-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJYAnNOAAoJEGu/nxmHO1GNOzQH/3p+j1yPUR08+qhlZBdF/vCH
i9Qb13yUT8yEN9tCZ7bsMhRZYQ70GuPMtLJbhklwGmnDAEZwzGoCrokexCsKoKiv
0RmzLUsbN7GM6LFXOyTj3QwFGxjQnVzk5TKXSR2qUpqvvffFsAFlTpg/JqRNpTjF
c85naRDFYmZ3fGi2mT/emoY8MAu90XnjWbAMrg+uipsriBqOcbUD487CubDeR0CK
svO3JSvv2W6vjMVzkLSWnpFrhiWmqAcOHFS4NEcCeQaJkDmyRCnmVNXBaB1YGZey
47+r8oLo64oByCt+Z60Dxb5rwDJfDLLDfRQeDOltgR4i2nnSZ5cS21V55Z5alqg=
=sDD1
-----END PGP SIGNATURE-----
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
...
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.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
Comment: Kees Cook <kees@outflux.net>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=1dUK
-----END PGP SIGNATURE-----
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
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()
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
...
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
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>
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
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>
ovl_fill_super calls ovl_new_inode to create a root inode for the new
superblock before initializing sb->s_xattr. This wrongly causes
IOP_XATTR to be cleared in i_opflags of the new inode, causing SELinux
to log the following message:
SELinux: (dev overlay, type overlay) has no xattr support
Fix this by initializing sb->s_xattr and similar fields before calling
ovl_new_inode.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Both import_iovec() and rw_copy_check_uvector() take an array
(typically small and on-stack) which is used to hold an iovec array copy
from userspace. This is to avoid an expensive memory allocation in the
fast path (i.e. few iovec elements).
The caller may have to check whether these functions actually used
the provided buffer or allocated a new one -- but this differs between
the too. Let's just add a kernel doc to clarify what the semantics are
for each function.
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
New mount option "idsfromsid" indicates to cifs.ko that
it should try to retrieve the uid and gid owner fields
from special sids. This patch adds the code to parse the owner
sids in the ACL to see if they match, and if so populate the
uid and/or gid from them. This is faster than upcalling for
them and asking winbind, and is a fairly common case, and is
also helpful when cifs.upcall and idmapping is not configured.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add "idsfromsid" mount option to indicate to cifs.ko that it should
try to retrieve the uid and gid owner fields from special sids in the
ACL if present. This first patch just adds the parsing for the mount
option.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Pull cgroup updates from Tejun Heo:
- tracepoints for basic cgroup management operations added
- kernfs and cgroup path formatting functions updated to behave in the
style of strlcpy()
- non-critical bug fixes
* 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL
cgroup: fix error handling regressions in proc_cgroup_show() and cgroup_release_agent()
cpuset: fix error handling regression in proc_cpuset_show()
cgroup: add tracepoints for basic operations
cgroup: make cgroup_path() and friends behave in the style of strlcpy()
kernfs: remove kernfs_path_len()
kernfs: make kernfs_path*() behave in the style of strlcpy()
kernfs: add dummy implementation of kernfs_path_from_node()
Resulting in a complete removal of a function basically implementing the
inverse of vfs_readlink().
As a bonus, now the proper security hook is also called.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This helper is for filesystems that want to read the symlink and are better
off with the get_link() interface (returning a char *) rather than the
readlink() interface (copy into a userspace buffer).
Also call the LSM hook for readlink (not get_link) since this is for
symlink reading not following.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
All filesystems that are backers for overlayfs would also use
generic_readlink(). Move this logic to the overlay itself, which is a nice
cleanup.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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
-----BEGIN PGP SIGNATURE-----
iQIcBAABCAAGBQJX/+ZfAAoJENfLVL+wpUDr5MUP/16s2Kp9ZZZZ7ICi3yrHOzb0
9WpCOmbKUIELXl8YgkxlvPUYMzTQTIc32TwbVgdFV0g41my/0+O3z3+IiTrUGxH5
8LgouMWBZ9KKmyUB//+KQAXr3j/bvDdF6Li6wJfz8a2o+9xT4oTkK1+Js8p0kn6e
HNKfRknfCKwvE+j4tPCLfs2RX5qDyBFILXwWhj1fAbmT3rbnp+QqkXD4mWUrXb9z
DBgxciXRhOkOQQAD2KQBFd2kUqWDZ5ED23b+aYsu9D3VCW45zitBqQFAxkQWL0hp
x8Mp+MDCxlgdEaGQPUmUiDtPkG1X9ZxUJCAwaJWWsZaItwR2Il+en2sETctnTZ1X
0IAxZVFdolzSeLzIfNx3OG32JdWJdaNjUzkIZam8gO6i1f6PAmK4alR0J3CT31nJ
/OEN76o1E7acGWRMmj+MAZ2U5gPfR7EitOzyE8ZUPcHgyeGMiynjwi56WIpeSvT2
F/Sp5kRe5+D5gtnYuppGp7Srp5vYdtFaz1zgPDUKpDLcxfDweO8AHGjJf3Zmrunx
X24yia4A14CnfcUy4vKpISXRykmkG/3Z0tpWwV53uXZm4nlQfRc7gPibiW7Ay521
af8sDoItW98K3DK5NQU7IUn83ua1TStzpoqlAEafRw//g9zPMTbhHvNvOyrRfrcX
kjWn6hNblMu9M34JOjtu
=XOrF
-----END PGP SIGNATURE-----
Merge tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
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()
...
