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2014-02-11block: Fix cloning of discard/write same biosKent Overstreet1-5/+10
Immutable biovecs changed the way bio segments are treated in such a way that bio_for_each_segment() cannot now do what we want for discard/write same bios, since bi_size means something completely different for them. Fortunately discard and write same bios never have more than a single biovec, so bio_for_each_segment() is unnecessary and not terribly meaningful for them, but we still have to special case them in a few places. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-01-08Revert "block: Warn and free bio if bi_end_io is not set"Jens Axboe1-9/+0
This reverts commit 95d4403889acbd98e06d41a255df76452210996a. The patch is broken for on-stack bios, amongst other things.
2014-01-08block: Warn and free bio if bi_end_io is not setMuthukumar Ratty1-0/+9
In bio_endio if bio doesn't have bi_end_io (should be an error case), we set bio to NULL and continue silently without freeing the bio. It would be good to have a WARN and free the bio to avoid memory leak. Signed-off-by: Muthukumar Ratty <muthur@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Kill bio_pair_split()Kent Overstreet1-90/+0
Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Introduce new bio_split()Kent Overstreet1-0/+36
The new bio_split() can split arbitrary bios - it's not restricted to single page bios, like the old bio_split() (previously renamed to bio_pair_split()). It also has different semantics - it doesn't allocate a struct bio_pair, leaving it up to the caller to handle completions. Then convert the existing bio_pair_split() users to the new bio_split() - and also nvme, which was open coding bio splitting. (We have to take that BUG_ON() out of bio_integrity_trim() because this bio_split() needs to use it, and there's no reason it has to be used on bios marked as cloned; BIO_CLONED doesn't seem to have clearly documented semantics anyways.) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Neil Brown <neilb@suse.de>
2013-11-23block: Rename bio_split() -> bio_pair_split()Kent Overstreet1-2/+2
This is prep work for introducing a more general bio_split(). Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Sage Weil <sage@inktank.com>
2013-11-23block: Generic bio chainingKent Overstreet1-6/+70
This adds a generic mechanism for chaining bio completions. This is going to be used for a bio_split() replacement, and it turns out to be very useful in a fair amount of driver code - a fair number of drivers were implementing this in their own roundabout ways, often painfully. Note that this means it's no longer to call bio_endio() more than once on the same bio! This can cause problems for drivers that save/restore bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all - in all but the simplest cases they'd be better off just cloning the bio, and immutable biovecs is making bio cloning cheaper. But for now, we add a bio_endio_nodec() for these cases. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Remove bi_idx hacksKent Overstreet1-23/+0
Now that drivers have been converted to the new bvec_iter primitives, there's no need to trim the bvec before we submit it; and we can't trim it once we start sharing bvecs. It used to be that passing a partially completed bio (i.e. one with nonzero bi_idx) to generic_make_request() was a dangerous thing - various drivers would choke on such things. But with immutable biovecs and our new bio splitting that shares the biovecs, submitting partially completed bios has to work (and should work, now that all the drivers have been completed to the new primitives) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Don't save/copy bvec array anymoreKent Overstreet1-41/+13
Now that drivers have been converted to the bvec_iter primitives, they shouldn't be modifying the biovec anymore and thus saving it is unnecessary - code that was previously making a backup of the bvec array can now just save bio->bi_iter. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23dm: Refactor for new bio cloning/splittingKent Overstreet1-72/+0
We need to convert the dm code to the new bvec_iter primitives which respect bi_bvec_done; they also allow us to drastically simplify dm's bio splitting code. Also, it's no longer necessary to save/restore the bvec array anymore - driver conversions for immutable bvecs are done, so drivers should never be modifying it. Also kill bio_sector_offset(), dm was the only user and it doesn't make much sense anymore. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Reviewed-by: Mike Snitzer <snitzer@redhat.com>
