Commit Graph

633258 Commits

Author SHA1 Message Date
Hannes Reinecke 91b385b490 target/tcm_fc: return detailed error in ft_sess_create()
Not every failure is due to out-of-memory; the ACLs might not be
set, too. So return a detailed error code in ft_sess_create()
instead of just a NULL pointer.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-21 01:19:42 -07:00
Hannes Reinecke b04bf5833e target/tcm_fc: print command pointer in debug message
When allocating a new command we should add the pointer to the
debug statements; that allows us to match this with other debug
statements for handling data.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-21 01:19:42 -07:00
Hannes Reinecke 1b4c59b7a1 target: fix potential race window in target_sess_cmd_list_waiting()
target_sess_cmd_list_waiting() might hit on a condition where
the kref for the command is already 0, but the destructor has
not been called yet (or is stuck in waiting for a spin lock).
Rather than leaving the command on the list we should explicitly
remove it to avoid race issues later on.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-21 01:19:41 -07:00
Nicholas Bellinger 61f36166c2 Revert "target: Fix residual overflow handling in target_complete_cmd_with_length"
This reverts commit c1ccbfe031.

Reverting this patch, as it incorrectly assumes the additional length
for INQUIRY in target_complete_cmd_with_length() is SCSI allocation
length, which breaks existing user-space code when SCSI allocation
length is smaller than additional length.

  root@scsi-mq:~# sg_inq --len=4 -vvvv /dev/sdb
  found bsg_major=253
  open /dev/sdb with flags=0x800
      inquiry cdb: 12 00 00 00 04 00
        duration=0 ms
      inquiry: pass-through requested 4 bytes (data-in) but got -28 bytes
      inquiry: pass-through can't get negative bytes, say it got none
      inquiry: got too few bytes (0)
  INQUIRY resid (32) should never exceed requested len=4
      inquiry: failed requesting 4 byte response: Malformed response to
               SCSI command [resid=32]

AFAICT the original change was not to address a specific host issue,
so go ahead and revert to original logic for now.

Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sumit Rai <sumitrai96@gmail.com>
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:34 -07:00
Dinesh Israni 926317de33 target: Don't override EXTENDED_COPY xcopy_pt_cmd SCSI status code
This patch addresses a bug where a local EXTENDED_COPY WRITE or READ
backend I/O request would always return SAM_STAT_CHECK_CONDITION,
even if underlying xcopy_pt_cmd->se_cmd generated a different
SCSI status code.

ESX host environments expect to hit SAM_STAT_RESERVATION_CONFLICT
for certain scenarios, and SAM_STAT_CHECK_CONDITION results in
non-retriable status for these cases.

Tested on v4.1.y with ESX v5.5u2+ with local IBLOCK backend copy.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Dinesh Israni <ddi@datera.io>
Signed-off-by: Dinesh Israni <ddi@datera.io>
Cc: Dinesh Israni <ddi@datera.io>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:33 -07:00
Nicholas Bellinger 449a137846 target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE
This patch addresses a bug where EXTENDED_COPY across multiple LUNs
results in a CHECK_CONDITION when the source + destination are not
located on the same physical node.

ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE
NOT REACHABLE to be returned when this occurs, in order to signal
fallback to local copy method.

As described in section 6.3.3 of spc4r22:

  "If it is not possible to complete processing of a segment because the
   copy manager is unable to establish communications with a copy target
   device, because the copy target device does not respond to INQUIRY,
   or because the data returned in response to INQUIRY indicates
   an unsupported logical unit, then the EXTENDED COPY command shall be
   terminated with CHECK CONDITION status, with the sense key set to
   COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE
   NOT REACHABLE."

Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Dinesh Israni <ddi@datera.io>
Signed-off-by: Dinesh Israni <ddi@datera.io>
Cc: Dinesh Israni <ddi@datera.io>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:32 -07:00
Nicholas Bellinger 527268df31 target: Re-add missing SCF_ACK_KREF assignment in v4.1.y
This patch fixes a regression in >= v4.1.y code where the original
SCF_ACK_KREF assignment in target_get_sess_cmd() was dropped upstream
in commit 054922bb, but the series for addressing TMR ABORT_TASK +
LUN_RESET with fabric session reinstatement in commit febe562c20 still
depends on this code in transport_cmd_finish_abort().

