diff options
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/zfs_vnops.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c index a4237f8f3..c2a2d98d1 100644 --- a/module/zfs/zfs_vnops.c +++ b/module/zfs/zfs_vnops.c @@ -52,6 +52,8 @@ #include <sys/policy.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; @@ -717,6 +719,163 @@ zfs_setsecattr(znode_t *zp, vsecattr_t *vsecp, int flag, cred_t *cr) 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, 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; + + ASSERT3P(lwb, !=, NULL); + ASSERT3P(zio, !=, 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)); + } + + zgd = (zgd_t *)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 */ + /* + * 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(os, object, offset, zgd, &db, + DMU_READ_NO_PREFETCH); + + if (error == 0) { + blkptr_t *bp = &lr->lr_blkptr; + + zgd->zgd_db = db; + zgd->zgd_bp = bp; + + ASSERT(db->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); +} + + +/* ARGSUSED */ +static void +zfs_get_done(zgd_t *zgd, int 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)); +} + EXPORT_SYMBOL(zfs_access); EXPORT_SYMBOL(zfs_fsync); EXPORT_SYMBOL(zfs_holey); |