2013-11-23block: Add bio_clone_fast()Kent Overstreet1-0/+60
bio_clone() just got more expensive - however, most users of bio_clone() don't actually need to modify the biovec. If they aren't modifying the biovec, and they can guarantee that the original bio isn't freed before the clone (also true in most cases), we can just point the clone at the original bio's biovec. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-23block: Refactor bio_clone_bioset() for immutable biovecsKent Overstreet1-13/+47
bio_clone() needs to produce a bio that's suitable for the caller to munge with the biovec. Part of the immutable biovec patch series is fixing stuff up so that submitting partially completed bios is safe and works: thus, we now need bio_clone() on a partially completed bio to produce a bio for which bi_idx and bi_bvec done are 0 - like they would be if the caller had just allocated a new bio. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Convert drivers to immutable biovecsKent Overstreet1-3/+11
Now that we've got a mechanism for immutable biovecs - bi_iter.bi_bvec_done - we need to convert drivers to use primitives that respect it instead of using the bvec array directly. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com
2013-11-23block: Kill bio_segments()/bi_vcnt usageKent Overstreet1-1/+1
When we start sharing biovecs, keeping bi_vcnt accurate for splits is going to be error prone - and unnecessary, if we refactor some code. So bio_segments() has to go - but most of the existing users just needed to know if the bio had multiple segments, which is easier - add a bio_multiple_segments() for them. (Two of the current uses of bio_segments() are going to go away in a couple patches, but the current implementation of bio_segments() is unsafe as soon as we start doing driver conversions for immutable biovecs - so implement a dumb version for bisectability, it'll go away in a couple patches) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
2013-11-23block: Convert bio_copy_data() to bvec_iterKent Overstreet1-35/+25
Our fancy new bvec iterator makes code like this much easier to write. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Immutable bio vecsKent Overstreet1-25/+2
This adds a mechanism by which we can advance a bio by an arbitrary number of bytes without modifying the biovec: bio->bi_iter.bi_bvec_done indicates the number of bytes completed in the current bvec. Various driver code still needs to be updated to not refer to the bvec directly before we can use this for interesting things, like efficient bio splitting. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net
2013-11-23block: Convert bio_for_each_segment() to bvec_iterKent Overstreet1-11/+11
More prep work for immutable biovecs - with immutable bvecs drivers won't be able to use the biovec directly, they'll need to use helpers that take into account bio->bi_iter.bi_bvec_done. This updates callers for the new usage without changing the implementation yet. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: Jim Paris <jim@jtan.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com> Cc: support@lsi.com Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Cc: linux-m68k@lists.linux-m68k.org Cc: linuxppc-dev@lists.ozlabs.org Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net Cc: cbe-oss-dev@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: linux-raid@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: DL-MPTFusionLinux@lsi.com Cc: linux-scsi@vger.kernel.org Cc: devel@driverdev.osuosl.org Cc: linux-fsdevel@vger.kernel.org Cc: cluster-devel@redhat.com Cc: linux-mm@kvack.org Acked-by: Geoff Levand <geoff@infradead.org>
2013-11-23block: Convert bio_iovec() to bvec_iterKent Overstreet1-10/+10
For immutable biovecs, we'll be introducing a new bio_iovec() that uses our new bvec iterator to construct a biovec, taking into account bvec_iter->bi_bvec_done - this patch updates existing users for the new usage. Some of the existing users really do need a pointer into the bvec array - those uses are all going to be removed, but we'll need the functionality from immutable to remove them - so for now rename the existing bio_iovec() -> __bio_iovec(), and it'll be removed in a couple patches. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
2013-11-23block: Abstract out bvec iteratorKent Overstreet1-27/+29
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
