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2009-05-11swim3: dequeue in-flight requestTejun Heo
swim3 has at most single request in flight and already tracks it using fd_req. Convert it to dequeuing model by updating request fetching and wrapping completion function. [ Impact: dequeue in-flight request ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11ataflop: dequeue and track in-flight requestTejun Heo
ataflop has single request in flight. Till now, whenever it needs to access the in-flight request it called elv_next_request(). This patch makes ataflop track the in-flight request directly and dequeue it when processing starts. The added complexity is minimal and this will help future block layer changes. [ Impact: dequeue in-flight request, one elv_next_request() per request ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11hd: dequeue and track in-flight requestTejun Heo
hd has at most single request in flight. Till now, whenever it needs to access the in-flight request it called elv_next_request(). This patch makes hd track the in-flight request directly and dequeue it when processing starts. The added complexity is minimal and this will help future block layer changes. [ Impact: dequeue in-flight request, one elv_next_request() per request ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11mg_disk: dequeue and track in-flight requestTejun Heo
mg_disk has at most single request in flight per device. Till now, whenever it needs to access the in-flight request it called elv_next_request(). This patch makes mg_disk track the in-flight request directly using mg_host->req and dequeue it when processing starts. q->queuedata is set to mg_host so that mg_host can be determined without fetching request from the queue. [ Impact: dequeue in-flight request, one elv_next_request() per request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11mg_disk: fix queue hang / infinite retry on !fs requestsTejun Heo
Both request functions in mg_disk simply return when they encounter a !fs request, which means the request will never be cleared from the queue causing queue hang and indefinite retry of the request. Fix it. While at it, flatten condition checks and add unlikely to !fs tests. [ Impact: fix possible queue hang / infinite retry of !fs requests ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11ide: dequeue in-flight requestTejun Heo
ide generally has single request in flight and tracks it using hwif->rq and all state handlers follow the following convention. * ide_started is returned if the request is in flight. * ide_stopped is returned if the queue needs to be restarted. The request might or might not have been processed fully or partially. * hwif->rq is set to NULL, when an issued request completes. So, dequeueing model can be implemented by dequeueing after fetch, requeueing if hwif->rq isn't NULL on ide_stopped return and doing about the same thing on completion / port unlock paths. These changes can be made in ide-io proper. In addition to the above main changes, the following updates are necessary. * ide-cd shouldn't dequeue a request when issuing REQUEST SENSE for it as the request is already dequeued. * ide-atapi uses request queue as stack when issuing REQUEST SENSE to put the REQUEST SENSE in front of the failed request. This now needs to be done using requeueing. [ Impact: dequeue in-flight request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: blk_rq_[cur_]_{sectors|bytes}() usage cleanupTejun Heo
With the previous changes, the followings are now guaranteed for all requests in any valid state. * blk_rq_sectors() == blk_rq_bytes() >> 9 * blk_rq_cur_sectors() == blk_rq_cur_bytes() >> 9 Clean up accessor usages. Notable changes are * nbd,i2o_block: end_all used instead of explicit byte count * scsi_lib: unnecessary conditional on request type removed [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul Clements <paul.clements@steeleye.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: hide request sector and data_lenTejun Heo
Block low level drivers for some reason have been pretty good at abusing block layer API. Especially struct request's fields tend to get violated in all possible ways. Make it clear that low level drivers MUST NOT access or manipulate rq->sector and rq->data_len directly by prefixing them with double underscores. This change is also necessary to break build of out-of-tree codes which assume the previous block API where internal fields can be manipulated and rq->data_len carries residual count on completion. [ Impact: hide internal fields, block API change ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11ide: cleanup rq->data_len usagesTejun Heo
With recent unification of fields, it's now guaranteed that rq->data_len always equals blk_rq_bytes(). Convert all direct users to accessors. [ Impact: convert direct rq->data_len usages to blk_rq_bytes() ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: cleanup rq->data_len usagesTejun Heo
With recent unification of fields, it's now guaranteed that rq->data_len always equals blk_rq_bytes(). Convert all non-IDE direct users to accessors. IDE will be converted in a separate patch. Boaz: spotted incorrect data_len/resid_len conversion in osd. [ Impact: convert direct rq->data_len usages to blk_rq_bytes() ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com> Cc: Darrick J. Wong <djwong@us.ibm.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: drop request->hard_* and *nr_sectorsTejun Heo
