From 296a4a369bc1078a694f88570972330985b3b1b8 Mon Sep 17 00:00:00 2001 From: Chunwei Chen Date: Fri, 19 Mar 2021 22:53:31 -0700 Subject: [PATCH] Fix zfs_get_data access to files with wrong generation If TX_WRITE is create on a file, and the file is later deleted and a new directory is created on the same object id, it is possible that when zil_commit happens, zfs_get_data will be called on the new directory. This may result in panic as it tries to do range lock. This patch fixes this issue by record the generation number during zfs_log_write, so zfs_get_data can check if the object is valid. Reviewed-by: Brian Behlendorf Signed-off-by: Chunwei Chen Closes #10593 Closes #11682 --- cmd/ztest/ztest.c | 4 ++-- include/sys/zil.h | 3 ++- include/sys/zvol_impl.h | 4 ++-- module/zfs/zfs_log.c | 5 +++++ module/zfs/zfs_vnops.c | 14 +++++++++++++- module/zfs/zil.c | 3 ++- module/zfs/zvol.c | 3 ++- 7 files changed, 28 insertions(+), 8 deletions(-) diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c index 1a03028070..7193eafe3d 100644 --- a/cmd/ztest/ztest.c +++ b/cmd/ztest/ztest.c @@ -2287,8 +2287,8 @@ ztest_get_done(zgd_t *zgd, int error) } static int -ztest_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, - zio_t *zio) +ztest_get_data(void *arg, uint64_t arg2, lr_write_t *lr, char *buf, + struct lwb *lwb, zio_t *zio) { ztest_ds_t *zd = arg; objset_t *os = zd->zd_os; diff --git a/include/sys/zil.h b/include/sys/zil.h index ec89de38d4..cefbccb32f 100644 --- a/include/sys/zil.h +++ b/include/sys/zil.h @@ -399,6 +399,7 @@ typedef struct itx { void *itx_callback_data; /* User data for the callback */ size_t itx_size; /* allocated itx structure size */ uint64_t itx_oid; /* object id */ + uint64_t itx_gen; /* gen number for zfs_get_data */ lr_t itx_lr; /* common part of log record */ /* followed by type-specific part of lr_xx_t and its immediate data */ } itx_t; @@ -467,7 +468,7 @@ typedef int zil_parse_blk_func_t(zilog_t *zilog, const blkptr_t *bp, void *arg, typedef int zil_parse_lr_func_t(zilog_t *zilog, const lr_t *lr, void *arg, uint64_t txg); typedef int zil_replay_func_t(void *arg1, void *arg2, boolean_t byteswap); -typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, +typedef int zil_get_data_t(void *arg, uint64_t arg2, lr_write_t *lr, char *dbuf, struct lwb *lwb, zio_t *zio); extern int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, diff --git a/include/sys/zvol_impl.h b/include/sys/zvol_impl.h index 5137d21720..89fe598004 100644 --- a/include/sys/zvol_impl.h +++ b/include/sys/zvol_impl.h @@ -85,8 +85,8 @@ void zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len, boolean_t sync); void zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset, uint64_t size, int sync); -int zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, - zio_t *zio); +int zvol_get_data(void *arg, uint64_t arg2, lr_write_t *lr, char *buf, + struct lwb *lwb, zio_t *zio); int zvol_init_impl(void); void zvol_fini_impl(void); void zvol_wait_close(zvol_state_t *zv); diff --git a/module/zfs/zfs_log.c b/module/zfs/zfs_log.c index 4bb529f788..30d5c4821a 100644 --- a/module/zfs/zfs_log.c +++ b/module/zfs/zfs_log.c @@ -540,6 +540,7 @@ zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype, uint32_t blocksize = zp->z_blksz; itx_wr_state_t write_state; uintptr_t fsync_cnt; + uint64_t gen = 0; if (zil_replaying(zilog, tx) || zp->z_unlinked || zfs_xattr_owner_unlinked(zp)) { @@ -562,6 +563,9 @@ zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype, (void) tsd_set(zfs_fsyncer_key, (void *)(fsync_cnt - 1)); } + (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(ZTOZSB(zp)), &gen, + sizeof (gen)); + while (resid) { itx_t *itx; lr_write_t *lr; @@ -609,6 +613,7 @@ zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype, BP_ZERO(&lr->lr_blkptr); itx->itx_private = ZTOZSB(zp); + itx->itx_gen = gen; if (!(ioflag & (O_SYNC | O_DSYNC)) && (zp->z_sync_cnt == 0) && (fsync_cnt == 0)) diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c index 0af03e9233..8229bc9a93 100644 --- a/module/zfs/zfs_vnops.c +++ b/module/zfs/zfs_vnops.c @@ -740,7 +740,8 @@ 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) +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; @@ -751,6 +752,7 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio) dmu_buf_t *db; zgd_t *zgd; int error = 0; + uint64_t zp_gen; ASSERT3P(lwb, !=, NULL); ASSERT3P(zio, !=, NULL); @@ -769,6 +771,16 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio) 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 = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP); zgd->zgd_lwb = lwb; diff --git a/module/zfs/zil.c b/module/zfs/zil.c index 7b52f92492..d9c3042084 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -1744,7 +1744,8 @@ cont: * completed after "lwb_write_zio" completed. */ error = zilog->zl_get_data(itx->itx_private, - lrwb, dbuf, lwb, lwb->lwb_write_zio); + itx->itx_gen, lrwb, dbuf, lwb, + lwb->lwb_write_zio); if (error == EIO) { txg_wait_synced(zilog->zl_dmu_pool, txg); diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c index 44f9832ce8..b6609363f0 100644 --- a/module/zfs/zvol.c +++ b/module/zfs/zvol.c @@ -673,7 +673,8 @@ zvol_get_done(zgd_t *zgd, int error) * Get data to generate a TX_WRITE intent log record. */ int -zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio) +zvol_get_data(void *arg, uint64_t arg2, lr_write_t *lr, char *buf, + struct lwb *lwb, zio_t *zio) { zvol_state_t *zv = arg; uint64_t offset = lr->lr_offset;