mirror_zfs/module/spl
Li Wei 4be55565fe Fix stack overflow in vn_rdwr() due to memory reclaim
Unless __GFP_IO and __GFP_FS are removed from the file mapping gfp
mask we may enter memory reclaim during IO.  In this case shrink_slab()
entered another file system which is notoriously hungry for stack.
This additional stack usage may cause a stack overflow.  This patch
removes __GFP_IO and __GFP_FS from the mapping gfp mask of each file
during vn_open() to avoid any reclaim in the vn_rdwr() IO path.  The
original mask is then restored at vn_close() time.  Hats off to the
loop driver which does something similiar for the same reason.

  [...]
  shrink_slab+0xdc/0x153
  try_to_free_pages+0x1da/0x2d7
  __alloc_pages+0x1d7/0x2da
  do_generic_mapping_read+0x2c9/0x36f
  file_read_actor+0x0/0x145
  __generic_file_aio_read+0x14f/0x19b
  generic_file_aio_read+0x34/0x39
  do_sync_read+0xc7/0x104
  vfs_read+0xcb/0x171
  :spl:vn_rdwr+0x2b8/0x402
  :zfs:vdev_file_io_start+0xad/0xe1
  [...]

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-08-12 09:34:33 -07:00
..
.gitignore sun-misc-gitignore 2010-01-08 09:37:54 -08:00
Makefile.in Add basic credential support and splat tests. 2009-07-27 17:18:59 -07:00
spl-atomic.c Public Release Prep 2010-05-17 15:18:00 -07:00
spl-condvar.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-cred.c Public Release Prep 2010-05-17 15:18:00 -07:00
spl-debug.c Remove deadcode caused by removal of format1 arg 2010-07-21 16:31:42 -07:00
spl-err.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-generic.c Display DEBUG keyword during module load when --enable-debug is used. 2010-07-20 15:31:03 -07:00
spl-kmem.c Strfree() should call kfree() not kmem_free() 2010-07-30 22:20:58 -07:00
spl-kobj.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-kstat.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-module.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-mutex.c Public Release Prep 2010-05-17 15:18:00 -07:00
spl-proc.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-rwlock.c Public Release Prep 2010-05-17 15:18:00 -07:00
spl-taskq.c Fix taskq code to not drop tasks when TQ_SLEEP is used. 2010-08-02 11:20:31 -07:00
spl-thread.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00
spl-time.c Minor 32-bit fix cast to hrtime_t before the mutliply. 2010-05-23 09:51:17 -07:00
spl-vnode.c Fix stack overflow in vn_rdwr() due to memory reclaim 2010-08-12 09:34:33 -07:00
spl-xdr.c Prefix all SPL debug macros with 'S' 2010-07-20 13:30:40 -07:00