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.
-----BEGIN PGP SIGNATURE-----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=nozl
-----END PGP SIGNATURE-----
Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux
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
< XFS has gained super CoW powers! >
----------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
Included in this update:
- 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
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=Sa+Y
-----END PGP SIGNATURE-----
Merge tag 'xfs-reflink-for-linus-4.9-rc1' of 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
...
We are already doing the same thing for an ordinary open case:
we can't keep read oplock on a file if we have mandatory byte-range
locks because pagereading can conflict with these locks on a server.
Fix it by setting oplock level to NONE.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
openFileList of tcon can be changed while cifs_reopen_file() is called
that can lead to an unexpected behavior when we return to the loop.
Fix this by introducing a temp list for keeping all file handles that
need to be reopen.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
We split the rawntlmssp authentication into negotiate and
authencate parts. We also clean up the code and add helpers.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add helper functions and split Kerberos authentication off
SMB2_sess_setup.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
/sys/module/cifs/parameters should display the three
other module load time configuration settings for cifs.ko
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Signed-off-by: Steve French <steve.french@primarydata.com>
Cleanup some missing mem frees on some cifs ioctls, and
clarify others to make more obvious that no data is returned.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
[CIFS] We had cases where we sent a SMB2/SMB3 setinfo request with all
timestamp (and DOS attribute) fields marked as 0 (ie do not change)
e.g. on chmod or chown.
Signed-off-by: Steve French <steve.french@primarydata.com>
CC: Stable <stable@vger.kernel.org>
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
...
Add mount option "max_credits" to allow setting maximum SMB3
credits to any value from 10 to 64000 (default is 32000).
This can be useful to workaround servers with problems allocating
credits, or to throttle the client to use smaller amount of
simultaneous i/o or to workaround server performance issues.
Also adds a cap, so that even if the server granted us more than
65000 credits due to a server bug, we would not use that many.
Signed-off-by: Steve French <steve.french@primarydata.com>
Continuous Availability features like persistent handles
require that clients reconnect their open files, not
just the sessions, soon after the network connection comes
back up, otherwise the server will throw away the state
(byte range locks, leases, deny modes) on those handles
after a timeout.
Add code to reconnect handles when use_persistent set
(e.g. Continuous Availability shares) after tree reconnect.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Remove the global file_list_lock to simplify cifs/smb3 locking and
have spinlocks that more closely match the information they are
protecting.
Add new tcon->open_file_lock and file->file_info_lock spinlocks.
Locks continue to follow a heirachy,
cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file
where global tcp_ses_lock still protects socket and cifs_ses, while the
the newer locks protect the lower level structure's information
(tcon and cifs_file respectively).
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
Patch a6b5058 results in -EREMOTE returned by is_path_accessible() in
cifs_mount() to be ignored which breaks DFS mounting.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
When we open a durable handle we give a Globally Unique
Identifier (GUID) to the server which we must keep for later reference
e.g. when reopening persistent handles on reconnection.
Without this the GUID generated for a new persistent handle was lost and
16 zero bytes were used instead on re-opening.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
GUIDs although random, and 16 bytes, need to be generated as
proper uuids.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reported-by: David Goebels <davidgoe@microsoft.com>
CC: Stable <stable@vger.kernel.org>
The kernel client requests 2 credits for many operations even though
they only use 1 credit (presumably to build up a buffer of credit).
Some servers seem to give the client as much credit as is requested. In
this case, the amount of credit the client has continues increasing to
the point where (server->credits * MAX_BUFFER_SIZE) overflows in
smb2_wait_mtu_credits().
Fix this by throttling the credit requests if an set limit is reached.
For async requests where the credit charge may be > 1, request as much
credit as what is charged.
The limit is chosen somewhat arbitrarily. The Windows client
defaults to 128 credits, the Windows server allows clients up to
512 credits (or 8192 for Windows 2016), and the NetApp server
(and at least one other) does not limit clients at all.
Choose a high enough value such that the client shouldn't limit
performance.
This behavior was seen with a NetApp filer (NetApp Release 9.0RC2).
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
In debugging smb3, it is useful to display the number
of credits available, so we can see when the server has not granted
sufficient operations for the client to make progress, or alternatively
the client has requested too many credits (as we saw in a recent bug)
so we can compare with the number of credits the server thinks
we have.
Add a /proc/fs/cifs/DebugData line to display the client view
on how many credits are available.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reported-by: Germano Percossi <germano.percossi@citrix.com>
CC: Stable <stable@vger.kernel.org>
Add parsing for new pseudo-xattr user.cifs.creationtime file
attribute to allow backup and test applications to view
birth time of file on cifs/smb3 mounts.
Signed-off-by: Steve French <steve.french@primarydata.com>
Add parsing for new pseudo-xattr user.cifs.dosattrib file attribute
so tools can recognize what kind of file it is, and verify if common
SMB3 attributes (system, hidden, archive, sparse, indexed etc.) are
set.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
Linus Torvalds
Oleg Nesterov
Vivek Goyal
Vegard Nossum
Steve French
Miklos Szeredi
Pavel Shilovsky
Sachin Prabhu
Germano Percossi
Chris Mason
Aurelien Aptel
Ross Lagerwall
Michal Hocko
Masahiro Yamada
Michael Kerrisk (man-pages)