dm: add statistics support
Support the collection of I/O statistics on user-defined regions of a DM device. If no regions are defined no statistics are collected so there isn't any performance impact. Only bio-based DM devices are currently supported. Each user-defined region specifies a starting sector, length and step. Individual statistics will be collected for each step-sized area within the range specified. The I/O statistics counters for each step-sized area of a region are in the same format as /sys/block/*/stat or /proc/diskstats but extra counters (12 and 13) are provided: total time spent reading and writing in milliseconds. All these counters may be accessed by sending the @stats_print message to the appropriate DM device via dmsetup. The creation of DM statistics will allocate memory via kmalloc or fallback to using vmalloc space. At most, 1/4 of the overall system memory may be allocated by DM statistics. The admin can see how much memory is used by reading /sys/module/dm_mod/parameters/stats_current_allocated_bytes See Documentation/device-mapper/statistics.txt for more details. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mikulas Patocka
Mike Snitzer
Родитель
94563badaf
Коммит
fd2ed4d252
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@ -0,0 +1,186 @@
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DM statistics
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=============
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Device Mapper supports the collection of I/O statistics on user-defined
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regions of a DM device. If no regions are defined no statistics are
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collected so there isn't any performance impact. Only bio-based DM
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devices are currently supported.
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Each user-defined region specifies a starting sector, length and step.
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Individual statistics will be collected for each step-sized area within
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the range specified.
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The I/O statistics counters for each step-sized area of a region are
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in the same format as /sys/block/*/stat or /proc/diskstats (see:
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Documentation/iostats.txt). But two extra counters (12 and 13) are
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provided: total time spent reading and writing in milliseconds. All
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these counters may be accessed by sending the @stats_print message to
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the appropriate DM device via dmsetup.
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Each region has a corresponding unique identifier, which we call a
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region_id, that is assigned when the region is created. The region_id
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must be supplied when querying statistics about the region, deleting the
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region, etc. Unique region_ids enable multiple userspace programs to
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request and process statistics for the same DM device without stepping
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on each other's data.
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The creation of DM statistics will allocate memory via kmalloc or
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fallback to using vmalloc space. At most, 1/4 of the overall system
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memory may be allocated by DM statistics. The admin can see how much
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memory is used by reading
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/sys/module/dm_mod/parameters/stats_current_allocated_bytes
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Messages
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========
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@stats_create <range> <step> [<program_id> [<aux_data>]]
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Create a new region and return the region_id.
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<range>
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"-" - whole device
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"<start_sector>+<length>" - a range of <length> 512-byte sectors
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starting with <start_sector>.
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<step>
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"<area_size>" - the range is subdivided into areas each containing
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<area_size> sectors.
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"/<number_of_areas>" - the range is subdivided into the specified
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number of areas.
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<program_id>
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An optional parameter. A name that uniquely identifies
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the userspace owner of the range. This groups ranges together
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so that userspace programs can identify the ranges they
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created and ignore those created by others.
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The kernel returns this string back in the output of
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@stats_list message, but it doesn't use it for anything else.
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<aux_data>
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An optional parameter. A word that provides auxiliary data
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that is useful to the client program that created the range.
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The kernel returns this string back in the output of
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@stats_list message, but it doesn't use this value for anything.
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@stats_delete <region_id>
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Delete the region with the specified id.
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<region_id>
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region_id returned from @stats_create
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@stats_clear <region_id>
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Clear all the counters except the in-flight i/o counters.
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<region_id>
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region_id returned from @stats_create
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@stats_list [<program_id>]
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List all regions registered with @stats_create.
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<program_id>
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An optional parameter.
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If this parameter is specified, only matching regions
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are returned.
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If it is not specified, all regions are returned.
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Output format:
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<region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
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@stats_print <region_id> [<starting_line> <number_of_lines>]
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Print counters for each step-sized area of a region.
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<region_id>
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region_id returned from @stats_create
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<starting_line>
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The index of the starting line in the output.
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If omitted, all lines are returned.
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<number_of_lines>
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The number of lines to include in the output.
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If omitted, all lines are returned.
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Output format for each step-sized area of a region:
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<start_sector>+<length> counters
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The first 11 counters have the same meaning as
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/sys/block/*/stat or /proc/diskstats.
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Please refer to Documentation/iostats.txt for details.
