mirror_zfs/module/zfs
Brian Behlendorf cfc9a5c88f Fix zpl_writepage() deadlock
Disable the normal reclaim path for zpl_putpage().  This ensures that
all memory allocations under this call path will never enter direct
reclaim.  If this were to happen the VM might try to write out
additional pages by calling zpl_putpage() again resulting in a
deadlock.

This sitution is typically handled in Linux by marking each offending
allocation GFP_NOFS.  However, since much of the code used is common
it makes more sense to use PF_MEMALLOC to flag the entire call tree.
Alternately, the code could be updated to pass the needed allocation
flags but that's a more invasive change.

The following example of the above described deadlock was triggered
by test 074 in the xfstest suite.

Call Trace:
 [<ffffffff814dcdb2>] down_write+0x32/0x40
 [<ffffffffa05af6e4>] dnode_new_blkid+0x94/0x2d0 [zfs]
 [<ffffffffa0597d66>] dbuf_dirty+0x556/0x750 [zfs]
 [<ffffffffa05987d1>] dmu_buf_will_dirty+0x81/0xd0 [zfs]
 [<ffffffffa059ee70>] dmu_write+0x90/0x170 [zfs]
 [<ffffffffa0611afe>] zfs_putpage+0x2ce/0x360 [zfs]
 [<ffffffffa062875e>] zpl_putpage+0x1e/0x60 [zfs]
 [<ffffffffa06287b2>] zpl_writepage+0x12/0x20 [zfs]
 [<ffffffff8115f907>] writeout+0xa7/0xd0
 [<ffffffff8115fa6b>] move_to_new_page+0x13b/0x170
 [<ffffffff8115fed4>] migrate_pages+0x434/0x4c0
 [<ffffffff811559ab>] compact_zone+0x4fb/0x780
 [<ffffffff81155ed1>] compact_zone_order+0xa1/0xe0
 [<ffffffff8115602c>] try_to_compact_pages+0x11c/0x190
 [<ffffffff811200bb>] __alloc_pages_nodemask+0x5eb/0x8b0
 [<ffffffff8115464a>] alloc_pages_current+0xaa/0x110
 [<ffffffff8111e36e>] __get_free_pages+0xe/0x50
 [<ffffffffa03f0e2f>] kv_alloc+0x3f/0xb0 [spl]
 [<ffffffffa03f11d9>] spl_kmem_cache_alloc+0x339/0x660 [spl]
 [<ffffffffa05950b3>] dbuf_create+0x43/0x370 [zfs]
 [<ffffffffa0596fb1>] __dbuf_hold_impl+0x241/0x480 [zfs]
 [<ffffffffa0597276>] dbuf_hold_impl+0x86/0xc0 [zfs]
 [<ffffffffa05977ff>] dbuf_hold_level+0x1f/0x30 [zfs]
 [<ffffffffa05a9dde>] dmu_tx_check_ioerr+0x4e/0x110 [zfs]
 [<ffffffffa05aa1f9>] dmu_tx_count_write+0x359/0x6f0 [zfs]
 [<ffffffffa05aa5df>] dmu_tx_hold_write+0x4f/0x70 [zfs]
 [<ffffffffa0611a6d>] zfs_putpage+0x23d/0x360 [zfs]
 [<ffffffffa062875e>] zpl_putpage+0x1e/0x60 [zfs]
 [<ffffffff811221f9>] write_cache_pages+0x1c9/0x4a0
 [<ffffffffa0628738>] zpl_writepages+0x18/0x20 [zfs]
 [<ffffffff81122521>] do_writepages+0x21/0x40
 [<ffffffff8119bbbd>] writeback_single_inode+0xdd/0x2c0
 [<ffffffff8119bfbe>] writeback_sb_inodes+0xce/0x180
 [<ffffffff8119c11b>] writeback_inodes_wb+0xab/0x1b0
 [<ffffffff8119c4bb>] wb_writeback+0x29b/0x3f0
 [<ffffffff8119c6cb>] wb_do_writeback+0xbb/0x240
 [<ffffffff811308ea>] bdi_forker_task+0x6a/0x310
 [<ffffffff8108ddf6>] kthread+0x96/0xa0