struct request has had a few different ways to represent some properties of a request. ->hard_* represent block layer's view of the request progress (completion cursor) and the ones without the prefix are supposed to represent the issue cursor and allowed to be updated as necessary by the low level drivers. The thing is that as block layer supports partial completion, the two cursors really aren't necessary and only cause confusion. In addition, manual management of request detail from low level drivers is cumbersome and error-prone at the very least. Another interesting duplicate fields are rq->[hard_]nr_sectors and rq->{hard_cur|current}_nr_sectors against rq->data_len and rq->bio->bi_size. This is more convoluted than the hard_ case. rq->[hard_]nr_sectors are initialized for requests with bio but blk_rq_bytes() uses it only for !pc requests. rq->data_len is initialized for all request but blk_rq_bytes() uses it only for pc requests. This causes good amount of confusion throughout block layer and its drivers and determining the request length has been a bit of black magic which may or may not work depending on circumstances and what the specific LLD is actually doing. rq->{hard_cur|current}_nr_sectors represent the number of sectors in the contiguous data area at the front. This is mainly used by drivers which transfers data by walking request segment-by-segment. This value always equals rq->bio->bi_size >> 9. However, data length for pc requests may not be multiple of 512 bytes and using this field becomes a bit confusing. In general, having multiple fields to represent the same property leads only to confusion and subtle bugs. With recent block low level driver cleanups, no driver is accessing or manipulating these duplicate fields directly. Drop all the duplicates. Now rq->sector means the current sector, rq->data_len the current total length and rq->bio->bi_size the current segment length. Everything else is defined in terms of these three and available only through accessors. * blk_recalc_rq_sectors() is collapsed into blk_update_request() and now handles pc and fs requests equally other than rq->sector update. This means that now pc requests can use partial completion too (no in-kernel user yet tho). * bio_cur_sectors() is replaced with bio_cur_bytes() as block layer now uses byte count as the primary data length. * blk_rq_pos() is now guranteed to be always correct. In-block users converted. * blk_rq_bytes() is now guaranteed to be always valid as is blk_rq_sectors(). In-block users converted. * blk_rq_sectors() is now guaranteed to equal blk_rq_bytes() >> 9. More convenient one is used. * blk_rq_bytes() and blk_rq_cur_bytes() are now inlined and take const pointer to request. [ Impact: API cleanup, single way to represent one property of a request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11ide: convert to rq pos and nr_sectors accessorsTejun Heo
ide doesn't manipulate request fields anymore and thus all hard and their soft equivalents are always equal. Convert all references to accessors. [ Impact: use pos and nr_sectors accessors ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: convert to pos and nr_sectors accessorsTejun Heo
With recent cleanups, there is no place where low level driver directly manipulates request fields. This means that the 'hard' request fields always equal the !hard fields. Convert all rq->sectors, nr_sectors and current_nr_sectors references to accessors. While at it, drop superflous blk_rq_pos() < 0 test in swim.c. [ Impact: use pos and nr_sectors accessors ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Tested-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Adrian McMenamin <adrian@mcmen.demon.co.uk> Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk> Acked-by: Mike Miller <mike.miller@hp.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Paul Clements <paul.clements@steeleye.com> Cc: Tim Waugh <tim@cyberelk.net> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Dario Ballabio <ballabio_dario@emc.com> Cc: David S. Miller <davem@davemloft.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: unsik Kim <donari75@gmail.com> Cc: Laurent Vivier <Laurent@lvivier.info> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: implement blk_rq_pos/[cur_]sectors() and convert obvious onesTejun Heo
Implement accessors - blk_rq_pos(), blk_rq_sectors() and blk_rq_cur_sectors() which return rq->hard_sector, rq->hard_nr_sectors and rq->hard_cur_sectors respectively and convert direct references of the said fields to the accessors. This is in preparation of request data length handling cleanup. Geert : suggested adding const to struct request * parameter to accessors Sergei : spotted error in patch description [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Grant Likely <grant.likely@secretlab.ca> Ackec-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: add rq->resid_lenTejun Heo
rq->data_len served two purposes - the length of data buffer on issue and the residual count on completion. This duality creates some headaches. First of all, block layer and low level drivers can't really determine what rq->data_len contains while a request is executing. It could be the total request length or it coulde be anything else one of the lower layers is using to keep track of residual count. This complicates things because blk_rq_bytes() and thus [__]blk_end_request_all() relies on rq->data_len for PC commands. Drivers which want to report residual count should first cache the total request length, update rq->data_len and then complete the request with the cached data length. Secondly, it makes requests default to reporting full residual count, ie. reporting that no data transfer occurred. The residual count is an exception not the norm; however, the driver should clear rq->data_len to zero to signify the normal cases while leaving it alone means no data transfer occurred at all. This reverse default behavior complicates code unnecessarily and renders block PC on some drivers (ide-tape/floppy) unuseable. This patch adds rq->resid_len which is used only for residual count. While at it, remove now unnecessasry blk_rq_bytes() caching in ide_pc_intr() as rq->data_len is not changed anymore. Boaz : spotted missing conversion in osd Sergei : spotted too early conversion to blk_rq_bytes() in ide-tape [ Impact: cleanup residual count handling, report 0 resid by default ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Darrick J. Wong <djwong@us.ibm.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11ide-tape: don't initialize rq->sector for rw requestsTejun Heo
