22 Mar, 2016
1 commit
-
Pull cgroup namespace support from Tejun Heo:
"These are changes to implement namespace support for cgroup which has
been pending for quite some time now. It is very straight-forward and
only affects what part of cgroup hierarchies are visible.After unsharing, mounting a cgroup fs will be scoped to the cgroups
the task belonged to at the time of unsharing and the cgroup paths
exposed to userland would be adjusted accordingly"* 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix and restructure error handling in copy_cgroup_ns()
cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns()
Add FS_USERNS_FLAG to cgroup fs
cgroup: Add documentation for cgroup namespaces
cgroup: mount cgroupns-root when inside non-init cgroupns
kernfs: define kernfs_node_dentry
cgroup: cgroup namespace setns support
cgroup: introduce cgroup namespaces
sched: new clone flag CLONE_NEWCGROUP for cgroup namespace
kernfs: Add API to generate relative kernfs path
17 Feb, 2016
2 commits
-
Add a new kernfs api is added to lookup the dentry for a particular
kernfs path.Signed-off-by: Aditya Kali
Signed-off-by: Serge E. Hallyn
Acked-by: Greg Kroah-Hartman
Signed-off-by: Tejun Heo -
The new function kernfs_path_from_node() generates and returns kernfs
path of a given kernfs_node relative to a given parent kernfs_node.Signed-off-by: Aditya Kali
Signed-off-by: Serge E. Hallyn
Acked-by: Greg Kroah-Hartman
Signed-off-by: Tejun Heo
08 Feb, 2016
1 commit
-
kernfs_walk_ns() uses a static path_buf[PATH_MAX] to separate out path
components. Keeping around the 4k buffer just for kernfs_walk_ns() is
wasteful. This patch makes it piggyback on kernfs_pr_cont_buf[]
instead. This requires kernfs_walk_ns() to hold kernfs_rename_lock.Signed-off-by: Tejun Heo
Reported-by: Geert Uytterhoeven
Signed-off-by: Greg Kroah-Hartman
23 Jan, 2016
1 commit
-
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.Signed-off-by: Al Viro
15 Jan, 2016
1 commit
-
Currently, all kmem allocations (namely every kmem_cache_alloc, kmalloc,
alloc_kmem_pages call) are accounted to memory cgroup automatically.
Callers have to explicitly opt out if they don't want/need accounting
for some reason. Such a design decision leads to several problems:- kmalloc users are highly sensitive to failures, many of them
implicitly rely on the fact that kmalloc never fails, while memcg
makes failures quite plausible.- A lot of objects are shared among different containers by design.
Accounting such objects to one of containers is just unfair.
Moreover, it might lead to pinning a dead memcg along with its kmem
caches, which aren't tiny, which might result in noticeable increase
in memory consumption for no apparent reason in the long run.- There are tons of short-lived objects. Accounting them to memcg will
only result in slight noise and won't change the overall picture, but
we still have to pay accounting overhead.For more info, see
- http://lkml.kernel.org/r/20151105144002.GB15111%40dhcp22.suse.cz
- http://lkml.kernel.org/r/20151106090555.GK29259@esperanzaTherefore this patchset switches to the white list policy. Now kmalloc
users have to explicitly opt in by passing __GFP_ACCOUNT flag.Currently, the list of accounted objects is quite limited and only
includes those allocations that (1) are known to be easily triggered
from userspace and (2) can fail gracefully (for the full list see patch
no. 6) and it still misses many object types. However, accounting only
those objects should be a satisfactory approximation of the behavior we
used to have for most sane workloads.This patch (of 6):
Revert 499611ed451508a42d1d7d ("kernfs: do not account ino_ida allocations
to memcg").Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be
fragile and difficult to maintain, because there seem to be many more
allocations that should not be accounted than those that should be.
Besides, false accounting an allocation might result in much worse
consequences than not accounting at all, namely increased memory
consumption due to pinned dead kmem caches.So it was decided to switch to the white-list policy. This patch reverts
bits introducing the black-list policy. The white-list policy will be
introduced later in the series.Signed-off-by: Vladimir Davydov
Acked-by: Johannes Weiner
Cc: Michal Hocko
Cc: Tejun Heo
Cc: Greg Thelen
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Jan, 2016
1 commit
-
Pull networking updates from Davic Miller:
1) Support busy polling generically, for all NAPI drivers. From Eric
Dumazet.2) Add byte/packet counter support to nft_ct, from Floriani Westphal.
