Document the implementation of error handlers into sysfs.
[dchinner: Added lots more detail.]
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
"make help" if sphinx isn't present.
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Merge tag 'doc-4.8-fixes' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"Three fixes for the docs build, including removing an annoying warning
on 'make help' if sphinx isn't present"
* tag 'doc-4.8-fixes' of git://git.lwn.net/linux:
DocBook: use DOCBOOKS="" to ignore DocBooks instead of IGNORE_DOCBOOKS=1
Documenation: update cgroup's document path
Documentation/sphinx: do not warn about missing tools in 'make help'
Pull more vfs updates from Al Viro:
"Assorted cleanups and fixes.
In the "trivial API change" department - ->d_compare() losing 'parent'
argument"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cachefiles: Fix race between inactivating and culling a cache object
9p: use clone_fid()
9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
vfs: make dentry_needs_remove_privs() internal
vfs: remove file_needs_remove_privs()
vfs: fix deadlock in file_remove_privs() on overlayfs
get rid of 'parent' argument of ->d_compare()
cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
affs ->d_compare(): don't bother with ->d_inode
fold _d_rehash() and __d_rehash() together
fold dentry_rcuwalk_invalidate() into its only remaining caller
cgroup's document path is changed to "cgroup-v1". update it.
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Merge yet more updates from Andrew Morton:
- the rest of ocfs2
- various hotfixes, mainly MM
- quite a bit of misc stuff - drivers, fork, exec, signals, etc.
- printk updates
- firmware
- checkpatch
- nilfs2
- more kexec stuff than usual
- rapidio updates
- w1 things
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
ipc: delete "nr_ipc_ns"
kcov: allow more fine-grained coverage instrumentation
init/Kconfig: add clarification for out-of-tree modules
config: add android config fragments
init/Kconfig: ban CONFIG_LOCALVERSION_AUTO with allmodconfig
relay: add global mode support for buffer-only channels
init: allow blacklisting of module_init functions
w1:omap_hdq: fix regression
w1: add helper macro module_w1_family
w1: remove need for ida and use PLATFORM_DEVID_AUTO
rapidio/switches: add driver for IDT gen3 switches
powerpc/fsl_rio: apply changes for RIO spec rev 3
rapidio: modify for rev.3 specification changes
rapidio: change inbound window size type to u64
rapidio/idt_gen2: fix locking warning
rapidio: fix error handling in mbox request/release functions
rapidio/tsi721_dma: advance queue processing from transfer submit call
rapidio/tsi721: add messaging mbox selector parameter
rapidio/tsi721: add PCIe MRRS override parameter
rapidio/tsi721_dma: add channel mask and queue size parameters
...
The header file "include/linux/nilfs2_fs.h" is composed of parts for
ioctl and disk format, and both are intended to be shared with user
space programs.
This moves them to the uapi directory "include/uapi/linux" splitting the
file to "nilfs2_api.h" and "nilfs2_ondisk.h". The following minor
changes are accompanied by this migration:
- nilfs_direct_node struct in nilfs2/direct.h is converged to
nilfs2_ondisk.h because it's an on-disk structure.
- inline functions nilfs_rec_len_from_disk() and
nilfs_rec_len_to_disk() are moved to nilfs2/dir.c.
Link: http://lkml.kernel.org/r/1465825507-3407-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Describe use of jiffy-based timeout values involved in inode maintenance.
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
1/ Replace pcommit with ADR / directed-flushing:
The pcommit instruction, which has not shipped on any product, is
deprecated. Instead, the requirement is that platforms implement either
ADR, or provide one or more flush addresses per nvdimm. ADR
(Asynchronous DRAM Refresh) flushes data in posted write buffers to the
memory controller on a power-fail event. Flush addresses are defined in
ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure:
"Flush Hint Address Structure". A flush hint is an mmio address that
when written and fenced assures that all previous posted writes
targeting a given dimm have been flushed to media.
2/ On-demand ARS (address range scrub):
Linux uses the results of the ACPI ARS commands to track bad blocks
in pmem devices. When latent errors are detected we re-scrub the media
to refresh the bad block list, userspace can also request a re-scrub at
any time.
3/ Support for the Microsoft DSM (device specific method) command format.
4/ Support for EDK2/OVMF virtual disk device memory ranges.
