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2016-10-27genetlink: mark families as __ro_after_initJohannes Berg
Now genl_register_family() is the only thing (other than the users themselves, perhaps, but I didn't find any doing that) writing to the family struct. In all families that I found, genl_register_family() is only called from __init functions (some indirectly, in which case I've add __init annotations to clarifly things), so all can actually be marked __ro_after_init. This protects the data structure from accidental corruption. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27genetlink: statically initialize familiesJohannes Berg
Instead of providing macros/inline functions to initialize the families, make all users initialize them statically and get rid of the macros. This reduces the kernel code size by about 1.6k on x86-64 (with allyesconfig). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27genetlink: no longer support using static family IDsJohannes Berg
Static family IDs have never really been used, the only use case was the workaround I introduced for those users that assumed their family ID was also their multicast group ID. Additionally, because static family IDs would never be reserved by the generic netlink code, using a relatively low ID would only work for built-in families that can be registered immediately after generic netlink is started, which is basically only the control family (apart from the workaround code, which I also had to add code for so it would reserve those IDs) Thus, anything other than GENL_ID_GENERATE is flawed and luckily not used except in the cases I mentioned. Move those workarounds into a few lines of code, and then get rid of GENL_ID_GENERATE entirely, making it more robust. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13Merge tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "Highlights include: Stable bugfixes: - sunrpc: fix writ espace race causing stalls - NFS: Fix inode corruption in nfs_prime_dcache() - NFSv4: Don't report revoked delegations as valid in nfs_have_delegation() - NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid - NFSv4: Open state recovery must account for file permission changes - NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic Features: - Add support for tracking multiple layout types with an ordered list - Add support for using multiple backchannel threads on the client - Add support for pNFS file layout session trunking - Delay xprtrdma use of DMA API (for device driver removal) - Add support for xprtrdma remote invalidation - Add support for larger xprtrdma inline thresholds - Use a scatter/gather list for sending xprtrdma RPC calls - Add support for the CB_NOTIFY_LOCK callback - Improve hashing sunrpc auth_creds by using both uid and gid Bugfixes: - Fix xprtrdma use of DMA API - Validate filenames before adding to the dcache - Fix corruption of xdr->nwords in xdr_copy_to_scratch - Fix setting buffer length in xdr_set_next_buffer() - Don't deadlock the state manager on the SEQUENCE status flags - Various delegation and stateid related fixes - Retry operations if an interrupted slot receives EREMOTEIO - Make nfs boot time y2038 safe" * tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (100 commits) NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic fs: nfs: Make nfs boot time y2038 safe sunrpc: replace generic auth_cred hash with auth-specific function sunrpc: add RPCSEC_GSS hash_cred() function sunrpc: add auth_unix hash_cred() function sunrpc: add generic_auth hash_cred() function sunrpc: add hash_cred() function to rpc_authops struct Retry operation on EREMOTEIO on an interrupted slot pNFS: Fix atime updates on pNFS clients sunrpc: queue work on system_power_efficient_wq NFSv4.1: Even if the stateid is OK, we may need to recover the open modes NFSv4: If recovery failed for a specific open stateid, then don't retry NFSv4: Fix retry issues with nfs41_test/free_stateid NFSv4: Open state recovery must account for file permission changes NFSv4: Mark the lock and open stateids as invalid after freeing them NFSv4: Don't test open_stateid unless it is set NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid NFS: Always call nfs_inode_find_state_and_recover() when revoking a delegation NFSv4: Fix a race when updating an open_stateid NFSv4: Fix a race in nfs_inode_reclaim_delegation() ...