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #327
2011-07-19 16:17:01 -07:00
..
arc.c Add L2ARC tunables 2011-07-08 12:44:11 -07:00
bplist.c Fix gcc missing parenthesis warnings 2010-08-31 08:38:35 -07:00
bpobj.c Update to onnv_147 2010-08-26 14:24:34 -07:00
dbuf.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
ddt_zap.c Fix stack ddt_zap_lookup() 2011-05-31 12:17:27 -07:00
ddt.c Fix stack ddt_class_contains() 2011-05-31 12:17:27 -07:00
dmu_diff.c Update to onnv_147 2010-08-26 14:24:34 -07:00
dmu_object.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
dmu_objset.c Merge branch 'zpl' 2011-02-18 09:31:25 -08:00
dmu_send.c Add linux kernel memory support 2010-08-31 13:41:57 -07:00
dmu_traverse.c Revert "Fix stack traverse_visitbp()" 2011-05-31 12:17:27 -07:00
dmu_tx.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
dmu_zfetch.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
dmu.c Suppress large kmem_alloc() warning 2011-02-10 09:27:22 -08:00
dnode_sync.c Fix dbuf eviction assertion 2010-08-31 08:38:45 -07:00
dnode.c Fix zio_execute() deadlock 2011-07-19 11:55:42 -07:00
dsl_dataset.c Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
dsl_deadlist.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
dsl_deleg.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
dsl_dir.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
dsl_pool.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
dsl_prop.c Fix enum compiler warning 2011-02-23 12:52:51 -08:00
dsl_scan.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
dsl_synctask.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
fm.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
gzip.c Fix zmod.h usage in userspace 2010-08-31 08:38:46 -07:00
lzjb.c Fix stack lzjb 2010-08-31 08:38:49 -07:00
Makefile.in Implemented NFS export_operations. 2011-04-29 12:36:13 -07:00
metaslab.c Fix metaslab 2010-08-31 08:38:45 -07:00
refcount.c Fix gcc uninitialized variable warnings 2010-08-31 08:38:43 -07:00
rrwlock.c Enable rrwlock.c compilation 2010-12-07 16:05:25 -08:00
sa.c Enable zfs_znode compilation 2011-02-10 09:27:20 -08:00
sha256.c Add linux sha2 support 2010-08-31 13:41:59 -07:00
spa_boot.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
spa_config.c Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
spa_errlog.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
spa_history.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
spa_misc.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
spa.c Disable direct reclaim for z_wr_* threads 2011-05-06 15:26:26 -07:00
space_map.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
txg.c Fix ASSERTION(!dsl_pool_sync_context(tx->tx_pool)) 2011-04-07 09:52:16 -07:00
uberblock.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
unique.c Fix gcc ident pragma warnings 2010-08-27 15:34:02 -07:00
vdev_cache.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
vdev_disk.c Linux 2.6.37 compat, WRITE_FLUSH_FUA 2011-06-17 14:37:26 -07:00
vdev_file.c Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
vdev_label.c Fix gcc uninitialized variable warnings 2010-08-31 08:38:43 -07:00
vdev_mirror.c Fix gcc c90 compliance warnings 2010-08-27 15:28:32 -07:00
vdev_missing.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
vdev_queue.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
vdev_raidz.c Fix variables named current 2010-08-31 08:38:44 -07:00
vdev_root.c Fix gcc c90 compliance warnings 2010-08-27 15:28:32 -07:00
vdev.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
zap_leaf.c Fix gcc uninitialized variable warnings 2010-08-31 08:38:43 -07:00
zap_micro.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
zap.c Fix rw_init() usage 2010-08-31 08:38:46 -07:00
zfs_acl.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zfs_byteswap.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
zfs_debug.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
zfs_dir.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zfs_fm.c Initial zio delay timing 2010-10-12 14:55:02 -07:00
zfs_fuid.c Drop HAVE_XVATTR macros 2011-03-02 11:44:34 -08:00
zfs_ioctl.c Fix send/recv 'dataset is busy' errors 2011-07-15 16:37:19 -07:00
zfs_log.c Drop HAVE_XVATTR macros 2011-03-02 11:44:34 -08:00
zfs_onexit.c Add linux kernel device support 2010-08-31 13:41:50 -07:00
zfs_replay.c Use Linux ATTR_ versions 2011-03-03 11:29:15 -08:00
zfs_rlock.c Range lock performance improvements 2011-03-08 12:44:06 -08:00
zfs_sa.c Drop HAVE_XVATTR macros 2011-03-02 11:44:34 -08:00
zfs_vfsops.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zfs_vnops.c Fix mmap(2)/write(2)/read(2) deadlock 2011-07-19 11:55:42 -07:00
zfs_znode.c Renamed HAVE_SHARE ifdefs to HAVE_SMB_SHARE. 2011-07-06 09:20:28 -07:00
zil.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
zio_checksum.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
zio_compress.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
zio_inject.c Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
zio.c Make tgx_sync_thread zio's async 2011-05-31 12:17:27 -07:00
zle.c Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00
zpl_export.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zpl_file.c Fix zpl_writepage() deadlock 2011-07-19 16:17:01 -07:00
zpl_inode.c Improve fstat(2) performance 2011-07-11 09:11:22 -07:00
zpl_super.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zpl_xattr.c Linux compat 2.6.39: mount_nodev() 2011-07-01 13:36:39 -07:00
zrlock.c Export ZFS symbols needed by Lustre. 2010-09-17 16:24:15 -07:00
zvol.c Fix 'zfs set volsize=N pool/dataset' 2011-05-02 08:54:40 -07:00