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1. the number of reads completed
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2. the number of reads merged
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3. the number of sectors read
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4. the number of milliseconds spent reading
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5. the number of writes completed
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6. the number of writes merged
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7. the number of sectors written
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8. the number of milliseconds spent writing
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9. the number of I/Os currently in progress
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10. the number of milliseconds spent doing I/Os
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11. the weighted number of milliseconds spent doing I/Os
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Additional counters:
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12. the total time spent reading in milliseconds
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13. the total time spent writing in milliseconds
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@stats_print_clear <region_id> [<starting_line> <number_of_lines>]
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Atomically print and then clear all the counters except the
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in-flight i/o counters. Useful when the client consuming the
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statistics does not want to lose any statistics (those updated
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between printing and clearing).
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<region_id>
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region_id returned from @stats_create
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<starting_line>
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The index of the starting line in the output.
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If omitted, all lines are printed and then cleared.
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<number_of_lines>
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The number of lines to process.
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If omitted, all lines are printed and then cleared.
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@stats_set_aux <region_id> <aux_data>
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Store auxiliary data aux_data for the specified region.
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<region_id>
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region_id returned from @stats_create
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<aux_data>
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The string that identifies data which is useful to the client
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program that created the range. The kernel returns this
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string back in the output of @stats_list message, but it
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doesn't use this value for anything.
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Examples
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========
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Subdivide the DM device 'vol' into 100 pieces and start collecting
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statistics on them:
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dmsetup message vol 0 @stats_create - /100
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Set the auxillary data string to "foo bar baz" (the escape for each
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space must also be escaped, otherwise the shell will consume them):
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dmsetup message vol 0 @stats_set_aux 0 foo\\ bar\\ baz
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List the statistics:
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dmsetup message vol 0 @stats_list
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Print the statistics:
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dmsetup message vol 0 @stats_print 0
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Delete the statistics:
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dmsetup message vol 0 @stats_delete 0
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@ -3,7 +3,7 @@
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#
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dm-mod-y += dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
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dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o
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dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-stats.o
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dm-multipath-y += dm-path-selector.o dm-mpath.o
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dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \
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dm-snap-persistent.o
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@ -1455,20 +1455,26 @@ static int table_status(struct dm_ioctl *param, size_t param_size)
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return 0;
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}
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static bool buffer_test_overflow(char *result, unsigned maxlen)
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{
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return !maxlen || strlen(result) + 1 >= maxlen;
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}
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/*
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* Process device-mapper dependent messages.
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* Process device-mapper dependent messages. Messages prefixed with '@'
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* are processed by the DM core. All others are delivered to the target.
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* Returns a number <= 1 if message was processed by device mapper.
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* Returns 2 if message should be delivered to the target.
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*/
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static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
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char *result, unsigned maxlen)
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{
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return 2;
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int r;
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if (**argv != '@')
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return 2; /* no '@' prefix, deliver to target */
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r = dm_stats_message(md, argc, argv, result, maxlen);
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if (r < 2)
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return r;
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DMERR("Unsupported message sent to DM core: %s", argv[0]);
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return -EINVAL;
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}
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/*
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@ -1542,7 +1548,7 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
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if (r == 1) {
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param->flags |= DM_DATA_OUT_FLAG;
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if (buffer_test_overflow(result, maxlen))
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if (dm_message_test_buffer_overflow(result, maxlen))
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param->flags |= DM_BUFFER_FULL_FLAG;
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else
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param->data_size = param->data_start + strlen(result) + 1;
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@ -0,0 +1,969 @@
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#include <linux/errno.h>
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#include <linux/numa.h>
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#include <linux/slab.h>
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#include <linux/rculist.h>
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#include <linux/threads.h>
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#include <linux/preempt.h>
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#include <linux/irqflags.h>
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#include <linux/vmalloc.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/device-mapper.h>
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#include "dm.h"
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#include "dm-stats.h"
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#define DM_MSG_PREFIX "stats"
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static int dm_stat_need_rcu_barrier;
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/*
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* Using 64-bit values to avoid overflow (which is a
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* problem that block/genhd.c's IO accounting has).
