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Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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Jeremy Fitzhardinge is stepping down as a paravirt maintainer. I'll
replace him.
While at it, update the file list to the actual pattern.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: chrisw@sous-sol.org
Cc: jeremy@goop.org
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170905143407.9227-1-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With removal of lguest some of the paravirt functions are no longer
needed:
->read_cr4()
->store_idt()
->set_pmd_at()
->set_pud_at()
->pte_update()
Remove them.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: chrisw@sous-sol.org
Cc: jeremy@goop.org
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170904102527.25409-1-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cpu_init() is weird: it's called rather late (after early
identification and after most MMU state is initialized) on the boot
CPU but is called extremely early (before identification) on secondary
CPUs. It's called just late enough on the boot CPU that its CR4 value
isn't propagated to mmu_cr4_features.
Even if we put CR4.PCIDE into mmu_cr4_features, we'd hit two
problems. First, we'd crash in the trampoline code. That's
fixable, and I tried that. It turns out that mmu_cr4_features is
totally ignored by secondary_start_64(), though, so even with the
trampoline code fixed, it wouldn't help.
This means that we don't currently have CR4.PCIDE reliably initialized
before we start playing with cpu_tlbstate. This is very fragile and
tends to cause boot failures if I make even small changes to the TLB
handling code.
Make it more robust: initialize CR4.PCIDE earlier on the boot CPU
and propagate it to secondary CPUs in start_secondary().
( Yes, this is ugly. I think we should have improved mmu_cr4_features
to actually control CR4 during secondary bootup, but that would be
fairly intrusive at this stage. )
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: 660da7c9228f ("x86/mm: Enable CR4.PCIDE on supported systems")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jiri reported a resume-from-hibernation failure triggered by PCID.
The root cause appears to be rather odd. The hibernation asm
restores a CR3 value that comes from the image header. If the image
kernel has PCID on, it's entirely reasonable for this CR3 value to
have one of the low 12 bits set. The restore code restores it with
CR4.PCIDE=0, which means that those low 12 bits are accepted by the
CPU but are either ignored or interpreted as a caching mode. This
is odd, but still works. We blow up later when the image kernel
restores CR4, though, since changing CR4.PCIDE with CR3[11:0] != 0
is illegal. Boom!
FWIW, it's entirely unclear to me what's supposed to happen if a PAE
kernel restores a non-PAE image or vice versa. Ditto for LA57.
Reported-by: Jiri Kosina <jikos@kernel.org>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 660da7c9228f ("x86/mm: Enable CR4.PCIDE on supported systems")
Link: http://lkml.kernel.org/r/18ca57090651a6341e97083883f9e814c4f14684.1504847163.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If we hit the VM_BUG_ON(), we're detecting a genuinely bad situation,
but we're very unlikely to get a useful call trace.
Make it a warning instead.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Jiri Kosina <jikos@kernel.org>
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/3b4e06bbb382ca54a93218407c93925ff5871546.1504847163.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've mostly tuned f2fs to provide better user
experience for Android. Especially, we've worked on atomic write
feature again with SQLite community in order to support it officially.
And we added or modified several facilities to analyze and enhance IO
behaviors.
Major changes include:
- add app/fs io stat
- add inode checksum feature
- support project/journalled quota
- enhance atomic write with new ioctl() which exposes feature set
- enhance background gc/discard/fstrim flows with new gc_urgent mode
- add F2FS_IOC_FS{GET,SET}XATTR
- fix some quota flows"
* tag 'f2fs-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (63 commits)
f2fs: hurry up to issue discard after io interruption
f2fs: fix to show correct discard_granularity in sysfs
f2fs: detect dirty inode in evict_inode
f2fs: clear radix tree dirty tag of pages whose dirty flag is cleared
f2fs: speed up gc_urgent mode with SSR
f2fs: better to wait for fstrim completion
f2fs: avoid race in between read xattr & write xattr
f2fs: make get_lock_data_page to handle encrypted inode
f2fs: use generic terms used for encrypted block management
f2fs: introduce f2fs_encrypted_file for clean-up
Revert "f2fs: add a new function get_ssr_cost"
f2fs: constify super_operations
f2fs: fix to wake up all sleeping flusher
f2fs: avoid race in between atomic_read & atomic_inc
f2fs: remove unneeded parameter of change_curseg
f2fs: update i_flags correctly
f2fs: don't check inode's checksum if it was dirtied or writebacked
f2fs: don't need to update inode checksum for recovery
f2fs: trigger fdatasync for non-atomic_write file
f2fs: fix to avoid race in between aio and gc
...