5/ Various fixes and cleanups across the subsystem.
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Merge tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
- Replace pcommit with ADR / directed-flushing.
The pcommit instruction, which has not shipped on any product, is
deprecated. Instead, the requirement is that platforms implement
either ADR, or provide one or more flush addresses per nvdimm.
ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers
to the memory controller on a power-fail event.
Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware
Interface Table (NFIT) sub-structure: "Flush Hint Address Structure".
A flush hint is an mmio address that when written and fenced assures
that all previous posted writes targeting a given dimm have been
flushed to media.
- On-demand ARS (address range scrub).
Linux uses the results of the ACPI ARS commands to track bad blocks
in pmem devices. When latent errors are detected we re-scrub the
media to refresh the bad block list, userspace can also request a
re-scrub at any time.
- Support for the Microsoft DSM (device specific method) command
format.
- Support for EDK2/OVMF virtual disk device memory ranges.
- Various fixes and cleanups across the subsystem.
* tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits)
libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register"
nfit: do an ARS scrub on hitting a latent media error
nfit: move to nfit/ sub-directory
nfit, libnvdimm: allow an ARS scrub to be triggered on demand
libnvdimm: register nvdimm_bus devices with an nd_bus driver
pmem: clarify a debug print in pmem_clear_poison
x86/insn: remove pcommit
Revert "KVM: x86: add pcommit support"
nfit, tools/testing/nvdimm/: unify shutdown paths
libnvdimm: move ->module to struct nvdimm_bus_descriptor
nfit: cleanup acpi_nfit_init calling convention
nfit: fix _FIT evaluation memory leak + use after free
tools/testing/nvdimm: add manufacturing_{date|location} dimm properties
tools/testing/nvdimm: add virtual ramdisk range
acpi, nfit: treat virtual ramdisk SPA as pmem region
pmem: kill __pmem address space
pmem: kill wmb_pmem()
libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes
fs/dax: remove wmb_pmem()
libnvdimm, pmem: flush posted-write queues on shutdown
...
Pull vfs updates from Al Viro:
"Assorted cleanups and fixes.
Probably the most interesting part long-term is ->d_init() - that will
have a bunch of followups in (at least) ceph and lustre, but we'll
need to sort the barrier-related rules before it can get used for
really non-trivial stuff.
Another fun thing is the merge of ->d_iput() callers (dentry_iput()
and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all
except the one in __d_lookup_lru())"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
fs/dcache.c: avoid soft-lockup in dput()
vfs: new d_init method
vfs: Update lookup_dcache() comment
bdev: get rid of ->bd_inodes
Remove last traces of ->sync_page
new helper: d_same_name()
dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()
vfs: clean up documentation
vfs: document ->d_real()
vfs: merge .d_select_inode() into .d_real()
unify dentry_iput() and dentry_unlink_inode()
binfmt_misc: ->s_root is not going anywhere
drop redundant ->owner initializations
ufs: get rid of redundant checks
orangefs: constify inode_operations
missed comment updates from ->direct_IO() prototype change
file_inode(f)->i_mapping is f->f_mapping
trim fsnotify hooks a bit
9p: new helper - v9fs_parent_fid()
debugfs: ->d_parent is never NULL or negative
...
replacing redundant inode page updates with mark_inode_dirty calls. And we tried
to reduce lock contentions as well to improve filesystem scalability.
Other feature is setting F2FS automatically when detecting host-managed SMR.
= Enhancement =
- ioctl to move a range of data between files
- inject orphan inode errors
- avoid flush commands congestion
- support lazytime
= Bug fixes =
- return proper results for some dentry operations
- fix deadlock in add_link failure
- disable extent_cache for fcollapse/finsert
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Merge tag 'for-f2fs-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"The major change in this version is mitigating cpu overheads on write
paths by replacing redundant inode page updates with mark_inode_dirty
calls. And we tried to reduce lock contentions as well to improve
filesystem scalability. Other feature is setting F2FS automatically
when detecting host-managed SMR.