2016-10-13Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd updates from Bruce Fields: "Some RDMA work and some good bugfixes, and two new features that could benefit from user testing: - Anna Schumacker contributed a simple NFSv4.2 COPY implementation. COPY is already supported on the client side, so a call to copy_file_range() on a recent client should now result in a server-side copy that doesn't require all the data to make a round trip to the client and back. - Jeff Layton implemented callbacks to notify clients when contended locks become available, which should reduce latency on workloads with contended locks" * tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux: NFSD: Implement the COPY call nfsd: handle EUCLEAN nfsd: only WARN once on unmapped errors exportfs: be careful to only return expected errors. nfsd4: setclientid_confirm with unmatched verifier should fail nfsd: randomize SETCLIENTID reply to help distinguish servers nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies nfs: add a new NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK constant nfsd: add a LRU list for blocked locks nfsd: have nfsd4_lock use blocking locks for v4.1+ locks nfsd: plumb in a CB_NOTIFY_LOCK operation NFSD: fix corruption in notifier registration svcrdma: support Remote Invalidation svcrdma: Server-side support for rpcrdma_connect_private rpcrdma: RDMA/CM private message data structure svcrdma: Skip put_page() when send_reply() fails svcrdma: Tail iovec leaves an orphaned DMA mapping nfsd: fix dprintk in nfsd4_encode_getdeviceinfo nfsd: eliminate cb_minorversion field nfsd: don't set a FL_LAYOUT lease for flexfiles layouts
2016-10-13Merge tag 'xfs-reflink-for-linus-4.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs < XFS has gained super CoW powers! > ---------------------------------- \ ^__^ \ (oo)\_______ (__)\ )\/\ ||----w | || || Pull XFS support for shared data extents from Dave Chinner: "This is the second part of the XFS updates for this merge cycle. This pullreq contains the new shared data extents feature for XFS. Given the complexity and size of this change I am expecting - like the addition of reverse mapping last cycle - that there will be some follow-up bug fixes and cleanups around the -rc3 stage for issues that I'm sure will show up once the code hits a wider userbase. What it is: At the most basic level we are simply adding shared data extents to XFS - i.e. a single extent on disk can now have multiple owners. To do this we have to add new on-disk features to both track the shared extents and the number of times they've been shared. This is done by the new "refcount" btree that sits in every allocation group. When we share or unshare an extent, this tree gets updated. Along with this new tree, the reverse mapping tree needs to be updated to track each owner or a shared extent. This also needs to be updated ever share/unshare operation. These interactions at extent allocation and freeing time have complex ordering and recovery constraints, so there's a significant amount of new intent-based transaction code to ensure that operations are performed atomically from both the runtime and integrity/crash recovery perspectives. We also need to break sharing when writes hit a shared extent - this is where the new copy-on-write implementation comes in. We allocate new storage and copy the original data along with the overwrite data into the new location. We only do this for data as we don't share metadata at all - each inode has it's own metadata that tracks the shared data extents, the extents undergoing CoW and it's own private extents. Of course, being XFS, nothing is simple - we use delayed allocation for CoW similar to how we use it for normal writes. ENOSPC is a significant issue here - we build on the reservation code added in 4.8-rc1 with the reverse mapping feature to ensure we don't get spurious ENOSPC issues part way through a CoW operation. These mechanisms also help minimise fragmentation due to repeated CoW operations. To further reduce fragmentation overhead, we've also introduced a CoW extent size hint, which indicates how large a region we should allocate when we execute a CoW operation. With all this functionality in place, we can hook up .copy_file_range, .clone_file_range and .dedupe_file_range and we gain all the capabilities of reflink and other vfs provided functionality that enable manipulation to shared extents. We also added a fallocate mode that explicitly unshares a range of a file, which we implemented as an explicit CoW of all the shared extents in a file. As such, it's a huge chunk of new functionality with new on-disk format features and internal infrastructure. It warns at mount time as an experimental feature and that it may eat data (as we do with all new on-disk features until they stabilise). We have not released userspace suport for it yet - userspace support currently requires download from Darrick's xfsprogs repo and build from source, so the access to this feature is really developer/tester only at this point. Initial userspace support will be released at the same time the kernel with this code in it is released. The new code causes 5-6 new failures with xfstests - these aren't serious functional failures but things the output of tests changing slightly due to perturbations in layouts, space usage, etc. OTOH, we've added 150+ new tests to xfstests that specifically exercise this new functionality so it's got far better test coverage than any functionality we've previously added to XFS. Darrick has done a pretty amazing job getting us to this stage, and special mention also needs to go to Christoph (review, testing, improvements and bug fixes) and Brian (caught several intricate bugs during review) for the effort they've also put in. Summary: - unshare range (FALLOC_FL_UNSHARE) support for fallocate - copy-on-write extent size hints (FS_XFLAG_COWEXTSIZE) for fsxattr interface - shared extent support for XFS - copy-on-write support for shared extents - copy_file_range support - clone_file_range support (implements reflink) - dedupe_file_range support - defrag support for reverse mapping enabled filesystems" * tag 'xfs-reflink-for-linus-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (71 commits) xfs: convert COW blocks to real blocks before unwritten extent conversion xfs: rework refcount cow recovery error handling xfs: clear reflink flag if setting realtime flag xfs: fix error initialization xfs: fix label inaccuracies xfs: remove isize check from unshare operation xfs: reduce stack usage of _reflink_clear_inode_flag xfs: check inode reflink flag before calling reflink functions xfs: implement swapext for rmap filesystems xfs: refactor swapext code xfs: various swapext cleanups xfs: recognize the reflink feature bit xfs: simulate per-AG reservations being critically low xfs: don't mix reflink and DAX mode for now xfs: check for invalid inode reflink flags xfs: set a default CoW extent size of 32 blocks xfs: convert unwritten status of reverse mappings for shared files xfs: use interval query for rmap alloc operations on shared files xfs: add shared rmap map/unmap/convert log item types xfs: increase log reservations for reflink ...
