*
* Copyright 2014 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2016 Actifio, Inc. All rights reserved.
+ * Copyright (c) 2012, 2018 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.
+ *
+ * It is also worth keeping in mind that once add_disk() is called, the zvol is
+ * announced to the world, and zvol_open()/zvol_release() can be called at any
+ * time. Incidentally, add_disk() itself calls zvol_open()->zvol_first_open()
+ * and zvol_release()->zvol_last_close() directly as well.
+ */
+
+#include <sys/dataset_kstats.h>
#include <sys/dbuf.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/zfs_znode.h>
#include <sys/spa_impl.h>
#include <sys/zvol.h>
+
#include <linux/blkdev_compat.h>
+#include <linux/task_io_accounting_ops.h>
unsigned int zvol_inhibit_dev = 0;
unsigned int zvol_major = ZVOL_MAJOR;
+unsigned int zvol_threads = 32;
+unsigned int zvol_request_sync = 0;
unsigned int zvol_prefetch_bytes = (128 * 1024);
unsigned long zvol_max_discard_blocks = 16384;
+unsigned int zvol_volmode = ZFS_VOLMODE_GEOM;
-static kmutex_t zvol_state_lock;
+static taskq_t *zvol_taskq;
+static krwlock_t zvol_state_lock;
static list_t zvol_state_list;
-void *zvol_tag = "zvol_tag";
+
+#define ZVOL_HT_SIZE 1024
+static struct hlist_head *zvol_htable;
+#define ZVOL_HT_HEAD(hash) (&zvol_htable[(hash) & (ZVOL_HT_SIZE-1)])
+
+static struct ida zvol_ida;
/*
* The in-core state of each volume.
*/
-typedef struct zvol_state {
+struct zvol_state {
char zv_name[MAXNAMELEN]; /* name */
uint64_t zv_volsize; /* advertised space */
uint64_t zv_volblocksize; /* volume block size */
uint32_t zv_changed; /* disk changed */
zilog_t *zv_zilog; /* ZIL handle */
zfs_rlock_t zv_range_lock; /* range lock */
- dmu_buf_t *zv_dbuf; /* bonus handle */
+ dnode_t *zv_dn; /* dnode hold */
dev_t zv_dev; /* device id */
struct gendisk *zv_disk; /* generic disk */
struct request_queue *zv_queue; /* request queue */
+ dataset_kstats_t zv_kstat; /* zvol kstats */
list_node_t zv_next; /* next zvol_state_t linkage */
-} zvol_state_t;
+ uint64_t zv_hash; /* name hash */
+ struct hlist_node zv_hlink; /* hash link */
+ kmutex_t zv_state_lock; /* protects zvol_state_t */
+ atomic_t zv_suspend_ref; /* refcount for suspend */
+ krwlock_t zv_suspend_lock; /* suspend lock */
+};
typedef enum {
ZVOL_ASYNC_CREATE_MINORS,
ZVOL_ASYNC_REMOVE_MINORS,
ZVOL_ASYNC_RENAME_MINORS,
ZVOL_ASYNC_SET_SNAPDEV,
+ ZVOL_ASYNC_SET_VOLMODE,
ZVOL_ASYNC_MAX
} zvol_async_op_t;
char name1[MAXNAMELEN];
char name2[MAXNAMELEN];
zprop_source_t source;
- uint64_t snapdev;
+ uint64_t value;
} zvol_task_t;
#define ZVOL_RDONLY 0x1
-/*
- * Find the next available range of ZVOL_MINORS minor numbers. The
- * zvol_state_list is kept in ascending minor order so we simply need
- * to scan the list for the first gap in the sequence. This allows us
- * to recycle minor number as devices are created and removed.
- */
-static int
-zvol_find_minor(unsigned *minor)
+static uint64_t
+zvol_name_hash(const char *name)
{
- zvol_state_t *zv;
-
- *minor = 0;
- ASSERT(MUTEX_HELD(&zvol_state_lock));
- for (zv = list_head(&zvol_state_list); zv != NULL;
- zv = list_next(&zvol_state_list, zv), *minor += ZVOL_MINORS) {
- if (MINOR(zv->zv_dev) != MINOR(*minor))
- break;
+ int i;
+ uint64_t crc = -1ULL;
+ uint8_t *p = (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];
}
-
- /* All minors are in use */
- if (*minor >= (1 << MINORBITS))
- return (SET_ERROR(ENXIO));
-
- return (0);
+ return (crc);
}
/*
- * Find a zvol_state_t given the full major+minor dev_t.
+ * Find a zvol_state_t given the full major+minor dev_t. If found,
+ * return with zv_state_lock taken, otherwise, return (NULL) without
+ * taking zv_state_lock.
*/
static zvol_state_t *
zvol_find_by_dev(dev_t dev)
{
zvol_state_t *zv;
- ASSERT(MUTEX_HELD(&zvol_state_lock));
+ rw_enter(&zvol_state_lock, RW_READER);
for (zv = list_head(&zvol_state_list); zv != NULL;
zv = list_next(&zvol_state_list, zv)) {
- if (zv->zv_dev == dev)
+ mutex_enter(&zv->zv_state_lock);
+ if (zv->zv_dev == dev) {
+ 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 provided at zvol_alloc() time.
+ * 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.
*/
static zvol_state_t *
-zvol_find_by_name(const char *name)
+zvol_find_by_name_hash(const char *name, uint64_t hash, int mode)
{
zvol_state_t *zv;
-
- ASSERT(MUTEX_HELD(&zvol_state_lock));
- for (zv = list_head(&zvol_state_list); zv != NULL;
- zv = list_next(&zvol_state_list, zv)) {
- if (strncmp(zv->zv_name, name, MAXNAMELEN) == 0)
+ 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));
+}
+
/*
* Given a path, return TRUE if path is a ZVOL.
return (SET_ERROR(error));
}
-static void
-zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
-{
- struct block_device *bdev;
-
- bdev = bdget_disk(zv->zv_disk, 0);
- if (bdev == NULL)
- return;
- set_capacity(zv->zv_disk, volsize >> 9);
- zv->zv_volsize = volsize;
- check_disk_size_change(zv->zv_disk, bdev);
-
- bdput(bdev);
-}
-
/*
* Sanity check volume size.
*/
int error;
uint64_t txg;
- ASSERT(MUTEX_HELD(&zvol_state_lock));
-
tx = dmu_tx_create(os);
dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
dmu_tx_mark_netfree(tx);
return (error);
}
-static int
-zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
-{
- zvol_size_changed(zv, volsize);
-
- /*
- * We should post a event here describing the expansion. However,
- * the zfs_ereport_post() interface doesn't nicely support posting
- * events for zvols, it assumes events relate to vdevs or zios.
- */
-
- return (0);
-}
-
/*
- * Set ZFS_PROP_VOLSIZE set entry point.
+ * 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)
{
- zvol_state_t *zv = NULL;
objset_t *os = NULL;
- int error;
- dmu_object_info_t *doi;
+ struct gendisk *disk = NULL;
uint64_t readonly;
+ int error;
boolean_t owned = B_FALSE;
error = dsl_prop_get_integer(name,
if (readonly)
return (SET_ERROR(EROFS));
- mutex_enter(&zvol_state_lock);
- zv = zvol_find_by_name(name);
+ 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 ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
+ 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) {
- mutex_exit(&zvol_state_lock);
+ if (zv != NULL)
+ mutex_exit(&zv->zv_state_lock);
return (SET_ERROR(error));
}
owned = B_TRUE;
os = zv->zv_objset;
}
- doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP);
+ 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;
+ disk = zv->zv_disk;
+ }
+out:
kmem_free(doi, sizeof (dmu_object_info_t));
- if (error == 0 && zv != NULL)
- error = zvol_update_live_volsize(zv, volsize);
-out:
if (owned) {
- dmu_objset_disown(os, FTAG);
+ dmu_objset_disown(os, B_TRUE, FTAG);
if (zv != NULL)
zv->zv_objset = NULL;
+ } else {
+ rw_exit(&zv->zv_suspend_lock);
}
- mutex_exit(&zvol_state_lock);
- return (error);
+
+ if (zv != NULL)
+ mutex_exit(&zv->zv_state_lock);
+
+ if (disk != NULL)
+ revalidate_disk(disk);
+
+ return (SET_ERROR(error));
}
/*
dmu_tx_t *tx;
int error;
- mutex_enter(&zvol_state_lock);
+ zv = zvol_find_by_name(name, RW_READER);
- zv = zvol_find_by_name(name);
- if (zv == NULL) {
- error = SET_ERROR(ENXIO);
- goto out;
- }
+ 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) {
- error = SET_ERROR(EROFS);
- goto out;
+ mutex_exit(&zv->zv_state_lock);
+ rw_exit(&zv->zv_suspend_lock);
+ return (SET_ERROR(EROFS));
}
tx = dmu_tx_create(zv->zv_objset);
if (error == 0)
zv->zv_volblocksize = volblocksize;
}
-out:
- mutex_exit(&zvol_state_lock);
+
+ mutex_exit(&zv->zv_state_lock);
+ rw_exit(&zv->zv_suspend_lock);
return (SET_ERROR(error));
}
* implement DKIOCFREE/free-long-range.