rq->sector is set to the tape->first_frame but it's never actually used and not even in the correct unit (512 byte sectors). Don't set it. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Borislav Petkov <petkovbb@gmail.com> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11nbd: don't clear rq->sector and nr_sectors unnecessarilyTejun Heo
There's no reason to clear rq->sector and nr_sectors after calling blk_rq_init(). They're guaranteed to be clear. Drop unnecessary clearing. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28mg_disk: use defines from <linux/ata.h>Bartlomiej Zolnierkiewicz
While at it: - remove MG_REG_HEAD_MUST_BE_ON define - remove MG_REG_CTRL_INTR_ENABLE define - remove MG_REG_HEAD_LBA_MODE define - remove unused defines Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28mg_disk: fix dependency on libataBartlomiej Zolnierkiewicz
Add local copies of ata_id_string() and ata_id_c_string() to mg_disk so there is no need for the driver to depend on ATA and SCSI. [ Impact: break dependency on libata by copying ata id string functions ] Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28mg_disk: clean up request completion pathsTejun Heo
mg_disk implements its own partial completion. Convert to standard block layer partial completion. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28mg_disk: fold mg_disk.h into mg_disk.cTejun Heo
include/linux/mg_disk.h is used only by drivers/block/mg_disk.c. No reason to put it in a separate header. Fold it into mg_disk.c. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28swim: clean up request completion pathsTejun Heo
swim curiously tries to update request parameters before calling __blk_end_request() when __blk_end_request() will do it anyway and unnecessarily checks whether current_nr_sectors is zero right after fetching. Drop unnecessary stuff and use standard block layer mechanisms. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Laurent Vivier <Laurent@lvivier.info> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28swim3: clean up request completion pathsTejun Heo
swim3 curiously tries to update request parameters before calling __blk_end_request() when __blk_end_request() will do it anyway, and it updates request for partial completion manually instead of using blk_update_request(). Also, it does some spurious checks on rq such as testing whether rq->sector is negative or current_nr_sectors is zero right after fetching. Drop unnecessary stuff and use standard block layer mechanisms. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28hd: clean up request completion pathsTejun Heo
hd read/write_intr() functions manually manipulate request to incrementally complete it, which block layer already supports. Simply use block layer completion routines instead of manual partial completion. While at it, clear unnecessary elv_next_request() check at the tail of read_intr(). This also makes read and write_intr() more consistent. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28ubd: drop unnecessary rq->sector manipulationTejun Heo
ubd curiously updates rq->sector while issuing the request in multiple pieces. Don't do it and simply use local copy of sector. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28ubd: cleanup completion pathTejun Heo
ubd had its own block request partial completion mechanism, which is unnecessary as block layer already does it. Kill ubd_end_request() and ubd_finish() and replace them with direct call to blk_end_request(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28sunvdc: kill vdc_end_request()Tejun Heo
vdc_end_request() is a thin silly wrapper on top of __blk_end_request(). Kill it. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28ps3disk: simplify request completionTejun Heo
ps3disk_interrupt() always completes requests fully but it uses rq->hard_cur_sectors for FLUSH requests for some reason. Drop them and simply use __blk_end_request_all(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28amiflop,ataflop,xd,mg_disk: clean up unnecessary stuff from block driversTejun Heo
rq_data_dir() can only be READ or WRITE and rq->sector and nr_sectors are always automatically updated after partial request completion. Don't worry about rq_data_dir() not being either READ or WRITE or manually update sector and nr_sectors. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jörg Dorchain <joerg@dorchain.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: unsik Kim <donari75@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: don't init rq fields unnecessarilyTejun Heo
blk_get_request() always returns properly zeroed requests. Don't set fields to zero/NULL unnecessarily. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: make blk_end_request_cur() return boolTejun Heo
In the process of mindlessly copying [__]blk_end_request_all(), [__]blk_end_request_cur() ended up returning void even though they're partial completion functions. Fix it. [ Impact: fix braindead API ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: catch trying to use more bits than request->cmd_flags hasNikanth Karthikesan