2016-10-13Merge git://www.linux-watchdog.org/linux-watchdogLinus Torvalds
Pull watchdog updates from Wim Van Sebroeck: - a new watchdog pretimeout governor framework - support to upload the firmware on the ziirave_wdt - several fixes and cleanups * git://www.linux-watchdog.org/linux-watchdog: (26 commits) watchdog: imx2_wdt: add pretimeout function support watchdog: softdog: implement pretimeout support watchdog: pretimeout: add pretimeout_available_governors attribute watchdog: pretimeout: add option to select a pretimeout governor in runtime watchdog: pretimeout: add panic pretimeout governor watchdog: pretimeout: add noop pretimeout governor watchdog: add watchdog pretimeout governor framework watchdog: hpwdt: add support for iLO5 fs: compat_ioctl: add pretimeout functions for watchdogs watchdog: add pretimeout support to the core watchdog: imx2_wdt: use preferred BIT macro instead of open coded values watchdog: st_wdt: Remove support for obsolete platforms watchdog: bindings: Remove obsolete platforms from dt doc. watchdog: mt7621_wdt: Remove assignment of dev pointer watchdog: rt2880_wdt: Remove assignment of dev pointer watchdog: constify watchdog_ops structures watchdog: tegra: constify watchdog_ops structures watchdog: iTCO_wdt: constify iTCO_wdt_pm structure watchdog: cadence_wdt: Fix the suspend resume watchdog: txx9wdt: Add missing clock (un)prepare calls for CCF ...
2016-10-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - a few block updates that fell in my lap - lib/ updates - checkpatch - autofs - ipc - a ton of misc other things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits) mm: split gfp_mask and mapping flags into separate fields fs: use mapping_set_error instead of opencoded set_bit treewide: remove redundant #include <linux/kconfig.h> hung_task: allow hung_task_panic when hung_task_warnings is 0 kthread: add kerneldoc for kthread_create() kthread: better support freezable kthread workers kthread: allow to modify delayed kthread work kthread: allow to cancel kthread work kthread: initial support for delayed kthread work kthread: detect when a kthread work is used by more workers kthread: add kthread_destroy_worker() kthread: add kthread_create_worker*() kthread: allow to call __kthread_create_on_node() with va_list args kthread/smpboot: do not park in kthread_create_on_cpu() kthread: kthread worker API cleanup kthread: rename probe_kthread_data() to kthread_probe_data() scripts/tags.sh: enable code completion in VIM mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping kdump, vmcoreinfo: report memory sections virtual addresses ipc/sem.c: add cond_resched in exit_sme ...
2016-10-11fs: use mapping_set_error instead of opencoded set_bitMichal Hocko
The mapping_set_error() helper sets the correct AS_ flag for the mapping so there is no reason to open code it. Use the helper directly. [akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO] Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11treewide: remove redundant #include <linux/kconfig.h>Masahiro Yamada
Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: cap initial pipe capacity according to pipe-max-size limitMichael Kerrisk (man-pages)
This is a patch that provides behavior that is more consistent, and probably less surprising to users. I consider the change optional, and welcome opinions about whether it should be applied. By default, pipes are created with a capacity of 64 kiB. However, /proc/sys/fs/pipe-max-size may be set smaller than this value. In this scenario, an unprivileged user could thus create a pipe whose initial capacity exceeds the limit. Therefore, it seems logical to cap the initial pipe capacity according to the value of pipe-max-size. The test program shown earlier in this patch series can be used to demonstrate the effect of the change brought about with this patch: # cat /proc/sys/fs/pipe-max-size 1048576 # sudo -u mtk ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 65536 # echo 10000 > /proc/sys/fs/pipe-max-size # cat /proc/sys/fs/pipe-max-size 16384 # sudo -u mtk ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 16384 # ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 65536 The last two executions of 'test_F_SETPIPE_SZ' show that pipe-max-size caps the initial allocation for a new pipe for unprivileged users, but not for privileged users. Link: http://lkml.kernel.org/r/31dc7064-2a17-9c5b-1df1-4e3012ee992c@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: make account_pipe_buffers() return a value, and use itMichael Kerrisk (man-pages)
This is an optional patch, to provide a small performance improvement. Alter account_pipe_buffers() so that it returns the new value in user->pipe_bufs. This means that we can refactor too_many_pipe_buffers_soft() and too_many_pipe_buffers_hard() to avoid the costs of repeated use of atomic_long_read() to get the value user->pipe_bufs. Link: http://lkml.kernel.org/r/93e5f193-1e5e-3e1f-3a20-eae79b7e1310@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: fix limit checking in alloc_pipe_info()Michael Kerrisk (man-pages)
