linux/drivers/md/dm-stats.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/numa.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/threads.h>
#include <linux/preempt.h>
#include <linux/irqflags.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/device-mapper.h>
#include "dm-core.h"
#include "dm-stats.h"
#define DM_MSG_PREFIX "stats"
static int dm_stat_need_rcu_barrier;
/*
* Using 64-bit values to avoid overflow (which is a
* problem that block/genhd.c's IO accounting has).
*/
struct dm_stat_percpu {
unsigned long long sectors[2];
unsigned long long ios[2];
unsigned long long merges[2];
unsigned long long ticks[2];
unsigned long long io_ticks[2];
unsigned long long io_ticks_total;
unsigned long long time_in_queue;
unsigned long long *histogram;
};
struct dm_stat_shared {
atomic_t in_flight[2];
unsigned long long stamp;
struct dm_stat_percpu tmp;
};
struct dm_stat {
struct list_head list_entry;
int id;
unsigned stat_flags;
size_t n_entries;
sector_t start;
sector_t end;
sector_t step;
unsigned n_histogram_entries;
unsigned long long *histogram_boundaries;
const char *program_id;
const char *aux_data;
struct rcu_head rcu_head;
size_t shared_alloc_size;
size_t percpu_alloc_size;
size_t histogram_alloc_size;
struct dm_stat_percpu *stat_percpu[NR_CPUS];
dm: replace zero-length array with flexible-array The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-07 18:51:58 +00:00
struct dm_stat_shared stat_shared[];
};
#define STAT_PRECISE_TIMESTAMPS 1
struct dm_stats_last_position {
sector_t last_sector;
unsigned last_rw;
};
/*
* A typo on the command line could possibly make the kernel run out of memory
* and crash. To prevent the crash we account all used memory. We fail if we
* exhaust 1/4 of all memory or 1/2 of vmalloc space.
*/
#define DM_STATS_MEMORY_FACTOR 4
#define DM_STATS_VMALLOC_FACTOR 2
static DEFINE_SPINLOCK(shared_memory_lock);
static unsigned long shared_memory_amount;
static bool __check_shared_memory(size_t alloc_size)
{
size_t a;
a = shared_memory_amount + alloc_size;
if (a < shared_memory_amount)
return false;
if (a >> PAGE_SHIFT > totalram_pages() / DM_STATS_MEMORY_FACTOR)
return false;
#ifdef CONFIG_MMU
if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR)
return false;
#endif
return true;
}
static bool check_shared_memory(size_t alloc_size)
{
bool ret;
spin_lock_irq(&shared_memory_lock);
ret = __check_shared_memory(alloc_size);
spin_unlock_irq(&shared_memory_lock);
return ret;
}
static bool claim_shared_memory(size_t alloc_size)
{
spin_lock_irq(&shared_memory_lock);
if (!__check_shared_memory(alloc_size)) {
spin_unlock_irq(&shared_memory_lock);
return false;
}
shared_memory_amount += alloc_size;
spin_unlock_irq(&shared_memory_lock);
return true;
}
static void free_shared_memory(size_t alloc_size)
{
unsigned long flags;
spin_lock_irqsave(&shared_memory_lock, flags);
if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) {
spin_unlock_irqrestore(&shared_memory_lock, flags);
DMCRIT("Memory usage accounting bug.");
return;
}
shared_memory_amount -= alloc_size;
spin_unlock_irqrestore(&shared_memory_lock, flags);
}
static void *dm_kvzalloc(size_t alloc_size, int node)
{
void *p;
if (!claim_shared_memory(alloc_size))
return NULL;
mm: introduce kv[mz]alloc helpers Patch series "kvmalloc", v5. There are many open coded kmalloc with vmalloc fallback instances in the tree. Most of them are not careful enough or simply do not care about the underlying semantic of the kmalloc/page allocator which means that a) some vmalloc fallbacks are basically unreachable because the kmalloc part will keep retrying until it succeeds b) the page allocator can invoke a really disruptive steps like the OOM killer to move forward which doesn't sound appropriate when we consider that the vmalloc fallback is available. As it can be seen implementing kvmalloc requires quite an intimate knowledge if the page allocator and the memory reclaim internals which strongly suggests that a helper should be implemented in the memory subsystem proper. Most callers, I could find, have been converted to use the helper instead. This is patch 6. There are some more relying on __GFP_REPEAT in the networking stack which I have converted as well and Eric Dumazet was not opposed [2] to convert them as well. [1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org [2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com This patch (of 9): Using kmalloc with