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*/
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struct dm_stat_percpu {
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unsigned long long sectors[2];
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unsigned long long ios[2];
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unsigned long long merges[2];
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unsigned long long ticks[2];
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unsigned long long io_ticks[2];
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unsigned long long io_ticks_total;
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unsigned long long time_in_queue;
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};
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struct dm_stat_shared {
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atomic_t in_flight[2];
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unsigned long stamp;
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struct dm_stat_percpu tmp;
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};
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struct dm_stat {
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struct list_head list_entry;
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int id;
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size_t n_entries;
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sector_t start;
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sector_t end;
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sector_t step;
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const char *program_id;
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const char *aux_data;
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struct rcu_head rcu_head;
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size_t shared_alloc_size;
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size_t percpu_alloc_size;
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struct dm_stat_percpu *stat_percpu[NR_CPUS];
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struct dm_stat_shared stat_shared[0];
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};
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struct dm_stats_last_position {
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sector_t last_sector;
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unsigned last_rw;
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};
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/*
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* A typo on the command line could possibly make the kernel run out of memory
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* and crash. To prevent the crash we account all used memory. We fail if we
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* exhaust 1/4 of all memory or 1/2 of vmalloc space.
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*/
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#define DM_STATS_MEMORY_FACTOR 4
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#define DM_STATS_VMALLOC_FACTOR 2
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static DEFINE_SPINLOCK(shared_memory_lock);
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static unsigned long shared_memory_amount;
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static bool __check_shared_memory(size_t alloc_size)
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{
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size_t a;
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a = shared_memory_amount + alloc_size;
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if (a < shared_memory_amount)
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return false;
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if (a >> PAGE_SHIFT > totalram_pages / DM_STATS_MEMORY_FACTOR)
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return false;
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#ifdef CONFIG_MMU
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if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR)
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return false;
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#endif
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return true;
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}
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static bool check_shared_memory(size_t alloc_size)
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{
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bool ret;
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spin_lock_irq(&shared_memory_lock);
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ret = __check_shared_memory(alloc_size);
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spin_unlock_irq(&shared_memory_lock);
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return ret;
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}
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static bool claim_shared_memory(size_t alloc_size)
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{
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spin_lock_irq(&shared_memory_lock);
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if (!__check_shared_memory(alloc_size)) {
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spin_unlock_irq(&shared_memory_lock);
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return false;
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}
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shared_memory_amount += alloc_size;
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spin_unlock_irq(&shared_memory_lock);
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return true;
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}
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static void free_shared_memory(size_t alloc_size)
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{
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unsigned long flags;
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spin_lock_irqsave(&shared_memory_lock, flags);
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if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) {
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spin_unlock_irqrestore(&shared_memory_lock, flags);
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DMCRIT("Memory usage accounting bug.");
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return;
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}
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shared_memory_amount -= alloc_size;
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spin_unlock_irqrestore(&shared_memory_lock, flags);
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}
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static void *dm_kvzalloc(size_t alloc_size, int node)
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{
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void *p;
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if (!claim_shared_memory(alloc_size))
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return NULL;
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if (alloc_size <= KMALLOC_MAX_SIZE) {
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p = kzalloc_node(alloc_size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, node);
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if (p)
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return p;
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}
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p = vzalloc_node(alloc_size, node);
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if (p)
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return p;
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free_shared_memory(alloc_size);
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return NULL;
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}
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static void dm_kvfree(void *ptr, size_t alloc_size)
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{
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if (!ptr)
