Android needs to mremap large regions of memory during memory management
related operations. The mremap system call can be really slow if THP is
not enabled. The bottleneck is move_page_tables, which is copying each
pte at a time, and can be really slow across a large map. Turning on
THP may not be a viable option, and is not for us. This patch speeds up
the performance for non-THP system by copying at the PMD level when
possible.
The speedup is an order of magnitude on x86 (~20x). On a 1GB mremap,
the mremap completion times drops from 3.4-3.6 milliseconds to 144-160
microseconds.
Before:
Total mremap time for 1GB data: 3521942 nanoseconds.
Total mremap time for 1GB data: 3449229 nanoseconds.
Total mremap time for 1GB data: 3488230 nanoseconds.
After:
Total mremap time for 1GB data: 150279 nanoseconds.
Total mremap time for 1GB data: 144665 nanoseconds.
Total mremap time for 1GB data: 158708 nanoseconds.
If THP is enabled the optimization is mostly skipped except in certain
situations.
[joel@joelfernandes.org: fix 'move_normal_pmd' unused function warning] Link: http://lkml.kernel.org/r/20181108224457.GB209347@google.com Link: http://lkml.kernel.org/r/20181108181201.88826-3-joelaf@google.com Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Michal Hocko <mhocko@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: treewide: remove unused address argument from pte_alloc functions
Patch series "Add support for fast mremap".
This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems. There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work. Also we find that there is no point in passing the 'address' to
pte_alloc since its unused. This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well. Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.
Build and boot tested on x86-64. Build tested on arm64. The config
enablement patch for arm64 will be posted in the future after more
testing.
The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.
// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.
virtual patch
@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@
fn(...
- , T2 E2
)
{ ... }
@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@
(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)
@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@
(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)
David Engraf [Thu, 3 Jan 2019 23:28:31 +0000 (15:28 -0800)]
initramfs: cleanup incomplete rootfs
Unpacking an external initrd may fail e.g. not enough memory. This
leads to an incomplete rootfs because some files might be extracted
already. Fixed by cleaning the rootfs so the kernel is not using an
incomplete rootfs.
Link: http://lkml.kernel.org/r/20181030151805.5519-1-david.engraf@sysgo.com Signed-off-by: David Engraf <david.engraf@sysgo.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Du Changbin [Thu, 3 Jan 2019 23:28:27 +0000 (15:28 -0800)]
scripts/gdb: fix lx-version string output
A bug is present in GDB which causes early string termination when
parsing variables. This has been reported [0], but we should ensure
that we can support at least basic printing of the core kernel strings.
For current gdb version (has been tested with 7.3 and 8.1), 'lx-version'
only prints one character.
(gdb) lx-version
L(gdb)
This can be fixed by casting 'linux_banner' as (char *).
(gdb) lx-version
Linux version 4.19.0-rc1+ (changbin@acer) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) #21 SMP Sat Sep 1 21:43:30 CST 2018
Anders Roxell [Thu, 3 Jan 2019 23:28:24 +0000 (15:28 -0800)]
kernel/kcov.c: mark write_comp_data() as notrace
Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the
function called from __sanitizer_cov_trace_const_cmp4 shouldn't be
traceable either. ftrace_graph_caller() gets called every time func
write_comp_data() gets called if it isn't marked 'notrace'. This is the
backtrace from gdb:
#0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
#1 0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
#2 0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116
#3 0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=<optimized out>, arg2=<optimized out>) at ../kernel/kcov.c:188
#4 0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27
#5 0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182
Rework so that write_comp_data() that are called from
__sanitizer_cov_trace_*_cmp*() are marked as 'notrace'.
Commit 903e8ff86753 ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace")
missed to mark write_comp_data() as 'notrace'. When that patch was
created gcc-7 was used. In lib/Kconfig.debug
config KCOV_ENABLE_COMPARISONS
depends on $(cc-option,-fsanitize-coverage=trace-cmp)
That code path isn't hit with gcc-7. However, it were that with gcc-8.
Link: http://lkml.kernel.org/r/20181206143011.23719-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Co-developed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Feng Tang [Thu, 3 Jan 2019 23:28:17 +0000 (15:28 -0800)]
panic: add options to print system info when panic happens
Kernel panic issues are always painful to debug, partially because it's
not easy to get enough information of the context when panic happens.
And we have ramoops and kdump for that, while this commit tries to
provide a easier way to show the system info by adding a cmdline
parameter, referring some idea from sysrq handler.
Link: http://lkml.kernel.org/r/1543398842-19295-2-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tigran Aivazian [Thu, 3 Jan 2019 23:28:14 +0000 (15:28 -0800)]
bfs: extra sanity checking and static inode bitmap
Strengthen validation of BFS superblock against corruption. Make
in-core inode bitmap static part of superblock info structure. Print a
warning when mounting a BFS filesystem created with "-N 512" option as
only 510 files can be created in the root directory. Make the kernel
messages more uniform. Update the 'prefix' passed to bfs_dump_imap() to
match the current naming of operations. White space and comments
cleanup.
Oleg Nesterov [Thu, 3 Jan 2019 23:28:11 +0000 (15:28 -0800)]
exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the
"extra" size for argv/envp pointers every time, this is a bit ugly and
even not strictly correct: acct_arg_size() must not account this size.
Remove all the rlimit code in get_arg_page(). Instead, add bprm->argmin
calculated once at the start of __do_execve_file() and change
copy_strings to check bprm->p >= bprm->argmin.
The patch adds the new helper, prepare_arg_pages() which initializes
bprm->argc/envc and bprm->argmin.
[oleg@redhat.com: fix !CONFIG_MMU version of get_arg_page()] Link: http://lkml.kernel.org/r/20181126122307.GA1660@redhat.com
[akpm@linux-foundation.org: use max_t] Link: http://lkml.kernel.org/r/20181112160910.GA28440@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
load_script() simply truncates bprm->buf and this is very wrong if the
length of shebang string exceeds BINPRM_BUF_SIZE-2. This can silently
truncate i_arg or (worse) we can execute the wrong binary if buf[2:126]
happens to be the valid executable path.
Change load_script() to return ENOEXEC if it can't find '\n' or zero in
bprm->buf. Note that '\0' can come from either
prepare_binprm()->memset() or from kernel_read(), we do not care.