*/
static int
-zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
+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)
* after a system failure
*/
static int
-zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
+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 off = lr->lr_offset;
- uint64_t len = lr->lr_length;
+ 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, off, len);
+ 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, off, len, data, tx);
+ dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
dmu_tx_commit(tx);
}
- return (SET_ERROR(error));
+ return (error);
}
static int
-zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
+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] = {
- (zil_replay_func_t)zvol_replay_err, /* no such transaction type */
- (zil_replay_func_t)zvol_replay_err, /* TX_CREATE */
- (zil_replay_func_t)zvol_replay_err, /* TX_MKDIR */
- (zil_replay_func_t)zvol_replay_err, /* TX_MKXATTR */
- (zil_replay_func_t)zvol_replay_err, /* TX_SYMLINK */
- (zil_replay_func_t)zvol_replay_err, /* TX_REMOVE */
- (zil_replay_func_t)zvol_replay_err, /* TX_RMDIR */
- (zil_replay_func_t)zvol_replay_err, /* TX_LINK */
- (zil_replay_func_t)zvol_replay_err, /* TX_RENAME */
- (zil_replay_func_t)zvol_replay_write, /* TX_WRITE */
- (zil_replay_func_t)zvol_replay_truncate, /* TX_TRUNCATE */
- (zil_replay_func_t)zvol_replay_err, /* TX_SETATTR */
- (zil_replay_func_t)zvol_replay_err, /* TX_ACL */
+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 */
};
/*
{
uint32_t blocksize = zv->zv_volblocksize;
zilog_t *zilog = zv->zv_zilog;
- boolean_t slogging;
- ssize_t immediate_write_sz;
+ itx_wr_state_t write_state;
if (zil_replaying(zilog, tx))
return;
- immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
- ? 0 : zvol_immediate_write_sz;
- slogging = spa_has_slogs(zilog->zl_spa) &&
- (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
+ 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;
- ssize_t len;
- itx_wr_state_t write_state;
+ itx_wr_state_t wr_state = write_state;
+ ssize_t len = size;
- /*
- * Unlike zfs_log_write() we can be called with
- * up to DMU_MAX_ACCESS/2 (5MB) writes.
- */
- if (blocksize > immediate_write_sz && !slogging &&
- size >= blocksize && offset % blocksize == 0) {
- write_state = WR_INDIRECT; /* uses dmu_sync */
- len = blocksize;
- } else if (sync) {
- write_state = WR_COPIED;
- len = MIN(ZIL_MAX_LOG_DATA, size);
- } else {
- write_state = WR_NEED_COPY;
- len = MIN(ZIL_MAX_LOG_DATA, size);
- }
+ if (wr_state == WR_COPIED && size > ZIL_MAX_COPIED_DATA)
+ 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) +
- (write_state == WR_COPIED ? len : 0));
+ (wr_state == WR_COPIED ? len : 0));
lr = (lr_write_t *)&itx->itx_lr;
- if (write_state == WR_COPIED && dmu_read(zv->zv_objset,
- ZVOL_OBJ, offset, len, lr+1, DMU_READ_NO_PREFETCH) != 0) {
+ 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;
- write_state = WR_NEED_COPY;
+ wr_state = WR_NEED_COPY;
}
- itx->itx_wr_state = write_state;
- if (write_state == WR_NEED_COPY)
- itx->itx_sod += len;
+ itx->itx_wr_state = wr_state;
lr->lr_foid = ZVOL_OBJ;
lr->lr_offset = offset;
lr->lr_length = len;
}
}
-static int
-zvol_write(zvol_state_t *zv, uio_t *uio, boolean_t sync)
+typedef struct zv_request {
+ zvol_state_t *zv;
+ struct bio *bio;
+ rl_t *rl;
+} zv_request_t;
+
+static void
+uio_from_bio(uio_t *uio, struct bio *bio)
+{
+ uio->uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
+ uio->uio_skip = BIO_BI_SKIP(bio);
+ uio->uio_resid = BIO_BI_SIZE(bio);
+ uio->uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
+ uio->uio_loffset = BIO_BI_SECTOR(bio) << 9;
+ uio->uio_limit = MAXOFFSET_T;
+ uio->uio_segflg = UIO_BVEC;
+}
+
+static void
+zvol_write(void *arg)
{
- uint64_t volsize = zv->zv_volsize;
- rl_t *rl;
int error = 0;
+ zv_request_t *zvr = arg;
+ struct bio *bio = zvr->bio;
+ uio_t uio;
+ uio_from_bio(&uio, bio);
+
+ zvol_state_t *zv = zvr->zv;
ASSERT(zv && zv->zv_open_count > 0);
- rl = zfs_range_lock(&zv->zv_range_lock, uio->uio_loffset,
- uio->uio_resid, RL_WRITER);
+ ssize_t start_resid = uio.uio_resid;
+ unsigned long start_jif = jiffies;
+ blk_generic_start_io_acct(zv->zv_queue, WRITE, bio_sectors(bio),
+ &zv->zv_disk->part0);
- 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;
+ boolean_t sync =
+ bio_is_fua(bio) || zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
+
+ uint64_t volsize = zv->zv_volsize;
+ 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 */
dmu_tx_abort(tx);
break;
}
- error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
- if (error == 0)
+ error = dmu_write_uio_dnode(zv->zv_dn, &uio, bytes, tx);
+ if (error == 0) {
zvol_log_write(zv, tx, off, bytes, sync);
+ }
dmu_tx_commit(tx);
if (error)
break;
}
- zfs_range_unlock(rl);
+ zfs_range_unlock(zvr->rl);
+
+ int64_t nwritten = start_resid - uio.uio_resid;
+ dataset_kstats_update_write_kstats(&zv->zv_kstat, nwritten);
+ task_io_account_write(nwritten);
+
if (sync)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
- return (error);
+
+ rw_exit(&zv->zv_suspend_lock);
+ blk_generic_end_io_acct(zv->zv_queue, WRITE, &zv->zv_disk->part0,
+ start_jif);
+ BIO_END_IO(bio, -error);
+ kmem_free(zvr, sizeof (zv_request_t));
}
/*
zil_itx_assign(zilog, itx, tx);
}
-static int
-zvol_discard(struct bio *bio)
+static void
+zvol_discard(void *arg)
{
- zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
+ zv_request_t *zvr = arg;
+ struct bio *bio = zvr->bio;
+ zvol_state_t *zv = zvr->zv;
uint64_t start = BIO_BI_SECTOR(bio) << 9;
uint64_t size = BIO_BI_SIZE(bio);
uint64_t end = start + size;
- int error;
- rl_t *rl;
+ boolean_t sync;
+ int error = 0;
dmu_tx_t *tx;
+ unsigned long start_jif;
ASSERT(zv && zv->zv_open_count > 0);
- if (end > zv->zv_volsize)
- return (SET_ERROR(EIO));
+ start_jif = jiffies;
+ blk_generic_start_io_acct(zv->zv_queue, WRITE, bio_sectors(bio),
+ &zv->zv_disk->part0);
+
+ sync = bio_is_fua(bio) || zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
+
+ if (end > zv->zv_volsize) {
+ error = SET_ERROR(EIO);
+ goto unlock;
+ }
/*
* Align the request to volume block boundaries when a secure erase is
}
if (start >= end)
- return (0);
+ goto unlock;
- rl = zfs_range_lock(&zv->zv_range_lock, start, size, RL_WRITER);
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_mark_netfree(tx);
error = dmu_tx_assign(tx, TXG_WAIT);
error = dmu_free_long_range(zv->zv_objset,