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return;
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free_shared_memory(alloc_size);
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if (is_vmalloc_addr(ptr))
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vfree(ptr);
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else
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kfree(ptr);
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}
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static void dm_stat_free(struct rcu_head *head)
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{
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int cpu;
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struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
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kfree(s->program_id);
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kfree(s->aux_data);
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for_each_possible_cpu(cpu)
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dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
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dm_kvfree(s, s->shared_alloc_size);
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}
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static int dm_stat_in_flight(struct dm_stat_shared *shared)
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{
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return atomic_read(&shared->in_flight[READ]) +
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atomic_read(&shared->in_flight[WRITE]);
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}
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void dm_stats_init(struct dm_stats *stats)
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{
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int cpu;
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struct dm_stats_last_position *last;
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mutex_init(&stats->mutex);
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INIT_LIST_HEAD(&stats->list);
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stats->last = alloc_percpu(struct dm_stats_last_position);
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for_each_possible_cpu(cpu) {
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last = per_cpu_ptr(stats->last, cpu);
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last->last_sector = (sector_t)ULLONG_MAX;
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last->last_rw = UINT_MAX;
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}
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}
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void dm_stats_cleanup(struct dm_stats *stats)
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{
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size_t ni;
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struct dm_stat *s;
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struct dm_stat_shared *shared;
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while (!list_empty(&stats->list)) {
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s = container_of(stats->list.next, struct dm_stat, list_entry);
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list_del(&s->list_entry);
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for (ni = 0; ni < s->n_entries; ni++) {
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shared = &s->stat_shared[ni];
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if (WARN_ON(dm_stat_in_flight(shared))) {
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DMCRIT("leaked in-flight counter at index %lu "
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"(start %llu, end %llu, step %llu): reads %d, writes %d",
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(unsigned long)ni,
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(unsigned long long)s->start,
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(unsigned long long)s->end,
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(unsigned long long)s->step,
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atomic_read(&shared->in_flight[READ]),
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atomic_read(&shared->in_flight[WRITE]));
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}
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}
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dm_stat_free(&s->rcu_head);
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}
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free_percpu(stats->last);
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}
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static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
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sector_t step, const char *program_id, const char *aux_data,
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void (*suspend_callback)(struct mapped_device *),
|
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void (*resume_callback)(struct mapped_device *),
|
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struct mapped_device *md)
|
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{
|
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struct list_head *l;
|
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struct dm_stat *s, *tmp_s;
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sector_t n_entries;
|
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size_t ni;
|
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size_t shared_alloc_size;
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size_t percpu_alloc_size;
|
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struct dm_stat_percpu *p;
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int cpu;
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int ret_id;
|
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int r;
|
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|
||||
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 = sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared);
|
||||
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;
|
||||
|
||||
if (!check_shared_memory(shared_alloc_size + num_possible_cpus() * percpu_alloc_size))
|
||||
return -ENOMEM;
|
||||
|
||||
s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
|
||||
if (!s)
|
||||
return -ENOMEM;
|
||||
|
||||
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->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);
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
/*
|
||||
* 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))
|
||||
goto do_sync_free;
|
||||
if (is_vmalloc_addr(s)) {
|
||||
do_sync_free:
|
||||
synchronize_rcu_expedited();
|
||||
dm_stat_free(&s->rcu_head);
|
||||
} else {
|
||||
ACCESS_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\n", s->id,
|
||||
(unsigned long long)s->start,
|
||||
(unsigned long long)len,
|
||||
(unsigned long long)s->step,
|
||||
s->program_id,
|
||||
s->aux_data);
|
||||
}
|
||||
}
|
||||
mutex_unlock(&stats->mutex);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void dm_stat_round(struct dm_stat_shared *shared, struct dm_stat_percpu *p)
|
||||
{
|
||||
/*
|
||||
* This is racy, but so is part_round_stats_single.
|
||||
*/
|
||||
unsigned long now = jiffies;
|
||||
unsigned in_flight_read;
|
||||
unsigned in_flight_write;
|
||||
unsigned long 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,
|
||||
unsigned long bi_rw, sector_t len, bool merged,
|
||||
bool end, unsigned long duration)
|
||||
{
|
||||
unsigned long idx = bi_rw & REQ_WRITE;
|
||||
struct dm_stat_shared *shared = &s->stat_shared[entry];
|
||||
struct dm_stat_percpu *p;
|
||||
|
||||
/*
|
||||
* For strict correctness we should use local_irq_disable/enable
|
||||
* instead of preempt_disable/enable.
|
||||
*
|
||||
* This is racy if the driver finishes bios from non-interrupt
|
||||
* context as well as from interrupt context or from more different
|
||||
* interrupts.
|
||||
*
|
||||
* However, the race only results in not counting some events,
|
||||
* so it is acceptable.
|
||||
*
|
||||
* part_stat_lock()/part_stat_unlock() have this race too.