The limit checking in alloc_pipe_info() (used by pipe(2) and when opening a FIFO) has the following problems: (1) When checking capacity required for the new pipe, the checks against the limit in /proc/sys/fs/pipe-user-pages-{soft,hard} are made against existing consumption, and exclude the memory required for the new pipe capacity. As a consequence: (1) the memory allocation throttling provided by the soft limit does not kick in quite as early as it should, and (2) the user can overrun the hard limit. (2) As currently implemented, accounting and checking against the limits is done as follows: (a) Test whether the user has exceeded the limit. (b) Make new pipe buffer allocation. (c) Account new allocation against the limits. This is racey. Multiple processes may pass point (a) simultaneously, and then allocate pipe buffers that are accounted for only in step (c). The race means that the user's pipe buffer allocation could be pushed over the limit (by an arbitrary amount, depending on how unlucky we were in the race). [Thanks to Vegard Nossum for spotting this point, which I had missed.] This patch addresses the above problems as follows: * Alter the checks against limits to include the memory required for the new pipe. * Re-order the accounting step so that it precedes the buffer allocation. If the accounting step determines that a limit has been reached, revert the accounting and cause the operation to fail. Link: http://lkml.kernel.org/r/8ff3e9f9-23f6-510c-644f-8e70cd1c0bd9@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: simplify logic in alloc_pipe_info()Michael Kerrisk (man-pages)
Replace an 'if' block that covers most of the code in this function with a 'goto'. This makes the code a little simpler to read, and also simplifies the next patch (fix limit checking in alloc_pipe_info()) Link: http://lkml.kernel.org/r/aef030c1-0257-98a9-4988-186efa48530c@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: fix limit checking in pipe_set_size()Michael Kerrisk (man-pages)
The limit checking in pipe_set_size() (used by fcntl(F_SETPIPE_SZ)) has the following problems: (1) When increasing the pipe capacity, the checks against the limits in /proc/sys/fs/pipe-user-pages-{soft,hard} are made against existing consumption, and exclude the memory required for the increased pipe capacity. The new increase in pipe capacity can then push the total memory used by the user for pipes (possibly far) over a limit. This can also trigger the problem described next. (2) The limit checks are performed even when the new pipe capacity is less than the existing pipe capacity. This can lead to problems if a user sets a large pipe capacity, and then the limits are lowered, with the result that the user will no longer be able to decrease the pipe capacity. (3) As currently implemented, accounting and checking against the limits is done as follows: (a) Test whether the user has exceeded the limit. (b) Make new pipe buffer allocation. (c) Account new allocation against the limits. This is racey. Multiple processes may pass point (a) simultaneously, and then allocate pipe buffers that are accounted for only in step (c). The race means that the user's pipe buffer allocation could be pushed over the limit (by an arbitrary amount, depending on how unlucky we were in the race). [Thanks to Vegard Nossum for spotting this point, which I had missed.] This patch addresses the above problems as follows: * Perform checks against the limits only when increasing a pipe's capacity; an unprivileged user can always decrease a pipe's capacity. * Alter the checks against limits to include the memory required for the new pipe capacity. * Re-order the accounting step so that it precedes the buffer allocation. If the accounting step determines that a limit has been reached, revert the accounting and cause the operation to fail. The program below can be used to demonstrate problems 1 and 2, and the effect of the fix. The program takes one or more command-line arguments. The first argument specifies the number of pipes that the program should create. The remaining arguments are, alternately, pipe capacities that should be set using fcntl(F_SETPIPE_SZ), and sleep intervals (in seconds) between the fcntl() operations. (The sleep intervals allow the possibility to change the limits between fcntl() operations.) Problem 1 ========= Using the test program on an unpatched kernel, we first set some limits: # echo 0 > /proc/sys/fs/pipe-user-pages-soft # echo 1000000000 > /proc/sys/fs/pipe-max-size # echo 10000 > /proc/sys/fs/pipe-user-pages-hard # 40.96 MB Then show that we can