ZVOL_OBJ, start, size);
}
+unlock:
+ zfs_range_unlock(zvr->rl);
+ if (error == 0 && sync)
+ zil_commit(zv->zv_zilog, ZVOL_OBJ);
- zfs_range_unlock(rl);
-
- return (error);
+ rw_exit(&zv->zv_suspend_lock);
+ blk_generic_end_io_acct(zv->zv_queue, WRITE, &zv->zv_disk->part0,
+ start_jif);
+ BIO_END_IO(bio, -error);
+ kmem_free(zvr, sizeof (zv_request_t));
}
-static int
-zvol_read(zvol_state_t *zv, uio_t *uio)
+static void
+zvol_read(void *arg)
{
- uint64_t volsize = zv->zv_volsize;
- rl_t *rl;
int error = 0;
+ zv_request_t *zvr = arg;
+ struct bio *bio = zvr->bio;
+ uio_t uio;
+ uio_from_bio(&uio, bio);
+
+ zvol_state_t *zv = zvr->zv;
ASSERT(zv && zv->zv_open_count > 0);
- rl = zfs_range_lock(&zv->zv_range_lock, 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);
+ ssize_t start_resid = uio.uio_resid;
+ unsigned long start_jif = jiffies;
+ blk_generic_start_io_acct(zv->zv_queue, READ, bio_sectors(bio),
+ &zv->zv_disk->part0);
+
+ uint64_t volsize = zv->zv_volsize;
+ 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;
+ if (bytes > volsize - uio.uio_loffset)
+ bytes = volsize - uio.uio_loffset;
- error = dmu_read_uio_dbuf(zv->zv_dbuf, uio, bytes);
+ error = dmu_read_uio_dnode(zv->zv_dn, &uio, bytes);
if (error) {
/* convert checksum errors into IO errors */
if (error == ECKSUM)
break;
}
}
- zfs_range_unlock(rl);
- return (error);
+ zfs_range_unlock(zvr->rl);
+
+ int64_t nread = start_resid - uio.uio_resid;
+ dataset_kstats_update_read_kstats(&zv->zv_kstat, nread);
+ task_io_account_read(nread);
+
+ rw_exit(&zv->zv_suspend_lock);
+ blk_generic_end_io_acct(zv->zv_queue, READ, &zv->zv_disk->part0,
+ start_jif);
+ BIO_END_IO(bio, -error);
+ kmem_free(zvr, sizeof (zv_request_t));
}
static MAKE_REQUEST_FN_RET
zvol_request(struct request_queue *q, struct bio *bio)
{
- uio_t uio;
zvol_state_t *zv = q->queuedata;
fstrans_cookie_t cookie = spl_fstrans_mark();
+ uint64_t offset = BIO_BI_SECTOR(bio) << 9;
+ uint64_t size = BIO_BI_SIZE(bio);
int rw = bio_data_dir(bio);
-#ifdef HAVE_GENERIC_IO_ACCT
- unsigned long start = jiffies;
-#endif
- int error = 0;
-
- uio.uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
- uio.uio_skip = BIO_BI_SKIP(bio);
- uio.uio_resid = BIO_BI_SIZE(bio);
- uio.uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
- uio.uio_loffset = BIO_BI_SECTOR(bio) << 9;
- uio.uio_limit = MAXOFFSET_T;
- uio.uio_segflg = UIO_BVEC;
+ zv_request_t *zvr;
- if (bio_has_data(bio) && uio.uio_loffset + uio.uio_resid >
- zv->zv_volsize) {
+ if (bio_has_data(bio) && offset + size > zv->zv_volsize) {
printk(KERN_INFO
"%s: bad access: offset=%llu, size=%lu\n",
zv->zv_disk->disk_name,
- (long long unsigned)uio.uio_loffset,
- (long unsigned)uio.uio_resid);
- error = SET_ERROR(EIO);
- goto out1;
- }
+ (long long unsigned)offset,
+ (long unsigned)size);
- generic_start_io_acct(rw, bio_sectors(bio), &zv->zv_disk->part0);
+ BIO_END_IO(bio, -SET_ERROR(EIO));
+ goto out;
+ }
if (rw == WRITE) {
+ boolean_t need_sync = B_FALSE;
+
if (unlikely(zv->zv_flags & ZVOL_RDONLY)) {
- error = SET_ERROR(EROFS);
- goto out2;
+ BIO_END_IO(bio, -SET_ERROR(EROFS));
+ goto out;
}
- if (bio_is_discard(bio) || bio_is_secure_erase(bio)) {
- error = zvol_discard(bio);
- goto out2;
+ /*
+ * To be released in the I/O function. See the comment on
+ * zfs_range_lock below.
+ */
+ rw_enter(&zv->zv_suspend_lock, RW_READER);
+
+ /* bio marked as FLUSH need to flush before write */
+ if (bio_is_flush(bio))
+ zil_commit(zv->zv_zilog, ZVOL_OBJ);
+
+ /* Some requests are just for flush and nothing else. */
+ if (size == 0) {
+ rw_exit(&zv->zv_suspend_lock);
+ BIO_END_IO(bio, 0);
+ goto out;
}
+ zvr = kmem_alloc(sizeof (zv_request_t), KM_SLEEP);
+ zvr->zv = zv;
+ zvr->bio = bio;
+
+ /*
+ * To be released in the I/O function. Since the I/O functions
+ * are asynchronous, we take it here synchronously to make
+ * sure overlapped I/Os are properly ordered.
+ */
+ zvr->rl = zfs_range_lock(&zv->zv_range_lock, offset, size,
+ RL_WRITER);
/*
- * Some requests are just for flush and nothing else.
+ * Sync writes and discards execute zil_commit() which may need
+ * to take a RL_READER lock on the whole block being modified
+ * via its zillog->zl_get_data(): to avoid circular dependency
+ * issues with taskq threads execute these requests
+ * synchronously here in zvol_request().
*/
- if (uio.uio_resid == 0) {
- if (bio_is_flush(bio))
- zil_commit(zv->zv_zilog, ZVOL_OBJ);
- goto out2;
+ need_sync = bio_is_fua(bio) ||
+ zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
+ if (bio_is_discard(bio) || bio_is_secure_erase(bio)) {
+ if (zvol_request_sync || need_sync ||
+ taskq_dispatch(zvol_taskq, zvol_discard, zvr,
+ TQ_SLEEP) == TASKQID_INVALID)
+ zvol_discard(zvr);
+ } else {
+ if (zvol_request_sync || need_sync ||
+ taskq_dispatch(zvol_taskq, zvol_write, zvr,
+ TQ_SLEEP) == TASKQID_INVALID)
+ zvol_write(zvr);
}
+ } else {
+ zvr = kmem_alloc(sizeof (zv_request_t), KM_SLEEP);
+ zvr->zv = zv;
+ zvr->bio = bio;
- error = zvol_write(zv, &uio,
- bio_is_flush(bio) || bio_is_fua(bio) ||
- zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
- } else
- error = zvol_read(zv, &uio);
+ rw_enter(&zv->zv_suspend_lock, RW_READER);
-out2:
- generic_end_io_acct(rw, &zv->zv_disk->part0, start);
-out1:
- BIO_END_IO(bio, -error);
+ zvr->rl = zfs_range_lock(&zv->zv_range_lock, offset, size,
+ RL_READER);
+ if (zvol_request_sync || taskq_dispatch(zvol_taskq,
+ zvol_read, zvr, TQ_SLEEP) == TASKQID_INVALID)
+ zvol_read(zvr);
+ }
+
+out:
spl_fstrans_unmark(cookie);
#ifdef HAVE_MAKE_REQUEST_FN_RET_INT
return (0);
zfs_range_unlock(zgd->zgd_rl);
if (error == 0 && zgd->zgd_bp)
- zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
+ zil_lwb_add_block(zgd->zgd_lwb, 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_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
{
zvol_state_t *zv = arg;
- objset_t *os = zv->zv_objset;
- uint64_t object = ZVOL_OBJ;
uint64_t offset = lr->lr_offset;
uint64_t size = lr->lr_length;
- blkptr_t *bp = &lr->lr_blkptr;
dmu_buf_t *db;
zgd_t *zgd;
int error;
- ASSERT(zio != NULL);
- ASSERT(size != 0);
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3P(zio, !=, NULL);
+ ASSERT3U(size, !=, 0);
zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
- zgd->zgd_zilog = zv->zv_zilog;
- zgd->zgd_rl = zfs_range_lock(&zv->zv_range_lock, offset, size,
- RL_READER);
+ zgd->zgd_lwb = lwb;
/*
* Write records come in two flavors: immediate and indirect.
