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zfs_vnops.c
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zfs_vnops.c
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/*
* 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 https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2018 by Delphix. All rights reserved.
* Copyright (c) 2015 by Chunwei Chen. All rights reserved.
* Copyright 2017 Nexenta Systems, Inc.
* Copyright (c) 2021, 2022 by Pawel Jakub Dawidek
*/
/* Portions Copyright 2007 Jeremy Teo */
/* Portions Copyright 2010 Robert Milkowski */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/sysmacros.h>
#include <sys/vfs.h>
#include <sys/uio_impl.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/kmem.h>
#include <sys/cmn_err.h>
#include <sys/errno.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_acl.h>
#include <sys/zfs_ioctl.h>
#include <sys/fs/zfs.h>
#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/dbuf.h>
#include <sys/policy.h>
#include <sys/zfeature.h>
#include <sys/zfs_vnops.h>
#include <sys/zfs_quota.h>
#include <sys/zfs_vfsops.h>
#include <sys/zfs_znode.h>
static ulong_t zfs_fsync_sync_cnt = 4;
int
zfs_fsync(znode_t *zp, int syncflag, cred_t *cr)
{
int error = 0;
zfsvfs_t *zfsvfs = ZTOZSB(zp);
(void) tsd_set(zfs_fsyncer_key, (void *)(uintptr_t)zfs_fsync_sync_cnt);
if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) {
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
goto out;
atomic_inc_32(&zp->z_sync_writes_cnt);
zil_commit(zfsvfs->z_log, zp->z_id);
atomic_dec_32(&zp->z_sync_writes_cnt);
zfs_exit(zfsvfs, FTAG);
}
out:
tsd_set(zfs_fsyncer_key, NULL);
return (error);
}
#if defined(SEEK_HOLE) && defined(SEEK_DATA)
/*
* Lseek support for finding holes (cmd == SEEK_HOLE) and
* data (cmd == SEEK_DATA). "off" is an in/out parameter.
*/
static int
zfs_holey_common(znode_t *zp, ulong_t cmd, loff_t *off)
{
zfs_locked_range_t *lr;
uint64_t noff = (uint64_t)*off; /* new offset */
uint64_t file_sz;
int error;
boolean_t hole;
file_sz = zp->z_size;
if (noff >= file_sz) {
return (SET_ERROR(ENXIO));
}
if (cmd == F_SEEK_HOLE)
hole = B_TRUE;
else
hole = B_FALSE;
/* Flush any mmap()'d data to disk */
if (zn_has_cached_data(zp, 0, file_sz - 1))
zn_flush_cached_data(zp, B_FALSE);
lr = zfs_rangelock_enter(&zp->z_rangelock, 0, UINT64_MAX, RL_READER);
error = dmu_offset_next(ZTOZSB(zp)->z_os, zp->z_id, hole, &noff);
zfs_rangelock_exit(lr);
if (error == ESRCH)
return (SET_ERROR(ENXIO));
/* File was dirty, so fall back to using generic logic */
if (error == EBUSY) {
if (hole)
*off = file_sz;
return (0);
}
/*
* We could find a hole that begins after the logical end-of-file,
* because dmu_offset_next() only works on whole blocks. If the
* EOF falls mid-block, then indicate that the "virtual hole"
* at the end of the file begins at the logical EOF, rather than
* at the end of the last block.
*/
if (noff > file_sz) {
ASSERT(hole);
noff = file_sz;
}
if (noff < *off)
return (error);
*off = noff;
return (error);
}
int
zfs_holey(znode_t *zp, ulong_t cmd, loff_t *off)
{
zfsvfs_t *zfsvfs = ZTOZSB(zp);
int error;
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
error = zfs_holey_common(zp, cmd, off);
zfs_exit(zfsvfs, FTAG);
return (error);
}
#endif /* SEEK_HOLE && SEEK_DATA */
int
zfs_access(znode_t *zp, int mode, int flag, cred_t *cr)
{
zfsvfs_t *zfsvfs = ZTOZSB(zp);
int error;
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
if (flag & V_ACE_MASK)
#if defined(__linux__)
error = zfs_zaccess(zp, mode, flag, B_FALSE, cr,
zfs_init_idmap);
#else
error = zfs_zaccess(zp, mode, flag, B_FALSE, cr,
NULL);
#endif
else
#if defined(__linux__)
error = zfs_zaccess_rwx(zp, mode, flag, cr, zfs_init_idmap);
#else
error = zfs_zaccess_rwx(zp, mode, flag, cr, NULL);
#endif
zfs_exit(zfsvfs, FTAG);
return (error);
}
static uint64_t zfs_vnops_read_chunk_size = 1024 * 1024; /* Tunable */
/*
* Read bytes from specified file into supplied buffer.