Enhancements:
- ioctl to move a range of data between files
- inject orphan inode errors
- avoid flush commands congestion
- support lazytime
Bug fixes:
- return proper results for some dentry operations
- fix deadlock in add_link failure
- disable extent_cache for fcollapse/finsert"
* tag 'for-f2fs-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (68 commits)
f2fs: clean up coding style and redundancy
f2fs: get victim segment again after new cp
f2fs: handle error case with f2fs_bug_on
f2fs: avoid data race when deciding checkpoin in f2fs_sync_file
f2fs: support an ioctl to move a range of data blocks
f2fs: fix to report error number of f2fs_find_entry
f2fs: avoid memory allocation failure due to a long length
f2fs: reset default idle interval value
f2fs: use blk_plug in all the possible paths
f2fs: fix to avoid data update racing between GC and DIO
f2fs: add maximum prefree segments
f2fs: disable extent_cache for fcollapse/finsert inodes
f2fs: refactor __exchange_data_block for speed up
f2fs: fix ERR_PTR returned by bio
f2fs: avoid mark_inode_dirty
f2fs: move i_size_write in f2fs_write_end
f2fs: fix to avoid redundant discard during fstrim
f2fs: avoid mismatching block range for discard
f2fs: fix incorrect f_bfree calculation in ->statfs
f2fs: use percpu_rw_semaphore
...
Merge updates from Andrew Morton:
- a few misc bits
- ocfs2
- most(?) of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
thp: fix comments of __pmd_trans_huge_lock()
cgroup: remove unnecessary 0 check from css_from_id()
cgroup: fix idr leak for the first cgroup root
mm: memcontrol: fix documentation for compound parameter
mm: memcontrol: remove BUG_ON in uncharge_list
mm: fix build warnings in <linux/compaction.h>
mm, thp: convert from optimistic swapin collapsing to conservative
mm, thp: fix comment inconsistency for swapin readahead functions
thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
shmem: split huge pages beyond i_size under memory pressure
thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
khugepaged: add support of collapse for tmpfs/shmem pages
shmem: make shmem_inode_info::lock irq-safe
khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
thp: extract khugepaged from mm/huge_memory.c
shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
shmem: add huge pages support
shmem: get_unmapped_area align huge page
shmem: prepare huge= mount option and sysfs knob
mm, rmap: account shmem thp pages
...
The idea borrowed from Peter's patch from patchset on speculative page
faults[1]:
Instead of passing around the endless list of function arguments,
replace the lot with a single structure so we can change context without
endless function signature changes.
The changes are mostly mechanical with exception of faultaround code:
filemap_map_pages() got reworked a bit.
This patch is preparation for the next one.
[1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org
Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have allowed migration for only LRU pages until now and it was enough
to make high-order pages. But recently, embedded system(e.g., webOS,
android) uses lots of non-movable pages(e.g., zram, GPU memory) so we
have seen several reports about troubles of small high-order allocation.
For fixing the problem, there were several efforts (e,g,. enhance
compaction algorithm, SLUB fallback to 0-order page, reserved memory,
vmalloc and so on) but if there are lots of non-movable pages in system,
their solutions are void in the long run.
So, this patch is to support facility to change non-movable pages with
movable. For the feature, this patch introduces functions related to
migration to address_space_operations as well as some page flags.
If a driver want to make own pages movable, it should define three
functions which are function pointers of struct
address_space_operations.
1. bool (*isolate_page) (struct page *page, isolate_mode_t mode);
What VM expects on isolate_page function of driver is to return *true*
if driver isolates page successfully. On returing true, VM marks the
page as PG_isolated so concurrent isolation in several CPUs skip the
page for isolation. If a driver cannot isolate the page, it should
return *false*.
Once page is successfully isolated, VM uses page.lru fields so driver
shouldn't expect to preserve values in that fields.
2. int (*migratepage) (struct address_space *mapping,
struct page *newpage, struct page *oldpage, enum migrate_mode);
After isolation, VM calls migratepage of driver with isolated page. The
function of migratepage is to move content of the old page to new page
and set up fields of struct page newpage. Keep in mind that you should
indicate to the VM the oldpage is no longer movable via
__ClearPageMovable() under page_lock if you migrated the oldpage
successfully and returns 0. If driver cannot migrate the page at the
moment, driver can return -EAGAIN. On -EAGAIN, VM will retry page
migration in a short time because VM interprets -EAGAIN as "temporal
migration failure". On returning any error except -EAGAIN, VM will give
up the page migration without retrying in this time.
