user/sven/linux.git/block, branch v2.6.29.5

block: include empty disks in /proc/diskstats

2009-05-08T22:45:00Z

commit 71982a409f12c50d011325a4471aa20666bb908d upstream. /proc/diskstats used to show stats for all disks whether they're zero-sized or not and their non-zero partitions. Commit 074a7aca7afa6f230104e8e65eba3420263714a5 accidentally changed the behavior such that it doesn't print out zero sized disks. This patch implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and uses it in diskstats_show() such that empty part0 is shown in /proc/diskstats. Reported and bisectd by Dianel Collins. Signed-off-by: Tejun Heo Reported-by: Daniel Collins Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: fix missing bio back/front segment size setting in blk_recount_segments()

2009-03-06T07:55:24Z

Commit 1e42807918d17e8c93bf14fbb74be84b141334c1 introduced a bug where we don't get front/back segment sizes in the bio in blk_recount_segments(). Fix this by tracking the back bio as well as the front bio in __blk_recalc_rq_segments(), this also cleans up the interface by getting rid of the segment size pointer passing. Tested-by: Thomas Gleixner Tested-by: Ingo Molnar Signed-off-by: Jens Axboe

block: reduce stack footprint of blk_recount_segments()

2009-02-26T09:45:48Z

blk_recalc_rq_segments() requires a request structure passed in, which we don't have from blk_recount_segments(). So the latter allocates one on the stack, using > 400 bytes of stack for that. This can cause us to spill over one page of stack from ext4 at least: 0) 4560 400 blk_recount_segments+0x43/0x62 1) 4160 32 bio_phys_segments+0x1c/0x24 2) 4128 32 blk_rq_bio_prep+0x2a/0xf9 3) 4096 32 init_request_from_bio+0xf9/0xfe 4) 4064 112 __make_request+0x33c/0x3f6 5) 3952 144 generic_make_request+0x2d1/0x321 6) 3808 64 submit_bio+0xb9/0xc3 7) 3744 48 submit_bh+0xea/0x10e 8) 3696 368 ext4_mb_init_cache+0x257/0xa6a [ext4] 9) 3328 288 ext4_mb_regular_allocator+0x421/0xcd9 [ext4] 10) 3040 160 ext4_mb_new_blocks+0x211/0x4b4 [ext4] 11) 2880 336 ext4_ext_get_blocks+0xb61/0xd45 [ext4] 12) 2544 96 ext4_get_blocks_wrap+0xf2/0x200 [ext4] 13) 2448 80 ext4_da_get_block_write+0x6e/0x16b [ext4] 14) 2368 352 mpage_da_map_blocks+0x7e/0x4b3 [ext4] 15) 2016 352 ext4_da_writepages+0x2ce/0x43c [ext4] 16) 1664 32 do_writepages+0x2d/0x3c 17) 1632 144 __writeback_single_inode+0x162/0x2cd 18) 1488 96 generic_sync_sb_inodes+0x1e3/0x32b 19) 1392 16 sync_sb_inodes+0xe/0x10 20) 1376 48 writeback_inodes+0x69/0xb3 21) 1328 208 balance_dirty_pages_ratelimited_nr+0x187/0x2f9 22) 1120 224 generic_file_buffered_write+0x1d4/0x2c4 23) 896 176 __generic_file_aio_write_nolock+0x35f/0x393 24) 720 80 generic_file_aio_write+0x6c/0xc8 25) 640 80 ext4_file_write+0xa9/0x137 [ext4] 26) 560 320 do_sync_write+0xf0/0x137 27) 240 48 vfs_write+0xb3/0x13c 28) 192 64 sys_write+0x4c/0x74 29) 128 128 system_call_fastpath+0x16/0x1b Split the segment counting out into a __blk_recalc_rq_segments() helper to avoid allocating an onstack request just for checking the physical segment count. Signed-off-by: Jens Axboe

block: add documentation for register_blkdev()

2009-02-26T09:45:48Z

Add documentation for register_blkdev() function and for the parameters. Signed-off-by: Márton Németh Cc: Greg Kroah-Hartman Signed-off-by: Jens Axboe

block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list

2009-02-18T09:34:16Z

blk_abort_queue() iterates the timeout list and aborts each request on the list, but if the driver error handling readds a request to the timeout list during this processing, we could be looping forever. Fix this by splicing current entries to a local list and run over that list instead. Signed-off-by: Jens Axboe

block: fix booting from partitioned md array

2009-02-18T09:33:59Z

Hi Tejun, it looks like your commit: block: don't depend on consecutive minor space f331c0296f2a9fee0d396a70598b954062603015 broke a particular case for booting from partitioned md/raid devices. That is the second time this has been broken recently. The previous time was fixed by block: do_mounts - accept root= 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Because the data isn't available when an md device is first created (we add disks and set it up after creation), the initial partition scan finds nothing. It is not until the device is opened that another partition scan happens and finds something. So at the point where the kernel parameter "root=/dev/md_d0p1" is being parsed, md_d0 exists, but md_d0p1 does not. However if we let blk_lookup_devt return the correct device number even though the device doesn't exist, then the attempt to mount it will successfully find the partition. I have tried in the past to find a way to get the partition table to be read as soon as the array is assembled but that proved impossible (at the time). I don't remember the details, and could possibly revisit it. However it would be really nice if blk_lookup_devt could be adjusted to again accept non existant partitions. Signed-off-by: Jens Axboe

block: fix bad definition of BIO_RW_SYNC

2009-02-18T09:32:00Z

We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe

bsg: Fix sense buffer bug in SG_IO

2009-02-18T09:32:00Z

When submitting requests via SG_IO, which does a sync io, a bsg_command is not allocated. So an in-Kernel sense_buffer was not set. However when calling blk_execute_rq() with no sense buffer one is provided from the stack. Now bsg at blk_complete_sgv4_hdr_rq() would check if rq->sense_len and a sense was requested by sg_io_v4 the rq->sense was copy_user() back, but by now it is already mangled stack memory. I have fixed that by forcing a sense_buffer when calling bsg_map_hdr(). The bsg_command->sense is provided in the write/read path like before, and on-the-stack buffer is provided when doing SG_IO. I have also fixed a dprintk message to print rq->errors in hex because of the scsi bit-field use of this member. For other block devices it does not matter anyway. Signed-off-by: Boaz Harrosh Acked-by: FUJITA Tomonori Signed-off-by: Jens Axboe

block: fix oops in blk_queue_io_stat()

2009-02-02T07:42:32Z

Some initial probe requests don't have disk->queue mapped yet, so we can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in blk_do_io_stat(). Signed-off-by: Jens Axboe

cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice

2009-01-30T11:47:33Z

This patch adds the ability to pre-empt an ongoing BE timeslice when a RT request is waiting for the current timeslice to complete. This reduces the wait time to disk for RT requests from an upper bound of 4 (current value of cfq_quantum) to 1 disk request. Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt() and retested. Latency(secs) for the RT task when doing sequential reads from 10G file. | only RT | RT + BE | RT + BE + this patch small (512 byte) reads | 143 | 163 | 145 large (1Mb) reads | 142 | 158 | 146 Signed-off-by: Divyesh Shah Signed-off-by: Jens Axboe