*
* IN: zp - inode of file to be read from.
* uio - structure supplying read location, range info,
* and return buffer.
* ioflag - O_SYNC flags; used to provide FRSYNC semantics.
* O_DIRECT flag; used to bypass page cache.
* cr - credentials of caller.
*
* OUT: uio - updated offset and range, buffer filled.
*
* RETURN: 0 on success, error code on failure.
*
* Side Effects:
* inode - atime updated if byte count > 0
*/
int
zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
{
(void) cr;
int error = 0;
boolean_t frsync = B_FALSE;
zfsvfs_t *zfsvfs = ZTOZSB(zp);
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
if (zp->z_pflags & ZFS_AV_QUARANTINED) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EACCES));
}
/* We don't copy out anything useful for directories. */
if (Z_ISDIR(ZTOTYPE(zp))) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EISDIR));
}
/*
* Validate file offset
*/
if (zfs_uio_offset(uio) < (offset_t)0) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EINVAL));
}
/*
* Fasttrack empty reads
*/
if (zfs_uio_resid(uio) == 0) {
zfs_exit(zfsvfs, FTAG);
return (0);
}
#ifdef FRSYNC
/*
* If we're in FRSYNC mode, sync out this znode before reading it.
* Only do this for non-snapshots.
*
* Some platforms do not support FRSYNC and instead map it
* to O_SYNC, which results in unnecessary calls to zil_commit. We
* only honor FRSYNC requests on platforms which support it.
*/
frsync = !!(ioflag & FRSYNC);
#endif
if (zfsvfs->z_log &&
(frsync || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS))
zil_commit(zfsvfs->z_log, zp->z_id);
/*
* Lock the range against changes.
*/
zfs_locked_range_t *lr = zfs_rangelock_enter(&zp->z_rangelock,
zfs_uio_offset(uio), zfs_uio_resid(uio), RL_READER);
/*
* If we are reading past end-of-file we can skip
* to the end; but we might still need to set atime.
*/
if (zfs_uio_offset(uio) >= zp->z_size) {
error = 0;
goto out;
}
ASSERT(zfs_uio_offset(uio) < zp->z_size);
#if defined(__linux__)
ssize_t start_offset = zfs_uio_offset(uio);
#endif
ssize_t n = MIN(zfs_uio_resid(uio), zp->z_size - zfs_uio_offset(uio));
ssize_t start_resid = n;
while (n > 0) {
ssize_t nbytes = MIN(n, zfs_vnops_read_chunk_size -
P2PHASE(zfs_uio_offset(uio), zfs_vnops_read_chunk_size));
#ifdef UIO_NOCOPY
if (zfs_uio_segflg(uio) == UIO_NOCOPY)
error = mappedread_sf(zp, nbytes, uio);
else
#endif
if (zn_has_cached_data(zp, zfs_uio_offset(uio),
zfs_uio_offset(uio) + nbytes - 1) && !(ioflag & O_DIRECT)) {
error = mappedread(zp, nbytes, uio);
} else {
error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
uio, nbytes);
}
if (error) {
/* convert checksum errors into IO errors */
if (error == ECKSUM)
error = SET_ERROR(EIO);
#if defined(__linux__)
/*
* if we actually read some bytes, bubbling EFAULT
* up to become EAGAIN isn't what we want here...
*
* ...on Linux, at least. On FBSD, doing this breaks.