Pull ceph updates from Ilya Dryomov:
"The highlights include:
- a large series of fixes and improvements to the snapshot-handling
code (Zheng Yan)
- individual read/write OSD requests passed down to libceph are now
limited to 16M in size to avoid hitting OSD-side limits (Zheng Yan)
- encode MStatfs v2 message to allow for more accurate space usage
reporting (Douglas Fuller)
- switch to the new writeback error tracking infrastructure (Jeff
Layton)"
* tag 'ceph-for-4.14-rc1' of git://github.com/ceph/ceph-client: (35 commits)
ceph: stop on-going cached readdir if mds revokes FILE_SHARED cap
ceph: wait on writeback after writing snapshot data
ceph: fix capsnap dirty pages accounting
ceph: ignore wbc->range_{start,end} when write back snapshot data
ceph: fix "range cyclic" mode writepages
ceph: cleanup local variables in ceph_writepages_start()
ceph: optimize pagevec iterating in ceph_writepages_start()
ceph: make writepage_nounlock() invalidate page that beyonds EOF
ceph: properly get capsnap's size in get_oldest_context()
ceph: remove stale check in ceph_invalidatepage()
ceph: queue cap snap only when snap realm's context changes
ceph: handle race between vmtruncate and queuing cap snap
ceph: fix message order check in handle_cap_export()
ceph: fix NULL pointer dereference in ceph_flush_snaps()
ceph: adjust 36 checks for NULL pointers
ceph: delete an unnecessary return statement in update_dentry_lease()
ceph: ENOMEM pr_err in __get_or_create_frag() is redundant
ceph: check negative offsets in ceph_llseek()
ceph: more accurate statfs
ceph: properly set snap follows for cap reconnect
...
Once we encounter I/O interruption during issuing discards, we will delay
long time before next round, but if system status is I/O idle during the
time, it may loses opportunity to issue discards. So this patch changes
to hurry up to issue discard after io interruption.
Besides, this patch also fixes to issue discards accurately with assigned
rate.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on
a directory in a filesystem that does not have a realtime device and
create a new file in that directory, it gets marked as a real time file.
When data is written and a fsync is issued, the filesystem attempts to
flush a non-existent rt device during the fsync process.
This results in a crash dereferencing a null buftarg pointer in
xfs_blkdev_issue_flush():
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: xfs_blkdev_issue_flush+0xd/0x20
.....
Call Trace:
xfs_file_fsync+0x188/0x1c0
vfs_fsync_range+0x3b/0xa0
do_fsync+0x3d/0x70
SyS_fsync+0x10/0x20
do_syscall_64+0x4d/0xb0
entry_SYSCALL64_slow_path+0x25/0x25
Setting RT inode flags does not require special privileges so any
unprivileged user can cause this oops to occur. To reproduce, confirm
kernel is compiled with CONFIG_XFS_RT=y and run:
# mkfs.xfs -f /dev/pmem0
# mount /dev/pmem0 /mnt/test
# mkdir /mnt/test/foo
# xfs_io -c 'chattr +t' /mnt/test/foo
# xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar
Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait.
Kernels built with CONFIG_XFS_RT=n are not exposed to this bug.
Fixes: f538d4da8d52 ("[XFS] write barrier support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Richard Wareing <rwareing@fb.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If directory's FILE_SHARED cap get revoked, dentry in the directory
can get spliced into other directory (Eg, other client move the
dentry into directory B, then we do readdir on directory B). So we
should stop on-going cached readdir. this can be achieved by marking
dir not complete, because __dcache_readdir() checks dir completeness
before emitting each dentry.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Fix below incorrect display when reading discard_granularity sysfs node.
$ cat /sys/fs/f2fs/<device>/discard_granularity
$ 16
$ echo 32 > /sys/fs/f2fs/<device>/discard_granularity
$ cat /sys/fs/f2fs/<device>/discard_granularity
$ 16
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull dma-mapping updates from Christoph Hellwig:
- removal of the old dma_alloc_noncoherent interface
- remove unused flags to dma_declare_coherent_memory
- restrict OF DMA configuration to specific physical busses
- use the iommu mailing list for dma-mapping questions and patches
* tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping:
dma-coherent: fix dma_declare_coherent_memory() logic error
ARM: imx: mx31moboard: Remove unused 'dma' variable
dma-coherent: remove an unused variable
MAINTAINERS: use the iommu list for the dma-mapping subsystem
dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags
dma-coherent: remove the DMA_MEMORY_INCLUDES_CHILDREN flag
of: restrict DMA configuration
dma-mapping: remove dma_alloc_noncoherent and dma_free_noncoherent
i825xx: switch to switch to dma_alloc_attrs
au1000_eth: switch to dma_alloc_attrs
sgiseeq: switch to dma_alloc_attrs
dma-mapping: reduce dma_mapping_error inline bloat
In sync mode, writepages() needs to write all dirty pages. But
it can only write dirty pages associated with the oldest snapc.
To write dirty pages associated with next snapc, it needs to wait
until current writes complete.
Without this wait, writepages() keeps looking up dirty pages, but
the found dirty pages are not writeable. It wastes CPU time.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add a bugon in f2fs_evict_inode to detect inconsistent status between
inode cache and related node page cache.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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