|
||||
*/
|
||||
preempt_disable();
|
||||
p = &s->stat_percpu[smp_processor_id()][entry];
|
||||
|
||||
if (!end) {
|
||||
dm_stat_round(shared, p);
|
||||
atomic_inc(&shared->in_flight[idx]);
|
||||
} else {
|
||||
dm_stat_round(shared, p);
|
||||
atomic_dec(&shared->in_flight[idx]);
|
||||
p->sectors[idx] += len;
|
||||
p->ios[idx] += 1;
|
||||
p->merges[idx] += merged;
|
||||
p->ticks[idx] += duration;
|
||||
}
|
||||
|
||||
preempt_enable();
|
||||
}
|
||||
|
||||
static void __dm_stat_bio(struct dm_stat *s, unsigned long bi_rw,
|
||||
sector_t bi_sector, sector_t end_sector,
|
||||
bool end, unsigned long duration,
|
||||
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->merged, end, duration);
|
||||
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, struct dm_stats_aux *stats_aux)
|
||||
{
|
||||
struct dm_stat *s;
|
||||
sector_t end_sector;
|
||||
struct dm_stats_last_position *last;
|
||||
|
||||
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 = __this_cpu_ptr(stats->last);
|
||||
stats_aux->merged =
|
||||
(bi_sector == (ACCESS_ONCE(last->last_sector) &&
|
||||
((bi_rw & (REQ_WRITE | REQ_DISCARD)) ==
|
||||
(ACCESS_ONCE(last->last_rw) & (REQ_WRITE | REQ_DISCARD)))
|
||||
));
|
||||
ACCESS_ONCE(last->last_sector) = end_sector;
|
||||
ACCESS_ONCE(last->last_rw) = bi_rw;
|
||||
}
|
||||
|
||||
rcu_read_lock();
|
||||
|
||||
list_for_each_entry_rcu(s, &stats->list, list_entry)
|
||||
__dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration, 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(shared, p);
|
||||
local_irq_enable();
|
||||
|
||||
memset(&shared->tmp, 0, sizeof(shared->tmp));
|
||||
for_each_possible_cpu(cpu) {
|
||||
p = &s->stat_percpu[cpu][x];
|
||||
shared->tmp.sectors[READ] += ACCESS_ONCE(p->sectors[READ]);
|
||||
shared->tmp.sectors[WRITE] += ACCESS_ONCE(p->sectors[WRITE]);
|
||||
shared->tmp.ios[READ] += ACCESS_ONCE(p->ios[READ]);
|
||||
shared->tmp.ios[WRITE] += ACCESS_ONCE(p->ios[WRITE]);
|
||||
shared->tmp.merges[READ] += ACCESS_ONCE(p->merges[READ]);
|
||||
shared->tmp.merges[WRITE] += ACCESS_ONCE(p->merges[WRITE]);
|
||||
shared->tmp.ticks[READ] += ACCESS_ONCE(p->ticks[READ]);
|
||||
shared->tmp.ticks[WRITE] += ACCESS_ONCE(p->ticks[WRITE]);
|
||||
shared->tmp.io_ticks[READ] += ACCESS_ONCE(p->io_ticks[READ]);
|
||||
shared->tmp.io_ticks[WRITE] += ACCESS_ONCE(p->io_ticks[WRITE]);
|
||||
shared->tmp.io_ticks_total += ACCESS_ONCE(p->io_ticks_total);
|
||||
shared->tmp.time_in_queue += ACCESS_ONCE(p->time_in_queue);
|
||||
}
|
||||
}
|
||||
|
||||
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();
|
||||
}
|
||||
}
|
||||
|
||||
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(unsigned long long j)
|
||||
{
|
||||
unsigned long long result = 0;
|
||||
unsigned mult;
|
||||
|
||||
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\n",
|
||||
(unsigned long long)start,
|
||||
(unsigned long long)step,
|
||||
shared->tmp.ios[READ],
|
||||
shared->tmp.merges[READ],
|
||||
shared->tmp.sectors[READ],
|
||||
dm_jiffies_to_msec64(shared->tmp.ticks[READ]),
|
||||
shared->tmp.ios[WRITE],
|
||||
shared->tmp.merges[WRITE],
|
||||
shared->tmp.sectors[WRITE],
|
||||
dm_jiffies_to_msec64(shared->tmp.ticks[WRITE]),
|
||||
dm_stat_in_flight(shared),
|
||||
dm_jiffies_to_msec64(shared->tmp.io_ticks_total),
|
||||
dm_jiffies_to_msec64(shared->tmp.time_in_queue),
|
||||
dm_jiffies_to_msec64(shared->tmp.io_ticks[READ]),