Link: http://lkml.kernel.org/r/20181112160931.GA28463@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ben Woodard <woodard@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yi Wang [Thu, 3 Jan 2019 23:28:03 +0000 (15:28 -0800)]
fork: fix some -Wmissing-prototypes warnings
We get a warning when building kernel with W=1:
kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes]
kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes]
Add the missing declaration in head file to fix this.
Also, remove arch_release_thread_stack() completely because no arch
seems to implement it since bb9d81264 (arch: remove tile port).
Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@zte.com.cn Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carmeli Tamir [Thu, 3 Jan 2019 23:28:00 +0000 (15:28 -0800)]
fat: new inline functions to determine the FAT variant (32, 16 or 12)
This patch introduces 3 new inline functions - is_fat12, is_fat16 and
is_fat32, and replaces every occurrence in the code in which the FS
variant (whether this is FAT12, FAT16 or FAT32) was previously checked
using msdos_sb_info->fat_bits.
Link: http://lkml.kernel.org/r/1544990640-11604-4-git-send-email-carmeli.tamir@gmail.com Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carmeli Tamir [Thu, 3 Jan 2019 23:27:56 +0000 (15:27 -0800)]
fat: move MAX_FAT to fat.h and change it to inline function
MAX_FAT is useless in msdos_fs.h, since it uses the MSDOS_SB function
that is defined in fat.h. So really, this macro can be only called from
code that already includes fat.h.
Hence, this patch moves it to fat.h, right after MSDOS_SB is defined. I
also changed it to an inline function in order to save the double call
to MSDOS_SB. This was suggested by joe@perches.com in the previous
version.
This patch is required for the next in the series, in which the variant
(whether this is FAT12, FAT16 or FAT32) checks are replaced with new
macros.
Link: http://lkml.kernel.org/r/1544990640-11604-3-git-send-email-carmeli.tamir@gmail.com Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carmeli Tamir [Thu, 3 Jan 2019 23:27:53 +0000 (15:27 -0800)]
fat: remove FAT_FIRST_ENT macro
The comment edited in this patch was the only reference to the
FAT_FIRST_ENT macro, which is not used anymore. Moreover, the commented
line of code does not compile with the current code.
Since the FAT_FIRST_ENT macro checks the FAT variant in a way that the
patch series changes, I removed it, and instead wrote a clear
explanation of what was checked.
I verified that the changed comment is correct according to Microsoft
FAT spec, search for "BPB_Media" in the following references:
1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.
Link: http://lkml.kernel.org/r/1544990640-11604-2-git-send-email-carmeli.tamir@gmail.com Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carmeli Tamir [Thu, 3 Jan 2019 23:27:49 +0000 (15:27 -0800)]
include/uapi/linux/msdos_fs.h: use MSDOS_NAME for volume label size
The FAT file system volume label file stored in the root directory
should match the volume label field in the FAT boot sector. As
consequence, the max length of these fields ought to be the same. This
patch replaces the magic '11' usef in the struct fat_boot_sector with
MSDOS_NAME, which is used in struct msdos_dir_entry.
Please check the following references:
1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.
3. User space code that creates FAT filesystem
sometimes uses MSDOS_NAME for the label, sometimes not.
Search for 'if (memcmp(label, NO_NAME, MSDOS_NAME))'.
I consider to make the same patch there as well.
https://github.com/dosfstools/dosfstools/blob/master/src/mkfs.fat.c
Link: http://lkml.kernel.org/r/1543096879-82837-1-git-send-email-carmeli.tamir@gmail.com Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jens Axboe <axboe@kernel.dk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The immutable, append-only and no-dump attributes can only be retrieved
with an ioctl; implement the ->getattr() method to return them on statx.
Do not return the inode birthtime yet, because the issue of how best to
handle the post-2038 timestamps is still under discussion.
This patch is needed to pass xfstests generic/424.
Link: http://lkml.kernel.org/r/20181014163558.sxorxlzjqccq2lpw@eaf Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Cc: Viacheslav Dubeyko <slava@dubeyko.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>
Ian Kent [Thu, 3 Jan 2019 23:27:43 +0000 (15:27 -0800)]
autofs: add strictexpire mount option
Commit 092a53452bb7 ("autofs: take more care to not update last_used on
path walk") helped to (partially) resolve a problem where automounts
were not expiring due to aggressive accesses from user space.
This patch was later reverted because, for very large environments, it
meant more mount requests from clients and when there are a lot of
clients this caused a fairly significant increase in server load.
But there is a need for both types of expire check, depending on use
case, so add a mount option to allow for strict update of last use of
autofs dentrys (which just means not updating the last use on path walk
access).
Ian Kent [Thu, 3 Jan 2019 23:27:33 +0000 (15:27 -0800)]
autofs: improve ioctl sbi checks
Al Viro made some suggestions to improve the implementation of commit 0633da48f0 ("fix autofs_sbi() does not check super block type").
The check is unnecessary in all cases except for ioctl usage so placing
the check in the super block accessor function adds a small overhead to
the common case where it isn't needed.
So it's sufficient to do this in the ioctl code only.
Also the check in the ioctl code is needlessly complex.
[akpm@linux-foundation.org: declare autofs_fs_type in .h, not .c] Link: http://lkml.kernel.org/r/154296970987.9889.1597442413573683096.stgit@pluto-themaw-net Signed-off-by: Ian Kent <raven@themaw.net> 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>
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:26 +0000 (15:27 -0800)]
fs/epoll: deal with wait_queue only once
There is no reason why we rearm the waitiqueue upon every fetch_events
retry (for when events are found yet send_events() fails). If nothing
else, this saves four lock operations per retry, and furthermore reduces
the scope of the lock even further.
[akpm@linux-foundation.org: restore code to original position, fix and reflow comment] Link: http://lkml.kernel.org/r/20181114182532.27981-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Jason Baron <jbaron@akamai.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>
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:22 +0000 (15:27 -0800)]
fs/epoll: rename check_events label to send_events
It is currently called check_events because it, well, did exactly that.
However, since the lockless ep_events_available() call, the label no
longer checks, but just sends the events. Rename as such.
Link: http://lkml.kernel.org/r/20181114182532.27981-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:19 +0000 (15:27 -0800)]
fs/epoll: avoid barrier after an epoll_wait(2) timeout
Upon timeout, we can just exit out of the loop, without the cost of the
changing the task's state with an smp_store_mb call. Just exit out of
the loop and be done - setting the task state afterwards will be, of
course, redundant.