*/
if (error == EFAULT &&
(zfs_uio_offset(uio) - start_offset) != 0)
error = 0;
#endif
break;
}
n -= nbytes;
}
int64_t nread = start_resid - n;
dataset_kstats_update_read_kstats(&zfsvfs->z_kstat, nread);
task_io_account_read(nread);
out:
zfs_rangelock_exit(lr);
ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
zfs_exit(zfsvfs, FTAG);
return (error);
}
static void
zfs_clear_setid_bits_if_necessary(zfsvfs_t *zfsvfs, znode_t *zp, cred_t *cr,
uint64_t *clear_setid_bits_txgp, dmu_tx_t *tx)
{
zilog_t *zilog = zfsvfs->z_log;
const uint64_t uid = KUID_TO_SUID(ZTOUID(zp));
ASSERT(clear_setid_bits_txgp != NULL);
ASSERT(tx != NULL);
/*
* Clear Set-UID/Set-GID bits on successful write if not
* privileged and at least one of the execute bits is set.
*
* It would be nice to do this after all writes have
* been done, but that would still expose the ISUID/ISGID
* to another app after the partial write is committed.
*
* Note: we don't call zfs_fuid_map_id() here because
* user 0 is not an ephemeral uid.
*/
mutex_enter(&zp->z_acl_lock);
if ((zp->z_mode & (S_IXUSR | (S_IXUSR >> 3) | (S_IXUSR >> 6))) != 0 &&
(zp->z_mode & (S_ISUID | S_ISGID)) != 0 &&
secpolicy_vnode_setid_retain(zp, cr,
((zp->z_mode & S_ISUID) != 0 && uid == 0)) != 0) {
uint64_t newmode;
zp->z_mode &= ~(S_ISUID | S_ISGID);
newmode = zp->z_mode;
(void) sa_update(zp->z_sa_hdl, SA_ZPL_MODE(zfsvfs),
(void *)&newmode, sizeof (uint64_t), tx);
mutex_exit(&zp->z_acl_lock);
/*
* Make sure SUID/SGID bits will be removed when we replay the
* log. If the setid bits are keep coming back, don't log more
* than one TX_SETATTR per transaction group.
*/
if (*clear_setid_bits_txgp != dmu_tx_get_txg(tx)) {
vattr_t va = {0};
va.va_mask = ATTR_MODE;
va.va_nodeid = zp->z_id;
va.va_mode = newmode;
zfs_log_setattr(zilog, tx, TX_SETATTR, zp, &va,
ATTR_MODE, NULL);
*clear_setid_bits_txgp = dmu_tx_get_txg(tx);
}
} else {
mutex_exit(&zp->z_acl_lock);
}
}
/*
* Write the bytes to a file.
*
* IN: zp - znode of file to be written to.
* uio - structure supplying write location, range info,
* and data buffer.
* ioflag - O_APPEND flag set if in append mode.
* O_DIRECT flag; used to bypass page cache.
* cr - credentials of caller.
*
* OUT: uio - updated offset and range.
*
* RETURN: 0 if success
* error code if failure
*
* Timestamps:
* ip - ctime|mtime updated if byte count > 0
*/
int
zfs_write(znode_t *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
{
int error = 0, error1;
ssize_t start_resid = zfs_uio_resid(uio);
uint64_t clear_setid_bits_txg = 0;
/*
* Fasttrack empty write
*/
ssize_t n = start_resid;
if (n == 0)
return (0);
zfsvfs_t *zfsvfs = ZTOZSB(zp);
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
sa_bulk_attr_t bulk[4];
int count = 0;
uint64_t mtime[2], ctime[2];
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
&zp->z_size, 8);
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
&zp->z_pflags, 8);
/*
* Callers might not be able to detect properly that we are read-only,
* so check it explicitly here.
*/
if (zfs_is_readonly(zfsvfs)) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EROFS));
}
/*
* If immutable or not appending then return EPERM.
* Intentionally allow ZFS_READONLY through here.