the vmalloc fallback for larger allocations is a common pattern in the kernel code. Yet we do not have any common helper for that and so users have invented their own helpers. Some of them are really creative when doing so. Let's just add kv[mz]alloc and make sure it is implemented properly. This implementation makes sure to not make a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also to not warn about allocation failures. This also rules out the OOM killer as the vmalloc is a more approapriate fallback than a disruptive user visible action. This patch also changes some existing users and removes helpers which are specific for them. In some cases this is not possible (e.g. ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and require GFP_NO{FS,IO} context which is not vmalloc compatible in general (note that the page table allocation is GFP_KERNEL). Those need to be fixed separately. While we are at it, document that __vmalloc{_node} about unsupported gfp mask because there seems to be a lot of confusion out there. kvmalloc_node will warn about GFP_KERNEL incompatible (which are not superset) flags to catch new abusers. Existing ones would have to die slowly. [sfr@canb.auug.org.au: f2fs fixup] Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Andreas Dilger <adilger@dilger.ca> [ext4 part] Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: John Hubbard <jhubbard@nvidia.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 22:57:09 +00:00
p = kvzalloc_node(alloc_size, GFP_KERNEL | __GFP_NOMEMALLOC, node);
if (p)
return p;
free_shared_memory(alloc_size);
return NULL;
}
static void dm_kvfree(void *ptr, size_t alloc_size)
{
if (!ptr)
return;
free_shared_memory(alloc_size);
kvfree(ptr);
}
static void dm_stat_free(struct rcu_head *head)
{
int cpu;
struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
kfree(s->histogram_boundaries);
kfree(s->program_id);
kfree(s->aux_data);
for_each_possible_cpu(cpu) {
dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
}
dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size);
dm_kvfree(s, s->shared_alloc_size);
}
static int dm_stat_in_flight(struct dm_stat_shared *shared)
{
return atomic_read(&shared->in_flight[READ]) +
atomic_read(&shared->in_flight[WRITE]);
}
void dm_stats_init(struct dm_stats *stats)
{
int cpu;
struct dm_stats_last_position *last;
mutex_init(&stats->mutex);
INIT_LIST_HEAD(&stats->list);
stats->last = alloc_percpu(struct dm_stats_last_position);
for_each_possible_cpu(cpu) {
last = per_cpu_ptr(stats->last, cpu);
last->last_sector = (sector_t)ULLONG_MAX;
last->last_rw = UINT_MAX;
}
}
void dm_stats_cleanup(struct dm_stats *stats)
{
size_t ni;
struct dm_stat *s;
struct dm_stat_shared *shared;
while (!list_empty(&stats->list)) {
s = container_of(stats->list.next, struct dm_stat, list_entry);
list_del(&s->list_entry);
for (ni = 0; ni < s->n_entries; ni++) {
shared = &s->stat_shared[ni];
if (WARN_ON(dm_stat_in_flight(shared))) {
DMCRIT("leaked in-flight counter at index %lu "
"(start %llu, end %llu, step %llu): reads %d, writes %d",
(unsigned long)ni,
(unsigned long long)s->start,
(unsigned long long)s->end,
(unsigned long long)s->step,
atomic_read(&shared->in_flight[READ]),
atomic_read(&shared->in_flight[WRITE]));
}
}
dm_stat_free(&s->rcu_head);
}
free_percpu(stats->last);
mutex_destroy(&stats->mutex);
}
static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
sector_t step, unsigned stat_flags,
unsigned n_histogram_entries,
unsigned long long *histogram_boundaries,
const char *program_id, const char *aux_data,
void (*suspend_callback)(struct mapped_device *),
void (*resume_callback)(struct mapped_device *),
struct mapped_device *md)
{
struct list_head *l;
struct dm_stat *s, *tmp_s;
sector_t n_entries;
size_t ni;
size_t shared_alloc_size;
size_t percpu_alloc_size;
size_t histogram_alloc_size;
struct dm_stat_percpu *p;
int cpu;
int ret_id;
int r;
if (end < start || !step)
return -EINVAL;
n_entries = end - start;
if (dm_sector_div64(n_entries, step))
n_entries++;
if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1))
return -EOVERFLOW;
shared_alloc_size = struct_size(s, stat_shared, n_entries);
if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries)
return -EOVERFLOW;
percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu);
if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries)
return -EOVERFLOW;
histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long);