3) Add RSS/XPS support to mvneta driver, from Gregory Clement.
4) Implement IPV6_HDRINCL socket option for raw sockets, from Hannes
Frederic Sowa.5) Add support for T6 adapter to cxgb4 driver, from Hariprasad Shenai.
6) Add support for VLAN device bridging to mlxsw switch driver, from
Ido Schimmel.7) Add driver for Netronome NFP4000/NFP6000, from Jakub Kicinski.
8) Provide hwmon interface to mlxsw switch driver, from Jiri Pirko.
9) Reorganize wireless drivers into per-vendor directories just like we
do for ethernet drivers. From Kalle Valo.10) Provide a way for administrators "destroy" connected sockets via the
SOCK_DESTROY socket netlink diag operation. From Lorenzo Colitti.11) Add support to add/remove multicast routes via netlink, from Nikolay
Aleksandrov.12) Make TCP keepalive settings per-namespace, from Nikolay Borisov.
13) Add forwarding and packet duplication facilities to nf_tables, from
Pablo Neira Ayuso.14) Dead route support in MPLS, from Roopa Prabhu.
15) TSO support for thunderx chips, from Sunil Goutham.
16) Add driver for IBM's System i/p VNIC protocol, from Thomas Falcon.
17) Rationalize, consolidate, and more completely document the checksum
offloading facilities in the networking stack. From Tom Herbert.18) Support aborting an ongoing scan in mac80211/cfg80211, from
Vidyullatha Kanchanapally.19) Use per-bucket spinlock for bpf hash facility, from Tom Leiming.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1375 commits)
net: bnxt: always return values from _bnxt_get_max_rings
net: bpf: reject invalid shifts
phonet: properly unshare skbs in phonet_rcv()
dwc_eth_qos: Fix dma address for multi-fragment skbs
phy: remove an unneeded condition
mdio: remove an unneed condition
mdio_bus: NULL dereference on allocation error
net: Fix typo in netdev_intersect_features
net: freescale: mac-fec: Fix build error from phy_device API change
net: freescale: ucc_geth: Fix build error from phy_device API change
bonding: Prevent IPv6 link local address on enslaved devices
IB/mlx5: Add flow steering support
net/mlx5_core: Export flow steering API
net/mlx5_core: Make ipv4/ipv6 location more clear
net/mlx5_core: Enable flow steering support for the IB driver
net/mlx5_core: Initialize namespaces only when supported by device
net/mlx5_core: Set priority attributes
net/mlx5_core: Connect flow tables
net/mlx5_core: Introduce modify flow table command
net/mlx5_core: Managing root flow table
...
12 Jan, 2016
1 commit
-
Pull vfs xattr updates from Al Viro:
"Andreas' xattr cleanup series.It's a followup to his xattr work that went in last cycle; -0.5KLoC"
* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
xattr handlers: Simplify list operation
ocfs2: Replace list xattr handler operations
nfs: Move call to security_inode_listsecurity into nfs_listxattr
xfs: Change how listxattr generates synthetic attributes
tmpfs: listxattr should include POSIX ACL xattrs
tmpfs: Use xattr handler infrastructure
btrfs: Use xattr handler infrastructure
vfs: Distinguish between full xattr names and proper prefixes
posix acls: Remove duplicate xattr name definitions
gfs2: Remove gfs2_xattr_acl_chmod
vfs: Remove vfs_xattr_cmp
31 Dec, 2015
1 commit
-
Signed-off-by: Al Viro
30 Dec, 2015
1 commit
-
all callers are better off with kfree_put_link()
Signed-off-by: Al Viro
09 Dec, 2015
1 commit
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new method: ->get_link(); replacement of ->follow_link(). The differences
are:
* inode and dentry are passed separately
* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.It's a flagday change - the old method is gone, all in-tree instances
converted. Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode. That'll change
in the next commits.Signed-off-by: Al Viro
07 Dec, 2015
2 commits
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When a file on tmpfs has an ACL or a Default ACL, listxattr should include the
corresponding xattr name.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Cc: Hugh Dickins
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro -
Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem. For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL. Use this to implement kernfs_iop_removexattr as well.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Cc: Hugh Dickins
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro
21 Nov, 2015
1 commit
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Implement kernfs_walk_and_get() which is similar to
kernfs_find_and_get() but can walk a path instead of just a name.v2: Use strlcpy() instead of strlen() + memcpy() as suggested by
David.Signed-off-by: Tejun Heo
Acked-by: Greg Kroah-Hartman
Cc: David Miller
19 Aug, 2015
1 commit