* See zfs_zaccess_common()
*/
if ((zp->z_pflags & ZFS_IMMUTABLE) ||
((zp->z_pflags & ZFS_APPENDONLY) && !(ioflag & O_APPEND) &&
(zfs_uio_offset(uio) < zp->z_size))) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EPERM));
}
/*
* Validate file offset
*/
offset_t woff = ioflag & O_APPEND ? zp->z_size : zfs_uio_offset(uio);
if (woff < 0) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EINVAL));
}
/*
* Pre-fault the pages to ensure slow (eg NFS) pages
* don't hold up txg.
*/
ssize_t pfbytes = MIN(n, DMU_MAX_ACCESS >> 1);
if (zfs_uio_prefaultpages(pfbytes, uio)) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EFAULT));
}
/*
* If in append mode, set the io offset pointer to eof.
*/
zfs_locked_range_t *lr;
if (ioflag & O_APPEND) {
/*
* Obtain an appending range lock to guarantee file append
* semantics. We reset the write offset once we have the lock.
*/
lr = zfs_rangelock_enter(&zp->z_rangelock, 0, n, RL_APPEND);
woff = lr->lr_offset;
if (lr->lr_length == UINT64_MAX) {
/*
* We overlocked the file because this write will cause
* the file block size to increase.
* Note that zp_size cannot change with this lock held.
*/
woff = zp->z_size;
}
zfs_uio_setoffset(uio, woff);
} else {
/*
* Note that if the file block size will change as a result of
* this write, then this range lock will lock the entire file
* so that we can re-write the block safely.
*/
lr = zfs_rangelock_enter(&zp->z_rangelock, woff, n, RL_WRITER);
}
if (zn_rlimit_fsize_uio(zp, uio)) {
zfs_rangelock_exit(lr);
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EFBIG));
}
const rlim64_t limit = MAXOFFSET_T;
if (woff >= limit) {
zfs_rangelock_exit(lr);
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EFBIG));
}
if (n > limit - woff)
n = limit - woff;
uint64_t end_size = MAX(zp->z_size, woff + n);
zilog_t *zilog = zfsvfs->z_log;
const uint64_t uid = KUID_TO_SUID(ZTOUID(zp));
const uint64_t gid = KGID_TO_SGID(ZTOGID(zp));
const uint64_t projid = zp->z_projid;
/*
* Write the file in reasonable size chunks. Each chunk is written
* in a separate transaction; this keeps the intent log records small
* and allows us to do more fine-grained space accounting.
*/
while (n > 0) {
woff = zfs_uio_offset(uio);
if (zfs_id_overblockquota(zfsvfs, DMU_USERUSED_OBJECT, uid) ||
zfs_id_overblockquota(zfsvfs, DMU_GROUPUSED_OBJECT, gid) ||
(projid != ZFS_DEFAULT_PROJID &&
zfs_id_overblockquota(zfsvfs, DMU_PROJECTUSED_OBJECT,
projid))) {
error = SET_ERROR(EDQUOT);
break;
}
uint64_t blksz;
if (lr->lr_length == UINT64_MAX && zp->z_size <= zp->z_blksz) {
if (zp->z_blksz > zfsvfs->z_max_blksz &&
!ISP2(zp->z_blksz)) {
/*
* File's blocksize is already larger than the
* "recordsize" property. Only let it grow to
* the next power of 2.
*/
blksz = 1 << highbit64(zp->z_blksz);
} else {
blksz = zfsvfs->z_max_blksz;
}
blksz = MIN(blksz, P2ROUNDUP(end_size,
SPA_MINBLOCKSIZE));
blksz = MAX(blksz, zp->z_blksz);
} else {
blksz = zp->z_blksz;
}
arc_buf_t *abuf = NULL;
ssize_t nbytes = n;
if (n >= blksz && woff >= zp->z_size &&
P2PHASE(woff, blksz) == 0 &&
(blksz >= SPA_OLD_MAXBLOCKSIZE || n < 4 * blksz)) {
/*
* This write covers a full block. "Borrow" a buffer
* from the dmu so that we can fill it before we enter
* a transaction. This avoids the possibility of
* holding up the transaction if the data copy hangs
* up on a pagefault (e.g., from an NFS server mapping).