if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long))
return -EOVERFLOW;
if (!check_shared_memory(shared_alloc_size + histogram_alloc_size +
num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size)))
return -ENOMEM;
s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
if (!s)
return -ENOMEM;
s->stat_flags = stat_flags;
s->n_entries = n_entries;
s->start = start;
s->end = end;
s->step = step;
s->shared_alloc_size = shared_alloc_size;
s->percpu_alloc_size = percpu_alloc_size;
s->histogram_alloc_size = histogram_alloc_size;
s->n_histogram_entries = n_histogram_entries;
s->histogram_boundaries = kmemdup(histogram_boundaries,
s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL);
if (!s->histogram_boundaries) {
r = -ENOMEM;
goto out;
}
s->program_id = kstrdup(program_id, GFP_KERNEL);
if (!s->program_id) {
r = -ENOMEM;
goto out;
}
s->aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!s->aux_data) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
atomic_set(&s->stat_shared[ni].in_flight[READ], 0);
atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0);
}
if (s->n_histogram_entries) {
unsigned long long *hi;
hi = dm_kvzalloc(s->histogram_alloc_size, NUMA_NO_NODE);
if (!hi) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
s->stat_shared[ni].tmp.histogram = hi;
hi += s->n_histogram_entries + 1;
}
}
for_each_possible_cpu(cpu) {
p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu));
if (!p) {
r = -ENOMEM;
goto out;
}
s->stat_percpu[cpu] = p;
if (s->n_histogram_entries) {
unsigned long long *hi;
hi = dm_kvzalloc(s->histogram_alloc_size, cpu_to_node(cpu));
if (!hi) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
p[ni].histogram = hi;
hi += s->n_histogram_entries + 1;
}
}
}
/*
* Suspend/resume to make sure there is no i/o in flight,
* so that newly created statistics will be exact.
*
* (note: we couldn't suspend earlier because we must not
* allocate memory while suspended)
*/
suspend_callback(md);
mutex_lock(&stats->mutex);
s->id = 0;
list_for_each(l, &stats->list) {
tmp_s = container_of(l, struct dm_stat, list_entry);
if (WARN_ON(tmp_s->id < s->id)) {
r = -EINVAL;
goto out_unlock_resume;
}
if (tmp_s->id > s->id)
break;
if (unlikely(s->id == INT_MAX)) {
r = -ENFILE;
goto out_unlock_resume;
}
s->id++;
}
ret_id = s->id;
list_add_tail_rcu(&s->list_entry, l);
mutex_unlock(&stats->mutex);
resume_callback(md);
return ret_id;
out_unlock_resume:
mutex_unlock(&stats->mutex);
resume_callback(md);
out:
dm_stat_free(&s->rcu_head);
return r;
}
static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id)
{
struct dm_stat *s;
list_for_each_entry(s, &stats->list, list_entry) {
if (s->id > id)
break;
if (s->id == id)
return s;
}
return NULL;
}
static int dm_stats_delete(struct dm_stats *stats, int id)
{
struct dm_stat *s;
int cpu;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
list_del_rcu(&s->list_entry);
mutex_unlock(&stats->mutex);
/*
* vfree can't be called from RCU callback
*/
for_each_possible_cpu(cpu)
if (is_vmalloc_addr(s->stat_percpu) ||
is_vmalloc_addr(s->stat_percpu[cpu][0].histogram))
goto do_sync_free;
if (is_vmalloc_addr(s) ||
is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) {
do_sync_free:
synchronize_rcu_expedited();
dm_stat_free(&s->rcu_head);
} else {
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
WRITE_ONCE(dm_stat_need_rcu_barrier, 1);
call_rcu(&s->rcu_head, dm_stat_free);
}
return 0;
}
static int dm_stats_list(struct dm_stats *stats, const char *program,
char *result, unsigned maxlen)
{
struct dm_stat *s;
sector_t len;
unsigned sz = 0;
/*
* Output format:
* <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
*/
mutex_lock(&stats->mutex);
list_for_each_entry(s, &stats->list, list_entry) {
if (!program || !strcmp(program, s->program_id)) {
len = s->end - s->start;
DMEMIT("%d: %llu+%llu %llu %s %s", s->id,
(unsigned long long)s->start,
(unsigned long long)len,
(unsigned long long)s->step,
s->program_id,
s->aux_data);
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
DMEMIT(" precise_timestamps");
if (s->n_histogram_entries) {
unsigned i;
DMEMIT(" histogram:");
for (i = 0; i < s->n_histogram_entries; i++) {
if (i)
DMEMIT(",");
DMEMIT("%llu", s->histogram_boundaries[i]);
}
}
DMEMIT("\n");
}
}
mutex_unlock(&stats->mutex);
return 1;
}
static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared,
struct dm_stat_percpu *p)
{
/*
* This is racy, but so is part_round_stats_single.
