linux_dsm_epyc7002/drivers/base
J. Bruce Fields b21996e36c locks: break delegations on unlink
We need to break delegations on any operation that changes the set of
links pointing to an inode.  Start with unlink.

Such operations also hold the i_mutex on a parent directory.  Breaking a
delegation may require waiting for a timeout (by default 90 seconds) in
the case of a unresponsive NFS client.  To avoid blocking all directory
operations, we therefore drop locks before waiting for the delegation.
The logic then looks like:

	acquire locks
	...
	test for delegation; if found:
		take reference on inode
		release locks
		wait for delegation break
		drop reference on inode
		retry

It is possible this could never terminate.  (Even if we take precautions
to prevent another delegation being acquired on the same inode, we could
get a different inode on each retry.)  But this seems very unlikely.

The initial test for a delegation happens after the lock on the target
inode is acquired, but the directory inode may have been acquired
further up the call stack.  We therefore add a "struct inode **"
argument to any intervening functions, which we use to pass the inode
back up to the caller in the case it needs a delegation synchronously
broken.

Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:42 -05:00
..
power ACPI and power management updates for 3.12-rc1 2013-09-03 15:59:39 -07:00
regmap Driver core patches for 3.12-rc1 2013-09-03 11:37:15 -07:00
attribute_container.c drivers: avoid format string in dev_set_name 2013-07-03 16:07:41 -07:00
base.h driver core: bus_type: add drv_groups 2013-08-12 15:33:31 -07:00
bus.c driver core: add #include <linux/sysfs.h> to core files. 2013-08-27 10:24:15 -07:00
class.c sysfs.h: remove attr_name() macro 2013-08-22 10:25:34 -07:00
core.c driver core : Fix use after free of dev->parent in device_shutdown 2013-09-26 14:46:11 -07:00
cpu.c ACPI and power management updates for 3.12-rc1 2013-09-03 15:59:39 -07:00
dd.c PM / Runtime: Idle devices asynchronously after probe|release 2013-04-11 12:42:52 -07:00
devres.c Linux 3.9-rc3 2013-03-17 19:40:50 -07:00
devtmpfs.c locks: break delegations on unlink 2013-11-09 00:16:42 -05:00
dma-buf.c dma-buf: Expose buffer size to userspace (v2) 2013-09-10 11:36:45 +05:30
dma-coherent.c drivers: dma-coherent: Fix typo in dma_mmap_from_coherent documentation 2012-10-23 14:05:32 +02:00
dma-contiguous.c drivers: dma-contiguous: clean source code and prepare for device tree 2013-08-27 09:18:29 +02:00
dma-mapping.c [media] dma-mapping: fix dma_common_get_sgtable() conditional compilation 2012-11-27 09:42:31 -02:00
driver.c driver core: add #include <linux/sysfs.h> to core files. 2013-08-27 10:24:15 -07:00
firmware_class.c firmware loader: fix pending_fw_head list corruption 2013-08-30 12:04:27 -07:00
firmware.c firmware: change firmware_kset to firmware_kobj 2008-01-24 20:40:23 -08:00
hypervisor.c drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required. 2011-10-31 19:31:38 -04:00
init.c driver-core: implement 'sysdev' functionality for regular devices and buses 2011-12-14 14:29:38 -08:00
isa.c dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) 2009-04-07 08:31:12 -07:00
Kconfig Merge remote-tracking branch 'dma-public/for-v3.12-cma-dma' into for-next 2013-07-15 11:13:54 +02:00
Makefile Merge remote-tracking branch 'origin/next' into kvm-ppc-next 2013-08-29 00:41:59 +02:00
map.c
memory.c ACPI and power management updates for 3.12-rc1 2013-09-03 15:59:39 -07:00
module.c driver core: module.c: Use kasprintf 2010-05-21 09:37:29 -07:00
node.c thp: account anon transparent huge pages into NR_ANON_PAGES 2013-09-12 15:38:03 -07:00
pinctrl.c drivers: pinctrl sleep and idle states in the core 2013-06-16 11:56:52 +02:00
platform.c driver-core: platform: convert bus code to use dev_groups 2013-08-23 14:43:44 -07:00
reservation.c reservation: cross-device reservation support, v4 2013-06-28 12:02:15 +10:00
soc.c mode_t whack-a-mole: ->is_visible() returns umode_t... 2012-05-29 23:28:42 -04:00
syscore.c PM: Reintroduce dropped call to check_wakeup_irqs 2011-07-11 10:51:49 +02:00
topology.c cpu topology: remove stale arch_provides_topology_pointers and define_siblings_show_map/list() 2013-07-29 13:12:45 -07:00
transport_class.c drivers/base: transport_class explicitly requires EXPORT_SYMBOL 2011-10-31 19:31:15 -04:00