set a pipe with capacity (100MB) that is over the hard limit # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000 Initial pipe capacity: 65536 Loop 1: set pipe capacity to 100000000 bytes F_SETPIPE_SZ returned 134217728 Now set the capacity to 100MB twice. The second call fails (which is probably surprising to most users, since it seems like a no-op): # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000 0 100000000 Initial pipe capacity: 65536 Loop 1: set pipe capacity to 100000000 bytes F_SETPIPE_SZ returned 134217728 Loop 2: set pipe capacity to 100000000 bytes Loop 2, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted With a patched kernel, setting a capacity over the limit fails at the first attempt: # echo 0 > /proc/sys/fs/pipe-user-pages-soft # echo 1000000000 > /proc/sys/fs/pipe-max-size # echo 10000 > /proc/sys/fs/pipe-user-pages-hard # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000 Initial pipe capacity: 65536 Loop 1: set pipe capacity to 100000000 bytes Loop 1, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted There is a small chance that the change to fix this problem could break user-space, since there are cases where fcntl(F_SETPIPE_SZ) calls that previously succeeded might fail. However, the chances are small, since (a) the pipe-user-pages-{soft,hard} limits are new (in 4.5), and the default soft/hard limits are high/unlimited. Therefore, it seems warranted to make these limits operate more precisely (and behave more like what users probably expect). Problem 2 ========= Running the test program on an unpatched kernel, we first set some limits: # getconf PAGESIZE 4096 # echo 0 > /proc/sys/fs/pipe-user-pages-soft # echo 1000000000 > /proc/sys/fs/pipe-max-size # echo 10000 > /proc/sys/fs/pipe-user-pages-hard # 40.96 MB Now perform two fcntl(F_SETPIPE_SZ) operations on a single pipe, first setting a pipe capacity (10MB), sleeping for a few seconds, during which time the hard limit is lowered, and then set pipe capacity to a smaller amount (5MB): # sudo -u mtk ./test_F_SETPIPE_SZ 1 10000000 15 5000000 & [1] 748 # Initial pipe capacity: 65536 Loop 1: set pipe capacity to 10000000 bytes F_SETPIPE_SZ returned 16777216 Sleeping 15 seconds # echo 1000 > /proc/sys/fs/pipe-user-pages-hard # 4.096 MB # Loop 2: set pipe capacity to 5000000 bytes Loop 2, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted In this case, the user should be able to lower the limit. With a kernel that has the patch below, the second fcntl() succeeds: # echo 0 > /proc/sys/fs/pipe-user-pages-soft # echo 1000000000 > /proc/sys/fs/pipe-max-size # echo 10000 > /proc/sys/fs/pipe-user-pages-hard # sudo -u mtk ./test_F_SETPIPE_SZ 1 10000000 15 5000000 & [1] 3215 # Initial pipe capacity: 65536 # Loop 1: set pipe capacity to 10000000 bytes F_SETPIPE_SZ returned 16777216 Sleeping 15 seconds # echo 1000 > /proc/sys/fs/pipe-user-pages-hard # Loop 2: set pipe capacity to 5000000 bytes F_SETPIPE_SZ returned 8388608 8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x--- /* test_F_SETPIPE_SZ.c (C) 2016, Michael Kerrisk; licensed under GNU GPL version 2 or later Test operation of fcntl(F_SETPIPE_SZ) for setting pipe capacity and interactions with limits defined by /proc/sys/fs/pipe-* files. */ #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> int main(int argc, char *argv[]) { int (*pfd)[2]; int npipes; int pcap, rcap; int j, p, s, stime, loop; if (argc < 2) { fprintf(stderr, "Usage: %s num-pipes " "[pipe-capacity sleep-time]...\n", argv[0]); exit(EXIT_FAILURE); } npipes = atoi(argv[1]); pfd = calloc(npipes, sizeof (int [2])); if (pfd == NULL) { perror("calloc"); exit(EXIT_FAILURE); } for (j = 0; j < npipes; j++) { if (pipe(pfd[j]) == -1) { fprintf(stderr, "Loop %d: pipe() failed: ", j); perror("pipe"); exit(EXIT_FAILURE); } } printf("Initial pipe capacity: %d\n", fcntl(pfd[0][0], F_GETPIPE_SZ)); for (j = 2; j < argc; j += 2 ) { loop = j / 2; pcap = atoi(argv[j]); printf(" Loop %d: set pipe capacity to %d bytes\n", loop, pcap); for (p = 0; p < npipes; p++) { s = fcntl(pfd[p][0], F_SETPIPE_SZ, pcap); if (s == -1) { fprintf(stderr, " Loop %d, pipe %d: F_SETPIPE_SZ " "failed: ", loop, p); perror("fcntl"); exit(EXIT_FAILURE); } if (p == 0) { printf(" F_SETPIPE_SZ returned %d\n", s); rcap = s; } else { if (s != rcap) { fprintf(stderr, " Loop %d, pipe %d: F_SETPIPE_SZ " "unexpected return: %d\n", loop, p, s); exit(EXIT_FAILURE); } } stime = (j + 1 < argc) ? atoi(argv[j + 1]) : 0; if (stime > 0) { printf(" Sleeping %d seconds\n", stime); sleep(stime); } } } exit(EXIT_SUCCESS); } 8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x--- Patch history: v2 * Switch order of test in 'if' statement to avoid function call (to capability()) in normal path. [This is a fix to a preexisting wart in the code. Thanks to Willy Tarreau] * Perform (size > pipe_max_size) check