*/
unsigned long long now, difference;
unsigned in_flight_read, in_flight_write;
if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)))
now = jiffies;
else
now = ktime_to_ns(ktime_get());
difference = now - shared->stamp;
if (!difference)
return;
in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]);
in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]);
if (in_flight_read)
p->io_ticks[READ] += difference;
if (in_flight_write)
p->io_ticks[WRITE] += difference;
if (in_flight_read + in_flight_write) {
p->io_ticks_total += difference;
p->time_in_queue += (in_flight_read + in_flight_write) * difference;
}
shared->stamp = now;
}
static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
int idx, sector_t len,
struct dm_stats_aux *stats_aux, bool end,
unsigned long duration_jiffies)
{
struct dm_stat_shared *shared = &s->stat_shared[entry];
struct dm_stat_percpu *p;
/*
* For strict correctness we should use local_irq_save/restore
* instead of preempt_disable/enable.
*
* preempt_disable/enable is racy if the driver finishes bios
* from non-interrupt context as well as from interrupt context
* or from more different interrupts.
*
* On 64-bit architectures the race only results in not counting some
* events, so it is acceptable. On 32-bit architectures the race could
* cause the counter going off by 2^32, so we need to do proper locking
* there.
*
* part_stat_lock()/part_stat_unlock() have this race too.
*/
#if BITS_PER_LONG == 32
unsigned long flags;
local_irq_save(flags);
#else
preempt_disable();
#endif
p = &s->stat_percpu[smp_processor_id()][entry];
if (!end) {
dm_stat_round(s, shared, p);
atomic_inc(&shared->in_flight[idx]);
} else {
unsigned long long duration;
dm_stat_round(s, shared, p);
atomic_dec(&shared->in_flight[idx]);
p->sectors[idx] += len;
p->ios[idx] += 1;
p->merges[idx] += stats_aux->merged;
if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) {
p->ticks[idx] += duration_jiffies;
duration = jiffies_to_msecs(duration_jiffies);
} else {
p->ticks[idx] += stats_aux->duration_ns;
duration = stats_aux->duration_ns;
}
if (s->n_histogram_entries) {
unsigned lo = 0, hi = s->n_histogram_entries + 1;
while (lo + 1 < hi) {
unsigned mid = (lo + hi) / 2;
if (s->histogram_boundaries[mid - 1] > duration) {
hi = mid;
} else {
lo = mid;
}
}
p->histogram[lo]++;
}
}
#if BITS_PER_LONG == 32
local_irq_restore(flags);
#else
preempt_enable();
#endif
}
static void __dm_stat_bio(struct dm_stat *s, int bi_rw,
sector_t bi_sector, sector_t end_sector,
bool end, unsigned long duration_jiffies,
struct dm_stats_aux *stats_aux)
{
sector_t rel_sector, offset, todo, fragment_len;
size_t entry;
if (end_sector <= s->start || bi_sector >= s->end)
return;
if (unlikely(bi_sector < s->start)) {
rel_sector = 0;
todo = end_sector - s->start;
} else {
rel_sector = bi_sector - s->start;
todo = end_sector - bi_sector;
}
if (unlikely(end_sector > s->end))
todo -= (end_sector - s->end);
offset = dm_sector_div64(rel_sector, s->step);
entry = rel_sector;
do {
if (WARN_ON_ONCE(entry >= s->n_entries)) {
DMCRIT("Invalid area access in region id %d", s->id);
return;
}
fragment_len = todo;
if (fragment_len > s->step - offset)
fragment_len = s->step - offset;
dm_stat_for_entry(s, entry, bi_rw, fragment_len,
stats_aux, end, duration_jiffies);
todo -= fragment_len;