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: include discard requests in IO accountingJens Axboe
We currently don't do merging on discard requests, but we potentially could. If we do, then we need to include discard requests in the IO accounting, or merging would end up decrementing in_flight IO counters for an IO which never incremented them. So enable accounting for discard requests. Problem found by Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: make blk_do_io_stat() do the full "is this rq accountable" checksJens Axboe
We currently check for file system requests outside of blk_do_io_stat(rq), but we may as well just include it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: kill rq->dataTejun Heo
Now that all block request data transfer is done via bio, rq->data isn't used. Kill it. While at it, make the roles of rq->special and buffer clear. [ Impact: drop now unncessary field from struct request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com>
2009-04-28arm-omap: don't abuse rq->dataTejun Heo
omap mailbox uses rq->data as the second opaque pointer to carry mbox_msg_t and rq->special message argument which is needed only for tx. Add and use omap_msg_tx_data struct for tx and use rq->special for mbox_msg_t for rx such that only rq->special is used as opaque pointer. [ Impact: cleanup rq->data usage, extra kmalloc in msg_send ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk>
2009-04-28block: replace end_request() with [__]blk_end_request_cur()Tejun Heo
end_request() has been kept around for backward compatibility; however, it's about time for it to go away. * There aren't too many users left. * Its use of @updtodate is pretty confusing. * In some cases, newer code ends up using mixture of end_request() and [__]blk_end_request[_all](), which is way too confusing. So, add [__]blk_end_request_cur() and replace end_request() with it. Most conversions are straightforward. Noteworthy ones are... * paride/pcd: next_request() updated to take 0/-errno instead of 1/0. * paride/pf: pf_end_request() and next_request() updated to take 0/-errno instead of 1/0. * xd: xd_readwrite() updated to return 0/-errno instead of 1/0. * mtd/mtd_blkdevs: blktrans_discard_request() updated to return 0/-errno instead of 1/0. Unnecessary local variable res initialization removed from mtd_blktrans_thread(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Joerg Dorchain <joerg@dorchain.net> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Laurent Vivier <Laurent@lvivier.info> Cc: Tim Waugh <tim@cyberelk.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: unsik Kim <donari75@gmail.com>
2009-04-28block: implement and use [__]blk_end_request_all()Tejun Heo
There are many [__]blk_end_request() call sites which call it with full request length and expect full completion. Many of them ensure that the request actually completes by doing BUG_ON() the return value, which is awkward and error-prone. This patch adds [__]blk_end_request_all() which takes @rq and @error and fully completes the request. BUG_ON() is added to to ensure that this actually happens. Most conversions are simple but there are a few noteworthy ones. * cdrom/viocd: viocd_end_request() replaced with direct calls to __blk_end_request_all(). * s390/block/dasd: dasd_end_request() replaced with direct calls to __blk_end_request_all(). * s390/char/tape_block: tapeblock_end_request() replaced with direct calls to blk_end_request_all(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Miller <mike.miller@hp.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-04-28block: move rq->start_time initialization to blk_rq_init()Tejun Heo
rq->start_time was initialized in init_request_from_bio() so special requests didn't have start_time set. This has been okay as start_time has been used only for fs requests; however, there is no indication of this actually is the case or not. Set rq->start_time in blk_rq_init() and guarantee that all initialized rq's have its start_time set. This improves consistency at virtually no cost and future changes will make use of the timestamp for !bio requests. [ Impact: rq->start_time is valid for all requests ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: clean up request completion APITejun Heo
Request completion has gone through several changes and became a bit messy over the time. Clean it up. 1. end_that_request_data() is a thin wrapper around end_that_request_data_first() which checks whether bio is NULL before doing anything and handles bidi completion. blk_update_request() is a thin wrapper around end_that_request_data() which clears nr_sectors on the last iteration but doesn't use the bidi completion. Clean it up by moving the initial bio NULL check and nr_sectors clearing on the last iteration into end_that_request_data() and renaming it to blk_update_request(), which makes blk_end_io() the only user of end_that_request_data(). Collapse end_that_request_data() into blk_end_io(). 2. There are four visible completion variants - blk_end_request(), __blk_end_request(), blk_end_bidi_request() and end_request(). blk_end_request() and blk_end_bidi_request() uses blk_end_request() as the backend but __blk_end_request() and end_request() use separate implementation in __blk_end_request() due to different locking rules. blk_end_bidi_request() is identical to blk_end_io(). Collapse blk_end_io() into blk_end_bidi_request(), separate out request update into internal helper blk_update_bidi_request() and add __blk_end_bidi_request(). Redefine [__]blk_end_request() as thin inline wrappers around [__]blk_end_bidi_request(). 