2013-11-18bio: fix argument of __bio_add_page() for max_sectors > 0xffffAkinobu Mita1-1/+1
The data type of max_sectors and max_hw_sectors in queue settings are unsigned int. But these values are passed to __bio_add_page() as an argument whose data type is unsigned short. In the worst case such as max_sectors is 0x10000, bio_add_page() can't add a page and IOs can't proceed. Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08block: Consolidate duplicated bio_trim() implementationsKent Overstreet1-0/+46
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on, we should know better than this. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-09-24block: Fix bio_copy_data()Kent Overstreet1-2/+2
The memcpy() in bio_copy_data() was using the wrong offset vars, leading to data corruption in weird unusual setups. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-stable <stable@vger.kernel.org> # >= v3.9 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-03Merge branch 'for-3.12' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on the cgroup front. Most changes aren't visible to userland at all at this point and are laying foundation for the planned unified hierarchy. - The biggest change is decoupling the lifetime management of css (cgroup_subsys_state) from that of cgroup's. Because controllers (cpu, memory, block and so on) will need to be dynamically enabled and disabled, css which is the association point between a cgroup and a controller may come and go dynamically across the lifetime of a cgroup. Till now, css's were created when the associated cgroup was created and stayed till the cgroup got destroyed. Assumptions around this tight coupling permeated through cgroup core and controllers. These assumptions are gradually removed, which consists bulk of patches, and css destruction path is completely decoupled from cgroup destruction path. Note that decoupling of creation path is relatively easy on top of these changes and the patchset is pending for the next window. - cgroup has its own event mechanism cgroup.event_control, which is only used by memcg. It is overly complex trying to achieve high flexibility whose benefits seem dubious at best. Going forward, new events will simply generate file modified event and the existing mechanism is being made specific to memcg. This pull request contains prepatory patches for such change. - Various fixes and cleanups" Fixed up conflict in kernel/cgroup.c as per Tejun. * 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (69 commits) cgroup: fix cgroup_css() invocation in css_from_id() cgroup: make cgroup_write_event_control() use css_from_dir() instead of __d_cgrp() cgroup: make cgroup_event hold onto cgroup_subsys_state instead of cgroup cgroup: implement CFTYPE_NO_PREFIX cgroup: make cgroup_css() take cgroup_subsys * instead and allow NULL subsys cgroup: rename cgroup_css_from_dir() to css_from_dir() and update its syntax cgroup: fix cgroup_write_event_control() cgroup: fix subsystem file accesses on the root cgroup cgroup: change cgroup_from_id() to css_from_id() cgroup: use css_get() in cgroup_create() to check CSS_ROOT cpuset: remove an unncessary forward declaration cgroup: RCU protect each cgroup_subsys_state release cgroup: move subsys file removal to kill_css() cgroup: factor out kill_css() cgroup: decouple cgroup_subsys_state destruction from cgroup destruction cgroup: replace cgroup->css_kill_cnt with ->nr_css cgroup: bounce cgroup_subsys_state ref kill confirmation to a work item cgroup: move cgroup->subsys[] assignment to online_css() cgroup: reorganize css init / exit paths cgroup: add __rcu modifier to cgroup->subsys[] ...
2013-08-21[SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signalRoland Dreier1-5/+15
There is a nasty bug in the SCSI SG_IO ioctl that in some circumstances leads to one process writing data into the address space of some other random unrelated process if the ioctl is interrupted by a signal. What happens is the following: - A process issues an SG_IO ioctl with direction DXFER_FROM_DEV (ie the underlying SCSI command will transfer data from the SCSI device to the buffer provided in the ioctl) - Before the command finishes, a signal is sent to the process waiting in the ioctl. This will end up waking up the sg_ioctl() code: result = wait_event_interruptible(sfp->read_wait, (srp_done(sfp, srp) || sdp->detached)); but neither srp_done() nor sdp->detached is true, so we end up just setting srp->orphan and returning to userspace: srp->orphan = 1; write_unlock_irq(&sfp->rq_list_lock); return result; /* -ERESTARTSYS because