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:15 +0000 (15:27 -0800)]
fs/epoll: reduce the scope of wq lock in epoll_wait()
This patch aims at reducing ep wq.lock hold times in epoll_wait(2). For
the blocking case, there is no need to constantly take and drop the
spinlock, which is only needed to manipulate the waitqueue.
The call to ep_events_available() is now lockless, and only exposed to
benign races. Here, if false positive (returns available events and
does not see another thread deleting an epi from the list) we call into
send_events and then the list's state is correctly seen. Otoh, if a
false negative and we don't see a list_add_tail(), for example, from irq
callback, then it is rechecked again before blocking, which will see the
correct state.
In order for more accuracy to see concurrent list_del_init(), use the
list_empty_careful() variant -- of course, this won't be safe against
insertions from wakeup.
For the overflow list we obviously need to prevent load/store tearing as
we don't want to see partial values while the ready list is disabled.
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:09 +0000 (15:27 -0800)]
fs/epoll: drop ovflist branch prediction
The ep->ovflist is a secondary ready-list to temporarily store events
that might occur when doing sproc without holding the ep->wq.lock. This
accounts for every time we check for ready events and also send events
back to userspace; both callbacks, particularly the latter because of
copy_to_user, can account for a non-trivial time.
As such, the unlikely() check to see if the pointer is being used, seems
both misleading and sub-optimal. In fact, we go to an awful lot of
trouble to sync both lists, and populating the ovflist is far from an
uncommon scenario.
For example, profiling a concurrent epoll_wait(2) benchmark, with
CONFIG_PROFILE_ANNOTATED_BRANCHES shows that for a two threads a 33%
incorrect rate was seen; and when incrementally increasing the number of
epoll instances (which is used, for example for multiple queuing load
balancing models), up to a 90% incorrect rate was seen.
Similarly, by deleting the prediction, 3% throughput boost was seen
across incremental threads.
Link: http://lkml.kernel.org/r/20181108051006.18751-4-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current logic is a bit convoluted. Lets simplify this with a
standard list_for_each_entry_safe() loop instead and just break out
after maxevents is reached.
While at it, remove an unnecessary indentation level in the loop when
there are in fact ready events.
Link: http://lkml.kernel.org/r/20181108051006.18751-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Thu, 3 Jan 2019 23:27:02 +0000 (15:27 -0800)]
fs/epoll: remove max_nests argument from ep_call_nested()
Patch series "epoll: some miscellaneous optimizations".
The following are some incremental optimizations on some of the epoll
core. Each patch has the details, but together, the series is seen to
shave off measurable cycles on a number of systems and workloads.
For example, on a 40-core IB, a pipetest as well as parallel
epoll_wait() benchmark show around a 20-30% increase in raw operations
per second when the box is fully occupied (incremental thread counts),
and up to 15% performance improvement with lower counts.
Passes ltp epoll related testcases.
This patch(of 6):
All callers pass the EP_MAX_NESTS constant already, so lets simplify
this a tad and get rid of the redundant parameter for nested eventpolls.
Link: http://lkml.kernel.org/r/20181108051006.18751-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Thu, 3 Jan 2019 23:26:59 +0000 (15:26 -0800)]
checkpatch: warn on const char foo[] = "bar"; declarations
These declarations should generally be static const to avoid poor
compilation and runtime performance where compilers tend to initialize
the const declaration for every call instead of using .rodata for the
string.
Miscellanea:
- Convert spaces to tabs for indentation in 2 adjacent checks
huang.zijiang [Thu, 3 Jan 2019 23:26:55 +0000 (15:26 -0800)]
drivers/firmware/memmap.c: modify memblock_alloc to memblock_alloc_nopanic
memblock_alloc() never returns NULL because panic never returns.
Link: http://lkml.kernel.org/r/1545640882-42009-1-git-send-email-huang.zijiang@zte.com.cn Signed-off-by: huang.zijiang <huang.zijiang@zte.com.cn> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Shijie [Thu, 3 Jan 2019 23:26:51 +0000 (15:26 -0800)]
lib/genalloc.c: use vzalloc_node() to allocate the bitmap
Some devices may have big memory on chip, such as over 1G. In some
cases, the nbytes maybe bigger then 4M which is the bounday of the
memory buddy system (4K default).
So use vzalloc_node() to allocate the bitmap. Also use vfree to free
it.
Yury Norov [Thu, 3 Jan 2019 23:26:48 +0000 (15:26 -0800)]
lib/find_bit_benchmark.c: align test_find_next_and_bit with others
Contrary to other tests, test_find_next_and_bit() test uses tab
formatting in output and get_cycles() instead of ktime_get().
get_cycles() is not supported by some arches, so ktime_get() fits better
in generic code.
Fix it and minor style issues, so the output looks like this:
Alexey Skidanov [Thu, 3 Jan 2019 23:26:44 +0000 (15:26 -0800)]
lib/genalloc.c: fix allocation of aligned buffer from non-aligned chunk
gen_pool_alloc_algo() uses different allocation functions implementing
different allocation algorithms. With gen_pool_first_fit_align()
allocation function, the returned address should be aligned on the
requested boundary.
If chunk start address isn't aligned on the requested boundary, the
returned address isn't aligned too. The only way to get properly
aligned address is to initialize the pool with chunks aligned on the
requested boundary. If want to have an ability to allocate buffers
aligned on different boundaries (for example, 4K, 1MB, ...), the chunk
start address should be aligned on the max possible alignment.
This happens because gen_pool_first_fit_align() looks for properly
aligned memory block without taking into account the chunk start address
alignment.
To fix this, we provide chunk start address to
gen_pool_first_fit_align() and change its implementation such that it
starts looking for properly aligned block with appropriate offset
(exactly as is done in CMA).
Matthew Wilcox [Thu, 3 Jan 2019 23:26:41 +0000 (15:26 -0800)]
fls: change parameter to unsigned int
When testing in userspace, UBSAN pointed out that shifting into the sign
bit is undefined behaviour. It doesn't really make sense to ask for the
highest set bit of a negative value, so just turn the argument type into
an unsigned int.
Some architectures (eg ppc) already had it declared as an unsigned int,
so I don't expect too many problems.
Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa [Thu, 3 Jan 2019 23:26:31 +0000 (15:26 -0800)]
kernel/hung_task.c: break RCU locks based on jiffies
check_hung_uninterruptible_tasks() is currently calling rcu_lock_break()
for every 1024 threads. But check_hung_task() is very slow if printk()
was called, and is very fast otherwise.