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Add a function to determine the path length of a kernfs node. This
for now will be used by writeback tracepoint updates.Signed-off-by: Tejun Heo
Acked-by: Greg Kroah-Hartman
Signed-off-by: Jens Axboe
04 Jul, 2015
1 commit
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Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.This set of changes also addresses an issue with how open file
descriptors from /proc//ns/* are displayed. Recently readlink of
/proc//fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.There is also a short list of issues that have not been fixed yet that
I will mention briefly.It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
01 Jul, 2015
1 commit
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Add a new function kernfs_create_empty_dir that can be used to create
directory that can not be modified.Update the code to use make_empty_dir_inode when reporting a
permanently empty directory to the vfs.Update the code to not allow adding to permanently empty directories.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman"
27 Jun, 2015
2 commits
-
Pull cgroup updates from Tejun Heo:
- threadgroup_lock got reorganized so that its users can pick the
actual locking mechanism to use. Its only user - cgroups - is
updated to use a percpu_rwsem instead of per-process rwsem.This makes things a bit lighter on hot paths and allows cgroups to
perform and fail multi-task (a process) migrations atomically.
Multi-task migrations are used in several places including the
unified hierarchy.- Delegation rule and documentation added to unified hierarchy. This
will likely be the last interface update from the cgroup core side
for unified hierarchy before lifting the devel mask.- Some groundwork for the pids controller which is scheduled to be
merged in the coming devel cycle.* 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: add delegation section to unified hierarchy documentation
cgroup: require write perm on common ancestor when moving processes on the default hierarchy
cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write()
kernfs: make kernfs_get_inode() public
MAINTAINERS: add a cgroup core co-maintainer
cgroup: fix uninitialised iterator in for_each_subsys_which
cgroup: replace explicit ss_mask checking with for_each_subsys_which
cgroup: use bitmask to filter for_each_subsys
cgroup: add seq_file forward declaration for struct cftype
cgroup: simplify threadgroup locking
sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem
sched, cgroup: reorganize threadgroup locking
cgroup: switch to unsigned long for bitmasks
cgroup: reorganize include/linux/cgroup.h
cgroup: separate out include/linux/cgroup-defs.h
cgroup: fix some comment typos -
Pull driver core updates from Greg KH:
"Here is the driver core / firmware changes for 4.2-rc1.A number of small changes all over the place in the driver core, and
in the firmware subsystem. Nothing really major, full details in the
shortlog. Some of it is a bit of churn, given that the platform
driver probing changes was found to not work well, so they were
reverted.All of these have been in linux-next for a while with no reported
issues"* tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (31 commits)
Revert "base/platform: Only insert MEM and IO resources"
Revert "base/platform: Continue on insert_resource() error"
Revert "of/platform: Use platform_device interface"
Revert "base/platform: Remove code duplication"
firmware: add missing kfree for work on async call
fs: sysfs: don't pass count == 0 to bin file readers
base:dd - Fix for typo in comment to function driver_deferred_probe_trigger().
base/platform: Remove code duplication
of/platform: Use platform_device interface
base/platform: Continue on insert_resource() error
base/platform: Only insert MEM and IO resources
firmware: use const for remaining firmware names
firmware: fix possible use after free on name on asynchronous request
firmware: check for file truncation on direct firmware loading
firmware: fix __getname() missing failure check
drivers: of/base: move of_init to driver_init
drivers/base: cacheinfo: fix annoying typo when DT nodes are absent
sysfs: disambiguate between "error code" and "failure" in comments
driver-core: fix build for !CONFIG_MODULES
driver-core: make __device_attach() static
...
23 Jun, 2015
1 commit
-
Pull vfs updates from Al Viro:
"In this pile: pathname resolution rewrite.- recursion in link_path_walk() is gone.
- nesting limits on symlinks are gone (the only limit remaining is
that the total amount of symlinks is no more than 40, no matter how
nested).- "fast" (inline) symlinks are handled without leaving rcuwalk mode.