Driver shouldn't touch page.lru field VM using in the functions.
3. void (*putback_page)(struct page *);
If migration fails on isolated page, VM should return the isolated page
to the driver so VM calls driver's putback_page with migration failed
page. In this function, driver should put the isolated page back to the
own data structure.
4. non-lru movable page flags
There are two page flags for supporting non-lru movable page.
* PG_movable
Driver should use the below function to make page movable under
page_lock.
void __SetPageMovable(struct page *page, struct address_space *mapping)
It needs argument of address_space for registering migration family
functions which will be called by VM. Exactly speaking, PG_movable is
not a real flag of struct page. Rather than, VM reuses page->mapping's
lower bits to represent it.
#define PAGE_MAPPING_MOVABLE 0x2
page->mapping = page->mapping | PAGE_MAPPING_MOVABLE;
so driver shouldn't access page->mapping directly. Instead, driver
should use page_mapping which mask off the low two bits of page->mapping
so it can get right struct address_space.
For testing of non-lru movable page, VM supports __PageMovable function.
However, it doesn't guarantee to identify non-lru movable page because
page->mapping field is unified with other variables in struct page. As
well, if driver releases the page after isolation by VM, page->mapping
doesn't have stable value although it has PAGE_MAPPING_MOVABLE (Look at
__ClearPageMovable). But __PageMovable is cheap to catch whether page
is LRU or non-lru movable once the page has been isolated. Because LRU
pages never can have PAGE_MAPPING_MOVABLE in page->mapping. It is also
good for just peeking to test non-lru movable pages before more
expensive checking with lock_page in pfn scanning to select victim.
For guaranteeing non-lru movable page, VM provides PageMovable function.
Unlike __PageMovable, PageMovable functions validates page->mapping and
mapping->a_ops->isolate_page under lock_page. The lock_page prevents
sudden destroying of page->mapping.
Driver using __SetPageMovable should clear the flag via
__ClearMovablePage under page_lock before the releasing the page.
* PG_isolated
To prevent concurrent isolation among several CPUs, VM marks isolated
page as PG_isolated under lock_page. So if a CPU encounters PG_isolated
non-lru movable page, it can skip it. Driver doesn't need to manipulate
the flag because VM will set/clear it automatically. Keep in mind that
if driver sees PG_isolated page, it means the page have been isolated by
VM so it shouldn't touch page.lru field. PG_isolated is alias with
PG_reclaim flag so driver shouldn't use the flag for own purpose.
[opensource.ganesh@gmail.com: mm/compaction: remove local variable is_lru]
Link: http://lkml.kernel.org/r/20160618014841.GA7422@leo-test
Link: http://lkml.kernel.org/r/1464736881-24886-3-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: John Einar Reitan <john.reitan@foss.arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are originally from Matthew Wilcox and were part of his huge
"mm,fs,dax: Change ->pmd_fault to ->huge_fault" patch that was part of
PUD support.
I'm breaking these small changes out as they stand on their own and add
useful information to Documentation/filesystems/dax.txt.
Link: http://lkml.kernel.org/r/20160714214049.20075-1-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
documentation mechanism based on the Sphinx system. The objectives here
are to make it easier to create better-integrated (and more attractive)
documents while (eventually) dumping our one-of-a-kind, cobbled-together
system for something that is widely used and maintained by others. There's
a fair amount of information what's being done, why, and how to use it in:
https://lwn.net/Articles/692704/https://lwn.net/Articles/692705/
Closer to home, Documentation/kernel-documentation.rst describes how it
works.
For now, the new system exists alongside the old one; you should soon see
the GPU documentation converted over in the DRM pull and some significant
media conversion work as well. Once all the docs have been moved over and
we're convinced that the rough edges (of which are are a few) have been
smoothed over, the DocBook-based stuff should go away.
Primary credit is to Jani Nikula for doing the heavy lifting to make this
stuff actually work; there has also been notable effort from Markus Heiser,
Daniel Vetter, and Mauro Carvalho Chehab.
Expect a couple of conflicts on the new index.rst file over the course of
the merge window; they are trivially resolvable. That file may be a bit of
a conflict magnet in the short term, but I don't expect that situation to
last for any real length of time.