If many threads within some 1024 threads called printk(), the RCU grace
period might be extended enough to trigger RCU stall warnings.
Therefore, calling rcu_lock_break() for every some fixed jiffies will be
safer.
Link: http://lkml.kernel.org/r/1544800658-11423-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Liu, Chuansheng [Thu, 3 Jan 2019 23:26:27 +0000 (15:26 -0800)]
kernel/hung_task.c: force console verbose before panic
Based on commit 401c636a0eeb ("kernel/hung_task.c: show all hung tasks
before panic"), we could get the call stack of hung task.
However, if the console loglevel is not high, we still can not see the
useful panic information in practice, and in most cases users don't set
console loglevel to high level.
This patch is to force console verbose before system panic, so that the
real useful information can be seen in the console, instead of being
like the following, which doesn't have hung task information.
INFO: task init:1 blocked for more than 120 seconds.
Tainted: G U W 4.19.0-quilt-2e5dc0ac-g51b6c21d76cc #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Kernel panic - not syncing: hung_task: blocked tasks
CPU: 2 PID: 479 Comm: khungtaskd Tainted: G U W 4.19.0-quilt-2e5dc0ac-g51b6c21d76cc #1
Call Trace:
dump_stack+0x4f/0x65
panic+0xde/0x231
watchdog+0x290/0x410
kthread+0x12c/0x150
ret_from_fork+0x35/0x40
reboot: panic mode set: p,w
Kernel Offset: 0x34000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
Link: http://lkml.kernel.org/r/27240C0AC20F114CBF8149A2696CBE4A6015B675@SHSMSX101.ccr.corp.intel.com Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Masahiro Yamada [Thu, 3 Jan 2019 23:26:23 +0000 (15:26 -0800)]
build_bug.h: remove most of dummy BUILD_BUG_ON stubs for Sparse
The introduction of these dummy BUILD_BUG_ON stubs dates back to commmit 903c0c7cdc21 ("sparse: define dummy BUILD_BUG_ON definition for
sparse").
At that time, BUILD_BUG_ON() was implemented with the negative array
trick *and* the link-time trick, like this:
extern int __build_bug_on_failed;
#define BUILD_BUG_ON(condition) \
do { \
((void)sizeof(char[1 - 2*!!(condition)])); \
if (condition) __build_bug_on_failed = 1; \
} while(0)
Sparse is more strict about the negative array trick than GCC because
Sparse requires the array length to be really constant.
Here is the simple test code for the macro above:
static const int x = 0;
BUILD_BUG_ON(x);
GCC is absolutely fine with it (-Wvla was enabled only very recently),
but Sparse warns like this:
error: bad constant expression
error: cannot size expression
(If you are using a newer version of Sparse, you will see a different
warning message, "warning: Variable length array is used".)
Anyway, Sparse was producing many false positives, and noisier than it
should be at that time.
With the previous commit, the leftover negative array trick is gone.
Sparse is fine with the current BUILD_BUG_ON(), which is implemented by
using the 'error' attribute.
I am keeping the stub for BUILD_BUG_ON_ZERO(). Otherwise, Sparse would
complain about the following code, which GCC is fine with:
static const int x = 0;
int y = BUILD_BUG_ON_ZERO(x);
Link: http://lkml.kernel.org/r/1542856462-18836-3-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Masahiro Yamada [Thu, 3 Jan 2019 23:26:20 +0000 (15:26 -0800)]
build_bug.h: remove negative-array fallback for BUILD_BUG_ON()
The kernel can only be compiled with an optimization option (-O2, -Os,
or the currently proposed -Og). Hence, __OPTIMIZE__ is always defined
in the kernel source.
The fallback for the -O0 case is just hypothetical and pointless.
Moreover, commit 0bb95f80a38f ("Makefile: Globally enable VLA warning")
enabled -Wvla warning. The use of variable length arrays is banned.
Link: http://lkml.kernel.org/r/1542856462-18836-2-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are three processing functions dealing with digital parameters,
__do_proc_dointvec/__do_proc_douintvec/__do_proc_doulongvec_minmax.
This patch deals with __do_proc_doulongvec_minmax, just as
__do_proc_dointvec does, adding a check for parameters 'left'. In
__do_proc_douintvec, its code implementation explicitly does not support
multiple inputs.
static int __do_proc_douintvec(...){
...
/*
* Arrays are not supported, keep this simple. *Do not* add
* support for them.
*/
if (vleft != 1) {
*lenp = 0;
return -EINVAL;
}
...
}
So, just __do_proc_doulongvec_minmax has the problem. And most use of
proc_doulongvec_minmax/proc_doulongvec_ms_jiffies_minmax just have one
parameter.
Link: http://lkml.kernel.org/r/1544081775-15720-1-git-send-email-cheng.lin130@zte.com.cn Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Biggers [Thu, 3 Jan 2019 23:26:00 +0000 (15:26 -0800)]
fs/proc/util.c: include fs/proc/internal.h for name_to_int()
name_to_int() is defined in fs/proc/util.c and declared in
fs/proc/internal.h, but the declaration isn't included at the point of
the definition. Include the header to enforce that the definition
matches the declaration.
This addresses a gcc warning when -Wmissing-prototypes is enabled.
Link: http://lkml.kernel.org/r/20181115001833.49371-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Benjamin Gordon [Thu, 3 Jan 2019 23:25:56 +0000 (15:25 -0800)]
fs/proc/base.c: use ns_capable instead of capable for timerslack_ns
Access to timerslack_ns is controlled by a process having CAP_SYS_NICE
in its effective capability set, but the current check looks in the root
namespace instead of the process' user namespace. Since a process is
allowed to do other activities controlled by CAP_SYS_NICE inside a
namespace, it should also be able to adjust timerslack_ns.