The regression manifests itself as a se_cmd->cmd_kref +1 leak, where
ABORT_TASK + LUN_RESET can hang indefinately for a specific I_T session
for drivers using SCF_ACK_KREF, resulting in hung kthreads.

This patch has been verified with v4.1.y code.

Reported-by: Vaibhav Tandon <vst@datera.io>
Tested-by: Vaibhav Tandon <vst@datera.io>
Cc: Vaibhav Tandon <vst@datera.io>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:31 -07:00
Varun Prakash 1a40f0a36f iscsi-target: fix iscsi cmd leak
If iscsi-target receives NOP OUT with ITT and TTT
set to 0xffffffff it allocates iscsi_cmd but
does not free the cmd, so free iscsi_cmd in this case.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:31 -07:00
Colin Ian King 3fc6a642e4 iscsi-target: fix spelling mistake "Unsolicitied" -> "Unsolicited"
Trivial fix to spelling mistakes in pr_debug message and comments

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:30 -07:00
Andy Grover 3d9b95558f target/user: Fix comments to not refer to data ring
We no longer use a ringbuffer for the data area, so this might cause
confusion. Just call it the data area.

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:23 -07:00
Andy Grover 554617b2bb target/user: Return an error if cmd data size is too large
Userspace should be implementing VPD B0 (Block Limits) to inform the
initiator of max data size, but just in case we do get a too-large request,
do what the spec says and return INVALID_CDB_FIELD.

Make sure to unlock udev->cmdr_lock before returning.

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:16 -07:00
Andy Grover 02eb924fab target/user: Use sense_reason_t in tcmu_queue_cmd_ring
Instead of using -ERROR-style returns, use sense_reason_t. This lets us
remove tcmu_pass_op(), and return more correct sense values.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:21:45 -07:00
Linus Torvalds 1001354ca3 Linux 4.9-rc1 2016-10-15 12:17:50 -07:00
Linus Torvalds df34d04a6f Merge tag 'befs-v4.9-rc1' of git://github.com/luisbg/linux-befs
Pull befs fixes from Luis de Bethencourt:
 "I recently took maintainership of the befs file system [0]. This is
  the first time I send you a git pull request, so please let me know if
  all the below is OK.

  Salah Triki and myself have been cleaning the code and fixing a few
  small bugs.

  Sorry I couldn't send this sooner in the merge window, I was waiting
  to have my GPG key signed by kernel members at ELCE in Berlin a few
  days ago."

[0] https://lkml.org/lkml/2016/7/27/502

* tag 'befs-v4.9-rc1' of git://github.com/luisbg/linux-befs: (39 commits)
  befs: befs: fix style issues in datastream.c
  befs: improve documentation in datastream.c
  befs: fix typos in datastream.c
  befs: fix typos in btree.c
  befs: fix style issues in super.c
  befs: fix comment style
  befs: add check for ag_shift in superblock
  befs: dump inode_size superblock information
  befs: remove unnecessary initialization
  befs: fix typo in befs_sb_info
  befs: add flags field to validate superblock state
  befs: fix typo in befs_find_key
  befs: remove unused BEFS_BT_PARMATCH
  fs: befs: remove ret variable
  fs: befs: remove in vain variable assignment
  fs: befs: remove unnecessary *befs_sb variable
  fs: befs: remove useless initialization to zero
  fs: befs: remove in vain variable assignment
  fs: befs: Insert NULL inode to dentry
  fs: befs: Remove useless calls to brelse in befs_find_brun_dblindirect
  ...
2016-10-15 12:09:13 -07:00
Linus Torvalds 9ffc66941d Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
2016-10-15 10:03:15 -07:00
Linus Torvalds 133d970e0d Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main MIPS pull request for 4.9:

  MIPS core arch code:
   - traps: 64bit kernels should read CP0_EBase 64bit
   - traps: Convert ebase to KSEG0
   - c-r4k: Drop bc_wback_inv() from icache flush
   - c-r4k: Split user/kernel flush_icache_range()
   - cacheflush: Use __flush_icache_user_range()
   - uprobes: Flush icache via kernel address
   - KVM: Use __local_flush_icache_user_range()
   - c-r4k: Fix flush_icache_range() for EVA
   - Fix -mabi=64 build of vdso.lds
   - VDSO: Drop duplicated -I*/-E* aflags
   - tracing: move insn_has_delay_slot to a shared header
   - tracing: disable uprobe/kprobe on compact branch instructions
   - ptrace: Fix regs_return_value for kernel context
   - Squash lines for simple wrapper functions
   - Move identification of VP(E) into proc.c from smp-mt.c
   - Add definitions of SYNC barrierstype values
   - traps: Ensure full EBase is written
   - tlb-r4k: If there are wired entries, don't use TLBINVF
   - Sanitise coherentio semantics
   - dma-default: Don't check hw_coherentio if device is non-coherent
   - Support per-device DMA coherence
   - Adjust MIPS64 CAC_BASE to reflect Config.K0
   - Support generating Flattened Image Trees (.itb)
   - generic: Introduce generic DT-based board support
   - generic: Convert SEAD-3 to a generic board
   - Enable hardened usercopy
   - Don't specify STACKPROTECTOR in defconfigs

  Octeon:
   - Delete dead code and files across the platform.
   - Change to use all memory into use by default.
   - Rename upper case variables in setup code to lowercase.
   - Delete legacy hack for broken bootloaders.
   - Leave maintaining the link state to the actual ethernet/PHY drivers.
   - Add DTS for D-Link DSR-500N.
   - Fix PCI interrupt routing on D-Link DSR-500N.

  Pistachio:
   - Remove ANDROID_TIMED_OUTPUT from defconfig

  TX39xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  TX49xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  txx9wdt:
   - Add missing clock (un)prepare calls for CCF

  BMIPS:
   - Add PW, GPIO SDHCI and NAND device node names
   - Support APPENDED_DTB
   - Add missing bcm97435svmb to DT_NONE
   - Rename bcm96358nb4ser to bcm6358-neufbox4-sercom
   - Add DT examples for BCM63268, BCM3368 and BCM6362
   - Add support for BCM3368 and BCM6362

  PCI
   - Reduce stack frame usage
   - Use struct list_head lists
   - Support for CONFIG_PCI_DOMAINS_GENERIC
   - Make pcibios_set_cache_line_size an initcall
   - Inline pcibios_assign_all_busses
   - Split pci.c into pci.c & pci-legacy.c
   - Introduce CONFIG_PCI_DRIVERS_LEGACY
   - Support generic drivers

  CPC
   - Convert bare 'unsigned' to 'unsigned int'
   - Avoid lock when MIPS CM >= 3 is present

  GIC:
   - Delete unused file smp-gic.c

  mt7620:
   - Delete unnecessary assignment for the field "owner" from PCI

  BCM63xx:
   - Let clk_disable() return immediately if clk is NULL

  pm-cps:
   - Change FSB workaround to CPU blacklist
   - Update comments on barrier instructions
   - Use MIPS standard lightweight ordering barrier
   - Use MIPS standard completion barrier
   - Remove selection of sync types
   - Add MIPSr6 CPU support
   - Support CM3 changes to Coherence Enable Register

  SMP:
   - Wrap call to mips_cpc_lock_other in mips_cm_lock_other
   - Introduce mechanism for freeing and allocating IPIs

  cpuidle:
   - cpuidle-cps: Enable use with MIPSr6 CPUs.

  SEAD3:
   - Rewrite to use DT and generic kernel feature.