Beyond that, of course, we have the usual collection of tweaks, updates,
and typo fixes.
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Merge tag 'docs-for-linus' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"Some big changes this month, headlined by the addition of a new
formatted documentation mechanism based on the Sphinx system.
The objectives here are to make it easier to create better-integrated
(and more attractive) documents while (eventually) dumping our
one-of-a-kind, cobbled-together system for something that is widely
used and maintained by others. There's a fair amount of information
what's being done, why, and how to use it in:
https://lwn.net/Articles/692704/https://lwn.net/Articles/692705/
Closer to home, Documentation/kernel-documentation.rst describes how
it works.
For now, the new system exists alongside the old one; you should soon
see the GPU documentation converted over in the DRM pull and some
significant media conversion work as well. Once all the docs have
been moved over and we're convinced that the rough edges (of which are
are a few) have been smoothed over, the DocBook-based stuff should go
away.
Primary credit is to Jani Nikula for doing the heavy lifting to make
this stuff actually work; there has also been notable effort from
Markus Heiser, Daniel Vetter, and Mauro Carvalho Chehab.
Expect a couple of conflicts on the new index.rst file over the course
of the merge window; they are trivially resolvable. That file may be
a bit of a conflict magnet in the short term, but I don't expect that
situation to last for any real length of time.
Beyond that, of course, we have the usual collection of tweaks,
updates, and typo fixes"
* tag 'docs-for-linus' of git://git.lwn.net/linux: (77 commits)
doc-rst: kernel-doc: fix handling of address_space tags
Revert "doc/sphinx: Enable keep_warnings"
doc-rst: kernel-doc directive, fix state machine reporter
docs: deprecate kernel-doc-nano-HOWTO.txt
doc/sphinx: Enable keep_warnings
Documentation: add watermark_scale_factor to the list of vm systcl file
kernel-doc: Fix up warning output
docs: Get rid of some kernel-documentation warnings
doc-rst: add an option to ignore DocBooks when generating docs
workqueue: Fix a typo in workqueue.txt
Doc: ocfs: Fix typo in filesystems/ocfs2-online-filecheck.txt
Documentation/sphinx: skip build if user requested specific DOCBOOKS
Documentation: add cleanmediadocs to the documentation targets
Add .pyc files to .gitignore
Doc: PM: Fix a typo in intel_powerclamp.txt
doc-rst: flat-table directive - initial implementation
Documentation: add meta-documentation for Sphinx and kernel-doc
Documentation: tiny typo fix in usb/gadget_multi.txt
Documentation: fix wrong value in md.txt
bcache: documentation formatting, edited for clarity, stripe alignment notes
...
The __pmem address space was meant to annotate codepaths that touch
persistent memory and need to coordinate a call to wmb_pmem(). Now that
wmb_pmem() is gone, there is little need to keep this annotation.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This command:
echo 5 > /proc/irq/10/smp_affinity
means only the first and third (not fourth) CPUs can handle irqs
That is, CPU0 is the first CPU and CPU2 is the third cpu
Signed-off-by: John Kacur <jkacur@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1466168715-8410-1-git-send-email-jkacur@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fix some spelling typo found in ocfs2-online-filecheck.txt
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Commit 7eaceaccab removed ->sync_page, but a few mentions of it still
existed in documentation and comments,
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This mount option is to enable original log-structured filesystem forcefully.
So, there should be no random writes for main area.
Especially, this supports host-managed SMR device.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in. If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem. Otherwise the open of /dev/ptmx fails.
The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.
Each mount of devpts is now a separate and equal filesystem.
Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.
A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it. The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.
In the implementation of devpts:
- devpts_mnt is killed as it is no longer meaningful if all mounts of
devpts are equal.
- pts_sb_from_inode is replaced by just inode->i_sb as all cached
inodes in the tty layer are now from the devpts filesystem.
- devpts_add_ref is rolled into the new function devpts_ptmx. And the
unnecessary inode hold is removed.
- devpts_del_ref is renamed devpts_release and reduced to just a
deacrivate_super.
- The newinstance mount option continues to be accepted but is now
ignored.
In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.
Documentation/filesystems/devices.txt is updated to describe the current
situation.