- stack footprint (independent of the nesting) is below kilobyte now,
about on par with what it used to be with one level of nested
symlinks and ~2.8 times lower than it used to be in the worst case.- struct nameidata is entirely private to fs/namei.c now (not even
opaque pointers are being passed around).- ->follow_link() and ->put_link() calling conventions had been
changed; all in-tree filesystems converted, out-of-tree should be
able to follow reasonably easily.For out-of-tree conversions, see Documentation/filesystems/porting
for details (and in-tree filesystems for examples of conversion).That has sat in -next since mid-May, seems to survive all testing
without regressions and merges clean with v4.1"* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (131 commits)
turn user_{path_at,path,lpath,path_dir}() into static inlines
namei: move saved_nd pointer into struct nameidata
inline user_path_create()
inline user_path_parent()
namei: trim do_last() arguments
namei: stash dfd and name into nameidata
namei: fold path_cleanup() into terminate_walk()
namei: saner calling conventions for filename_parentat()
namei: saner calling conventions for filename_create()
namei: shift nameidata down into filename_parentat()
namei: make filename_lookup() reject ERR_PTR() passed as name
namei: shift nameidata inside filename_lookup()
namei: move putname() call into filename_lookup()
namei: pass the struct path to store the result down into path_lookupat()
namei: uninline set_root{,_rcu}()
namei: be careful with mountpoint crossings in follow_dotdot_rcu()
Documentation: remove outdated information from automount-support.txt
get rid of assorted nameidata-related debris
lustre: kill unused helper
lustre: kill unused macro (LOOKUP_CONTINUE)
...
19 Jun, 2015
1 commit
-
Move kernfs_get_inode() prototype from fs/kernfs/kernfs-internal.h to
include/linux/kernfs.h. It obtains the matching inode for a
kernfs_node.It will be used by cgroup for inode based permission checks for now
but is generally useful.Signed-off-by: Tejun Heo
Acked-by: Greg Kroah-Hartman
25 May, 2015
1 commit
-
Grabbing the parent is not happening anymore since 2010 (e72ceb8ccac5f7
"sysfs: Remove sysfs_get/put_active_two"). Remove this confusing
comment.Signed-off-by: Wolfram Sang
Acked-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
15 May, 2015
1 commit
-
root->ino_ida is used for kernfs inode number allocations. Since IDA has
a layered structure, different IDs can reside on the same layer, which
is currently accounted to some memory cgroup. The problem is that each
kmem cache of a memory cgroup has its own directory on sysfs (under
/sys/fs/kernel//cgroup). If the inode number of such a
directory or any file in it gets allocated from a layer accounted to the
cgroup which the cache is created for, the cgroup will get pinned for
good, because one has to free all kmem allocations accounted to a cgroup
in order to release it and destroy all its kmem caches. That said we
must not account layers of ino_ida to any memory cgroup.Since per net init operations may create new sysfs entries directly
(e.g. lo device) or indirectly (nf_conntrack creates a new kmem cache
per each namespace, which, in turn, creates new sysfs entries), an easy
way to reproduce this issue is by creating network namespace(s) from
inside a kmem-active memory cgroup.Signed-off-by: Vladimir Davydov
Acked-by: Tejun Heo
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Cc: Greg Thelen
Cc: Greg Kroah-Hartman
Cc: [4.0.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 May, 2015
4 commits
-
similar to kfree_put_link()
Signed-off-by: Al Viro
-
only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.Signed-off-by: Al Viro
-
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidataSigned-off-by: Al Viro
-
a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks. Stored pointer
is ignored in all cases except the last one.Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is. In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.Signed-off-by: Al Viro
16 Apr, 2015
1 commit
-
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells
Signed-off-by: Al Viro
17 Mar, 2015
1 commit
-
Kernfs supports two styles of read: direct_read and seqfile_read.
The latter supports 'poll' correctly thanks to the update of
'->event' in kernfs_seq_show.
The former does not as '->event' is never updated on a read.So add an appropriate update in kernfs_file_direct_read().
This was noticed because some 'md' sysfs attributes were
recently changed to use direct reads.Reported-by: Prakash Punnoor
Reported-by: Torsten Kaiser
Fixes: 750f199ee8b578062341e6ddfe36c59ac8ff2dcb
Signed-off-by: NeilBrown
Acked-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
14 Feb, 2015
2 commits
-
When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid
making a separate copy of its name. It's currently only used for sysfs
attributes whose filenames are required to stay accessible and unchanged.