* we don't have to write the data twice.
*/
if (buf != NULL) { /* immediate write */
- error = dmu_read(os, object, offset, size, buf,
+ zgd->zgd_rl = zfs_range_lock(&zv->zv_range_lock, offset, size,
+ RL_READER);
+ error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf,
DMU_READ_NO_PREFETCH);
- } else {
+ } 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);
- error = dmu_buf_hold(os, object, offset, zgd, &db,
+ zgd->zgd_rl = zfs_range_lock(&zv->zv_range_lock, 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 *obp = dmu_buf_get_blkptr(db);
- if (obp) {
- ASSERT(BP_IS_HOLE(bp));
- *bp = *obp;
- }
+ blkptr_t *bp = &lr->lr_blkptr;
zgd->zgd_db = db;
- zgd->zgd_bp = &lr->lr_blkptr;
+ zgd->zgd_bp = bp;
ASSERT(db != NULL);
ASSERT(db->db_offset == offset);
}
/*
- * The zvol_state_t's are inserted in increasing MINOR(dev_t) order.
+ * The zvol_state_t's are inserted into zvol_state_list and zvol_htable.
*/
static void
-zvol_insert(zvol_state_t *zv_insert)
+zvol_insert(zvol_state_t *zv)
{
- zvol_state_t *zv = NULL;
-
- ASSERT(MUTEX_HELD(&zvol_state_lock));
- ASSERT3U(MINOR(zv_insert->zv_dev) & ZVOL_MINOR_MASK, ==, 0);
- for (zv = list_head(&zvol_state_list); zv != NULL;
- zv = list_next(&zvol_state_list, zv)) {
- if (MINOR(zv->zv_dev) > MINOR(zv_insert->zv_dev))
- break;
- }
-
- list_insert_before(&zvol_state_list, zv, zv_insert);
+ ASSERT(RW_WRITE_HELD(&zvol_state_lock));
+ ASSERT3U(MINOR(zv->zv_dev) & ZVOL_MINOR_MASK, ==, 0);
+ 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_remove)
+zvol_remove(zvol_state_t *zv)
{
- ASSERT(MUTEX_HELD(&zvol_state_lock));
- list_remove(&zvol_state_list, zv_remove);
+ 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_first_open(zvol_state_t *zv)
+zvol_setup_zv(zvol_state_t *zv)
{
- objset_t *os;
uint64_t volsize;
int error;
uint64_t ro;
+ objset_t *os = zv->zv_objset;
- /* lie and say we're read-only */
- error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, 1, zvol_tag, &os);
- if (error)
- return (SET_ERROR(-error));
-
- zv->zv_objset = os;
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+ ASSERT(RW_LOCK_HELD(&zv->zv_suspend_lock));
error = dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL);
if (error)
- goto out_owned;
+ return (SET_ERROR(error));
error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
if (error)
- goto out_owned;
+ return (SET_ERROR(error));
- error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
+ error = dnode_hold(os, ZVOL_OBJ, FTAG, &zv->zv_dn);
if (error)
- goto out_owned;
+ return (SET_ERROR(error));
set_capacity(zv->zv_disk, volsize >> 9);
zv->zv_volsize = volsize;
set_disk_ro(zv->zv_disk, 0);
zv->zv_flags &= ~ZVOL_RDONLY;
}
-
-out_owned:
- if (error) {
- dmu_objset_disown(os, zvol_tag);
- zv->zv_objset = NULL;
- }
-
- return (SET_ERROR(-error));
+ return (0);
}
+/*
+ * Shutdown every zv_objset related stuff except zv_objset itself.
+ * The is the reverse of zvol_setup_zv.
+ */
static void
-zvol_last_close(zvol_state_t *zv)
+zvol_shutdown_zv(zvol_state_t *zv)
{
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
+ RW_LOCK_HELD(&zv->zv_suspend_lock));
+
zil_close(zv->zv_zilog);
zv->zv_zilog = NULL;
- dmu_buf_rele(zv->zv_dbuf, zvol_tag);
- zv->zv_dbuf = NULL;
+ dnode_rele(zv->zv_dn, FTAG);
+ zv->zv_dn = NULL;
/*
* Evict cached data
!(zv->zv_flags & ZVOL_RDONLY))
txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
(void) dmu_objset_evict_dbufs(zv->zv_objset);
+}
- dmu_objset_disown(zv->zv_objset, zvol_tag);
- zv->zv_objset = NULL;
+/*
+ * 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);
}
-static int
-zvol_open(struct block_device *bdev, fmode_t flag)
+/*
+ * Suspend the zvol for recv and rollback.
+ */
+zvol_state_t *
+zvol_suspend(const char *name)
{
zvol_state_t *zv;
- int error = 0, drop_mutex = 0;
+
+ 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));
+}
+
+static int
+zvol_first_open(zvol_state_t *zv, boolean_t readonly)
+{
+ objset_t *os;
+ int error, locked = 0;
+ boolean_t ro;
+
+ ASSERT(RW_READ_HELD(&zv->zv_suspend_lock));
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
/*
- * If the caller is already holding the mutex do not take it
- * again, this will happen as part of zvol_create_minor_impl().
- * Once add_disk() is called the device is live and the kernel
- * will attempt to open it to read the partition information.
+ * In all other cases the spa_namespace_lock is taken before the
+ * bdev->bd_mutex lock. But in this case the Linux __blkdev_get()
+ * function calls fops->open() with the bdev->bd_mutex lock held.
+ * This deadlock can be easily observed with zvols used as vdevs.
+ *
+ * To avoid a potential lock inversion deadlock we preemptively
+ * try to take the spa_namespace_lock(). Normally it will not
+ * be contended and this is safe because spa_open_common() handles
+ * the case where the caller already holds the spa_namespace_lock.
+ *
+ * When it is contended we risk a lock inversion if we were to
+ * block waiting for the lock. Luckily, the __blkdev_get()
+ * function allows us to return -ERESTARTSYS which will result in
+ * bdev->bd_mutex being dropped, reacquired, and fops->open() being
+ * called again. This process can be repeated safely until both
+ * locks are acquired.