Link: http://lkml.kernel.org/r/20181030180012.232896-1-bmgordon@google.com Signed-off-by: Benjamin Gordon <bmgordon@google.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: John Stultz <john.stultz@linaro.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 3 Jan 2019 02:56:59 +0000 (18:56 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
"A tiny pull request this merge window unfortunately, should get more
material in for the next release:
- new driver for Raspberry Pi's touchscreen (firmware interface)
- miscellaneous input driver fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elan_i2c - add ACPI ID for touchpad in ASUS Aspire F5-573G
Input: atmel_mxt_ts - don't try to free unallocated kernel memory
Input: drv2667 - fix indentation issues
Input: touchscreen - fix coding style issue
Input: add official Raspberry Pi's touchscreen driver
Input: nomadik-ske-keypad - fix a loop timeout test
Input: rotary-encoder - don't log EPROBE_DEFER to kernel log
Input: olpc_apsp - remove set but not used variable 'np'
Input: olpc_apsp - enable the SP clock
Input: olpc_apsp - check FIFO status on open(), not probe()
Input: olpc_apsp - drop CONFIG_OLPC dependency
clk: mmp2: add SP clock
dt-bindings: marvell,mmp2: Add clock id for the SP clock
Input: ad7879 - drop platform data support
Linus Torvalds [Thu, 3 Jan 2019 02:54:45 +0000 (18:54 -0800)]
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost updates from Michael Tsirkin:
"Features, fixes, cleanups:
- discard in virtio blk
- misc fixes and cleanups"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: correct the related warning message
vhost: split structs into a separate header file
virtio: remove deprecated VIRTIO_PCI_CONFIG()
vhost/vsock: switch to a mutex for vhost_vsock_hash
virtio_blk: add discard and write zeroes support
Linus Torvalds [Thu, 3 Jan 2019 02:49:58 +0000 (18:49 -0800)]
Merge tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block
Pull more block updates from Jens Axboe:
- Dead code removal for loop/sunvdc (Chengguang)
- Mark BIDI support for bsg as deprecated, logging a single dmesg
warning if anyone is actually using it (Christoph)
- blkcg cleanup, killing a dead function and making the tryget_closest
variant easier to read (Dennis)
- Floppy fixes, one fixing a regression in swim3 (Finn)
- lightnvm use-after-free fix (Gustavo)
- gdrom leak fix (Wenwen)
- a set of drbd updates (Lars, Luc, Nathan, Roland)
* tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block: (28 commits)
block/swim3: Fix regression on PowerBook G3
block/swim3: Fix -EBUSY error when re-opening device after unmount
block/swim3: Remove dead return statement
block/amiflop: Don't log error message on invalid ioctl
gdrom: fix a memory leak bug
lightnvm: pblk: fix use-after-free bug
block: sunvdc: remove redundant code
block: loop: remove redundant code
bsg: deprecate BIDI support in bsg
blkcg: remove unused __blkg_release_rcu()
blkcg: clean up blkg_tryget_closest()
drbd: Change drbd_request_detach_interruptible's return type to int
drbd: Avoid Clang warning about pointless switch statment
drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")
drbd: skip spurious timeout (ping-timeo) when failing promote
drbd: don't retry connection if peers do not agree on "authentication" settings
drbd: fix print_st_err()'s prototype to match the definition
drbd: avoid spurious self-outdating with concurrent disconnect / down
drbd: do not block when adjusting "disk-options" while IO is frozen
drbd: fix comment typos
...
Linus Torvalds [Thu, 3 Jan 2019 02:43:57 +0000 (18:43 -0800)]
Merge tag 'devprop-4.21-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull device properties framework fixes from Rafael Wysocki:
"Fix two potential NULL pointer dereferences found by Coverity in the
software nodes code introduced recently (Colin Ian King)"
* tag 'devprop-4.21-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
drivers: base: swnode: check if swnode is NULL before dereferencing it
drivers: base: swnode: check if pointer p is NULL before dereferencing it
Linus Torvalds [Thu, 3 Jan 2019 02:41:38 +0000 (18:41 -0800)]
Merge tag 'mailbox-v4.21' of git://git.linaro.org/landing-teams/working/fujitsu/integration
Pull mailbox updates from Jassi Brar:
- Introduce device-managed registration
devm_mbox_controller_un/register and convert drivers to use it
- Introduce flush api to support clients that must busy-wait in atomic
context
- Support multiple controllers per device
- Hi3660: a bugfix and constify ops structure
- TI-MsgMgr: off by one bugfix.
- BCM: switch to spdx license
- Tegra-HSP: support for shared mailboxes and suspend/resume.
* tag 'mailbox-v4.21' of git://git.linaro.org/landing-teams/working/fujitsu/integration: (30 commits)
mailbox: tegra-hsp: Use device-managed registration API
mailbox: tegra-hsp: use devm_kstrdup_const()
mailbox: tegra-hsp: Add suspend/resume support
mailbox: tegra-hsp: Add support for shared mailboxes
dt-bindings: tegra186-hsp: Add shared mailboxes
mailbox: Allow multiple controllers per device
mailbox: Support blocking transfers in atomic context
mailbox: ti-msgmgr: Use device-managed registration API
mailbox: stm32-ipcc: Use device-managed registration API
mailbox: rockchip: Use device-managed registration API
mailbox: qcom-apcs: Use device-managed registration API
mailbox: platform-mhu: Use device-managed registration API
mailbox: omap: Use device-managed registration API
mailbox: mtk-cmdq: Remove needless devm_kfree() calls
mailbox: mtk-cmdq: Use device-managed registration API
mailbox: xgene-slimpro: Use device-managed registration API
mailbox: sti: Use device-managed registration API
mailbox: altera: Use device-managed registration API
mailbox: imx: Use device-managed registration API
mailbox: hi6220: Use device-managed registration API
...