  USB:
   - host: ehci-sead3: Remove SEAD-3 EHCI code

  FBDEV:
   - cobalt_lcdfb: Drop SEAD3 support

  dt-bindings:
   -  Document a binding for simple ASCII LCDs

  auxdisplay:
   - img-ascii-lcd: driver for simple ASCII LCD displays

  irqchip i8259:
   - i8259: Add domain before mapping parent irq
   - i8259: Allow platforms to override poll function
   - i8259: Remove unused i8259A_irq_pending

  Malta:
   - Rewrite to use DT

  of/platform:
   - Probe "isa" busses by default

  CM:
   - Print CM error reports upon bus errors

  Module:
   - Migrate exception table users off module.h and onto extable.h
   - Make various drivers explicitly non-modular:
   - Audit and remove any unnecessary uses of module.h

  mailmap:
   - Canonicalize to Qais' current email address.

  Documentation:
   - MIPS supports HAVE_REGS_AND_STACK_ACCESS_API

  Loongson1C:
   - Add CPU support for Loongson1C
   - Add board support
   - Add defconfig
   - Add RTC support for Loongson1C board

  All this except one Documentation fix has sat in linux-next and has
  survived Imagination's automated build test system"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits)
  Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API
  MIPS: ptrace: Fix regs_return_value for kernel context
  MIPS: VDSO: Drop duplicated -I*/-E* aflags
  MIPS: Fix -mabi=64 build of vdso.lds
  MIPS: Enable hardened usercopy
  MIPS: generic: Convert SEAD-3 to a generic board
  MIPS: generic: Introduce generic DT-based board support
  MIPS: Support generating Flattened Image Trees (.itb)
  MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0
  MIPS: Print CM error reports upon bus errors
  MIPS: Support per-device DMA coherence
  MIPS: dma-default: Don't check hw_coherentio if device is non-coherent
  MIPS: Sanitise coherentio semantics
  MIPS: PCI: Support generic drivers
  MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY
  MIPS: PCI: Split pci.c into pci.c & pci-legacy.c
  MIPS: PCI: Inline pcibios_assign_all_busses
  MIPS: PCI: Make pcibios_set_cache_line_size an initcall
  MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC
  MIPS: PCI: Use struct list_head lists
  ...
2016-10-15 09:26:12 -07:00
Linus Torvalds 050aaeab99 Merge tag 'sound-fix-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
 "Just a few trivial small fixes"

* tag 'sound-fix-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: line6: fix a crash in line6_hwdep_write()
  ALSA: seq: fix passing wrong pointer in function call of compatibility layer
  ALSA: hda - Fix a failure of micmute led when having multi adcs
  ALSA: line6: Fix POD X3 Live audio input
2016-10-15 09:20:54 -07:00
Linus Torvalds b26b5ef5ec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more misc uaccess and vfs updates from Al Viro:
 "The rest of the stuff from -next (more uaccess work) + assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  score: traps: Add missing include file to fix build error
  fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
  fs/super.c: fix race between freeze_super() and thaw_super()
  overlayfs: Fix setting IOP_XATTR flag
  iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()
  blackfin: no access_ok() for __copy_{to,from}_user()
  arm64: don't zero in __copy_from_user{,_inatomic}
  arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()
  arc: don't leak bits of kernel stack into coredump
  alpha: get rid of tail-zeroing in __copy_user()
2016-10-14 18:19:05 -07:00
Linus Torvalds 87dbe42a16 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
 "Including:

   - nine bug fixes for stable. Some of these we found at the recent two
     weeks of SMB3 test events/plugfests.

   - significant improvements in reconnection (e.g. if server or network
     crashes) especially when mounted with "persistenthandles" or to
     server which advertises Continuous Availability on the share.

   - a new mount option "idsfromsid" which improves POSIX compatibility
     in some cases (when winbind not configured e.g.) by better (and
     faster) fetching uid/gid from acl (when "cifsacl" mount option is
     enabled). NB: we are almost complete work on "cifsacl" (querying
     mode/uid/gid from ACL) for SMB3, but SMB3 support for cifsacl is
     not included in this set.