*/
- if (!mutex_owned(&zvol_state_lock)) {
- mutex_enter(&zvol_state_lock);
- drop_mutex = 1;
+ if (!mutex_owned(&spa_namespace_lock)) {
+ locked = mutex_tryenter(&spa_namespace_lock);
+ if (!locked)
+ return (-SET_ERROR(ERESTARTSYS));
}
+ ro = (readonly || (strchr(zv->zv_name, '@') != NULL));
+ error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, ro, B_TRUE, zv, &os);
+ if (error)
+ goto out_mutex;
+
+ zv->zv_objset = os;
+
+ error = zvol_setup_zv(zv);
+
+ if (error) {
+ dmu_objset_disown(os, 1, zv);
+ zv->zv_objset = NULL;
+ }
+
+out_mutex:
+ if (locked)
+ mutex_exit(&spa_namespace_lock);
+ return (SET_ERROR(-error));
+}
+
+static 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;
+}
+
+static int
+zvol_open(struct block_device *bdev, fmode_t flag)
+{
+ zvol_state_t *zv;
+ int error = 0;
+ boolean_t drop_suspend = B_TRUE;
+
+ rw_enter(&zvol_state_lock, RW_READER);
/*
- * Obtain a copy of private_data under the lock to make sure
- * that either the result of zvol_freeg() setting
+ * Obtain a copy of private_data under the zvol_state_lock to make
+ * sure that either the result of zvol free code path setting
* bdev->bd_disk->private_data to NULL is observed, or zvol_free()
* is not called on this zv because of the positive zv_open_count.
*/
zv = bdev->bd_disk->private_data;
if (zv == NULL) {
- error = -ENXIO;
- goto out_mutex;
+ rw_exit(&zvol_state_lock);
+ return (SET_ERROR(-ENXIO));
+ }
+
+ mutex_enter(&zv->zv_state_lock);
+ /*
+ * make sure zvol is not suspended during first open
+ * (hold zv_suspend_lock) and respect proper lock acquisition
+ * ordering - zv_suspend_lock before zv_state_lock
+ */
+ if (zv->zv_open_count == 0) {
+ if (!rw_tryenter(&zv->zv_suspend_lock, RW_READER)) {
+ mutex_exit(&zv->zv_state_lock);
+ rw_enter(&zv->zv_suspend_lock, RW_READER);
+ mutex_enter(&zv->zv_state_lock);
+ /* check to see if zv_suspend_lock is needed */
+ if (zv->zv_open_count != 0) {
+ rw_exit(&zv->zv_suspend_lock);
+ drop_suspend = B_FALSE;
+ }
+ }
+ } else {
+ drop_suspend = B_FALSE;
}
+ rw_exit(&zvol_state_lock);
+
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+ ASSERT(zv->zv_open_count != 0 || RW_READ_HELD(&zv->zv_suspend_lock));
if (zv->zv_open_count == 0) {
- error = zvol_first_open(zv);
+ error = zvol_first_open(zv, !(flag & FMODE_WRITE));
if (error)
goto out_mutex;
}
zv->zv_open_count++;
+ mutex_exit(&zv->zv_state_lock);
+ if (drop_suspend)
+ rw_exit(&zv->zv_suspend_lock);
+
check_disk_change(bdev);
+ return (0);
+
out_open_count:
if (zv->zv_open_count == 0)
zvol_last_close(zv);
out_mutex:
- if (drop_mutex)
- mutex_exit(&zvol_state_lock);
+ mutex_exit(&zv->zv_state_lock);
+ if (drop_suspend)
+ rw_exit(&zv->zv_suspend_lock);
+ if (error == -ERESTARTSYS)
+ schedule();
return (SET_ERROR(error));
}
#endif
zvol_release(struct gendisk *disk, fmode_t mode)
{
- zvol_state_t *zv = disk->private_data;
- int drop_mutex = 0;
+ zvol_state_t *zv;
+ boolean_t drop_suspend = B_TRUE;
- ASSERT(zv && zv->zv_open_count > 0);
+ rw_enter(&zvol_state_lock, RW_READER);
+ zv = disk->private_data;
- if (!mutex_owned(&zvol_state_lock)) {
- mutex_enter(&zvol_state_lock);
- drop_mutex = 1;
+ mutex_enter(&zv->zv_state_lock);
+ ASSERT(zv->zv_open_count > 0);
+ /*
+ * make sure zvol is not suspended during last close
+ * (hold zv_suspend_lock) and respect proper lock acquisition
+ * ordering - zv_suspend_lock before zv_state_lock
+ */
+ if (zv->zv_open_count == 1) {
+ if (!rw_tryenter(&zv->zv_suspend_lock, RW_READER)) {
+ mutex_exit(&zv->zv_state_lock);
+ rw_enter(&zv->zv_suspend_lock, RW_READER);
+ mutex_enter(&zv->zv_state_lock);
+ /* check to see if zv_suspend_lock is needed */
+ if (zv->zv_open_count != 1) {
+ rw_exit(&zv->zv_suspend_lock);
+ drop_suspend = B_FALSE;
+ }
+ }
+ } else {
+ drop_suspend = B_FALSE;
}
+ rw_exit(&zvol_state_lock);
+
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+ ASSERT(zv->zv_open_count != 1 || RW_READ_HELD(&zv->zv_suspend_lock));
zv->zv_open_count--;
if (zv->zv_open_count == 0)
zvol_last_close(zv);
- if (drop_mutex)
- mutex_exit(&zvol_state_lock);
+ mutex_exit(&zv->zv_state_lock);
+
+ if (drop_suspend)
+ rw_exit(&zv->zv_suspend_lock);
#ifndef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
return (0);
zvol_state_t *zv = bdev->bd_disk->private_data;
int error = 0;
- ASSERT(zv && zv->zv_open_count > 0);
+ ASSERT3U(zv->zv_open_count, >, 0);
switch (cmd) {
case BLKFLSBUF:
- zil_commit(zv->zv_zilog, ZVOL_OBJ);
+ fsync_bdev(bdev);
+ invalidate_bdev(bdev);
+ rw_enter(&zv->zv_suspend_lock, RW_READER);
+
+ if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
+ !(zv->zv_flags & ZVOL_RDONLY))
+ txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
+
+ rw_exit(&zv->zv_suspend_lock);
break;
+
case BLKZNAME:
+ mutex_enter(&zv->zv_state_lock);
error = copy_to_user((void *)arg, zv->zv_name, MAXNAMELEN);
+ mutex_exit(&zv->zv_state_lock);
break;
default:
error = -ENOTTY;
break;
-
}
return (SET_ERROR(error));
#define zvol_compat_ioctl NULL
#endif
+/*
+ * Linux 2.6.38 preferred interface.