signal hit process */ At this point the original process is done with the ioctl and blithely goes ahead handling the signal, reissuing the ioctl, etc. - Eventually, the SCSI command issued by the first ioctl finishes and ends up in sg_rq_end_io(). At the end of that function, we run through: write_lock_irqsave(&sfp->rq_list_lock, iflags); if (unlikely(srp->orphan)) { if (sfp->keep_orphan) srp->sg_io_owned = 0; else done = 0; } srp->done = done; write_unlock_irqrestore(&sfp->rq_list_lock, iflags); if (likely(done)) { /* Now wake up any sg_read() that is waiting for this * packet. */ wake_up_interruptible(&sfp->read_wait); kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN); kref_put(&sfp->f_ref, sg_remove_sfp); } else { INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext); schedule_work(&srp->ew.work); } Since srp->orphan *is* set, we set done to 0 (assuming the userspace app has not set keep_orphan via an SG_SET_KEEP_ORPHAN ioctl), and therefore we end up scheduling sg_rq_end_io_usercontext() to run in a workqueue. - In workqueue context we go through sg_rq_end_io_usercontext() -> sg_finish_rem_req() -> blk_rq_unmap_user() -> ... -> bio_uncopy_user() -> __bio_copy_iov() -> copy_to_user(). The key point here is that we are doing copy_to_user() on a workqueue -- that is, we're on a kernel thread with current->mm equal to whatever random previous user process was scheduled before this kernel thread. So we end up copying whatever data the SCSI command returned to the virtual address of the buffer passed into the original ioctl, but it's quite likely we do this copying into a different address space! As suggested by James Bottomley <James.Bottomley@hansenpartnership.com>, add a check for current->mm (which is NULL if we're on a kernel thread without a real userspace address space) in bio_uncopy_user(), and skip the copy if we're on a kernel thread. There's no reason that I can think of for any caller of bio_uncopy_user() to want to do copying on a kernel thread with a random active userspace address space. Huge thanks to Costa Sapuntzakis <costa@purestorage.com> for the original pointer to this bug in the sg code. Signed-off-by: Roland Dreier <roland@purestorage.com> Tested-by: David Milburn <dmilburn@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-08cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/Tejun Heo1-1/+1
The names of the two struct cgroup_subsys_state accessors - cgroup_subsys_state() and task_subsys_state() - are somewhat awkward. The former clashes with the type name and the latter doesn't even indicate it's somehow related to cgroup. We're about to revamp large portion of cgroup API, so, let's rename them so that they're less awkward. Most per-controller usages of the accessors are localized in accessor wrappers and given the amount of scheduled changes, this isn't gonna add any noticeable headache. Rename cgroup_subsys_state() to cgroup_css() and task_subsys_state() to task_css(). This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-05-08Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-42/+324
Pull block core updates from Jens Axboe: - Major bit is Kents prep work for immutable bio vecs. - Stable candidate fix for a scheduling-while-atomic in the queue bypass operation. - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging discard bios. - Tejuns changes to convert the writeback thread pool to the generic workqueue mechanism. - Runtime PM framework, SCSI patches exists on top of these in James' tree. - A few random fixes. * 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits) relay: move remove_buf_file inside relay_close_buf partitions/efi.c: replace useless kzalloc's by kmalloc's fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read() block: fix max discard sectors limit blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Documentation: cfq-iosched: update documentation help for cfq tunables writeback: expose the bdi_wq workqueue writeback: replace custom worker pool implementation with unbound workqueue writeback: remove unused bdi_pending_list aoe: Fix unitialized var usage bio-integrity: Add explicit field for owner of bip_buf block: Add an explicit bio flag for bios that own their bvec block: Add bio_alloc_pages() block: Convert some code to bio_for_each_segment_all() block: Add bio_for_each_segment_all() bounce: Refactor __blk_queue_bounce to not use bi_io_vec raid1: use bio_copy_data() pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage pktcdvd: use bio_copy_data() block: Add bio_copy_data() ...