|
||||
dm_jiffies_to_msec64(shared->tmp.io_ticks[WRITE]));
|
||||
|
||||
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 message_stats_create(struct mapped_device *md,
|
||||
unsigned argc, char **argv,
|
||||
char *result, unsigned maxlen)
|
||||
{
|
||||
int id;
|
||||
char dummy;
|
||||
unsigned long long start, end, len, step;
|
||||
unsigned divisor;
|
||||
const char *program_id, *aux_data;
|
||||
|
||||
/*
|
||||
* Input format:
|
||||
* <range> <step> [<program_id> [<aux_data>]]
|
||||
*/
|
||||
|
||||
if (argc < 3 || argc > 5)
|
||||
return -EINVAL;
|
||||
|
||||
if (!strcmp(argv[1], "-")) {
|
||||
start = 0;
|
||||
len = dm_get_size(md);
|
||||
if (!len)
|
||||
len = 1;
|
||||
} else if (sscanf(argv[1], "%llu+%llu%c", &start, &len, &dummy) != 2 ||
|
||||
start != (sector_t)start || len != (sector_t)len)
|
||||
return -EINVAL;
|
||||
|
||||
end = start + len;
|
||||
if (start >= end)
|
||||
return -EINVAL;
|
||||
|
||||
if (sscanf(argv[2], "/%u%c", &divisor, &dummy) == 1) {
|
||||
step = end - start;
|
||||
if (do_div(step, divisor))
|
||||
step++;
|
||||
if (!step)
|
||||
step = 1;
|
||||
} else if (sscanf(argv[2], "%llu%c", &step, &dummy) != 1 ||
|
||||
step != (sector_t)step || !step)
|
||||
return -EINVAL;
|
||||
|
||||
program_id = "-";
|
||||
aux_data = "-";
|
||||
|
||||
if (argc > 3)
|
||||
program_id = argv[3];
|
||||
|
||||
if (argc > 4)
|
||||
aux_data = argv[4];
|
||||
|
||||
/*
|
||||
* 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))
|
||||
return 1;
|
||||
|
||||
id = dm_stats_create(dm_get_stats(md), start, end, step, program_id, aux_data,
|
||||
dm_internal_suspend, dm_internal_resume, md);
|
||||
if (id < 0)
|
||||
return id;
|
||||
|
||||
snprintf(result, maxlen, "%d", id);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
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;
|
||||
|
||||
if (dm_request_based(md)) {
|
||||
DMWARN("Statistics are only supported for bio-based devices");
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
/* 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)
|
||||
{
|
||||
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");
|
||||
|
|
@ -0,0 +1,40 @@
|
|||
#ifndef DM_STATS_H
|
||||
#define DM_STATS_H
|
||||
|
||||
#include <linux/types.h>
|
||||
#include <linux/mutex.h>
|
||||
#include <linux/list.h>
|
||||
|
||||
int dm_statistics_init(void);
|
||||
void dm_statistics_exit(void);
|
||||
|
||||
struct dm_stats {
|
||||
struct mutex mutex;
|
||||
struct list_head list; /* list of struct dm_stat */
|
||||
struct dm_stats_last_position __percpu *last;
|
||||
sector_t last_sector;
|
||||
unsigned last_rw;
|
||||
};
|
||||
|
||||
struct dm_stats_aux {
|
||||
bool merged;
|
||||
};
|
||||
|
||||
void dm_stats_init(struct dm_stats *st);
|
||||
void dm_stats_cleanup(struct dm_stats *st);
|
||||
|
||||
struct mapped_device;
|
||||
|
||||
int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
|
||||
char *result, unsigned maxlen);
|
||||
|
||||
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, struct dm_stats_aux *aux);
|
||||
|
||||
static inline bool dm_stats_used(struct dm_stats *st)
|
||||
{
|
||||
return !list_empty(&st->list);
|
||||
}
|
||||
|
||||
#endif
|
||||
|
|
@ -60,6 +60,7 @@ struct dm_io {
|
|||
struct bio *bio;
|
||||
unsigned long start_time;
|
||||
spinlock_t endio_lock;
|
||||
struct dm_stats_aux stats_aux;
|
||||
};
|
||||
|
||||
/*
|
||||
|
|