+ */
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+static unsigned int
+zvol_check_events(struct gendisk *disk, unsigned int clearing)
+{
+ unsigned int mask = 0;
+
+ rw_enter(&zvol_state_lock, RW_READER);
+
+ zvol_state_t *zv = disk->private_data;
+ if (zv != NULL) {
+ mutex_enter(&zv->zv_state_lock);
+ mask = zv->zv_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+ zv->zv_changed = 0;
+ mutex_exit(&zv->zv_state_lock);
+ }
+
+ rw_exit(&zvol_state_lock);
+
+ return (mask);
+}
+#else
static int zvol_media_changed(struct gendisk *disk)
{
+ int changed = 0;
+
+ rw_enter(&zvol_state_lock, RW_READER);
+
zvol_state_t *zv = disk->private_data;
+ if (zv != NULL) {
+ mutex_enter(&zv->zv_state_lock);
+ changed = zv->zv_changed;
+ zv->zv_changed = 0;
+ mutex_exit(&zv->zv_state_lock);
+ }
- ASSERT(zv && zv->zv_open_count > 0);
+ rw_exit(&zvol_state_lock);
- return (zv->zv_changed);
+ return (changed);
}
+#endif
static int zvol_revalidate_disk(struct gendisk *disk)
{
- zvol_state_t *zv = disk->private_data;
+ rw_enter(&zvol_state_lock, RW_READER);
- ASSERT(zv && zv->zv_open_count > 0);
+ zvol_state_t *zv = disk->private_data;
+ if (zv != NULL) {
+ mutex_enter(&zv->zv_state_lock);
+ set_capacity(zv->zv_disk, zv->zv_volsize >> SECTOR_BITS);
+ mutex_exit(&zv->zv_state_lock);
+ }
- zv->zv_changed = 0;
- set_capacity(zv->zv_disk, zv->zv_volsize >> 9);
+ rw_exit(&zvol_state_lock);
return (0);
}
zvol_state_t *zv = bdev->bd_disk->private_data;
sector_t sectors;
- ASSERT(zv && zv->zv_open_count > 0);
+ ASSERT3U(zv->zv_open_count, >, 0);
sectors = get_capacity(zv->zv_disk);
zvol_state_t *zv;
struct kobject *kobj;
- mutex_enter(&zvol_state_lock);
zv = zvol_find_by_dev(dev);
- kobj = zv ? get_disk(zv->zv_disk) : NULL;
- mutex_exit(&zvol_state_lock);
+ kobj = zv ? get_disk_and_module(zv->zv_disk) : NULL;
+ ASSERT(zv == NULL || MUTEX_HELD(&zv->zv_state_lock));
+ if (zv)
+ mutex_exit(&zv->zv_state_lock);
return (kobj);
}
-#ifdef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
static struct block_device_operations zvol_ops = {
.open = zvol_open,
.release = zvol_release,
.ioctl = zvol_ioctl,
.compat_ioctl = zvol_compat_ioctl,
- .media_changed = zvol_media_changed,
- .revalidate_disk = zvol_revalidate_disk,
- .getgeo = zvol_getgeo,
- .owner = THIS_MODULE,
-};
-
-#else /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
-
-static int
-zvol_open_by_inode(struct inode *inode, struct file *file)
-{
- return (zvol_open(inode->i_bdev, file->f_mode));
-}
-
-static int
-zvol_release_by_inode(struct inode *inode, struct file *file)
-{
- return (zvol_release(inode->i_bdev->bd_disk, file->f_mode));
-}
-
-static int
-zvol_ioctl_by_inode(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- if (file == NULL || inode == NULL)
- return (SET_ERROR(-EINVAL));
-
- return (zvol_ioctl(inode->i_bdev, file->f_mode, cmd, arg));
-}
-
-#ifdef CONFIG_COMPAT
-static long
-zvol_compat_ioctl_by_inode(struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- if (file == NULL)
- return (SET_ERROR(-EINVAL));
-
- return (zvol_compat_ioctl(file->f_dentry->d_inode->i_bdev,
- file->f_mode, cmd, arg));
-}
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+ .check_events = zvol_check_events,
#else
-#define zvol_compat_ioctl_by_inode NULL
-#endif
-
-static struct block_device_operations zvol_ops = {
- .open = zvol_open_by_inode,
- .release = zvol_release_by_inode,
- .ioctl = zvol_ioctl_by_inode,
- .compat_ioctl = zvol_compat_ioctl_by_inode,
.media_changed = zvol_media_changed,
+#endif
.revalidate_disk = zvol_revalidate_disk,
.getgeo = zvol_getgeo,
.owner = THIS_MODULE,
};
-#endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
/*
* Allocate memory for a new zvol_state_t and setup the required
zvol_alloc(dev_t dev, const char *name)
{
zvol_state_t *zv;
+ uint64_t volmode;
+
+ if (dsl_prop_get_integer(name, "volmode", &volmode, NULL) != 0)
+ return (NULL);
+
+ if (volmode == ZFS_VOLMODE_DEFAULT)
+ volmode = zvol_volmode;
+
+ if (volmode == ZFS_VOLMODE_NONE)
+ return (NULL);
zv = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
list_link_init(&zv->zv_next);
+ mutex_init(&zv->zv_state_lock, NULL, MUTEX_DEFAULT, NULL);
+
zv->zv_queue = blk_alloc_queue(GFP_ATOMIC);
if (zv->zv_queue == NULL)
goto out_kmem;
blk_queue_make_request(zv->zv_queue, zvol_request);
blk_queue_set_write_cache(zv->zv_queue, B_TRUE, B_TRUE);
+ /* Limit read-ahead to a single page to prevent over-prefetching. */
+ blk_queue_set_read_ahead(zv->zv_queue, 1);
+
+ /* Disable write merging in favor of the ZIO pipeline. */
+ blk_queue_flag_set(QUEUE_FLAG_NOMERGES, zv->zv_queue);
+
zv->zv_disk = alloc_disk(ZVOL_MINORS);
if (zv->zv_disk == NULL)
goto out_queue;
strlcpy(zv->zv_name, name, MAXNAMELEN);
zfs_rlock_init(&zv->zv_range_lock);
+ rw_init(&zv->zv_suspend_lock, NULL, RW_DEFAULT, NULL);
zv->zv_disk->major = zvol_major;
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+ zv->zv_disk->events = DISK_EVENT_MEDIA_CHANGE;
+#endif
+
+ if (volmode == ZFS_VOLMODE_DEV) {
+ /*
+ * ZFS_VOLMODE_DEV disable partitioning on ZVOL devices: set
+ * gendisk->minors = 1 as noted in include/linux/genhd.h.
+ * Also disable extended partition numbers (GENHD_FL_EXT_DEVT)
+ * and suppresses partition scanning (GENHD_FL_NO_PART_SCAN)
+ * setting gendisk->flags accordingly.
+ */
+ zv->zv_disk->minors = 1;
+#if defined(GENHD_FL_EXT_DEVT)
+ zv->zv_disk->flags &= ~GENHD_FL_EXT_DEVT;
+#endif
+#if defined(GENHD_FL_NO_PART_SCAN)
+ zv->zv_disk->flags |= GENHD_FL_NO_PART_SCAN;
+#endif
+ }
zv->zv_disk->first_minor = (dev & MINORMASK);
zv->zv_disk->fops = &zvol_ops;
zv->zv_disk->private_data = zv;
/*
* Cleanup then free a zvol_state_t which was created by zvol_alloc().
+ * At this time, the structure is not opened by anyone, is taken off
+ * the zvol_state_list, and has its private data set to NULL.
+ * The zvol_state_lock is dropped.
*/
static void
-zvol_free(zvol_state_t *zv)
+zvol_free(void *arg)
{
- ASSERT(MUTEX_HELD(&zvol_state_lock));
+ zvol_state_t *zv = arg;
+
+ ASSERT(!RW_LOCK_HELD(&zv->zv_suspend_lock));
+ ASSERT(!MUTEX_HELD(&zv->zv_state_lock));
ASSERT(zv->zv_open_count == 0);
+ ASSERT(zv->zv_disk->private_data == NULL);
+ rw_destroy(&zv->zv_suspend_lock);
zfs_rlock_destroy(&zv->zv_range_lock);
- zv->zv_disk->private_data = NULL;
-
del_gendisk(zv->zv_disk);
blk_cleanup_queue(zv->zv_queue);
put_disk(zv->zv_disk);
+ ida_simple_remove(&zvol_ida, MINOR(zv->zv_dev) >> ZVOL_MINOR_BITS);
+
+ mutex_destroy(&zv->zv_state_lock);
+ dataset_kstats_destroy(&zv->zv_kstat);
+
kmem_free(zv, sizeof (zvol_state_t));
}
uint64_t len;
unsigned minor = 0;
int error = 0;
+ int idx;
+ uint64_t hash = zvol_name_hash(name);
+
+ if (zvol_inhibit_dev)
+ return (0);
- mutex_enter(&zvol_state_lock);
+ idx = ida_simple_get(&zvol_ida, 0, 0, kmem_flags_convert(KM_SLEEP));
+ if (idx < 0)
+ return (SET_ERROR(-idx));
+ minor = idx << ZVOL_MINOR_BITS;
- zv = zvol_find_by_name(name);
+ zv = zvol_find_by_name_hash(name, hash, RW_NONE);
if (zv) {
- error = SET_ERROR(EEXIST);
- goto out;
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+ mutex_exit(&zv->zv_state_lock);
+ ida_simple_remove(&zvol_ida, idx);
+ return (SET_ERROR(EEXIST));
}
doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP);
- error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, zvol_tag, &os);
+ error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, B_TRUE, FTAG, &os);
if (error)
goto out_doi;
if (error)
goto out_dmu_objset_disown;
- error = zvol_find_minor(&minor);
- if (error)
- goto out_dmu_objset_disown;
-
zv = zvol_alloc(MKDEV(zvol_major, minor), name);
if (zv == NULL) {
error = SET_ERROR(EAGAIN);
goto out_dmu_objset_disown;
}
+ zv->zv_hash = hash;
if (dmu_objset_is_snapshot(os))
zv->zv_flags |= ZVOL_RDONLY;
blk_queue_max_discard_sectors(zv->zv_queue,
(zvol_max_discard_blocks * zv->zv_volblocksize) >> 9);
blk_queue_discard_granularity(zv->zv_queue, zv->zv_volblocksize);
- queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zv->zv_queue);
+ blk_queue_flag_set(QUEUE_FLAG_DISCARD, zv->zv_queue);
#ifdef QUEUE_FLAG_NONROT
- queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zv->zv_queue);
+ blk_queue_flag_set(QUEUE_FLAG_NONROT, zv->zv_queue);
#endif
#ifdef QUEUE_FLAG_ADD_RANDOM
- queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, zv->zv_queue);
+ blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, zv->zv_queue);
#endif
if (spa_writeable(dmu_objset_spa(os))) {
else
zil_replay(os, zv, zvol_replay_vector);
}
+ ASSERT3P(zv->zv_kstat.dk_kstats, ==, NULL);
+ dataset_kstats_create(&zv->zv_kstat, zv->zv_objset);
/*
* When udev detects the addition of the device it will immediately
if (len > 0) {
dmu_prefetch(os, ZVOL_OBJ, 0, 0, len, ZIO_PRIORITY_SYNC_READ);
dmu_prefetch(os, ZVOL_OBJ, 0, volsize - len, len,
- ZIO_PRIORITY_SYNC_READ);
+ ZIO_PRIORITY_SYNC_READ);
}
zv->zv_objset = NULL;
out_dmu_objset_disown:
- dmu_objset_disown(os, zvol_tag);
+ dmu_objset_disown(os, B_TRUE, FTAG);
out_doi:
kmem_free(doi, sizeof (dmu_object_info_t));
-out:
if (error == 0) {
+ rw_enter(&zvol_state_lock, RW_WRITER);
zvol_insert(zv);
- /*
- * Drop the lock to prevent deadlock with sys_open() ->
- * zvol_open(), which first takes bd_disk->bd_mutex and then
- * takes zvol_state_lock, whereas this code path first takes
- * zvol_state_lock, and then takes bd_disk->bd_mutex.