2013-05-07aio: don't include aio.h in sched.hKent Overstreet1-0/+1
Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-18Revert "block: add missing block_bio_complete() tracepoint"Linus Torvalds1-2/+0
This reverts commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Requested-by: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-23block: Add an explicit bio flag for bios that own their bvecKent Overstreet1-1/+3
This is for the new bio splitting code. When we split a bio, if the split occured on a bvec boundry we reuse the bvec for the new bio. But that means bio_free() can't free it, hence the explicit flag. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> Acked-by: Tejun Heo <tj@kernel.org>
2013-03-23block: Add bio_alloc_pages()Kent Overstreet1-0/+28
More utility code to replace stuff that's getting open coded. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de>
2013-03-23block: Convert some code to bio_for_each_segment_all()Kent Overstreet1-10/+10
More prep work for immutable bvecs: A few places in the code were either open coding or using the wrong version - fix. After we introduce the bvec iter, it'll no longer be possible to modify the biovec through bio_for_each_segment_all() - it doesn't increment a pointer to the current bvec, you pass in a struct bio_vec (not a pointer) which is updated with what the current biovec would be (taking into account bi_bvec_done and bi_size). So because of that it's more worthwhile to be consistent about bio_for_each_segment()/bio_for_each_segment_all() usage. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: dm-devel@redhat.com CC: Alexander Viro <viro@zeniv.linux.org.uk>
2013-03-23block: Add bio_for_each_segment_all()Kent Overstreet1-6/+6
__bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Neil Brown <neilb@suse.de> CC: Boaz Harrosh <bharrosh@panasas.com>
2013-03-23block: Add bio_copy_data()Kent Overstreet1-0/+70
This gets open coded quite a bit and it's tricky to get right, so make a generic version and convert some existing users over to it instead. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
2013-03-23block: Add submit_bio_wait(), remove from mdKent Overstreet1-0/+36
Random cleanup - this code was duplicated and it's not really specific to md. Also added the ability to return the actual error code. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org>
2013-03-23block: Change bio_split() to respect the current value of bi_idxKent Overstreet1-4/+3
In the current code bio_split() won't be seeing partially completed bios so this doesn't change any behaviour, but this makes the code a bit clearer as to what bio_split() actually requires. The immediate purpose of the patch is removing unnecessary bi_idx references, but the end goal is to allow partial completed bios to be submitted, which along with immutable biovecs enables effecient bio splitting. Some of the callers were (double) checking that bios could be split, so update their checks too. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Lars Ellenberg <drbd-dev@lists.linbit.com> CC: Neil Brown <neilb@suse.de> CC: Martin K. Petersen <martin.petersen@oracle.com>
2013-03-23block: Add bio_advance()Kent Overstreet1-0/+41
This is prep work for immutable bio vecs; we first want to centralize where bvecs are modified. Next two patches convert some existing code to use this function. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
2013-03-23block: Convert integrity to bvec_alloc_bs()Kent Overstreet1-21/+15
This adds a pointer to the bvec array to struct bio_integrity_payload, instead of the bvecs always being inline; then the bvecs are allocated with bvec_alloc_bs(). Changed bvec_alloc_bs() and bvec_free_bs() to take a pointer to a mempool instead of the bioset, so that bio integrity can use a different mempool for its bvecs, and thus avoid a potential deadlock. This is eventually for immutable bio vecs - immutable bvecs aren't useful if we still have to copy them, hence the need for the pointer. Less code is always nice too, though. Also, bio_integrity_alloc() was using fs_bio_set if no bio_set was specified. This was wrong - using the bio_set doesn't protect us from memory allocation failures, because we just used kmalloc for the bio_integrity_payload. But it does introduce the possibility of deadlock, if for some reason we weren't supposed to be using fs_bio_set. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Martin K. Petersen <martin.petersen@oracle.com>
2013-03-23block: Avoid deadlocks with bio allocation by stacking driversKent Overstreet1-2/+114
