diff options
| author | Brian Behlendorf <[email protected]> | 2011-07-22 13:55:27 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2011-07-22 15:24:57 -0700 |
| commit | beb982690293310b14a4835d3ffeb883ba03cc0a (patch) | |
| tree | 4a9cbed83508e2802e137c0af366c47c263d56c5 /module/zfs | |
| parent | f7ef846ea19809b2f373c0542741ac04c65a07cb (diff) | |
Fix txg_sync_thread deadlock
Update two kmem_alloc()'s in dbuf_dirty() to use KM_PUSHPAGE.
Because these functions are called from txg_sync_thread we
must ensure they don't reenter the zfs filesystem code via
the .writepage callback. This would result in a deadlock.
This deadlock is rare and has only been observed once under
an abusive mmap() write workload.
Signed-off-by: Brian Behlendorf <[email protected]>
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/dbuf.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index 1ebac4ee6..e166c81df 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -1095,7 +1095,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) dn->dn_dirtyctx = (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN); ASSERT(dn->dn_dirtyctx_firstset == NULL); - dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP); + dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_PUSHPAGE); } mutex_exit(&dn->dn_mtx); @@ -1172,7 +1172,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) * to make a copy of it so that the changes we make in this * transaction group won't leak out when we sync the older txg. */ - dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP); + dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_PUSHPAGE); list_link_init(&dr->dr_dirty_node); if (db->db_level == 0) { void *data_old = db->db_buf; |