   - improved handling for SMB3 "credits" (even if server is buggy)

  Still working on two sets of changes:

   - cifsacl enablement for SMB3

   - cleanup of RFC1001 length calculation (so we can handle encryption
     and multichannel and RDMA)

  And a couple of new bugs were reported recently (unrelated to above)
  so will probably have another merge request next week"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (21 commits)
  CIFS: Retrieve uid and gid from special sid if enabled
  CIFS: Add new mount option to set owner uid and gid from special sids in acl
  CIFS: Reset read oplock to NONE if we have mandatory locks after reopen
  CIFS: Fix persistent handles re-opening on reconnect
  SMB2: Separate RawNTLMSSP authentication from SMB2_sess_setup
  SMB2: Separate Kerberos authentication from SMB2_sess_setup
  Expose cifs module parameters in sysfs
  Cleanup missing frees on some ioctls
  Enable previous version support
  Do not send SMB3 SET_INFO request if nothing is changing
  SMB3: Add mount parameter to allow user to override max credits
  fs/cifs: reopen persistent handles on reconnect
  Clarify locking of cifs file and tcon structures and make more granular
  Fix regression which breaks DFS mounting
  fs/cifs: keep guid when assigning fid to fileinfo
  SMB3: GUIDs should be constructed as random but valid uuids
  Set previous session id correctly on SMB3 reconnect
  cifs: Limit the overall credit acquired
  Display number of credits available
  Add way to query creation time of file via cifs xattr
  ...
2016-10-14 17:47:31 -07:00
Linus Torvalds d3304cadb2 Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Some fixes from Omar and Dave Sterba for our new free space tree.

  This isn't heavily used yet, but as we move toward making it the new
  default we wanted to nail down an endian bug"

* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: tests: uninline member definitions in free_space_extent
  btrfs: tests: constify free space extent specs
  Btrfs: expand free space tree sanity tests to catch endianness bug
  Btrfs: fix extent buffer bitmap tests on big-endian systems
  Btrfs: catch invalid free space trees
  Btrfs: fix mount -o clear_cache,space_cache=v2
  Btrfs: fix free space tree bitmaps on big-endian systems
2016-10-14 17:44:56 -07:00
Al Viro 2692a71bbd Merge branch 'work.uaccess' into for-linus 2016-10-14 20:42:44 -04:00
Guenter Roeck 7041c57709 score: traps: Add missing include file to fix build error
score images fail to build as follows.

arch/score/kernel/traps.c: In function 'show_stack':
arch/score/kernel/traps.c:55:3: error:
	implicit declaration of function '__get_user'

__get_user() is declared in asm/uaccess.h, which was previously included
through asm/module.h.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 88dd4a748d ("score: separate extable.h, switch module.h to it")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:42:28 -04:00
Oleg Nesterov f1a9622037 fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
sb_wait_write()->percpu_rwsem_release() fools lockdep to avoid the
false-positives. Now that xfs was fixed by Dave's commit dbad7c9930
("xfs: stop holding ILOCK over filldir callbacks") we can remove it and
change freeze_super() and thaw_super() to run with s_writers.rw_sem locks
held; we add two trivial helpers for that, lockdep_sb_freeze_release()
and lockdep_sb_freeze_acquire().

xfstests-dev/check `grep -il freeze tests/*/???` does not trigger any
warning from lockdep.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:41:59 -04:00
Linus Torvalds 1a892b485f Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
 "This update contains fixes to the "use mounter's permission to access
  underlying layers" area, and miscellaneous other fixes and cleanups.

  No new features this time"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: use vfs_get_link()
  vfs: add vfs_get_link() helper
  ovl: use generic_readlink
  ovl: explain error values when removing acl from workdir
  ovl: Fix info leak in ovl_lookup_temp()
  ovl: during copy up, switch to mounter's creds early
  ovl: lookup: do getxattr with mounter's permission
  ovl: copy_up_xattr(): use strnlen
2016-10-14 17:23:33 -07:00
Oleg Nesterov 89f39af129 fs/super.c: fix race between freeze_super() and thaw_super()
Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than
frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which
drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering.

In this case thaw_super() will wrongly call s_op->unfreeze_fs() before
it was actually frozen, and call sb_freeze_unlock() which leads to the
unbalanced percpu_up_write(). Unfortunately lockdep can't detect this,
so this triggers misc BUG_ON()'s in kernel/rcu/sync.c.

Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:00:34 -04:00