entry++;
offset = 0;
} while (unlikely(todo != 0));
}
void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
sector_t bi_sector, unsigned bi_sectors, bool end,
unsigned long duration_jiffies,
struct dm_stats_aux *stats_aux)
{
struct dm_stat *s;
sector_t end_sector;
struct dm_stats_last_position *last;
bool got_precise_time;
if (unlikely(!bi_sectors))
return;
end_sector = bi_sector + bi_sectors;
if (!end) {
/*
* A race condition can at worst result in the merged flag being
* misrepresented, so we don't have to disable preemption here.
*/
last = raw_cpu_ptr(stats->last);
stats_aux->merged =
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
(bi_sector == (READ_ONCE(last->last_sector) &&
((bi_rw == WRITE) ==
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
(READ_ONCE(last->last_rw) == WRITE))
));
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
WRITE_ONCE(last->last_sector, end_sector);
WRITE_ONCE(last->last_rw, bi_rw);
}
rcu_read_lock();
got_precise_time = false;
list_for_each_entry_rcu(s, &stats->list, list_entry) {
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) {
if (!end)
stats_aux->duration_ns = ktime_to_ns(ktime_get());
else
stats_aux->duration_ns = ktime_to_ns(ktime_get()) - stats_aux->duration_ns;
got_precise_time = true;
}
__dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux);
}
rcu_read_unlock();
}
static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared,
struct dm_stat *s, size_t x)
{
int cpu;
struct dm_stat_percpu *p;
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
dm_stat_round(s, shared, p);
local_irq_enable();
shared->tmp.sectors[READ] = 0;
shared->tmp.sectors[WRITE] = 0;
shared->tmp.ios[READ] = 0;
shared->tmp.ios[WRITE] = 0;
shared->tmp.merges[READ] = 0;
shared->tmp.merges[WRITE] = 0;
shared->tmp.ticks[READ] = 0;
shared->tmp.ticks[WRITE] = 0;
shared->tmp.io_ticks[READ] = 0;
shared->tmp.io_ticks[WRITE] = 0;
shared->tmp.io_ticks_total = 0;
shared->tmp.time_in_queue = 0;
if (s->n_histogram_entries)
memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long));
for_each_possible_cpu(cpu) {
p = &s->stat_percpu[cpu][x];
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
shared->tmp.sectors[READ] += READ_ONCE(p->sectors[READ]);
shared->tmp.sectors[WRITE] += READ_ONCE(p->sectors[WRITE]);
shared->tmp.ios[READ] += READ_ONCE(p->ios[READ]);
shared->tmp.ios[WRITE] += READ_ONCE(p->ios[WRITE]);
shared->tmp.merges[READ] += READ_ONCE(p->merges[READ]);
shared->tmp.merges[WRITE] += READ_ONCE(p->merges[WRITE]);
shared->tmp.ticks[READ] += READ_ONCE(p->ticks[READ]);
shared->tmp.ticks[WRITE] += READ_ONCE(p->ticks[WRITE]);
shared->tmp.io_ticks[READ] += READ_ONCE(p->io_ticks[READ]);
shared->tmp.io_ticks[WRITE] += READ_ONCE(p->io_ticks[WRITE]);
shared->tmp.io_ticks_total += READ_ONCE(p->io_ticks_total);
shared->tmp.time_in_queue += READ_ONCE(p->time_in_queue);
if (s->n_histogram_entries) {
unsigned i;
for (i = 0; i < s->n_histogram_entries + 1; i++)
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
shared->tmp.histogram[i] += READ_ONCE(p->histogram[i]);
}
}
}
static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
bool init_tmp_percpu_totals)
{
size_t x;
struct dm_stat_shared *shared;
struct dm_stat_percpu *p;
for (x = idx_start; x < idx_end; x++) {
shared = &s->stat_shared[x];