@ -198,6 +199,8 @@ struct mapped_device {
|
|||
|
||||
/* zero-length flush that will be cloned and submitted to targets */
|
||||
struct bio flush_bio;
|
||||
|
||||
struct dm_stats stats;
|
||||
};
|
||||
|
||||
/*
|
||||
|
|
@ -269,6 +272,7 @@ static int (*_inits[])(void) __initdata = {
|
|||
dm_io_init,
|
||||
dm_kcopyd_init,
|
||||
dm_interface_init,
|
||||
dm_statistics_init,
|
||||
};
|
||||
|
||||
static void (*_exits[])(void) = {
|
||||
|
|
@ -279,6 +283,7 @@ static void (*_exits[])(void) = {
|
|||
dm_io_exit,
|
||||
dm_kcopyd_exit,
|
||||
dm_interface_exit,
|
||||
dm_statistics_exit,
|
||||
};
|
||||
|
||||
static int __init dm_init(void)
|
||||
|
|
@ -384,6 +389,16 @@ int dm_lock_for_deletion(struct mapped_device *md)
|
|||
return r;
|
||||
}
|
||||
|
||||
sector_t dm_get_size(struct mapped_device *md)
|
||||
{
|
||||
return get_capacity(md->disk);
|
||||
}
|
||||
|
||||
struct dm_stats *dm_get_stats(struct mapped_device *md)
|
||||
{
|
||||
return &md->stats;
|
||||
}
|
||||
|
||||
static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
|
||||
{
|
||||
struct mapped_device *md = bdev->bd_disk->private_data;
|
||||
|
|
@ -466,8 +481,9 @@ static int md_in_flight(struct mapped_device *md)
|
|||
static void start_io_acct(struct dm_io *io)
|
||||
{
|
||||
struct mapped_device *md = io->md;
|
||||
struct bio *bio = io->bio;
|
||||
int cpu;
|
||||
int rw = bio_data_dir(io->bio);
|
||||
int rw = bio_data_dir(bio);
|
||||
|
||||
io->start_time = jiffies;
|
||||
|
||||
|
|
@ -476,6 +492,10 @@ static void start_io_acct(struct dm_io *io)
|
|||
part_stat_unlock();
|
||||
atomic_set(&dm_disk(md)->part0.in_flight[rw],
|
||||
atomic_inc_return(&md->pending[rw]));
|
||||
|
||||
if (unlikely(dm_stats_used(&md->stats)))
|
||||
dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
|
||||
bio_sectors(bio), false, 0, &io->stats_aux);
|
||||
}
|
||||
|
||||
static void end_io_acct(struct dm_io *io)
|
||||
|
|
@ -491,6 +511,10 @@ static void end_io_acct(struct dm_io *io)
|
|||
part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
|
||||
part_stat_unlock();
|
||||
|
||||
if (unlikely(dm_stats_used(&md->stats)))
|
||||
dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
|
||||
bio_sectors(bio), true, duration, &io->stats_aux);
|
||||
|
||||
/*
|
||||
* After this is decremented the bio must not be touched if it is
|
||||
* a flush.
|
||||
|
|
@ -1519,7 +1543,7 @@ static void _dm_request(struct request_queue *q, struct bio *bio)
|
|||
return;
|
||||
}
|
||||
|
||||
static int dm_request_based(struct mapped_device *md)
|
||||
int dm_request_based(struct mapped_device *md)
|
||||
{
|
||||
return blk_queue_stackable(md->queue);
|
||||
}
|
||||
|
|
@ -1958,6 +1982,8 @@ static struct mapped_device *alloc_dev(int minor)
|
|||
md->flush_bio.bi_bdev = md->bdev;
|
||||
md->flush_bio.bi_rw = WRITE_FLUSH;
|
||||
|
||||
dm_stats_init(&md->stats);
|
||||
|
||||
/* Populate the mapping, nobody knows we exist yet */
|
||||
spin_lock(&_minor_lock);
|
||||
old_md = idr_replace(&_minor_idr, md, minor);
|
||||
|
|
@ -2009,6 +2035,7 @@ static void free_dev(struct mapped_device *md)
|
|||
|
||||
put_disk(md->disk);
|
||||
blk_cleanup_queue(md->queue);
|
||||
dm_stats_cleanup(&md->stats);
|
||||
module_put(THIS_MODULE);
|
||||
kfree(md);
|
||||
}
|
||||
|
|
@ -2150,7 +2177,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
|
|||
/*
|
||||
* Wipe any geometry if the size of the table changed.
