diff options
Diffstat (limited to 'module/zfs/zvol.c')
| -rw-r--r-- | module/zfs/zvol.c | 1722 |
1 files changed, 1722 insertions, 0 deletions
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c new file mode 100644 index 000000000..4e993060c --- /dev/null +++ b/module/zfs/zvol.c @@ -0,0 +1,1722 @@ +/* + * 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/<pool_name>/<dataset_name> + * /dev/zvol/rdsk/<pool_name>/<dataset_name> + * + * 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 <sys/types.h> +#include <sys/param.h> +#include <sys/errno.h> +#include <sys/uio.h> +#include <sys/buf.h> +#include <sys/modctl.h> +#include <sys/open.h> +#include <sys/kmem.h> +#include <sys/conf.h> +#include <sys/cmn_err.h> +#include <sys/stat.h> +#include <sys/zap.h> +#include <sys/spa.h> +#include <sys/zio.h> +#include <sys/dmu_traverse.h> +#include <sys/dnode.h> +#include <sys/dsl_dataset.h> +#include <sys/dsl_prop.h> +#include <sys/dkio.h> +#include <sys/efi_partition.h> +#include <sys/byteorder.h> +#include <sys/pathname.h> +#include <sys/ddi.h> +#include <sys/sunddi.h> +#include <sys/crc32.h> +#include <sys/dirent.h> +#include <sys/policy.h> +#include <sys/fs/zfs.h> +#include <sys/zfs_ioctl.h> +#include <sys/mkdev.h> +#include <sys/zil.h> +#include <sys/refcount.h> +#include <sys/zfs_znode.h> +#include <sys/zfs_rlock.h> +#include <sys/vdev_disk.h> +#include <sys/vdev_impl.h> +#include <sys/zvol.h> +#include <sys/dumphdr.h> + +#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; + +typedef struct zvol_extent { + list_node_t ze_node; + dva_t ze_dva; /* dva associated with this extent */ + uint64_t ze_nblks; /* number of blocks in extent */ +} zvol_extent_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 */ + list_t zv_extents; /* 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); +} + +/* extent mapping arg */ +struct maparg { + zvol_state_t *ma_zv; + uint64_t ma_blks; +}; + +/*ARGSUSED*/ +static int +zvol_map_block(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb, + const dnode_phys_t *dnp, void *arg) +{ + struct maparg *ma = arg; + zvol_extent_t *ze; + int bs = ma->ma_zv->zv_volblocksize; + + if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0) + return (0); + + VERIFY3U(ma->ma_blks, ==, zb->zb_blkid); + ma->ma_blks++; + + /* Abort immediately if we have encountered gang blocks */ + if (BP_IS_GANG(bp)) + return (EFRAGS); + + /* + * See if the block is at the end of the previous extent. + */ + ze = list_tail(&ma->ma_zv->zv_extents); + if (ze && + DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) && + DVA_GET_OFFSET(BP_IDENTITY(bp)) == + DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) { + ze->ze_nblks++; + return (0); + } + + dprintf_bp(bp, "%s", "next blkptr:"); + + /* start a new extent */ + ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP); + ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ + ze->ze_nblks = 1; + list_insert_tail(&ma->ma_zv->zv_extents, ze); + return (0); +} + +static void +zvol_free_extents(zvol_state_t *zv) +{ + zvol_extent_t *ze; + + while (ze = list_head(&zv->zv_extents)) { + list_remove(&zv->zv_extents, ze); + kmem_free(ze, sizeof (zvol_extent_t)); + } +} + +static int +zvol_get_lbas(zvol_state_t *zv) +{ + struct maparg ma; + int err; + + ma.ma_zv = zv; + ma.ma_blks = 0; + zvol_free_extents(zv); + + err = traverse_dataset(dmu_objset_ds(zv->zv_objset), 0, + TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma); + if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) { + zvol_free_extents(zv); + return (err ? err : EIO); + } + + 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 */ +}; + +/* + * 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)); + list_create(&zv->zv_extents, sizeof (zvol_extent_t), + offsetof(zvol_extent_t, ze_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; + 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); + + 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); + (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); + return (error); + } + dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx); + dmu_tx_commit(tx); + off += bytes; + resid -= bytes; + } + 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; + boolean_t needlock; + + /* + * The lock may already be held if we are being called from + * zvol_dump_init(). + */ + needlock = !MUTEX_HELD(&zvol_state_lock); + if (needlock) + mutex_enter(&zvol_state_lock); + + if ((zv = zvol_minor_lookup(name)) == NULL) { + if (needlock) + mutex_exit(&zvol_state_lock); + return (ENXIO); + } + if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) { + if (needlock) + 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); + if (error == 0) + zv->zv_volblocksize = volblocksize; + } + + if (needlock) + 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; + } +} + +static int +zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size, + boolean_t doread, boolean_t isdump) +{ + vdev_disk_t *dvd; + int c; + int numerrors = 0; + + for (c = 0; c < vd->vdev_children; c++) { + ASSERT(vd->vdev_ops == &vdev_mirror_ops); + int err = zvol_dumpio_vdev(vd->vdev_child[c], + addr, offset, size, doread, isdump); + if (err != 0) { + numerrors++; + } else if (doread) { + break; + } + } + + if (!vd->vdev_ops->vdev_op_leaf) + return (numerrors < vd->vdev_children ? 0 : EIO); + + if (doread && !vdev_readable(vd)) + return (EIO); + else if (!doread && !vdev_writeable(vd)) + return (EIO); + + dvd = vd->vdev_tsd; + ASSERT3P(dvd, !=, NULL); + offset += VDEV_LABEL_START_SIZE; + + if (ddi_in_panic() || isdump) { + ASSERT(!doread); + if (doread) + return (EIO); + return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), + lbtodb(size))); + } else { + return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, + doread ? B_READ : B_WRITE)); + } +} + +static int +zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size, + boolean_t doread, boolean_t isdump) +{ + vdev_t *vd; + int error; + zvol_extent_t *ze; + spa_t *spa = dmu_objset_spa(zv->zv_objset); + + /* Must be sector aligned, and not stradle a block boundary. */ + if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) || + P2BOUNDARY(offset, size, zv->zv_volblocksize)) { + return (EINVAL); + } + ASSERT(size <= zv->zv_volblocksize); + + /* Locate the extent this belongs to */ + ze = list_head(&zv->zv_extents); + while (offset >= ze->ze_nblks * zv->zv_volblocksize) { + offset -= ze->ze_nblks * zv->zv_volblocksize; + ze = list_next(&zv->zv_extents, ze); + } + spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); + vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva)); + offset += DVA_GET_OFFSET(&ze->ze_dva); + error = zvol_dumpio_vdev(vd, addr, offset, size, doread, 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 resid; + char *addr; + objset_t *os; + rl_t *rl; + int error = 0; + boolean_t doread = bp->b_flags & B_READ; + boolean_t 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)) { + bioerror(bp, EIO); + biodone(bp); + return (0); + } + + /* + * There must be no buffer changes when doing a dmu_sync() because + * we can't change the data whilst calculating the checksum. + */ + rl = zfs_range_lock(&zv->zv_znode, off, resid, + doread ? RL_READER : RL_WRITER); + + while (resid != 0 && off < volsize) { + size_t size = MIN(resid, zvol_maxphys); + if (is_dump) { + size = MIN(size, P2END(off, zv->zv_volblocksize) - off); + error = zvol_dumpio(zv, addr, off, size, + doread, B_FALSE); + } else if (doread) { + 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) && !doread && !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); + + VERIFY3U(boff + resid, <=, zv->zv_volsize); + + while (resid) { + size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); + error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE); + 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); + + if (zv->zv_flags & ZVOL_DUMPIFIED) { + error = physio(zvol_strategy, NULL, dev, B_READ, + zvol_minphys, uio); + return (error); + } + + 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; + + 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 { + uint64_t checksum, compress, refresrv, vbs; + + 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 : dsl_prop_get_integer(zv->zv_name, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, 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); + error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, + &vbs, 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); + VERIFY(nvlist_add_uint64(nv, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), + SPA_MAXBLOCKSIZE) == 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, vbs; + + /* + * 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); + (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs); + + 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) nvlist_add_uint64(nv, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), vbs); + (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); +} |