno); resid = ldbtob(nblocks); if (boff + resid > zv->zv_volsize) { /* dump should know better than to write here */ ASSERT(blkno + resid <= zv->zv_volsize); return (EIO); } while (resid) { /* can't straddle a block boundary */ size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); error = zvol_physio(zv, B_WRITE, boff, size, addr, 1); if (error) break; boff += size; addr += size; resid -= size; } return (error); } /*ARGSUSED*/ int zvol_read(dev_t dev, uio_t *uio, cred_t *cr) { minor_t minor = getminor(dev); zvol_state_t *zv; uint64_t volsize; rl_t *rl; int error = 0; if (minor == 0) /* This is the control device */ return (ENXIO); zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) return (ENXIO); volsize = zv->zv_volsize; if (uio->uio_resid > 0 && (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) return (EIO); rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, RL_READER); while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); /* don't read past the end */ if (bytes > volsize - uio->uio_loffset) bytes = volsize - uio->uio_loffset; error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes); if (error) { /* convert checksum errors into IO errors */ if (error == ECKSUM) error = EIO; break; } } zfs_range_unlock(rl); return (error); } /*ARGSUSED*/ int zvol_write(dev_t dev, uio_t *uio, cred_t *cr) { minor_t minor = getminor(dev); zvol_state_t *zv; uint64_t volsize; rl_t *rl; int error = 0; if (minor == 0) /* This is the control device */ return (ENXIO); zv = ddi_get_soft_state(zvol_state, minor); if (zv == NULL) return (ENXIO); volsize = zv->zv_volsize; if (uio->uio_resid > 0 && (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) return (EIO); if (zv->zv_flags & ZVOL_DUMPIFIED) { error = physio(zvol_strategy, NULL, dev, B_WRITE, zvol_minphys, uio); return (error); } rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, RL_WRITER); while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); uint64_t off = uio->uio_loffset; dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); if (bytes > volsize - off) /* don't write past the end */ bytes = volsize - off; dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); break; } error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes, tx); if (error == 0) zvol_log_write(zv, tx, off, bytes); dmu_tx_commit(tx); if (error) break; } zfs_range_unlock(rl); return (error); } int zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs) { struct uuid uuid = EFI_RESERVED; efi_gpe_t gpe = { 0 }; uint32_t crc; dk_efi_t efi; int length; char *ptr; if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag)) return (EFAULT); ptr = (char *)(uintptr_t)efi.dki_data_64; length = efi.dki_length; /* * Some clients may attempt to request a PMBR for the * zvol. Currently this interface will return EINVAL to * such requests. These requests could be supported by * adding a check for lba == 0 and consing up an appropriate * PMBR. */ if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0) return (EINVAL); gpe.efi_gpe_StartingLBA = LE_64(34ULL); gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1); UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); if (efi.dki_lba == 1) { efi_gpt_t gpt = { 0 }; gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); gpt.efi_gpt_MyLBA = LE_64(1ULL); gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL); gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1); gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL); gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); gpt.efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (efi_gpe_t)); CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length), flag)) return (EFAULT); ptr += sizeof (gpt); length -= sizeof (gpt); } if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe), length), flag)) return (EFAULT); return (0); } /* * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). */ /*ARGSUSED*/ int zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) { zvol_state_t *zv; struct dk_cinfo dki; struct dk_minfo dkm; struct dk_callback *dkc; int error = 0; rl_t *rl; mutex_enter(&zvol_state_lock); zv = ddi_get_soft_state(zvol_state, getminor(dev)); if (zv == NULL) { mutex_exit(&zvol_state_lock); return (ENXIO); } switch (cmd) { case DKIOCINFO: bzero(&dki, sizeof (dki)); (void) strcpy(dki.dki_cname, "zvol"); (void) strcpy(dki.dki_dname, "zvol"); dki.dki_ctype = DKC_UNKNOWN; dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); mutex_exit(&zvol_state_lock); if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag)) error = EFAULT; return (error); case DKIOCGMEDIAINFO: bzero(&dkm, sizeof (dkm)); dkm.dki_lbsize = 1U << zv->zv_min_bs; dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; dkm.dki_media_type = DK_UNKNOWN; mutex_exit(&zvol_state_lock); if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) error = EFAULT; return (error); case DKIOCGETEFI: { uint64_t vs = zv->zv_volsize; uint8_t bs = zv->zv_min_bs; mutex_exit(&zvol_state_lock); error = zvol_getefi((void *)arg, flag, vs, bs); return (error); } case DKIOCFLUSHWRITECACHE: dkc = (struct dk_callback *)arg; zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) { (*dkc->dkc_callback)(dkc->dkc_cookie, error); error = 0; } break; case DKIOCGGEOM: case DKIOCGVTOC: /* * commands using these (like prtvtoc) expect ENOTSUP * since we're emulating an EFI