|
||||
*/
|
||||
if (size != get_capacity(md->disk))
|
||||
if (size != dm_get_size(md))
|
||||
memset(&md->geometry, 0, sizeof(md->geometry));
|
||||
|
||||
__set_size(md, size);
|
||||
|
|
@ -2696,6 +2723,38 @@ out:
|
|||
return r;
|
||||
}
|
||||
|
||||
/*
|
||||
* Internal suspend/resume works like userspace-driven suspend. It waits
|
||||
* until all bios finish and prevents issuing new bios to the target drivers.
|
||||
* It may be used only from the kernel.
|
||||
*
|
||||
* Internal suspend holds md->suspend_lock, which prevents interaction with
|
||||
* userspace-driven suspend.
|
||||
*/
|
||||
|
||||
void dm_internal_suspend(struct mapped_device *md)
|
||||
{
|
||||
mutex_lock(&md->suspend_lock);
|
||||
if (dm_suspended_md(md))
|
||||
return;
|
||||
|
||||
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
||||
synchronize_srcu(&md->io_barrier);
|
||||
flush_workqueue(md->wq);
|
||||
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
|
||||
}
|
||||
|
||||
void dm_internal_resume(struct mapped_device *md)
|
||||
{
|
||||
if (dm_suspended_md(md))
|
||||
goto done;
|
||||
|
||||
dm_queue_flush(md);
|
||||
|
||||
done:
|
||||
mutex_unlock(&md->suspend_lock);
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------
|
||||
* Event notification.
|
||||
*---------------------------------------------------------------*/
|
||||
|
|
|
|||
|
|
@ -16,6 +16,8 @@
|
|||
#include <linux/blkdev.h>
|
||||
#include <linux/hdreg.h>
|
||||
|
||||
#include "dm-stats.h"
|
||||
|
||||
/*
|
||||
* Suspend feature flags
|
||||
*/
|
||||
|
|
@ -157,10 +159,16 @@ void dm_destroy(struct mapped_device *md);
|
|||
void dm_destroy_immediate(struct mapped_device *md);
|
||||
int dm_open_count(struct mapped_device *md);
|
||||
int dm_lock_for_deletion(struct mapped_device *md);
|
||||
int dm_request_based(struct mapped_device *md);
|
||||
sector_t dm_get_size(struct mapped_device *md);
|
||||
struct dm_stats *dm_get_stats(struct mapped_device *md);
|
||||
|
||||
int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
|
||||
unsigned cookie);
|
||||
|
||||
void dm_internal_suspend(struct mapped_device *md);
|
||||
void dm_internal_resume(struct mapped_device *md);
|
||||
|
||||
int dm_io_init(void);
|
||||
void dm_io_exit(void);
|
||||
|
||||
|
|
@ -173,4 +181,12 @@ void dm_kcopyd_exit(void);
|
|||
struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size);
|
||||
void dm_free_md_mempools(struct dm_md_mempools *pools);
|
||||
|
||||
/*
|
||||
* Helpers that are used by DM core
|
||||
*/
|
||||
static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
|
||||
{
|
||||
return !maxlen || strlen(result) + 1 >= maxlen;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
|
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@ -10,6 +10,7 @@
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/math64.h>
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#include <linux/ratelimit.h>
|
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|
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struct dm_dev;
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|
|
@ -550,6 +551,14 @@ extern struct ratelimit_state dm_ratelimit_state;
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#define DM_MAPIO_REMAPPED 1
|
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#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
|
||||
|
||||
#define dm_sector_div64(x, y)( \
|
||||
{ \
|
||||
u64 _res; \
|
||||
(x) = div64_u64_rem(x, y, &_res); \
|
||||
_res; \
|
||||
} \
|
||||
)
|
||||
|
||||
/*
|
||||
* Ceiling(n / sz)
|
||||
*/
|
||||
|
|
|
|||
|
|
@ -267,9 +267,9 @@ enum {
|
|||
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
|
||||
|
||||
#define DM_VERSION_MAJOR 4
|
||||
#define DM_VERSION_MINOR 25
|
||||
#define DM_VERSION_MINOR 26
|
||||
#define DM_VERSION_PATCHLEVEL 0
|
||||
#define DM_VERSION_EXTRA "-ioctl (2013-06-26)"
|
||||
#define DM_VERSION_EXTRA "-ioctl (2013-08-15)"
|
||||
|
||||
/* Status bits */
|
||||
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
|
||||
|
|
|
|||
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