before calling account_pipe_buffers(). [Thanks to Vegard Nossum] Quoting Vegard: The potential problem happens if the user passes a very large number which will overflow pipe->user->pipe_bufs. On 32-bit, sizeof(int) == sizeof(long), so if they pass arg = INT_MAX then round_pipe_size() returns INT_MAX. Although it's true that the accounting is done in terms of pages and not bytes, so you'd need on the order of (1 << 13) = 8192 processes hitting the limit at the same time in order to make it overflow, which seems a bit unlikely. (See https://lkml.org/lkml/2016/8/12/215 for another discussion on the limit checking) Link: http://lkml.kernel.org/r/1e464945-536b-2420-798b-e77b9c7e8593@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: refactor argument for account_pipe_buffers()Michael Kerrisk (man-pages)
This is a preparatory patch for following work. account_pipe_buffers() performs accounting in the 'user_struct'. There is no need to pass a pointer to a 'pipe_inode_info' struct (which is then dereferenced to obtain a pointer to the 'user' field). Instead, pass a pointer directly to the 'user_struct'. This change is needed in preparation for a subsequent patch that the fixes the limit checking in alloc_pipe_info() (and the resulting code is a little more logical). Link: http://lkml.kernel.org/r/7277bf8c-a6fc-4a7d-659c-f5b145c981ab@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: move limit checking logic into pipe_set_size()Michael Kerrisk (man-pages)
This is a preparatory patch for following work. Move the F_SETPIPE_SZ limit-checking logic from pipe_fcntl() into pipe_set_size(). This simplifies the code a little, and allows for reworking required in a later patch that fixes the limit checking in pipe_set_size() Link: http://lkml.kernel.org/r/3701b2c5-2c52-2c3e-226d-29b9deb29b50@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: relocate round_pipe_size() above pipe_set_size()Michael Kerrisk (man-pages)
Patch series "pipe: fix limit handling", v2. When changing a pipe's capacity with fcntl(F_SETPIPE_SZ), various limits defined by /proc/sys/fs/pipe-* files are checked to see if unprivileged users are exceeding limits on memory consumption. While documenting and testing the operation of these limits I noticed that, as currently implemented, these checks have a number of problems: (1) When increasing the pipe capacity, the checks against the limits in /proc/sys/fs/pipe-user-pages-{soft,hard} are made against existing consumption, and exclude the memory required for the increased pipe capacity. The new increase in pipe capacity can then push the total memory used by the user for pipes (possibly far) over a limit. This can also trigger the problem described next. (2) The limit checks are performed even when the new pipe capacity is less than the existing pipe capacity. This can lead to problems if a user sets a large pipe capacity, and then the limits are lowered, with the result that the user will no longer be able to decrease the pipe capacity. (3) As currently implemented, accounting and checking against the limits is done as follows: (a) Test whether the user has exceeded the limit. (b) Make new pipe buffer allocation. (c) Account new allocation against the limits. This is racey. Multiple processes may pass point (a) simultaneously, and then allocate pipe buffers that are accounted for only in step (c). The race means that the user's pipe buffer allocation could be pushed over the limit (by an arbitrary amount, depending on how unlucky we were in the race). [Thanks to Vegard Nossum for spotting this point, which I had missed.] This patch series addresses these three problems. This patch (of 8): This is a minor preparatory patch. After subsequent patches, round_pipe_size() will be called from pipe_set_size(), so place round_pipe_size() above pipe_set_size(). Link: http://lkml.kernel.org/r/91a91fdb-a959-ba7f-b551-b62477cc98a1@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: refactor ioctl fn vector in iookup_dev_ioctl()Tomohiro Kusumi
cmd part of this struct is the same as an index of itself within _ioctls[]. In fact this cmd is unused, so we can drop this part. Link: http://lkml.kernel.org/r/20160831033414.9910.66697.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: remove possibly misleading /* #define DEBUG */Tomohiro Kusumi
Having this in autofs_i.h gives illusion that uncommenting this enables pr_debug(), but it doesn't enable all the pr_debug() in autofs because inclusion order matters. XFS has the same DEBUG macro in its core header fs/xfs/xfs.h, however XFS seems to have a rule to include this prior to other XFS headers as well as kernel headers. This is not the case with autofs, and DEBUG could be enabled via Makefile, so autofs should just get rid of this comment to make the code less confusing. It's a comment, so there is literally no functional difference. Link: http://lkml.kernel.org/r/20160831033409.9910.77067.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: fix print format for ioctl warning messageTomohiro Kusumi