This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01. With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs fixes from Al Viro:
"Followups to the parallel lookup work:
- update docs
- restore killability of the places that used to take ->i_mutex
killably now that we have down_write_killable() merged
- Additionally, it turns out that I missed a prerequisite for
security_d_instantiate() stuff - ->getxattr() wasn't the only thing
that could be called before dentry is attached to inode; with smack
we needed the same treatment applied to ->setxattr() as well"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch ->setxattr() to passing dentry and inode separately
switch xattr_handler->set() to passing dentry and inode separately
restore killability of old mutex_lock_killable(&inode->i_mutex) users
add down_write_killable_nested()
update D/f/directory-locking
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull overlayfs update from Miklos Szeredi:
"The meat of this is a change to use the mounter's credentials for
operations that require elevated privileges (such as whiteout
creation). This fixes behavior under user namespaces as well as being
a nice cleanup"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: Do d_type check only if work dir creation was successful
ovl: update documentation
ovl: override creds with the ones from the superblock mounter
- Until now, dax has been disabled if media errors were found on
any device. This enables the use of DAX in the presence of these
errors by making all sector-aligned zeroing go through the driver.
- The driver (already) has the ability to clear errors on writes that
are sent through the block layer using 'DSMs' defined in ACPI 6.1.
Other misc changes:
- When mounting DAX filesystems, check to make sure the partition
is page aligned. This is a requirement for DAX, and previously, we
allowed such unaligned mounts to succeed, but subsequent reads/writes
would fail.
- Misc/cleanup fixes from Jan that remove unused code from DAX related to
zeroing, writeback, and some size checks.
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Merge tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull misc DAX updates from Vishal Verma:
"DAX error handling for 4.7
- Until now, dax has been disabled if media errors were found on any
device. This enables the use of DAX in the presence of these
errors by making all sector-aligned zeroing go through the driver.
- The driver (already) has the ability to clear errors on writes that
are sent through the block layer using 'DSMs' defined in ACPI 6.1.
Other misc changes:
- When mounting DAX filesystems, check to make sure the partition is
page aligned. This is a requirement for DAX, and previously, we
allowed such unaligned mounts to succeed, but subsequent
reads/writes would fail.
- Misc/cleanup fixes from Jan that remove unused code from DAX
related to zeroing, writeback, and some size checks"
* tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dax: fix a comment in dax_zero_page_range and dax_truncate_page
dax: for truncate/hole-punch, do zeroing through the driver if possible
dax: export a low-level __dax_zero_page_range helper
dax: use sb_issue_zerout instead of calling dax_clear_sectors
dax: enable dax in the presence of known media errors (badblocks)
dax: fallback from pmd to pte on error
block: Update blkdev_dax_capable() for consistency
xfs: Add alignment check for DAX mount
ext2: Add alignment check for DAX mount
ext4: Add alignment check for DAX mount
block: Add bdev_dax_supported() for dax mount checks
block: Add vfs_msg() interface
dax: Remove redundant inode size checks
dax: Remove pointless writeback from dax_do_io()
dax: Remove zeroing from dax_io()
dax: Remove dead zeroing code from fault handlers
ext2: Avoid DAX zeroing to corrupt data
ext2: Fix block zeroing in ext2_get_blocks() for DAX
dax: Remove complete_unwritten argument
DAX: move RADIX_DAX_ definitions to dax.c
To respond to a certain developer's request, this explicitly state that
developers can reimplement the nilfs2 design for other operating systems
to share data stored in that format.
Link: http://lkml.kernel.org/r/1461935747-10380-7-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's not possible to read the process umask without also modifying it,
which is what umask(2) does. A library cannot read umask safely,
especially if the main program might be multithreaded.
Add a new status line ("Umask") in /proc/<PID>/status. It contains the
file mode creation mask (umask) in octal. It is only shown for tasks
which have task->fs.
This patch is adapted from one originally written by Pierre Carrier.
The use case is that we have endless trouble with people setting weird
umask() values (usually on the grounds of "security"), and then
everything breaking. I'm on the hook to fix these. We'd like to add
debugging to our program so we can dump out the umask in debug reports.
Previous versions of the patch used a syscall so you could only read
your own umask. That's all I need. However there was quite a lot of
push-back from those, so this new version exports it in /proc.