*/
abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
blksz);
ASSERT(abuf != NULL);
ASSERT(arc_buf_size(abuf) == blksz);
if ((error = zfs_uiocopy(abuf->b_data, blksz,
UIO_WRITE, uio, &nbytes))) {
dmu_return_arcbuf(abuf);
break;
}
ASSERT3S(nbytes, ==, blksz);
} else {
nbytes = MIN(n, (DMU_MAX_ACCESS >> 1) -
P2PHASE(woff, blksz));
if (pfbytes < nbytes) {
if (zfs_uio_prefaultpages(nbytes, uio)) {
error = SET_ERROR(EFAULT);
break;
}
pfbytes = nbytes;
}
}
/*
* Start a transaction.
*/
dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
dmu_buf_impl_t *db = (dmu_buf_impl_t *)sa_get_db(zp->z_sa_hdl);
DB_DNODE_ENTER(db);
dmu_tx_hold_write_by_dnode(tx, DB_DNODE(db), woff, nbytes);
DB_DNODE_EXIT(db);
zfs_sa_upgrade_txholds(tx, zp);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
if (abuf != NULL)
dmu_return_arcbuf(abuf);
break;
}
/*
* NB: We must call zfs_clear_setid_bits_if_necessary before
* committing the transaction!
*/
/*
* If rangelock_enter() over-locked we grow the blocksize
* and then reduce the lock range. This will only happen
* on the first iteration since rangelock_reduce() will
* shrink down lr_length to the appropriate size.
*/
if (lr->lr_length == UINT64_MAX) {
zfs_grow_blocksize(zp, blksz, tx);
zfs_rangelock_reduce(lr, woff, n);
}
ssize_t tx_bytes;
if (abuf == NULL) {
tx_bytes = zfs_uio_resid(uio);
zfs_uio_fault_disable(uio, B_TRUE);
error = dmu_write_uio_dbuf(sa_get_db(zp->z_sa_hdl),
uio, nbytes, tx);
zfs_uio_fault_disable(uio, B_FALSE);
#ifdef __linux__
if (error == EFAULT) {
zfs_clear_setid_bits_if_necessary(zfsvfs, zp,
cr, &clear_setid_bits_txg, tx);
dmu_tx_commit(tx);
/*
* Account for partial writes before
* continuing the loop.
* Update needs to occur before the next
* zfs_uio_prefaultpages, or prefaultpages may
* error, and we may break the loop early.
*/
n -= tx_bytes - zfs_uio_resid(uio);
pfbytes -= tx_bytes - zfs_uio_resid(uio);
continue;
}
#endif
/*
* On FreeBSD, EFAULT should be propagated back to the
* VFS, which will handle faulting and will retry.
*/
if (error != 0 && error != EFAULT) {
zfs_clear_setid_bits_if_necessary(zfsvfs, zp,
cr, &clear_setid_bits_txg, tx);
dmu_tx_commit(tx);
break;
}
tx_bytes -= zfs_uio_resid(uio);
} else {
/*
* Thus, we're writing a full block at a block-aligned
* offset and extending the file past EOF.
*
* dmu_assign_arcbuf_by_dbuf() will directly assign the
* arc buffer to a dbuf.
*/
error = dmu_assign_arcbuf_by_dbuf(
sa_get_db(zp->z_sa_hdl), woff, abuf, tx);
if (error != 0) {
/*
* XXX This might not be necessary if
* dmu_assign_arcbuf_by_dbuf is guaranteed
* to be atomic.
*/
zfs_clear_setid_bits_if_necessary(zfsvfs, zp,
cr, &clear_setid_bits_txg, tx);
dmu_return_arcbuf(abuf);
dmu_tx_commit(tx);
break;
}
ASSERT3S(nbytes, <=, zfs_uio_resid(uio));
zfs_uioskip(uio, nbytes);
tx_bytes = nbytes;
}
if (tx_bytes &&
zn_has_cached_data(zp, woff, woff + tx_bytes - 1) &&
!(ioflag & O_DIRECT)) {
update_pages(zp, woff, tx_bytes, zfsvfs->z_os);
}
/*
* If we made no progress, we're done. If we made even
* partial progress, update the znode and ZIL accordingly.