- */
- mutex_exit(&zvol_state_lock);
+ rw_exit(&zvol_state_lock);
add_disk(zv->zv_disk);
} else {
- mutex_exit(&zvol_state_lock);
+ ida_simple_remove(&zvol_ida, idx);
}
return (SET_ERROR(error));
{
int readonly = get_disk_ro(zv->zv_disk);
- ASSERT(MUTEX_HELD(&zvol_state_lock));
+ ASSERT(RW_LOCK_HELD(&zvol_state_lock));
+ ASSERT(MUTEX_HELD(&zv->zv_state_lock));
strlcpy(zv->zv_name, newname, sizeof (zv->zv_name));
+ /* move to new hashtable entry */
+ zv->zv_hash = zvol_name_hash(zv->zv_name);
+ hlist_del(&zv->zv_hlink);
+ hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash));
+
/*
* The block device's read-only state is briefly changed causing
* a KOBJ_CHANGE uevent to be issued. This ensures udev detects
set_disk_ro(zv->zv_disk, readonly);
}
+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)
{
- const char *name = (const char *)arg;
+ minors_job_t *j = arg;
+ list_t *minors_list = j->list;
+ const char *name = j->name;
ASSERT0(MUTEX_HELD(&spa_namespace_lock));
/* at this point, the dsname should name a snapshot */
if (strchr(dsname, '@') == 0) {
dprintf("zvol_create_snap_minor_cb(): "
- "%s is not a shapshot name\n", dsname);
+ "%s is not a shapshot name\n", dsname);
} else {
- (void) zvol_create_minor_impl(dsname);
+ minors_job_t *job;
+ char *n = 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);
{
uint64_t snapdev;
int error;
+ list_t *minors_list = arg;
ASSERT0(MUTEX_HELD(&spa_namespace_lock));
* snapshots and create device minor nodes for those.
*/
if (strchr(dsname, '@') == 0) {
- /* create minor for the 'dsname' explicitly */
- error = zvol_create_minor_impl(dsname);
- if ((error == 0 || error == EEXIST) &&
- (snapdev == ZFS_SNAPDEV_VISIBLE)) {
- fstrans_cookie_t cookie = spl_fstrans_mark();
+ minors_job_t *job;
+ char *n = 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);
+
+ if (snapdev == ZFS_SNAPDEV_VISIBLE) {
/*
* traverse snapshots only, do not traverse children,
* and skip the 'dsname'
*/
error = dmu_objset_find((char *)dsname,
- zvol_create_snap_minor_cb, (void *)dsname,
+ zvol_create_snap_minor_cb, (void *)job,
DS_FIND_SNAPSHOTS);
- spl_fstrans_unmark(cookie);
}
} else {
dprintf("zvol_create_minors_cb(): %s is not a zvol name\n",
- dsname);
+ dsname);
}
return (0);
* - 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 perfromed if the snapshot is
+ * 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.
*/
int error = 0;
fstrans_cookie_t cookie;
char *atp, *parent;
+ list_t minors_list;
+ minors_job_t *job;
if (zvol_inhibit_dev)
return (0);
+ /*
+ * 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));
+
parent = kmem_alloc(MAXPATHLEN, KM_SLEEP);
(void) strlcpy(parent, name, MAXPATHLEN);
} else {
cookie = spl_fstrans_mark();
error = dmu_objset_find(parent, zvol_create_minors_cb,
- NULL, DS_FIND_CHILDREN);
+ &minors_list, DS_FIND_CHILDREN);
spl_fstrans_unmark(cookie);
}
kmem_free(parent, MAXPATHLEN);
+ 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)
+ zvol_create_minor_impl(job->name);
+ strfree(job->name);
+ kmem_free(job, sizeof (minors_job_t));
+ }
+
+ list_destroy(&minors_list);
return (SET_ERROR(error));
}
{
zvol_state_t *zv, *zv_next;
int namelen = ((name) ? strlen(name) : 0);
+ taskqid_t t, tid = TASKQID_INVALID;
+ list_t free_list;
if (zvol_inhibit_dev)
return;
- mutex_enter(&zvol_state_lock);
+ 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)
+ if (zv->zv_open_count > 0 ||
+ atomic_read(&zv->zv_suspend_ref)) {
+ mutex_exit(&zv->zv_state_lock);
continue;
+ }
zvol_remove(zv);
- zvol_free(zv);
+
+ /*
+ * Cleared while holding zvol_state_lock as a writer
+ * which will prevent zvol_open() from opening it.
+ */
+ zv->zv_disk->private_data = NULL;
+
+ /* 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, zv,
+ TQ_SLEEP);
+ if (t == TASKQID_INVALID)
+ list_insert_head(&free_list, zv);
+ else
+ tid = t;
+ } 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);
+ zvol_free(zv);
+ }
- mutex_exit(&zvol_state_lock);
+ if (tid != TASKQID_INVALID)
+ taskq_wait_outstanding(system_taskq, tid);
}
-/* Remove minor for this specific snapshot only */
+/* Remove minor for this specific volume only */
static void
zvol_remove_minor_impl(const char *name)
{
- zvol_state_t *zv, *zv_next;
+ zvol_state_t *zv = NULL, *zv_next;
if (zvol_inhibit_dev)
return;
- if (strchr(name, '@') == NULL)
- return;
-
- mutex_enter(&zvol_state_lock);
+ 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)
+ if (zv->zv_open_count > 0 ||
+ atomic_read(&zv->zv_suspend_ref)) {
+ mutex_exit(&zv->zv_state_lock);
continue;
+ }
zvol_remove(zv);
- zvol_free(zv);
+
+ /*
+ * Cleared while holding zvol_state_lock as a writer
+ * which will prevent zvol_open() from opening it.