See:
https://lkml.org/lkml/2016/4/13/704 [umask2]
https://lkml.org/lkml/2016/4/13/487 [getumask]
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pierre Carrier <pierre@spotify.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
infrastructural work to allow documents to be written using restructured
text. Maybe someday, in a galaxy far far away, we'll be able to eliminate
the DocBook dependency and have a much better integrated set of kernel
docs. Someday.
Beyond that, there's a new document on security hardening from Kees, the
movement of some sample code over to samples/, a number of improvements to
the serial docs from Geert, and the usual collection of corrections, typo
fixes, etc.
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Merge tag 'docs-for-linus' of git://git.lwn.net/linux
Pull Documentation updates from Jon Corbet:
"A bit busier this time around.
The most interesting thing (IMO) this time around is some beginning
infrastructural work to allow documents to be written using
restructured text. Maybe someday, in a galaxy far far away, we'll be
able to eliminate the DocBook dependency and have a much better
integrated set of kernel docs. Someday.
Beyond that, there's a new document on security hardening from Kees,
the movement of some sample code over to samples/, a number of
improvements to the serial docs from Geert, and the usual collection
of corrections, typo fixes, etc"
* tag 'docs-for-linus' of git://git.lwn.net/linux: (55 commits)
doc: self-protection: provide initial details
serial: doc: Use port->state instead of info
serial: doc: Always refer to tty_port->mutex
Documentation: vm: Spelling s/paltform/platform/g
Documentation/memcg: update kmem limit doc as codes behavior
docproc: print a comment about autogeneration for rst output
docproc: add support for reStructuredText format via --rst option
docproc: abstract terminating lines at first space
docproc: abstract docproc directive detection
docproc: reduce unnecessary indentation
docproc: add variables for subcommand and filename
kernel-doc: use rst C domain directives and references for types
kernel-doc: produce RestructuredText output
kernel-doc: rewrite usage description, remove duplicated comments
Doc: correct the location of sysrq.c
Documentation: fix common spelling mistakes
samples: v4l: from Documentation to samples directory
samples: connector: from Documentation to samples directory
Documentation: xillybus: fix spelling mistake
Documentation: x86: fix spelling mistakes
...
In the truncate or hole-punch path in dax, we clear out sub-page ranges.
If these sub-page ranges are sector aligned and sized, we can do the
zeroing through the driver instead so that error-clearing is handled
automatically.
For sub-sector ranges, we still have to rely on clear_pmem and have the
possibility of tripping over errors.
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Pull vfs cleanups from Al Viro:
"More cleanups from Christoph"
* 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
nfsd: use RWF_SYNC
fs: add RWF_DSYNC aand RWF_SYNC
ceph: use generic_write_sync
fs: simplify the generic_write_sync prototype
fs: add IOCB_SYNC and IOCB_DSYNC
direct-io: remove the offset argument to dio_complete
direct-io: eliminate the offset argument to ->direct_IO
xfs: eliminate the pos variable in xfs_file_dio_aio_write
filemap: remove the pos argument to generic_file_direct_write
filemap: remove pos variables in generic_file_read_iter
New method: ->iterate_shared(). Same arguments as in ->iterate(),
called with the directory locked only shared. Once all filesystems
switch, the old one will be gone.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ta-da!
The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.
lockdep side also might need more work
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We'll need to verify that there's neither a hashed nor in-lookup
dentry with desired parent/name before adding to in-lookup set.
One possible solution would be to hold the parent's ->d_lock through
both checks, but while the in-lookup set is relatively small at any
time, dcache is not. And holding the parent's ->d_lock through
something like __d_lookup_rcu() would suck too badly.
So we leave the parent's ->d_lock alone, which means that we watch
out for the following scenario:
* we verify that there's no hashed match
* existing in-lookup match gets hashed by another process
* we verify that there's no in-lookup matches and decide
that everything's fine.
Solution: per-directory kinda-sorta seqlock, bumped around the times
we hash something that used to be in-lookup or move (and hash)
something in place of in-lookup. Then the above would turn into
* read the counter
* do dcache lookup
* if no matches found, check for in-lookup matches
* if there had been none of those either, check if the
counter has changed; repeat if it has.
The "kinda-sorta" part is due to the fact that we don't have much spare
space in inode. There is a spare word (shared with i_bdev/i_cdev/i_pipe),
so the counter part is not a problem, but spinlock is a different story.
