From ab8c935ea65e1a4d92311c9b84adc77047ba0b2f Mon Sep 17 00:00:00 2001 From: Christian Schwarz Date: Mon, 2 Nov 2020 21:07:07 +0100 Subject: [PATCH] zfs_vnops: make zfs_get_data OS-independent Move zfs_get_data() in to platform-independent code. The only platform-specific aspect of it is the way we release an inode (Linux) / vnode_t (FreeBSD). I am not aware of a platform that could be supported by ZFS that couldn't implement zfs_rele_async itself. It's sibling zvol_get_data already is platform-independent. Reviewed-by: Ryan Moeller Reviewed-by: Brian Behlendorf Signed-off-by: Christian Schwarz Closes #10979 --- include/os/freebsd/zfs/sys/zfs_znode_impl.h | 1 - include/os/linux/zfs/sys/zfs_znode_impl.h | 1 - include/sys/zfs_vnops.h | 13 ++ module/os/freebsd/zfs/zfs_vfsops.c | 1 + module/os/freebsd/zfs/zfs_vnops_os.c | 161 +------------------- module/os/linux/zfs/zfs_vnops_os.c | 159 ------------------- module/zfs/zfs_vnops.c | 159 +++++++++++++++++++ 7 files changed, 179 insertions(+), 316 deletions(-) diff --git a/include/os/freebsd/zfs/sys/zfs_znode_impl.h b/include/os/freebsd/zfs/sys/zfs_znode_impl.h index d87938f097..62570da58f 100644 --- a/include/os/freebsd/zfs/sys/zfs_znode_impl.h +++ b/include/os/freebsd/zfs/sys/zfs_znode_impl.h @@ -173,7 +173,6 @@ extern void zfs_tstamp_update_setup_ext(struct znode *, uint_t, uint64_t [2], uint64_t [2], boolean_t have_tx); extern void zfs_znode_free(struct znode *); -extern zil_get_data_t zfs_get_data; extern zil_replay_func_t *zfs_replay_vector[TX_MAX_TYPE]; extern int zfsfstype; diff --git a/include/os/linux/zfs/sys/zfs_znode_impl.h b/include/os/linux/zfs/sys/zfs_znode_impl.h index a4a136f010..5c31d8309a 100644 --- a/include/os/linux/zfs/sys/zfs_znode_impl.h +++ b/include/os/linux/zfs/sys/zfs_znode_impl.h @@ -163,7 +163,6 @@ extern caddr_t zfs_map_page(page_t *, enum seg_rw); extern void zfs_unmap_page(page_t *, caddr_t); #endif /* HAVE_UIO_RW */ -extern zil_get_data_t zfs_get_data; extern zil_replay_func_t *zfs_replay_vector[TX_MAX_TYPE]; extern int zfsfstype; diff --git a/include/sys/zfs_vnops.h b/include/sys/zfs_vnops.h index b2767cb0e6..5aaa64b342 100644 --- a/include/sys/zfs_vnops.h +++ b/include/sys/zfs_vnops.h @@ -39,4 +39,17 @@ extern int mappedread(znode_t *, int, uio_t *); extern int mappedread_sf(znode_t *, int, uio_t *); extern void update_pages(znode_t *, int64_t, int, objset_t *, uint64_t); +/* + * Platform code that asynchronously drops zp's inode / vnode_t. + * + * Asynchronous dropping ensures that the caller will never drop the + * last reference on an inode / vnode_t in the current context. + * Doing so while holding open a tx could result in a deadlock if + * the platform calls into filesystem again in the implementation + * of inode / vnode_t dropping (e.g. call from iput_final()). + */ +extern void zfs_zrele_async(znode_t *zp); + +extern zil_get_data_t zfs_get_data; + #endif diff --git a/module/os/freebsd/zfs/zfs_vfsops.c b/module/os/freebsd/zfs/zfs_vfsops.c index 55ed2e25d5..7587d02ae5 100644 --- a/module/os/freebsd/zfs/zfs_vfsops.c +++ b/module/os/freebsd/zfs/zfs_vfsops.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include diff --git a/module/os/freebsd/zfs/zfs_vnops_os.c b/module/os/freebsd/zfs/zfs_vnops_os.c index 758cea21fb..484ab3d648 100644 --- a/module/os/freebsd/zfs/zfs_vnops_os.c +++ b/module/os/freebsd/zfs/zfs_vnops_os.c @@ -29,6 +29,7 @@ /* Portions Copyright 2007 Jeremy Teo */ /* Portions Copyright 2010 Robert Milkowski */ + #include #include #include @@ -669,163 +670,13 @@ zfs_write_simple(znode_t *zp, const void *data, size_t len, return (error); } -static void -zfs_get_done(zgd_t *zgd, int error) +void +zfs_zrele_async(znode_t *zp) { - znode_t *zp = zgd->zgd_private; - objset_t *os = zp->z_zfsvfs->z_os; + vnode_t *vp = ZTOV(zp); + objset_t *os = ITOZSB(vp)->z_os; - 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. - */ - VN_RELE_ASYNC(ZTOV(zp), dsl_pool_zrele_taskq(dmu_objset_pool(os))); - - kmem_free(zgd, sizeof (zgd_t)); -} - -#ifdef ZFS_DEBUG -static int zil_fault_io = 0; -#endif - -/* - * 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. - */ - VN_RELE_ASYNC(ZTOV(zp), - dsl_pool_zrele_taskq(dmu_objset_pool(os))); - 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, - * so there's no need to zio_flush() its - * vdevs (flushing would needlesly hurt - * performance, and doesn't work on - * indirect vdevs). - */ - zgd->zgd_bp = NULL; - BP_ZERO(bp); - error = 0; - } - } - } - - zfs_get_done(zgd, error); - - return (error); + VN_RELE_ASYNC(vp, dsl_pool_zrele_taskq(dmu_objset_pool(os))); } static int diff --git a/module/os/linux/zfs/zfs_vnops_os.c b/module/os/linux/zfs/zfs_vnops_os.c index 5a56534b93..056b8900a4 100644 --- a/module/os/linux/zfs/zfs_vnops_os.c +++ b/module/os/linux/zfs/zfs_vnops_os.c @@ -381,12 +381,6 @@ zfs_write_simple(znode_t *zp, const void *data, size_t len, return (error); } -/* - * Drop a reference on the passed inode asynchronously. This ensures - * that the caller will never drop the last reference on an inode in - * the current context. Doing so while holding open a tx could result - * in a deadlock if iput_final() re-enters the filesystem code. - */ void zfs_zrele_async(znode_t *zp) { @@ -403,159 +397,6 @@ zfs_zrele_async(znode_t *zp) zrele(zp); } -/* 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)); -} - -#ifdef ZFS_DEBUG -static int zil_fault_io = 0; -#endif - -/* - * 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 = 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); -} /* * Lookup an entry in a directory, or an extended attribute directory. diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c index a4237f8f34..c2a2d98d17 100644 --- a/module/zfs/zfs_vnops.c +++ b/module/zfs/zfs_vnops.c @@ -52,6 +52,8 @@ #include #include #include +#include +#include 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);