*/
if (tx_bytes == 0) {
(void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
(void *)&zp->z_size, sizeof (uint64_t), tx);
dmu_tx_commit(tx);
ASSERT(error != 0);
break;
}
zfs_clear_setid_bits_if_necessary(zfsvfs, zp, cr,
&clear_setid_bits_txg, tx);
zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime);
/*
* Update the file size (zp_size) if it has changed;
* account for possible concurrent updates.
*/
while ((end_size = zp->z_size) < zfs_uio_offset(uio)) {
(void) atomic_cas_64(&zp->z_size, end_size,
zfs_uio_offset(uio));
ASSERT(error == 0 || error == EFAULT);
}
/*
* If we are replaying and eof is non zero then force
* the file size to the specified eof. Note, there's no
* concurrency during replay.
*/
if (zfsvfs->z_replay && zfsvfs->z_replay_eof != 0)
zp->z_size = zfsvfs->z_replay_eof;
error1 = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
if (error1 != 0)
/* Avoid clobbering EFAULT. */
error = error1;
/*
* NB: During replay, the TX_SETATTR record logged by
* zfs_clear_setid_bits_if_necessary must precede any of
* the TX_WRITE records logged here.
*/
zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag,
NULL, NULL);
dmu_tx_commit(tx);
if (error != 0)
break;
ASSERT3S(tx_bytes, ==, nbytes);
n -= nbytes;
pfbytes -= nbytes;
}
zfs_znode_update_vfs(zp);
zfs_rangelock_exit(lr);
/*
* If we're in replay mode, or we made no progress, or the
* uio data is inaccessible return an error. Otherwise, it's
* at least a partial write, so it's successful.
*/
if (zfsvfs->z_replay || zfs_uio_resid(uio) == start_resid ||
error == EFAULT) {
zfs_exit(zfsvfs, FTAG);
return (error);
}
if (ioflag & (O_SYNC | O_DSYNC) ||
zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zilog, zp->z_id);
const int64_t nwritten = start_resid - zfs_uio_resid(uio);
dataset_kstats_update_write_kstats(&zfsvfs->z_kstat, nwritten);
task_io_account_write(nwritten);
zfs_exit(zfsvfs, FTAG);
return (0);
}
int
zfs_getsecattr(znode_t *zp, vsecattr_t *vsecp, int flag, cred_t *cr)
{
zfsvfs_t *zfsvfs = ZTOZSB(zp);
int error;
boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
error = zfs_getacl(zp, vsecp, skipaclchk, cr);
zfs_exit(zfsvfs, FTAG);
return (error);
}
int
zfs_setsecattr(znode_t *zp, vsecattr_t *vsecp, int flag, cred_t *cr)
{
zfsvfs_t *zfsvfs = ZTOZSB(zp);
int error;
boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
zilog_t *zilog = zfsvfs->z_log;
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
error = zfs_setacl(zp, vsecp, skipaclchk, cr);
if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zilog, 0);
zfs_exit(zfsvfs, FTAG);
return (error);
}
#ifdef ZFS_DEBUG
static int zil_fault_io = 0;
#endif
static void zfs_get_done(zgd_t *zgd, int error);
/*
* Get data to generate a TX_WRITE intent log record.
*/
int
zfs_get_data(void *arg, uint64_t gen, lr_write_t *lr, char *buf,
struct lwb *lwb, zio_t *zio)
{
zfsvfs_t *zfsvfs = arg;
objset_t *os = zfsvfs->z_os;
znode_t *zp;
uint64_t object = lr->lr_foid;
uint64_t offset = lr->lr_offset;
uint64_t size = lr->lr_length;
dmu_buf_t *db;
zgd_t *zgd;
int error = 0;
uint64_t zp_gen;
ASSERT3P(lwb, !=, NULL);
ASSERT3U(size, !=, 0);
/*
* Nothing to do if the file has been removed
*/
if (zfs_zget(zfsvfs, object, &zp) != 0)
return (SET_ERROR(ENOENT));
if (zp->z_unlinked) {
/*
* Release the vnode asynchronously as we currently have the
* txg stopped from syncing.