We could use the parent's ->d_lock, and it would be less painful in
terms of contention, for __d_add() it would be rather inconvenient to
grab; we could do that (using lock_parent()), but...
Fortunately, we can get serialization on the counter itself, and it
might be a good idea in general; we can use cmpxchg() in a loop to
get from even to odd and smp_store_release() from odd to even.
This commit adds the counter and updating logics; the readers will be
added in the next commit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Including blkdev_direct_IO and dax_do_io. It has to be ki_pos to actually
work, so eliminate the superflous argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This fixes several spelling mistakes in the Documentation/ tree, which
are caught by checkpatch.pl's spell checking.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Mostly direct substitution with occasional adjustment or removing
outdated comments.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull orangefs filesystem from Mike Marshall.
This finally merges the long-pending orangefs filesystem, which has been
much cleaned up with input from Al Viro over the last six months. From
the documentation file:
"OrangeFS is an LGPL userspace scale-out parallel storage system. It
is ideal for large storage problems faced by HPC, BigData, Streaming
Video, Genomics, Bioinformatics.
Orangefs, originally called PVFS, was first developed in 1993 by Walt
Ligon and Eric Blumer as a parallel file system for Parallel Virtual
Machine (PVM) as part of a NASA grant to study the I/O patterns of
parallel programs.
Orangefs features include:
- Distributes file data among multiple file servers
- Supports simultaneous access by multiple clients
- Stores file data and metadata on servers using local file system
and access methods
- Userspace implementation is easy to install and maintain
- Direct MPI support
- Stateless"
see Documentation/filesystems/orangefs.txt for more in-depth details.
* tag 'ofs-pull-tag-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux: (174 commits)
orangefs: fix orangefs_superblock locking
orangefs: fix do_readv_writev() handling of error halfway through
orangefs: have ->kill_sb() evict the VFS side of things first
orangefs: sanitize ->llseek()
orangefs-bufmap.h: trim unused junk
orangefs: saner calling conventions for getting a slot
orangefs_copy_{to,from}_bufmap(): don't pass bufmap pointer
orangefs: get rid of readdir_handle_s
ornagefs: ensure that truncate has an up to date inode size
orangefs: move code which sets i_link to orangefs_inode_getattr
orangefs: remove needless wrapper around GFP_KERNEL
orangefs: remove wrapper around mutex_lock(&inode->i_mutex)
orangefs: refactor inode type or link_target change detection
orangefs: use new getattr for revalidate and remove old getattr
orangefs: use new getattr in inode getattr and permission
orangefs: use new orangefs_inode_getattr to get size in write and llseek
orangefs: use new orangefs_inode_getattr to create new inodes
orangefs: rename orangefs_inode_getattr to orangefs_inode_old_getattr
orangefs: remove inode->i_lock wrapper
orangefs: put register_chrdev immediately before register_filesystem
...
pnfs layout type from Christoph Hellwig. The new layout type is a
variant of the block layout which uses SCSI features to offer improved
fencing and device identification.
Note this pull request also includes the client side of SCSI layout,
with Trond's permission.
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Merge tag 'nfsd-4.6-1' of git://linux-nfs.org/~bfields/linux
Pull more nfsd updates from Bruce Fields:
"Apologies for the previous request, which omitted the top 8 commits
from my for-next branch (including the SCSI layout commits). Thanks
to Trond for spotting my error!"
This actually includes the new layout types, so here's that part of
the pull message repeated:
"Support for a new pnfs layout type from Christoph Hellwig. The new
layout type is a variant of the block layout which uses SCSI features
to offer improved fencing and device identification.
Note this pull request also includes the client side of SCSI layout,
with Trond's permission"
* tag 'nfsd-4.6-1' of git://linux-nfs.org/~bfields/linux:
nfsd: use short read as well as i_size to set eof
nfsd: better layoutupdate bounds-checking
nfsd: block and scsi layout drivers need to depend on CONFIG_BLOCK
nfsd: add SCSI layout support
nfsd: move some blocklayout code
nfsd: add a new config option for the block layout driver
nfs/blocklayout: add SCSI layout support
nfs4.h: add SCSI layout definitions