3. As the whole request issue/completion usages are about to be modified and audited, it's a good chance to convert completion functions return bool which better indicates the intended meaning of return values. 4. The function name end_that_request_last() is from the days when it was a public interface and slighly confusing. Give it a proper internal name - blk_finish_request(). 5. Add description explaning that blk_end_bidi_request() can be safely used for uni requests as suggested by Boaz Harrosh. The only visible behavior change is from #1. nr_sectors counts are cleared after the final iteration no matter which function is used to complete the request. I couldn't find any place where the code assumes those nr_sectors counters contain the values for the last segment and this change is good as it makes the API much more consistent as the end result is now same whether a request is completed using [__]blk_end_request() alone or in combination with blk_update_request(). API further cleaned up per Christoph's suggestion. [ Impact: cleanup, rq->*nr_sectors always updated after req completion ] Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Christoph Hellwig <hch@infradead.org>
2009-04-28block: kill blk_end_request_callback()Tejun Heo
With recent IDE updates, blk_end_request_callback() doesn't have any user now. Kill it. [ Impact: removal of unused convoluted interface ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: reorganize request fetching functionsTejun Heo
Impact: code reorganization elv_next_request() and elv_dequeue_request() are public block layer interface than actual elevator implementation. They mostly deal with how requests interact with block layer and low level drivers at the beginning of rqeuest processing whereas __elv_next_request() is the actual eleveator request fetching interface. Move the two functions to blk-core.c. This prepares for further interface cleanup. Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: reorder request completion functionsTejun Heo
Reorder request completion functions such that * All request completion functions are located together. * Functions which are used by only one caller is put right above the caller. * end_request() is put after other completion functions but before blk_update_request(). This change is for completion function cleanup which will follow. [ Impact: cleanup, code reorganization ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: clean up misc stuff after block layer timeout conversionTejun Heo
* In blk_rq_timed_out_timer(), else { if } to else if * In blk_add_timer(), simplify if/else block [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: cleanup REQ_SOFTBARRIER usagesTejun Heo
blk_insert_request() doesn't need to worry about REQ_SOFTBARRIER. Don't set it. Combined with recent ide updates, REQ_SOFTBARRIER is now only used in elevator proper and for discard requests. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: don't set REQ_NOMERGE unnecessarilyTejun Heo
RQ_NOMERGE_FLAGS already clears defines which REQ flags aren't mergeable. There is no reason to specify it superflously. It only adds to confusion. Don't set REQ_NOMERGE for barriers and requests with specific queueing directive. REQ_NOMERGE is now exclusively used by the merging code. [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: kill blk_start_queueing()Tejun Heo
blk_start_queueing() is identical to __blk_run_queue() except that it doesn't check for recursion. None of the current users depends on blk_start_queueing() running request_fn directly. Replace usages of blk_start_queueing() with [__]blk_run_queue() and kill it. [ Impact: removal of mostly duplicate interface function ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: merge blk_invoke_request_fn() into __blk_run_queue()Tejun Heo
__blk_run_queue wraps blk_invoke_request_fn() such that it additionally removes plug and bails out early if the queue is empty. Both extra operations have their own pending mechanisms and don't cause any harm correctness-wise when they are done superflously. The only user of blk_invoke_request_fn() being blk_start_queue(), there isn't much reason to keep both functions around. Merge blk_invoke_request_fn() into __blk_run_queue() and make blk_start_queue() use __blk_run_queue() instead. [ Impact: merge two subtly different internal functions ] Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28block: implement blkdev_readpagesJeff Moyer
Doing a proper block dev ->readpages() speeds up the crazy dump(8) approach of using interleaved process IO. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28block: enable by default support for large devices and files on 32-bit archsBartlomiej Zolnierkiewicz
Enable by default support for large devices and files (CONFIG_LBD): - With 1TB disks being a commodity hardware it is quite easy to hit 2TB limitation while building RAIDs etc. and many distros have been using CONFIG_LBD=y by default already (at least Fedora 10 and openSUSE 11.1). - This should also prevent a subtle ext4 filesystem compatibility issue: mke2fs.ext4 defaults to creating filesystems with huge_files feature enabled and such filesystems cannot be later mounted read-write on machines with CONFIG_LBD=n (it should be quite easy to hit this issue when trying to use filesystem created using distro kernel on system running the self-build kernel, think about USB disk enclosures & co.). While at it: - Clarify config option help text w.r.t. mounting ext4 filesystems (they can be mounted with CONFIG_LBD=n but in the read-only mode). Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>