Linus Torvalds [Thu, 3 Jan 2019 02:39:22 +0000 (18:39 -0800)]
Merge branch 'for-linus-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
- DISCARD support for our block device driver
- Many TLB flush optimizations
- Various smaller fixes
- And most important, Anton agreed to help me maintaining UML
* 'for-linus-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Remove obsolete reenable_XX calls
um: writev needs <sys/uio.h>
Add Anton Ivanov to UML maintainers
um: remove redundant generic-y
um: Optimize Flush TLB for force/fork case
um: Avoid marking pages with "changed protection"
um: Skip TLB flushing where not needed
um: Optimize TLB operations v2
um: Remove unnecessary faulted check in uaccess.c
um: Add support for DISCARD in the UBD Driver
um: Remove unsafe printks from the io thread
um: Clean-up command processing in UML UBD driver
um: Switch to block-mq constants in the UML UBD driver
um: Make GCOV depend on !KCOV
um: Include sys/uio.h to have writev()
um: Add HAVE_DEBUG_BUGVERBOSE
um: Update maintainers file entry
Linus Torvalds [Thu, 3 Jan 2019 02:37:01 +0000 (18:37 -0800)]
Merge tag 's390-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
- A larger update for the zcrypt / AP bus code:
+ Update two inline assemblies in the zcrypt driver to make gcc happy
+ Add a missing reply code for invalid special commands for zcrypt
+ Allow AP device reset to be triggered from user space
+ Split the AP scan function into smaller, more readable functions
- Updates for vfio-ccw and vfio-ap
+ Add maintainers and reviewer for vfio-ccw
+ Include facility.h in vfio_ap_drv.c to avoid fragile include chain
+ Simplicy vfio-ccw state machine
- Use the common code version of bust_spinlocks
- Make use of the DEFINE_SHOW_ATTRIBUTE
- Fix three incorrect file permissions in the DASD driver
- Remove bit spin-lock from the PCI interrupt handler
- Fix GFP_ATOMIC vs GFP_KERNEL in the PCI code
* tag 's390-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/zcrypt: rework ap scan bus code
s390/zcrypt: make sysfs reset attribute trigger queue reset
s390/pci: fix sleeping in atomic during hotplug
s390/pci: remove bit_lock usage in interrupt handler
s390/drivers: fix proc/debugfs file permissions
s390: convert to DEFINE_SHOW_ATTRIBUTE
MAINTAINERS/vfio-ccw: add Farhan and Eric, make Halil Reviewer
vfio: ccw: Merge BUSY and BOXED states
s390: use common bust_spinlocks()
s390/zcrypt: improve special ap message cmd handling
s390/ap: rework assembler functions to use unions for in/out register variables
s390: vfio-ap: include <asm/facility> for test_facility()
Linus Torvalds [Thu, 3 Jan 2019 00:35:23 +0000 (16:35 -0800)]
Merge tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
"Stable bugfixes:
- xprtrdma: Yet another double DMA-unmap # v4.20
Features:
- Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG
- Per-xprt rdma receive workqueues
- Drop support for FMR memory registration
- Make port= mount option optional for RDMA mounts
Other bugfixes and cleanups:
- Remove unused nfs4_xdev_fs_type declaration
- Fix comments for behavior that has changed
- Remove generic RPC credentials by switching to 'struct cred'
- Fix crossing mountpoints with different auth flavors
- Various xprtrdma fixes from testing and auditing the close code
- Fixes for disconnect issues when using xprtrdma with krb5
- Clean up and improve xprtrdma trace points
- Fix NFS v4.2 async copy reboot recovery"
* tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits)
sunrpc: convert to DEFINE_SHOW_ATTRIBUTE
sunrpc: Add xprt after nfs4_test_session_trunk()
sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS
sunrpc: handle ENOMEM in rpcb_getport_async
NFS: remove unnecessary test for IS_ERR(cred)
xprtrdma: Prevent leak of rpcrdma_rep objects
NFSv4.2 fix async copy reboot recovery
xprtrdma: Don't leak freed MRs
xprtrdma: Add documenting comment for rpcrdma_buffer_destroy
xprtrdma: Replace outdated comment for rpcrdma_ep_post
xprtrdma: Update comments in frwr_op_send
SUNRPC: Fix some kernel doc complaints
SUNRPC: Simplify defining common RPC trace events
NFS: Fix NFSv4 symbolic trace point output
xprtrdma: Trace mapping, alloc, and dereg failures
xprtrdma: Add trace points for calls to transport switch methods
xprtrdma: Relocate the xprtrdma_mr_map trace points
xprtrdma: Clean up of xprtrdma chunk trace points
xprtrdma: Remove unused fields from rpcrdma_ia
xprtrdma: Cull dprintk() call sites
...
Linus Torvalds [Thu, 3 Jan 2019 00:21:50 +0000 (16:21 -0800)]
Merge tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Thanks to Vasily Averin for fixing a use-after-free in the
containerized NFSv4.2 client, and cleaning up some convoluted
backchannel server code in the process.
Otherwise, miscellaneous smaller bugfixes and cleanup"
* tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux: (25 commits)
nfs: fixed broken compilation in nfs_callback_up_net()
nfs: minor typo in nfs4_callback_up_net()
sunrpc: fix debug message in svc_create_xprt()
sunrpc: make visible processing error in bc_svc_process()
sunrpc: remove unused xpo_prep_reply_hdr callback
sunrpc: remove svc_rdma_bc_class
sunrpc: remove svc_tcp_bc_class
sunrpc: remove unused bc_up operation from rpc_xprt_ops
sunrpc: replace svc_serv->sv_bc_xprt by boolean flag
sunrpc: use-after-free in svc_process_common()
sunrpc: use SVC_NET() in svcauth_gss_* functions
nfsd: drop useless LIST_HEAD
lockd: Show pid of lockd for remote locks
NFSD remove OP_CACHEME from 4.2 op_flags
nfsd: Return EPERM, not EACCES, in some SETATTR cases
sunrpc: fix cache_head leak due to queued request
nfsd: clean up indentation, increase indentation in switch statement
svcrdma: Optimize the logic that selects the R_key to invalidate
nfsd: fix a warning in __cld_pipe_upcall()
nfsd4: fix crash on writing v4_end_grace before nfsd startup
...
Linus Torvalds [Wed, 2 Jan 2019 20:11:01 +0000 (12:11 -0800)]
Merge tag '9p-for-4.21' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet:
"Missing prototype warning fix and a syzkaller fix when a 9p server
advertises a too small msize"
* tag '9p-for-4.21' of git://github.com/martinetd/linux:
9p/net: put a lower bound on msize
net/9p: include trans_common.h to fix missing prototype warning.
Linus Torvalds [Wed, 2 Jan 2019 20:08:29 +0000 (12:08 -0800)]
Merge tag '4.21-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs updates from Steve French:
- four fixes for stable
- improvements to DFS including allowing failover to alternate targets
- some small performance improvements
* tag '4.21-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: (39 commits)
cifs: update internal module version number
cifs: we can not use small padding iovs together with encryption
cifs: Minor Kconfig clarification
cifs: Always resolve hostname before reconnecting
cifs: Add support for failover in cifs_reconnect_tcon()
cifs: Add support for failover in smb2_reconnect()
cifs: Only free DFS target list if we actually got one
cifs: start DFS cache refresher in cifs_mount()
cifs: Use GFP_ATOMIC when a lock is held in cifs_mount()
cifs: Add support for failover in cifs_reconnect()
cifs: Add support for failover in cifs_mount()
cifs: remove set but not used variable 'sep'
cifs: Make use of DFS cache to get new DFS referrals
cifs: minor updates to documentation
cifs: check kzalloc return
cifs: remove set but not used variable 'server'
cifs: Use kzfree() to free password
cifs: Fix to use kmem_cache_free() instead of kfree()
cifs: update for current_kernel_time64() removal
cifs: Add DFS cache routines
...