Previously, if we ever try to allocate more than once from the same bio set while running under generic_make_request() (i.e. a stacking block driver), we risk deadlock. This is because of the code in generic_make_request() that converts recursion to iteration; any bios we submit won't actually be submitted (so they can complete and eventually be freed) until after we return - this means if we allocate a second bio, we're blocking the first one from ever being freed. Thus if enough threads call into a stacking block driver at the same time with bios that need multiple splits, and the bio_set's reserve gets used up, we deadlock. This can be worked around in the driver code - we could check if we're running under generic_make_request(), then mask out __GFP_WAIT when we go to allocate a bio, and if the allocation fails punt to workqueue and retry the allocation. But this is tricky and not a generic solution. This patch solves it for all users by inverting the previously described technique. We allocate a rescuer workqueue for each bio_set, and then in the allocation code if there are bios on current->bio_list we would be blocking, we punt them to the rescuer workqueue to be submitted. This guarantees forward progress for bio allocations under generic_make_request() provided each bio is submitted before allocating the next, and provided the bios are freed after they complete. Note that this doesn't do anything for allocation from other mempools. Instead of allocating per bio data structures from a mempool, code should use bio_set's front_pad. Tested it by forcing the rescue codepath to be taken (by disabling the first GFP_NOWAIT) attempt, and then ran it with bcache (which does a lot of arbitrary bio splitting) and verified that the rescuer was being invoked. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Muthukumar Ratty <muthur@gmail.com>
2013-01-14block: add missing block_bio_complete() tracepointTejun Heo1-0/+2
bio completion didn't kick block_bio_complete TP. Only dm was explicitly triggering the TP on IO completion. This makes block_bio_complete TP useless for tracers which want to know about bios, and all other bio based drivers skip generating blktrace completion events. This patch makes all bio completions via bio_endio() generate block_bio_complete TP. * Explicit trace_block_bio_complete() invocation removed from dm and the trace point is unexported. * @rq dropped from trace_block_bio_complete(). bios may fly around w/o queue associated. Verifying and accessing the assocaited queue belongs to TP probes. * blktrace now gets both request and bio completions. Make it ignore bio completions if request completion path is happening. This makes all bio based drivers generate blktrace completion events properly and makes the block_bio_complete TP actually useful. v2: With this change, block_bio_complete TP could be invoked on sg commands which have bio's with %NULL bi_bdev. Update TP assignment code to check whether bio->bi_bdev is %NULL before dereferencing. Signed-off-by: Tejun Heo <tj@kernel.org> Original-patch-by: Namhyung Kim <namhyung@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-10-22vfs: fix: don't increase bio_slab_max if krealloc() failsAnna Leuschner1-2/+4
Without the patch, bio_slab_max, representing bio_slabs capacity, is increased before krealloc() of bio_slabs. If krealloc() fails, bio_slab_max is too high. Fix that by only updating bio_slab_max if krealloc() is successful. Signed-off-by: Anna Leuschner <anna.m.leuschner@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-28block: makes bio_split support bio without dataShaohua Li1-12/+14
discard bio hasn't data attached. We hit a BUG_ON with such bio. This makes bio_split works for such bio. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-20block: Implement support for WRITE SAMEMartin K. Petersen1-3/+6
The WRITE SAME command supported on some SCSI devices allows the same block to be efficiently replicated throughout a block range. Only a single logical block is transferred from the host and the storage device writes the same data to all blocks described by the I/O. This patch implements support for WRITE SAME in the block layer. The blkdev_issue_write_same() function can be used by filesystems and block drivers to replicate a buffer across a block range. This can be used to efficiently initialize software RAID devices, etc. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Add bio_clone_bioset(), bio_clone_kmalloc()Kent Overstreet1-4/+7
Previously, there was bio_clone() but it only allocated from the fs bio set; as a result various users were open coding it and using __bio_clone(). This changes bio_clone() to become bio_clone_bioset(), and then we add bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of the functionality the last patch adedd. This will also help in a later patch changing how bio cloning works. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: Boaz Harrosh <bharrosh@panasas.com> CC: Jeff Garzik <jeff@garzik.org> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Consolidate bio_alloc_bioset(), bio_kmalloc()Kent Overstreet1-73/+37