All other warnings use "cmd(0x%08x)" and this is the only one with "cmd(%d)". (below comes from my userspace debug program, but not automount daemon) [ 1139.905676] autofs4:pid:1640:check_dev_ioctl_version: ioctl control interface version mismatch: kernel(1.0), user(0.0), cmd(-1072131215) Link: http://lkml.kernel.org/r/20160812024851.12352.75458.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMDIan Kent
No functional changes, based on the following justification. 1. Make the code more consistent using the ioctl vector _ioctls[], rather than assigning NULL only for this ioctl command. 2. Remove goto done; for better maintainability in the long run. 3. The existing code is based on the fact that validate_dev_ioctl() sets ioctl version for any command, but AUTOFS_DEV_IOCTL_VERSION_CMD should explicitly set it regardless of the default behavior. Link: http://lkml.kernel.org/r/20160812024846.12352.9885.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: fix dev ioctl number range checkIan Kent
The count of miscellaneous device ioctls in fs/autofs4/autofs_i.h is wrong. The number of ioctls is the difference between AUTOFS_DEV_IOCTL_VERSION_CMD and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD (14) not the difference between AUTOFS_IOC_COUNT and 11 (21). [kusumi.tomohiro@gmail.com: fix typo that made the count macro negative] Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net Link: http://lkml.kernel.org/r/20160812024841.12352.11975.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: fix pr_debug() messageTomohiro Kusumi
This isn't a return value, so change the message to indicate the status is the result of may_umount(). (or locate pr_debug() after put_user() with the same message) Link: http://lkml.kernel.org/r/20160812024836.12352.74628.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: don't fail to free_dev_ioctl(param)Tomohiro Kusumi
Returning -ENOTTY here fails to free dynamically allocated param. Link: http://lkml.kernel.org/r/20160812024815.12352.69153.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: remove obsolete sb fieldsTomohiro Kusumi
These two were left from commit aa55ddf340c9 ("autofs4: remove unused ioctls") which removed unused ioctls. Link: http://lkml.kernel.org/r/20160812024810.12352.96377.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: use autofs4_free_ino() to kfree dentry dataTomohiro Kusumi
kfree dentry data allocated by autofs4_new_ino() with autofs4_free_ino() instead of raw kfree. (since we have the interface to free autofs_info*) This patch was modified to remove the need to set the dentry info field to NULL dew to a change in the previous patch. Link: http://lkml.kernel.org/r/20160812024805.12352.43650.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: remove ino free in autofs4_dir_symlink()Ian Kent
The inode allocation failure case in autofs4_dir_symlink() frees the autofs dentry info of the dentry without setting ->d_fsdata to NULL. That could lead to a double free so just get rid of the free and leave it to ->d_release(). Link: http://lkml.kernel.org/r/20160812024759.12352.10653.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: add WARN_ON(1) for non dir/link inode caseTomohiro Kusumi
It's invalid if the given mode is neither dir nor link, so warn on else case. Link: http://lkml.kernel.org/r/20160812024754.12352.8536.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: fix autofs4_fill_super() error exit handlingIan Kent
Somewhere along the line the error handling gotos have become incorrect. Link: http://lkml.kernel.org/r/20160812024749.12352.15100.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: test autofs versions first on sb initializationTomohiro Kusumi
This patch does what the below comment says. It could be and it's considered better to do this first before various functions get called during initialization. /* Couldn't this be tested earlier? */ Link: http://lkml.kernel.org/r/20160812024744.12352.43075.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11autofs: drop unnecessary extern in autofs_i.hTomohiro Kusumi
autofs4_kill_sb() doesn't need to be declared as extern, and no other functions in .h are explicitly declared as extern. Link: http://lkml.kernel.org/r/20160812024739.12352.99354.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11fs/select: add vmalloc fallback for select(2)Vlastimil Babka