+ */
+ zv->zv_disk->private_data = NULL;
+
+ mutex_exit(&zv->zv_state_lock);
break;
+ } else {
+ mutex_exit(&zv->zv_state_lock);
}
}
- mutex_exit(&zvol_state_lock);
+ /* Drop zvol_state_lock before calling zvol_free() */
+ rw_exit(&zvol_state_lock);
+
+ if (zv != NULL)
+ zvol_free(zv);
}
/*
{
zvol_state_t *zv, *zv_next;
int oldnamelen, newnamelen;
- char *name;
if (zvol_inhibit_dev)
return;
oldnamelen = strlen(oldname);
newnamelen = strlen(newname);
- name = kmem_alloc(MAXNAMELEN, KM_SLEEP);
- mutex_enter(&zvol_state_lock);
+ 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 in use, leave alone */
- if (zv->zv_open_count > 0)
+ if (zv->zv_open_count > 0) {
+ mutex_exit(&zv->zv_state_lock);
continue;
+ }
if (strcmp(zv->zv_name, oldname) == 0) {
zvol_rename_minor(zv, newname);
} else if (strncmp(zv->zv_name, oldname, oldnamelen) == 0 &&
(zv->zv_name[oldnamelen] == '/' ||
zv->zv_name[oldnamelen] == '@')) {
- snprintf(name, MAXNAMELEN, "%s%c%s", newname,
+ char *name = kmem_asprintf("%s%c%s", newname,
zv->zv_name[oldnamelen],
zv->zv_name + oldnamelen + 1);
zvol_rename_minor(zv, name);
+ kmem_free(name, strlen(name + 1));
}
- }
- mutex_exit(&zvol_state_lock);
+ mutex_exit(&zv->zv_state_lock);
+ }
- kmem_free(name, MAXNAMELEN);
+ rw_exit(&zvol_state_lock);
}
typedef struct zvol_snapdev_cb_arg {
} zvol_snapdev_cb_arg_t;
static int
-zvol_set_snapdev_cb(const char *dsname, void *param) {
+zvol_set_snapdev_cb(const char *dsname, void *param)
+{
zvol_snapdev_cb_arg_t *arg = param;
if (strchr(dsname, '@') == NULL)
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 = spl_fstrans_mark();
+
+ 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)
+ * coule be different when we set, for instance, volmode from "geom"
+ * to "dev" (or vice versa).
+ * A possible optimization is to modify our consumers so we don't get
+ * called when "volmode" does not change.
+ */
+ 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) zvol_create_minor_impl(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) zvol_create_minor_impl(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 snapdev)
+ uint64_t value)
{
zvol_task_t *task;
char *delim;
task = kmem_zalloc(sizeof (zvol_task_t), KM_SLEEP);
task->op = op;
- task->snapdev = snapdev;
+ task->value = value;
delim = strchr(name1, '/');
strlcpy(task->pool, name1, delim ? (delim - name1 + 1) : MAXNAMELEN);
zvol_rename_minors_impl(task->name1, task->name2);
break;
case ZVOL_ASYNC_SET_SNAPDEV:
- zvol_set_snapdev_impl(task->name1, task->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);
zvol_task_free(task);
}
-typedef struct zvol_set_snapdev_arg {
+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_snapdev_arg_t;
+} zvol_set_prop_int_arg_t;
/*
* Sanity check the dataset for safe use by the sync task. No additional
static int
zvol_set_snapdev_check(void *arg, dmu_tx_t *tx)
{
- zvol_set_snapdev_arg_t *zsda = arg;
+ zvol_set_prop_int_arg_t *zsda = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dir_t *dd;
int error;
return (error);
}
+/* ARGSUSED */
static int
zvol_set_snapdev_sync_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
{
- zvol_set_snapdev_arg_t *zsda = arg;
char dsname[MAXNAMELEN];
zvol_task_t *task;
+ uint64_t snapdev;
dsl_dataset_name(ds, dsname);
- 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);
-
- task = zvol_task_alloc(ZVOL_ASYNC_SET_SNAPDEV, dsname,
- NULL, zsda->zsda_value);
+ 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);
+ task, TQ_SLEEP);
return (0);
}
/*
- * Traverse all child snapshot datasets and apply snapdev appropriately.
+ * 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_snapdev_arg_t *zsda = arg;
+ 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);
int
zvol_set_snapdev(const char *ddname, zprop_source_t source, uint64_t snapdev)
{
- zvol_set_snapdev_arg_t zsda;
+ zvol_set_prop_int_arg_t zsda;
zsda.zsda_name = ddname;
zsda.zsda_source = source;
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_create_minors(spa_t *spa, const char *name, boolean_t async)
{
int
zvol_init(void)
{
- int error;
+ int threads = MIN(MAX(zvol_threads, 1), 1024);
+ int i, error;
list_create(&zvol_state_list, sizeof (zvol_state_t),
offsetof(zvol_state_t, zv_next));
- mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL);
+ rw_init(&zvol_state_lock, NULL, RW_DEFAULT, NULL);
+ ida_init(&zvol_ida);
+
+ zvol_taskq = taskq_create(ZVOL_DRIVER, threads, maxclsyspri,
+ threads * 2, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
+ if (zvol_taskq == NULL) {
+ printk(KERN_INFO "ZFS: taskq_create() failed\n");
+ error = -ENOMEM;
+ goto out;
+ }
+
+ zvol_htable = kmem_alloc(ZVOL_HT_SIZE * sizeof (struct hlist_head),
+ KM_SLEEP);
+ if (!zvol_htable) {
+ error = -ENOMEM;
+ goto out_taskq;
+ }
+ for (i = 0; i < ZVOL_HT_SIZE; i++)
+ INIT_HLIST_HEAD(&zvol_htable[i]);
error = register_blkdev(zvol_major, ZVOL_DRIVER);
if (error) {
printk(KERN_INFO "ZFS: register_blkdev() failed %d\n", error);
- goto out;
+ goto out_free;
}
blk_register_region(MKDEV(zvol_major, 0), 1UL << MINORBITS,
return (0);
+out_free:
+ kmem_free(zvol_htable, ZVOL_HT_SIZE * sizeof (struct hlist_head));
+out_taskq:
+ taskq_destroy(zvol_taskq);
out:
- mutex_destroy(&zvol_state_lock);
+ ida_destroy(&zvol_ida);
+ rw_destroy(&zvol_state_lock);
list_destroy(&zvol_state_list);
return (SET_ERROR(error));
blk_unregister_region(MKDEV(zvol_major, 0), 1UL << MINORBITS);
unregister_blkdev(zvol_major, ZVOL_DRIVER);
+ kmem_free(zvol_htable, ZVOL_HT_SIZE * sizeof (struct hlist_head));
+ taskq_destroy(zvol_taskq);
list_destroy(&zvol_state_list);
- mutex_destroy(&zvol_state_lock);
+ rw_destroy(&zvol_state_lock);
+
+ ida_destroy(&zvol_ida);
}
+/* BEGIN CSTYLED */
module_param(zvol_inhibit_dev, uint, 0644);
MODULE_PARM_DESC(zvol_inhibit_dev, "Do not create zvol device nodes");
module_param(zvol_major, uint, 0444);
MODULE_PARM_DESC(zvol_major, "Major number for zvol device");
+module_param(zvol_threads, uint, 0444);
+MODULE_PARM_DESC(zvol_threads, "Max number of threads to handle I/O requests");
+
+module_param(zvol_request_sync, uint, 0644);
+MODULE_PARM_DESC(zvol_request_sync, "Synchronously handle bio requests");
+
module_param(zvol_max_discard_blocks, ulong, 0444);
MODULE_PARM_DESC(zvol_max_discard_blocks, "Max number of blocks to discard");
module_param(zvol_prefetch_bytes, uint, 0644);
MODULE_PARM_DESC(zvol_prefetch_bytes, "Prefetch N bytes at zvol start+end");
+
+module_param(zvol_volmode, uint, 0644);
+MODULE_PARM_DESC(zvol_volmode, "Default volmode property value");
+/* END CSTYLED */
projects / mirror_zfs.git / blobdiff