Previously, bio_kmalloc() and bio_alloc_bioset() behaved slightly different because there was some almost-duplicated code - this fixes some of that. The important change is that previously bio_kmalloc() always set bi_io_vec = bi_inline_vecs, even if nr_iovecs == 0 - unlike bio_alloc_bioset(). This would cause bio_has_data() to return true; I don't know if this resulted in any actual bugs but it was certainly wrong. bio_kmalloc() and bio_alloc_bioset() also have different arbitrary limits on nr_iovecs - 1024 (UIO_MAXIOV) for bio_kmalloc(), 256 (BIO_MAX_PAGES) for bio_alloc_bioset(). This patch doesn't fix that, but at least they're enforced closer together and hopefully they will be fixed in a later patch. This'll also help with some future cleanups - there are a fair number of functions that allocate bios (e.g. bio_clone()), and now they don't have to be duplicated for bio_alloc(), bio_alloc_bioset(), and bio_kmalloc(). Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> v7: Re-add dropped comments, improv patch description Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Kill bi_destructorKent Overstreet1-38/+26
Now that we've got generic code for freeing bios allocated from bio pools, this isn't needed anymore. This patch also makes bio_free() static, since without bi_destructor there should be no need for it to be called anywhere else. bio_free() is now only called from bio_put, so we can refactor those a bit - move some code from bio_put() to bio_free() and kill the redundant bio->bi_next = NULL. v5: Switch to BIO_KMALLOC_POOL ((void *)~0), per Boaz v6: BIO_KMALLOC_POOL now NULL, drop bio_free's EXPORT_SYMBOL v7: No #define BIO_KMALLOC_POOL anymore Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Add bio_reset()Kent Overstreet1-0/+24
Reusing bios is something that's been highly frowned upon in the past, but driver code keeps doing it anyways. If it's going to happen anyways, we should provide a generic method. This'll help with getting rid of bi_destructor - drivers/block/pktcdvd.c was open coding it, by doing a bio_init() and resetting bi_destructor. This required reordering struct bio, but the block layer is not yet nearly fast enough for any cacheline effects to matter here. v5: Add a define BIO_RESET_BITS, to be very explicit about what parts of bio->bi_flags are saved. v6: Further commenting verbosity, per Tejun v9: Add a function comment Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Ues bi_pool for bio_integrity_alloc()Kent Overstreet1-3/+3
Now that bios keep track of where they were allocated from, bio_integrity_alloc_bioset() becomes redundant. Remove bio_integrity_alloc_bioset() and drop bio_set argument from the related functions and make them use bio->bi_pool. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09block: Generalized bio pool freeingKent Overstreet1-18/+13
With the old code, when you allocate a bio from a bio pool you have to implement your own destructor that knows how to find the bio pool the bio was originally allocated from. This adds a new field to struct bio (bi_pool) and changes bio_alloc_bioset() to use it. This makes various bio destructors unnecessary, so they're then deleted. v6: Explain the temporary if statement in bio_put Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: Nicholas Bellinger <nab@linux-iscsi.org> CC: Lars Ellenberg <lars.ellenberg@linbit.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-25Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+6
Pull block-related fixes from Jens Axboe: - Improvements to the buffered and direct write IO plugging from Fengguang. - Abstract out the mapping of a bio in a request, and use that to provide a blk_bio_map_sg() helper. Useful for mapping just a bio instead of a full request. - Regression fix from Hugh, fixing up a patch that went into the previous release cycle (and marked stable, too) attempting to prevent a loop in __getblk_slow(). - Updates to discard requests, fixing up the sizing and how we align them. Also a change to disallow merging of discard requests, since that doesn't really work properly yet. - A few drbd fixes. - Documentation updates. * 'for-linus' of git://git.kernel.dk/linux-block: block: replace __getblk_slow misfix by grow_dev_page fix drbd: Write all pages of the bitmap after an online resize drbd: Finish requests that completed while IO was frozen drbd: fix drbd wire compatibility for empty flushes Documentation: update tunable options in block/cfq-iosched.txt Documentation: update tunable options in block/cfq-iosched.txt Documentation: update missing index files in block/00-INDEX block: move down direct IO plugging block: remove plugging at buffered write time block: disable discard request merge temporarily bio: Fix potential memory leak in bio_find_or_create_slab() block: Don't use static to define "void *p" in show_partition_start() block: Add blk_bio_map_sg() helper block: Introduce __blk_segment_map_sg() helper fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices block: split discard into aligned requests block: reorganize rounding of max_discard_sectors
2012-08-09bio: Fix potential memory leak in bio_find_or_create_slab()Alexey Khoroshilov1-5/+6
Do not leak memory by updating pointer with potentially NULL realloc return value. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>