if (init_tmp_percpu_totals)
__dm_stat_init_temporary_percpu_totals(shared, s, x);
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
p->sectors[READ] -= shared->tmp.sectors[READ];
p->sectors[WRITE] -= shared->tmp.sectors[WRITE];
p->ios[READ] -= shared->tmp.ios[READ];
p->ios[WRITE] -= shared->tmp.ios[WRITE];
p->merges[READ] -= shared->tmp.merges[READ];
p->merges[WRITE] -= shared->tmp.merges[WRITE];
p->ticks[READ] -= shared->tmp.ticks[READ];
p->ticks[WRITE] -= shared->tmp.ticks[WRITE];
p->io_ticks[READ] -= shared->tmp.io_ticks[READ];
p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE];
p->io_ticks_total -= shared->tmp.io_ticks_total;
p->time_in_queue -= shared->tmp.time_in_queue;
local_irq_enable();
if (s->n_histogram_entries) {
unsigned i;
for (i = 0; i < s->n_histogram_entries + 1; i++) {
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
p->histogram[i] -= shared->tmp.histogram[i];
local_irq_enable();
}
}
}
}
static int dm_stats_clear(struct dm_stats *stats, int id)
{
struct dm_stat *s;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
__dm_stat_clear(s, 0, s->n_entries, true);
mutex_unlock(&stats->mutex);
return 1;
}
/*
* This is like jiffies_to_msec, but works for 64-bit values.
*/
static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j)
{
unsigned long long result;
unsigned mult;
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
return j;
result = 0;
if (j)
result = jiffies_to_msecs(j & 0x3fffff);
if (j >= 1 << 22) {
mult = jiffies_to_msecs(1 << 22);
result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff);
}
if (j >= 1ULL << 44)
result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44);
return result;
}
static int dm_stats_print(struct dm_stats *stats, int id,
size_t idx_start, size_t idx_len,
bool clear, char *result, unsigned maxlen)
{
unsigned sz = 0;
struct dm_stat *s;
size_t x;
sector_t start, end, step;
size_t idx_end;
struct dm_stat_shared *shared;
/*
* Output format:
* <start_sector>+<length> counters
*/
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
idx_end = idx_start + idx_len;
if (idx_end < idx_start ||
idx_end > s->n_entries)
idx_end = s->n_entries;
if (idx_start > idx_end)
idx_start = idx_end;
step = s->step;
start = s->start + (step * idx_start);
for (x = idx_start; x < idx_end; x++, start = end) {
shared = &s->stat_shared[x];
end = start + step;
if (unlikely(end > s->end))
end = s->end;
__dm_stat_init_temporary_percpu_totals(shared, s, x);
DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu",
(unsigned long long)start,
(unsigned long long)step,
shared->tmp.ios[READ],
shared->tmp.merges[READ],
shared->tmp.sectors[READ],
dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]),
shared->tmp.ios[WRITE],
shared->tmp.merges[WRITE],
shared->tmp.sectors[WRITE],
dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]),
dm_stat_in_flight(shared),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total),
dm_jiffies_to_msec64(s, shared->tmp.time_in_queue),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE]));
if (s->n_histogram_entries) {
unsigned i;
for (i = 0; i < s->n_histogram_entries + 1; i++) {
DMEMIT("%s%llu", !i ? " " : ":", shared->tmp.histogram[i]);
}
}
DMEMIT("\n");
if (unlikely(sz + 1 >= maxlen))
goto buffer_overflow;
}
if (clear)