There are rare exceptions where these names are allocated and formatted
dynamically but for the vast majority of cases they're consts in the
rodata section.Now that kernfs is converted to use kstrdup_const() and kfree_const(),
there's little point in keeping KERNFS_STATIC_NAME around. Remove it.Signed-off-by: Tejun Heo
Cc: Andrzej Hajda
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
sysfs frequently performs duplication of strings located in read-only
memory section. Replacing kstrdup by kstrdup_const allows to avoid such
operations.Signed-off-by: Andrzej Hajda
Cc: Marek Szyprowski
Cc: Kyungmin Park
Cc: Mike Turquette
Cc: Alexander Viro
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Acked-by: Tejun Heo
Cc: Greg KH
Cc: Geert Uytterhoeven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Jan, 2015
2 commits
-
Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.Signed-off-by: Christoph Hellwig
Acked-by: Ryusuke Konishi
Reviewed-by: Tejun Heo
Reviewed-by: Jan Kara
Signed-off-by: Jens Axboe -
hugetlbfs, kernfs and dlmfs can simply use noop_backing_dev_info instead
of creating a local duplicate.Signed-off-by: Christoph Hellwig
Reviewed-by: Jan Kara
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe
10 Jan, 2015
1 commit
-
Returning a difference from a comparison functions is usually wrong
(see acbbe6fbb240 "kcmp: fix standard comparison bug" for the long
story). Here there is the additional twist that if the void pointers
ns and kn->ns happen to differ by a multiple of 2^32,
kernfs_name_compare returns 0, falsely reporting a match to the
caller.Technically 'hash - kn->hash' is ok since the hashes are restricted to
31 bits, but it's better to avoid that subtlety.Signed-off-by: Rasmus Villemoes
Acked-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
17 Dec, 2014
1 commit
-
the only instance this method has ever grown was one in kernfs -
one that call ->migrate() of another vm_ops if it exists.Signed-off-by: Al Viro
15 Dec, 2014
1 commit
-
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev__once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
20 Nov, 2014
1 commit
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Signed-off-by: Al Viro
08 Nov, 2014
2 commits
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To match the previous patch which used the pre-alloc buffer for
writes, this patch causes reads to use the same buffer.
This is not strictly necessary as the current seq_read() will allocate
on first read, so user-space can trigger the required pre-alloc. But
consistency is valuable.The read function is somewhat simpler than seq_read() and, for example,
does not support reading from an offset into the file: reads must be
at the start of the file.As seq_read() does not use the prealloc buffer, ->seq_show is
incompatible with ->prealloc and caused an EINVAL return from open().
sysfs code which calls into kernfs always chooses the correct function.As the buffer is shared with writes and other reads, the mutex is
extended to cover the copy_to_user.Signed-off-by: NeilBrown
Reviewed-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman -
md/raid allows metadata management to be performed in user-space.
A various times, particularly on device failure, the metadata needs
to be updated before further writes can be permitted.
This means that the user-space program which updates metadata much
not block on writeout, and so must not allocate memory.mlockall(MCL_CURRENT|MCL_FUTURE) and pre-allocation can avoid all
memory allocation issues for user-memory, but that does not help
kernel memory.
Several kernel objects can be pre-allocated. e.g. files opened before
any writes to the array are permitted.
However some kernel allocation happens in places that cannot be
pre-allocated.
In particular, writes to sysfs files (to tell md that it can now
allow writes to the array) allocate a buffer using GFP_KERNEL.This patch allows attributes to be marked as "PREALLOC". In that case
the maximal buffer is allocated when the file is opened, and then used
on each write instead of allocating a new buffer.As the same buffer is now shared for all writes on the same file
description, the mutex is extended to cover full use of the buffer
including the copy_from_user().The new __ATTR_PREALLOC() 'or's a new flag in to the 'mode', which is
inspected by sysfs_add_file_mode_ns() to determine if the file should be
marked as requiring prealloc.Despite the comment, we *do* use ->seq_show together with ->prealloc
in this patch. The next patch fixes that.Signed-off-by: NeilBrown
Reviewed-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
09 Oct, 2014
1 commit
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Now that check_submounts_and_drop can not fail and is called from
d_invalidate there is no longer a need to call check_submounts_and_drom
from filesystem d_revalidate methods so remove it.Reviewed-by: Miklos Szeredi
Signed-off-by: "Eric W. Biederman"
Signed-off-by: Al Viro