Linus Torvalds [Wed, 2 Jan 2019 19:05:43 +0000 (11:05 -0800)]
Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull TPM updates from James Morris:
- Support for partial reads of /dev/tpm0.
- Clean up for TPM 1.x code: move the commands to tpm1-cmd.c and make
everything to use the same data structure for building TPM commands
i.e. struct tpm_buf.
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (25 commits)
tpm: add support for partial reads
tpm: tpm_ibmvtpm: fix kdoc warnings
tpm: fix kdoc for tpm2_flush_context_cmd()
tpm: tpm_try_transmit() refactor error flow.
tpm: use u32 instead of int for PCR index
tpm1: reimplement tpm1_continue_selftest() using tpm_buf
tpm1: reimplement SAVESTATE using tpm_buf
tpm1: rename tpm1_pcr_read_dev to tpm1_pcr_read()
tpm1: implement tpm1_pcr_read_dev() using tpm_buf structure
tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure
tpm: tpm-space.c remove unneeded semicolon
tpm: tpm-interface.c drop unused macros
tpm: add tpm_auto_startup() into tpm-interface.c
tpm: factor out tpm_startup function
tpm: factor out tpm 1.x pm suspend flow into tpm1-cmd.c
tpm: move tpm 1.x selftest code from tpm-interface.c tpm1-cmd.c
tpm: factor out tpm1_get_random into tpm1-cmd.c
tpm: move tpm_getcap to tpm1-cmd.c
tpm: move tpm1_pcr_extend to tpm1-cmd.c
tpm: factor out tpm_get_timeouts()
...
Linus Torvalds [Wed, 2 Jan 2019 18:46:03 +0000 (10:46 -0800)]
block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)
This mostly reverts commit 849a370016a5 ("block: avoid ordered task
state change for polled IO"). It was wrongly claiming that the ordering
wasn't necessary. The memory barrier _is_ necessary.
If something is truly polling and not going to sleep, it's the whole
state setting that is unnecessary, not the memory barrier. Whenever you
set your state to a sleeping state, you absolutely need the memory
barrier.
Note that sometimes the memory barrier can be elsewhere. For example,
the ordering might be provided by an external lock, or by setting the
process state to sleeping before adding yourself to the wait queue list
that is used for waking up (where the wait queue lock itself will
guarantee that any wakeup will correctly see the sleeping state).
But none of those cases were true here.
NOTE! Some of the polling paths may indeed be able to drop the state
setting entirely, at which point the memory barrier also goes away.
(Also note that this doesn't revert the TASK_RUNNING cases: there is no
race between a wakeup and setting the process state to TASK_RUNNING,
since the end result doesn't depend on ordering).
Linus Torvalds [Wed, 2 Jan 2019 17:48:13 +0000 (09:48 -0800)]
Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull seccomp updates from James Morris:
- Add SECCOMP_RET_USER_NOTIF
- seccomp fixes for sparse warnings and s390 build (Tycho)
* 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
seccomp, s390: fix build for syscall type change
seccomp: fix poor type promotion
samples: add an example of seccomp user trap
seccomp: add a return code to trap to userspace
seccomp: switch system call argument type to void *
seccomp: hoist struct seccomp_data recalculation higher
Linus Torvalds [Wed, 2 Jan 2019 17:43:14 +0000 (09:43 -0800)]
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
"In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
Different signature verification methods exist for verifying the
kexec'ed kernel image. This adds additional support in IMA to prevent
loading unsigned kernel images via the kexec_load syscall,
independently of the IMA policy rules, based on the runtime "secure
boot" flag. An initial IMA kselftest is included.
In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.
(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here)"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
integrity: Remove references to module keyring
ima: Use inode_is_open_for_write
ima: Support platform keyring for kernel appraisal
efi: Allow the "db" UEFI variable to be suppressed
efi: Import certificates from UEFI Secure Boot
efi: Add an EFI signature blob parser
efi: Add EFI signature data types
integrity: Load certs to the platform keyring
integrity: Define a trusted platform keyring
selftests/ima: kexec_load syscall test
ima: don't measure/appraise files on efivarfs
x86/ima: retry detecting secure boot mode
docs: Extend trusted keys documentation for TPM 2.0
x86/ima: define arch_get_ima_policy() for x86
ima: add support for arch specific policies
ima: refactor ima_init_policy()
ima: prevent kexec_load syscall based on runtime secureboot flag
x86/ima: define arch_ima_get_secureboot
integrity: support new struct public_key_signature encoding field
Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds
the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns
success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify
the path along with check for session trunking.
Add the xprt in nfs4_test_session_trunk() only when
nfs4_detect_session_trunking() returns success. Also release refcount
hold by rpc_clnt_setup_test_and_add_xprt().
J. Bruce Fields [Thu, 20 Dec 2018 15:42:36 +0000 (10:42 -0500)]
sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS
It's OK to sleep here, we just don't want to recurse into the filesystem
as a writeout could be waiting on this.
Future work: the documentation for GFP_NOFS says "Please try to avoid
using this flag directly and instead use memalloc_nofs_{save,restore} to
mark the whole scope which cannot/shouldn't recurse into the FS layer
with a short explanation why. All allocation requests will inherit
GFP_NOFS implicitly."
But I'm not sure where to do this. Should the workqueue be arranging
that for us in the case of workqueues created with WQ_MEM_RECLAIM?
Reported-by: Trond Myklebust <trondmy@hammer.space> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
J. Bruce Fields [Thu, 20 Dec 2018 15:35:11 +0000 (10:35 -0500)]
sunrpc: handle ENOMEM in rpcb_getport_async
If we ignore the error we'll hit a null dereference a little later.
Reported-by: syzbot+4b98281f2401ab849f4b@syzkaller.appspotmail.com Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Fri, 7 Dec 2018 16:11:44 +0000 (11:11 -0500)]
xprtrdma: Prevent leak of rpcrdma_rep objects
If a reply has been processed but the RPC is later retransmitted
anyway, the req->rl_reply field still contains the only pointer to
the old rpcrdma rep. When the next reply comes in, the reply handler
will stomp on the rl_reply field, leaking the old rep.
A trace event is added to capture such leaks.