__dm_stat_clear(s, idx_start, idx_end, false);
buffer_overflow:
mutex_unlock(&stats->mutex);
return 1;
}
static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data)
{
struct dm_stat *s;
const char *new_aux_data;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
new_aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!new_aux_data) {
mutex_unlock(&stats->mutex);
return -ENOMEM;
}
kfree(s->aux_data);
s->aux_data = new_aux_data;
mutex_unlock(&stats->mutex);
return 0;
}
static int parse_histogram(const char *h, unsigned *n_histogram_entries,
unsigned long long **histogram_boundaries)
{
const char *q;
unsigned n;
unsigned long long last;
*n_histogram_entries = 1;
for (q = h; *q; q++)
if (*q == ',')
(*n_histogram_entries)++;
treewide: kmalloc() -> kmalloc_array() The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 20:55:00 +00:00
*histogram_boundaries = kmalloc_array(*n_histogram_entries,
sizeof(unsigned long long),
GFP_KERNEL);
if (!*histogram_boundaries)
return -ENOMEM;
n = 0;
last = 0;
while (1) {
unsigned long long hi;
int s;
char ch;
s = sscanf(h, "%llu%c", &hi, &ch);
if (!s || (s == 2 && ch != ','))
return -EINVAL;
if (hi <= last)
return -EINVAL;
last = hi;
(*histogram_boundaries)[n] = hi;
if (s == 1)
return 0;
h = strchr(h, ',') + 1;
n++;
}
}
static int message_stats_create(struct mapped_device *md,
unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int r;
int id;
char dummy;
unsigned long long start, end, len, step;
unsigned divisor;
const char *program_id, *aux_data;
unsigned stat_flags = 0;
unsigned n_histogram_entries = 0;
unsigned long long *histogram_boundaries = NULL;
struct dm_arg_set as, as_backup;
const char *a;
unsigned feature_args;
/*
* Input format:
* <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]]
*/
if (argc < 3)
goto ret_einval;
as.argc = argc;
as.argv = argv;
dm_consume_args(&as, 1);
a = dm_shift_arg(&as);
if (!strcmp(a, "-")) {
start = 0;
len = dm_get_size(md);
if (!len)
len = 1;
} else if (sscanf(a, "%llu+%llu%c", &start, &len, &dummy) != 2 ||
start != (sector_t)start || len != (sector_t)len)
goto ret_einval;
end = start + len;
if (start >= end)
goto ret_einval;
a = dm_shift_arg(&as);
if (sscanf(a, "/%u%c", &divisor, &dummy) == 1) {
if (!divisor)
return -EINVAL;
step = end - start;
if (do_div(step, divisor))
step++;
if (!step)
step = 1;
} else if (sscanf(a, "%llu%c", &step, &dummy) != 1 ||
step != (sector_t)step || !step)
goto ret_einval;
as_backup = as;
a = dm_shift_arg(&as);
if (a && sscanf(a, "%u%c", &feature_args, &dummy) == 1) {
while (feature_args--) {
a = dm_shift_arg(&as);
if (!a)
goto ret_einval;
if (!strcasecmp(a, "precise_timestamps"))
stat_flags |= STAT_PRECISE_TIMESTAMPS;
else if (!strncasecmp(a, "histogram:", 10)) {
if (n_histogram_entries)
goto ret_einval;
if ((r = parse_histogram(a + 10, &n_histogram_entries, &histogram_boundaries)))
goto ret;
} else
goto ret_einval;
}
} else {
as = as_backup;
}
program_id = "-";
aux_data = "-";
a = dm_shift_arg(&as);
if (a)
program_id = a;
a = dm_shift_arg(&as);
if (a)
aux_data = a;
if (as.argc)
goto ret_einval;
/*
* If a buffer overflow happens after we created the region,
* it's too late (the userspace would retry with a larger
* buffer, but the region id that caused the overflow is already
* leaked). So we must detect buffer overflow in advance.