*/
zfs_zrele_async(zp);
return (SET_ERROR(ENOENT));
}
/* check if generation number matches */
if (sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs), &zp_gen,
sizeof (zp_gen)) != 0) {
zfs_zrele_async(zp);
return (SET_ERROR(EIO));
}
if (zp_gen != gen) {
zfs_zrele_async(zp);
return (SET_ERROR(ENOENT));
}
zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
zgd->zgd_lwb = lwb;
zgd->zgd_private = zp;
/*
* Write records come in two flavors: immediate and indirect.
* For small writes it's cheaper to store the data with the
* log record (immediate); for large writes it's cheaper to
* sync the data and get a pointer to it (indirect) so that
* we don't have to write the data twice.
*/
if (buf != NULL) { /* immediate write */
zgd->zgd_lr = zfs_rangelock_enter(&zp->z_rangelock,
offset, size, RL_READER);
/* test for truncation needs to be done while range locked */
if (offset >= zp->z_size) {
error = SET_ERROR(ENOENT);
} else {
error = dmu_read(os, object, offset, size, buf,
DMU_READ_NO_PREFETCH);
}
ASSERT(error == 0 || error == ENOENT);
} else { /* indirect write */
ASSERT3P(zio, !=, NULL);
/*
* 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. We need to re-check
* blocksize after we get the lock in case it's changed!
*/
for (;;) {
uint64_t blkoff;
size = zp->z_blksz;
blkoff = ISP2(size) ? P2PHASE(offset, size) : offset;
offset -= blkoff;
zgd->zgd_lr = zfs_rangelock_enter(&zp->z_rangelock,
offset, size, RL_READER);
if (zp->z_blksz == size)
break;
offset += blkoff;
zfs_rangelock_exit(zgd->zgd_lr);
}
/* test for truncation needs to be done while range locked */
if (lr->lr_offset >= zp->z_size)
error = SET_ERROR(ENOENT);
#ifdef ZFS_DEBUG
if (zil_fault_io) {
error = SET_ERROR(EIO);
zil_fault_io = 0;
}
#endif
if (error == 0)
error = dmu_buf_hold_noread(os, object, offset, zgd,
&db);
if (error == 0) {
blkptr_t *bp = &lr->lr_blkptr;
zgd->zgd_db = db;
zgd->zgd_bp = bp;
ASSERT(db->db_offset == offset);
ASSERT(db->db_size == size);
error = dmu_sync(zio, lr->lr_common.lrc_txg,
zfs_get_done, zgd);
ASSERT(error || lr->lr_length <= size);
/*
* On success, we need to wait for the write I/O
* initiated by dmu_sync() to complete before we can
* release this dbuf. We will finish everything up
* in the zfs_get_done() callback.
*/
if (error == 0)
return (0);
if (error == EALREADY) {
lr->lr_common.lrc_txtype = TX_WRITE2;
/*
* TX_WRITE2 relies on the data previously
* written by the TX_WRITE that caused
* EALREADY. We zero out the BP because
* it is the old, currently-on-disk BP.
*/
zgd->zgd_bp = NULL;
BP_ZERO(bp);
error = 0;
}
}
}
zfs_get_done(zgd, error);
return (error);
}
static void
zfs_get_done(zgd_t *zgd, int error)
{
(void) error;
znode_t *zp = zgd->zgd_private;
if (zgd->zgd_db)
dmu_buf_rele(zgd->zgd_db, zgd);
zfs_rangelock_exit(zgd->zgd_lr);
/*
* Release the vnode asynchronously as we currently have the
* txg stopped from syncing.
*/
zfs_zrele_async(zp);
kmem_free(zgd, sizeof (zgd_t));
}
static int
zfs_enter_two(zfsvfs_t *zfsvfs1, zfsvfs_t *zfsvfs2, const char *tag)
{
int error;
/* Swap. Not sure if the order of zfs_enter()s is important. */
if (zfsvfs1 > zfsvfs2) {
zfsvfs_t *tmpzfsvfs;
tmpzfsvfs = zfsvfs2;
zfsvfs2 = zfsvfs1;
zfsvfs1 = tmpzfsvfs;
}
error = zfs_enter(zfsvfs1, tag);