label */ error = ENOTSUP; break; case DKIOCDUMPINIT: rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, RL_WRITER); error = zvol_dumpify(zv); zfs_range_unlock(rl); break; case DKIOCDUMPFINI: rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, RL_WRITER); error = zvol_dump_fini(zv); zfs_range_unlock(rl); break; default: error = ENOTTY; break; } mutex_exit(&zvol_state_lock); return (error); } int zvol_busy(void) { return (zvol_minors != 0); } void zvol_init(void) { VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); } void zvol_fini(void) { mutex_destroy(&zvol_state_lock); ddi_soft_state_fini(&zvol_state); } static boolean_t zvol_is_swap(zvol_state_t *zv) { vnode_t *vp; boolean_t ret = B_FALSE; char *devpath; size_t devpathlen; int error; devpathlen = strlen(ZVOL_FULL_DEV_DIR) + strlen(zv->zv_name) + 1; devpath = kmem_alloc(devpathlen, KM_SLEEP); (void) sprintf(devpath, "%s%s", ZVOL_FULL_DEV_DIR, zv->zv_name); error = lookupname(devpath, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp); kmem_free(devpath, devpathlen); ret = !error && IS_SWAPVP(common_specvp(vp)); if (vp != NULL) VN_RELE(vp); return (ret); } static int zvol_dump_init(zvol_state_t *zv, boolean_t resize) { dmu_tx_t *tx; int error = 0; objset_t *os = zv->zv_objset; nvlist_t *nv = NULL; uint64_t checksum, compress, refresrv; ASSERT(MUTEX_HELD(&zvol_state_lock)); tx = dmu_tx_create(os); dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); return (error); } /* * If we are resizing the dump device then we only need to * update the refreservation to match the newly updated * zvolsize. Otherwise, we save off the original state of the * zvol so that we can restore them if the zvol is ever undumpified. */ if (resize) { error = zap_update(os, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &zv->zv_volsize, tx); } else { error = dsl_prop_get_integer(zv->zv_name, zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL); error = error ? error : dsl_prop_get_integer(zv->zv_name, zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL); error = error ? error : dsl_prop_get_integer(zv->zv_name, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL); error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress, tx); error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx); error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv, tx); } dmu_tx_commit(tx); /* Truncate the file */ if (!error) error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0, DMU_OBJECT_END); if (error) return (error); /* * We only need update the zvol's property if we are initializing * the dump area for the first time. */ if (!resize) { VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); VERIFY(nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0); VERIFY(nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_COMPRESSION), ZIO_COMPRESS_OFF) == 0); VERIFY(nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_CHECKSUM), ZIO_CHECKSUM_OFF) == 0); error = zfs_set_prop_nvlist(zv->zv_name, nv); nvlist_free(nv); if (error) return (error); } /* Allocate the space for the dump */ error = zvol_prealloc(zv); return (error); } static int zvol_dumpify(zvol_state_t *zv) { int error = 0; uint64_t dumpsize = 0; dmu_tx_t *tx; objset_t *os = zv->zv_objset; if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) return (EROFS); /* * We do not support swap devices acting as dump devices. */ if (zvol_is_swap(zv)) return (ENOTSUP); if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) { boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE; if ((error = zvol_dump_init(zv, resize)) != 0) { (void) zvol_dump_fini(zv); return (error); } } /* * Build up our lba mapping. */ error = zvol_get_lbas(zv); if (error) { (void) zvol_dump_fini(zv); return (error); } tx = dmu_tx_create(os); dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); (void) zvol_dump_fini(zv); return (error); } zv->zv_flags |= ZVOL_DUMPIFIED; error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, &zv->zv_volsize, tx); dmu_tx_commit(tx); if (error) { (void) zvol_dump_fini(zv); return (error); } txg_wait_synced(dmu_objset_pool(os), 0); return (0); } static int zvol_dump_fini(zvol_state_t *zv) { dmu_tx_t *tx; objset_t *os = zv->zv_objset; nvlist_t *nv; int error = 0; uint64_t checksum, compress, refresrv; /* * Attempt to restore the zvol back to its pre-dumpified state. * This is a best-effort attempt as it's possible that not all * of these properties were initialized during the dumpify process * (i.e. error during zvol_dump_init). */ tx = dmu_tx_create(os); dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); return (error); } (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx); dmu_tx_commit(tx); (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum); (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress); (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv); VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); (void) nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum); (void) nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress); (void) nvlist_add_uint64(nv, zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv); (void) zfs_set_prop_nvlist(zv->zv_name, nv); nvlist_free(nv); zvol_free_extents(zv); zv->zv_flags &= ~ZVOL_DUMPIFIED; (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END); return (0); }