The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows with the number of fds passed. We had a customer report page allocation failures of order-4 for this allocation. This is a costly order, so it might easily fail, as the VM expects such allocation to have a lower-order fallback. Such trivial fallback is vmalloc(), as the memory doesn't have to be physically contiguous and the allocation is temporary for the duration of the syscall only. There were some concerns, whether this would have negative impact on the system by exposing vmalloc() to userspace. Although an excessive use of vmalloc can cause some system wide performance issues - TLB flushes etc. - a large order allocation is not for free either and an excessive reclaim/compaction can have a similar effect. Also note that the size is effectively limited by RLIMIT_NOFILE which defaults to 1024 on the systems I checked. That means the bitmaps will fit well within single page and thus the vmalloc() fallback could be only excercised for processes where root allows a higher limit. Note that the poll(2) syscall seems to use a linked list of order-0 pages, so it doesn't need this kind of fallback. [eric.dumazet@gmail.com: fix failure path logic] [akpm@linux-foundation.org: use proper type for size] Link: http://lkml.kernel.org/r/20160927084536.5923-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11block: implement (some of) fallocate for block devicesDarrick J. Wong
After much discussion, it seems that the fallocate feature flag FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been whitelisted for zeroing SCSI UNMAP. Punch still requires that FALLOC_FL_KEEP_SIZE is set. A length that goes past the end of the device will be clamped to the device size if KEEP_SIZE is set; or will return -EINVAL if not. Both start and length must be aligned to the device's logical block size. Since the semantics of fallocate are fairly well established already, wire up the two pieces. The other fallocate variants (collapse range, insert range, and allocate blocks) are not supported. Link: http://lkml.kernel.org/r/147518379992.22791.8849838163218235007.stgit@birch.djwong.org Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> # tweaked header Cc: Brian Foster <bfoster@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ocfs2: fix memory leak in dlm_migrate_request_handler()Guozhonghua
In the dlm_migrate_request_handler(), when `ret' is -EEXIST, the mle should be freed, otherwise the memory will be leaked. Link: http://lkml.kernel.org/r/71604351584F6A4EBAE558C676F37CA4A3D3522A@H3CMLB12-EX.srv.huawei-3com.com Signed-off-by: Guozhonghua <guozhonghua@h3c.com> Reviewed-by: Mark Fasheh <mfasheh@versity.com> Cc: Eric Ren <zren@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11Merge tag 'libnvdimm-for-4.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "Aside from the recently added pmem sub-division support these have been in -next for several releases with no reported issues. The sub- division support was included in next-20161010 with no reported issues. It passes all unit tests including new tests for all the new functionality below. Summary: - PMEM sub-division support: Allow a single PMEM region to be divided into multiple namespaces. Originally, ~2 years ago, it was thought that partitions of a /dev/pmemX block device could handle sub-allocations of persistent memory for different use cases. With the decision to not support DAX mappings of raw block-devices, and the genesis of device-dax, the need for having multiple pmem-namespace per region has grown. - Device-DAX unified inode: In support of dynamic-resizing of a device-dax instance the kernel arranges for all mappings of a device-dax node to share the same inode. This allows unmap / truncate / invalidation events to affect all instances of the device similar to the behavior of mmap on block devices. - Hardware error scrubbing reworks: The original address-range-scrub and badblocks tracking solution allowed clearing entries at the individual namespace level, but it failed to clear the internal list of media errors maintained at the bus level. The result was that the next scrub or namespace disable/re-enable event would restore the cleared badblocks, but now that is fixed. The v4.8 kernel introduced an auto-scrub-on-machine-check behavior to repopulate the badblocks list. Now, in v4.9, the auto-scrub behavior can be disabled and simply arrange for the error reported in the machine-check to be added to the list. - DIMM health-event notification support: ACPI 6.1 defines a notification event code that can be send to ACPI NVDIMM devices. A poll(2) capable file descriptor for these events can be obtained from the nmemX/nfit/flags sysfs-attribute of a libnvdimm memory device. - Miscellaneous fixes: NVDIMM-N probe error, device-dax build error, and a change to dedup the flush hint list to not flush the memory controller more than necessary" * tag 'libnvdimm-for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (39 commits) /dev/dax: fix Kconfig dependency build breakage dax: use correct dev_t value dax: convert devm_create_dax_dev