*/
snprintf(result, maxlen, "%d", INT_MAX);
if (dm_message_test_buffer_overflow(result, maxlen)) {
r = 1;
goto ret;
}
id = dm_stats_create(dm_get_stats(md), start, end, step, stat_flags,
n_histogram_entries, histogram_boundaries, program_id, aux_data,
dm: enhance internal suspend and resume interface Rename dm_internal_{suspend,resume} to dm_internal_{suspend,resume}_fast -- dm-stats will continue using these methods to avoid all the extra suspend/resume logic that is not needed in order to quickly flush IO. Introduce dm_internal_suspend_noflush() variant that actually calls the mapped_device's target callbacks -- otherwise target-specific hooks are avoided (e.g. dm-thin's thin_presuspend and thin_postsuspend). Common code between dm_internal_{suspend_noflush,resume} and dm_{suspend,resume} was factored out as __dm_{suspend,resume}. Update dm_internal_{suspend_noflush,resume} to always take and release the mapped_device's suspend_lock. Also update dm_{suspend,resume} to be aware of potential for DM_INTERNAL_SUSPEND_FLAG to be set and respond accordingly by interruptibly waiting for the DM_INTERNAL_SUSPEND_FLAG to be cleared. Add lockdep annotation to dm_suspend() and dm_resume(). The existing DM_SUSPEND_FLAG remains unchanged. DM_INTERNAL_SUSPEND_FLAG is set by dm_internal_suspend_noflush() and cleared by dm_internal_resume(). Both DM_SUSPEND_FLAG and DM_INTERNAL_SUSPEND_FLAG may be set if a device was already suspended when dm_internal_suspend_noflush() was called -- this can be thought of as a "nested suspend". A "nested suspend" can occur with legacy userspace dm-thin code that might suspend all active thin volumes before suspending the pool for resize. But otherwise, in the normal dm-thin-pool suspend case moving forward: the thin-pool will have DM_SUSPEND_FLAG set and all active thins from that thin-pool will have DM_INTERNAL_SUSPEND_FLAG set. Also add DM_INTERNAL_SUSPEND_FLAG to status report. This new DM_INTERNAL_SUSPEND_FLAG state is being reported to assist with debugging (e.g. 'dmsetup info' will report an internally suspended device accordingly). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
2014-10-28 22:34:52 +00:00
dm_internal_suspend_fast, dm_internal_resume_fast, md);
if (id < 0) {
r = id;
goto ret;
}
snprintf(result, maxlen, "%d", id);
r = 1;
goto ret;
ret_einval:
r = -EINVAL;
ret:
kfree(histogram_boundaries);
return r;
}
static int message_stats_delete(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_delete(dm_get_stats(md), id);
}
static int message_stats_clear(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_clear(dm_get_stats(md), id);
}
static int message_stats_list(struct mapped_device *md,
unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int r;
const char *program = NULL;
if (argc < 1 || argc > 2)
return -EINVAL;
if (argc > 1) {
program = kstrdup(argv[1], GFP_KERNEL);
if (!program)
return -ENOMEM;
}
r = dm_stats_list(dm_get_stats(md), program, result, maxlen);
kfree(program);
return r;
}
static int message_stats_print(struct mapped_device *md,
unsigned argc, char **argv, bool clear,
char *result, unsigned maxlen)
{
int id;
char dummy;
unsigned long idx_start = 0, idx_len = ULONG_MAX;
if (argc != 2 && argc != 4)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
if (argc > 3) {
if (strcmp(argv[2], "-") &&
sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1)
return -EINVAL;
if (strcmp(argv[3], "-") &&
sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1)
return -EINVAL;
}
return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear,
result, maxlen);
}
static int message_stats_set_aux(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 3)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_set_aux(dm_get_stats(md), id, argv[2]);
}
int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int r;
/* All messages here must start with '@' */
if (!strcasecmp(argv[0], "@stats_create"))
r = message_stats_create(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_delete"))
r = message_stats_delete(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_clear"))
r = message_stats_clear(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_list"))
r = message_stats_list(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print"))
r = message_stats_print(md, argc, argv, false, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print_clear"))
r = message_stats_print(md, argc, argv, true, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_set_aux"))
r = message_stats_set_aux(md, argc, argv);
else
return 2; /* this wasn't a stats message */
if (r == -EINVAL)
DMWARN("Invalid parameters for message %s", argv[0]);
return r;
}
int __init dm_statistics_init(void)
{
shared_memory_amount = 0;
dm_stat_need_rcu_barrier = 0;
return 0;
}
void dm_statistics_exit(void)
{
if (dm_stat_need_rcu_barrier)
rcu_barrier();
if (WARN_ON(shared_memory_amount))
DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount);
}
module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, S_IRUGO);
MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");