This problem seems to be worsened by the restructuring of the RPC
Call path in v4.20. Fully addressing this issue will require at
least a re-architecture of the disconnect logic, which is not
appropriate during -rc.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Original commit (e4648aa4f98a "NFS recover from destination server
reboot for copies") used memcmp() and then it was changed to use
nfs4_stateid_match_other() but that function returns opposite of
memcmp. As the result, recovery can't find the copy leading
to copy hanging.
Fixes: 80f42368868e ("NFSv4: Split out NFS v4.2 copy completion functions") Fixes: cb7a8384dc02 ("NFS: Split out the body of nfs4_reclaim_open_state") Signed-of-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 16:00:32 +0000 (11:00 -0500)]
xprtrdma: Replace outdated comment for rpcrdma_ep_post
Since commit 7c8d9e7c8863 ("xprtrdma: Move Receive posting to
Receive handler"), rpcrdma_ep_post is no longer responsible for
posting Receive buffers. Update the documenting comment to reflect
this change.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 16:00:27 +0000 (11:00 -0500)]
xprtrdma: Update comments in frwr_op_send
Commit f2877623082b ("xprtrdma: Chain Send to FastReg WRs") was
written before commit ce5b37178283 ("xprtrdma: Replace all usage of
"frmr" with "frwr""), but was merged afterwards. Thus it still
refers to FRMR and MWs.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 16:00:11 +0000 (11:00 -0500)]
NFS: Fix NFSv4 symbolic trace point output
These symbolic values were not being displayed in string form.
TRACE_DEFINE_ENUM was missing in many cases. It also turns out that
__print_symbolic wants an unsigned long in the first field...
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:33 +0000 (10:59 -0500)]
xprtrdma: Simplify locking that protects the rl_allreqs list
Clean up: There's little chance of contention between the use of
rb_lock and rb_reqslock, so merge the two. This avoids having to
take both in some (possibly future) cases.
Transport tear-down is already serialized, thus there is no need for
locking at all when destroying rpcrdma_reqs.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:23 +0000 (10:59 -0500)]
xprtrdma: Remove request_module from backchannel
Since commit ffe1f0df5862 ("rpcrdma: Merge svcrdma and xprtrdma
modules into one"), the forward and backchannel components are part
of the same kernel module. A separate request_module() call in the
backchannel code is no longer necessary.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:17 +0000 (10:59 -0500)]
xprtrdma: Recognize XDRBUF_SPARSE_PAGES
Commit 431f6eb3570f ("SUNRPC: Add a label for RPC calls that require
allocation on receive") didn't update similar logic in rpc_rdma.c.
I don't think this is a bug, per-se; the commit just adds more
careful checking for broken upper layer behavior.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:12 +0000 (10:59 -0500)]
NFS: Make "port=" mount option optional for RDMA mounts
Having to specify "proto=rdma,port=20049" is cumbersome.
RFC 8267 Section 6.3 requires NFSv4 clients to use "the alternative
well-known port number", which is 20049. Make the use of the well-
known port number automatic, just as it is for NFS/TCP and port
2049.
For NFSv2/3, Section 4.2 allows clients to simply choose 20049 as
the default or use rpcbind. I don't know of an NFS/RDMA server
implementation that registers it's NFS/RDMA service with rpcbind,
so automatically choosing 20049 seems like the better choice. The
other widely-deployed NFS/RDMA client, Solaris, also uses 20049
as the default port.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:07 +0000 (10:59 -0500)]
xprtrdma: Plant XID in on-the-wire RDMA offset (FRWR)
Place the associated RPC transaction's XID in the upper 32 bits of
each RDMA segment's rdma_offset field. There are two reasons to do
this:
- The R_key only has 8 bits that are different from registration to
registration. The XID adds more uniqueness to each RDMA segment to
reduce the likelihood of a software bug on the server reading from
or writing into memory it's not supposed to.
- On-the-wire RDMA Read and Write requests do not otherwise carry
any identifier that matches them up to an RPC. The XID in the
upper 32 bits will act as an eye-catcher in network captures.
Suggested-by: Tom Talpey <ttalpey@microsoft.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:59:01 +0000 (10:59 -0500)]
xprtrdma: Remove rpcrdma_memreg_ops
Clean up: Now that there is only FRWR, there is no need for a memory
registration switch. The indirect calls to the memreg operations can
be replaced with faster direct calls.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:58:56 +0000 (10:58 -0500)]
xprtrdma: Remove support for FMR memory registration
FMR is not supported on most recent RDMA devices. It is also less
secure than FRWR because an FMR memory registration can expose
adjacent bytes to remote reading or writing. As discussed during the
RDMA BoF at LPC 2018, it is time to remove support for FMR in the
NFS/RDMA client stack.
Note that NFS/RDMA server-side uses either local memory registration
or FRWR. FMR is not used.
There are a few Infiniband/RoCE devices in the kernel tree that do
not appear to support MEM_MGT_EXTENSIONS (FRWR), and therefore will
not support client-side NFS/RDMA after this patch. These are:
- mthca
- qib
- hns (RoCE)
Users of these devices can use NFS/TCP on IPoIB instead.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:58:51 +0000 (10:58 -0500)]
xprtrdma: Reduce max_frwr_depth
Some devices advertise a large max_fast_reg_page_list_len
capability, but perform optimally when MRs are significantly smaller
than that depth -- probably when the MR itself is no larger than a
page.
By default, the RDMA R/W core API uses max_sge_rd as the maximum
page depth for MRs. For some devices, the value of max_sge_rd is
1, which is also not optimal. Thus, when max_sge_rd is larger than
1, use that value. Otherwise use the value of the
max_fast_reg_page_list_len attribute.
I've tested this with CX-3 Pro, FastLinq, and CX-5 devices. It
reproducibly improves the throughput of large I/Os by several
percent.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Wed, 19 Dec 2018 15:58:45 +0000 (10:58 -0500)]
xprtrdma: Fix ri_max_segs and the result of ro_maxpages
With certain combinations of krb5i/p, MR size, and r/wsize, I/O can
fail with EMSGSIZE. This is because the calculated value of
ri_max_segs (the max number of MRs per RPC) exceeded
RPCRDMA_MAX_HDR_SEGS, which caused Read or Write list encoding to
walk off the end of the transport header.
Once that was addressed, the ro_maxpages result has to be corrected
to account for the number of MRs needed for Reply chunks, which is
2 MRs smaller than a normal Read or Write chunk.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
projects / mirror_ubuntu-hirsute-kernel.git / log