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path: root/drivers/md/dm-table.c
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2009-01-06dm table: rework reference countingMikulas Patocka
Rework table reference counting. The existing code uses a reference counter. When the last reference is dropped and the counter reaches zero, the table destructor is called. Table reference counters are acquired/released from upcalls from other kernel code (dm_any_congested, dm_merge_bvec, dm_unplug_all). If the reference counter reaches zero in one of the upcalls, the table destructor is called from almost random kernel code. This leads to various problems: * dm_any_congested being called under a spinlock, which calls the destructor, which calls some sleeping function. * the destructor attempting to take a lock that is already taken by the same process. * stale reference from some other kernel code keeps the table constructed, which keeps some devices open, even after successful return from "dmsetup remove". This can confuse lvm and prevent closing of underlying devices or reusing device minor numbers. The patch changes reference counting so that the table destructor can be called only at predetermined places. The table has always exactly one reference from either mapped_device->map or hash_cell->new_map. After this patch, this reference is not counted in table->holders. A pair of dm_create_table/dm_destroy_table functions is used for table creation/destruction. Temporary references from the other code increase table->holders. A pair of dm_table_get/dm_table_put functions is used to manipulate it. When the table is about to be destroyed, we wait for table->holders to reach 0. Then, we call the table destructor. We use active waiting with msleep(1), because the situation happens rarely (to one user in 5 years) and removing the device isn't performance-critical task: the user doesn't care if it takes one tick more or not. This way, the destructor is called only at specific points (dm_table_destroy function) and the above problems associated with lazy destruction can't happen. Finally remove the temporary protection added to dm_any_congested(). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06dm: support barriers on simple devicesAndi Kleen
Implement barrier support for single device DM devices This patch implements barrier support in DM for the common case of dm linear just remapping a single underlying device. In this case we can safely pass the barrier through because there can be no reordering between devices. NB. Any DM device might cease to support barriers if it gets reconfigured so code must continue to allow for a possible -EOPNOTSUPP on every barrier bio submitted. - agk Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-12-03block: fix setting of max_segment_size and seg_boundary maskMilan Broz
Fix setting of max_segment_size and seg_boundary mask for stacked md/dm devices. When stacking devices (LVM over MD over SCSI) some of the request queue parameters are not set up correctly in some cases by default, namely max_segment_size and and seg_boundary mask. If you create MD device over SCSI, these attributes are zeroed. Problem become when there is over this mapping next device-mapper mapping - queue attributes are set in DM this way: request_queue max_segment_size seg_boundary_mask SCSI 65536 0xffffffff MD RAID1 0 0 LVM 65536 -1 (64bit) Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of physical segments according to these parameters. During the generic_make_request() is segment cout recalculated and can increase bio->bi_phys_segments count over the allowed limit. (After bio_clone() in stack operation.) Thi is specially problem in CCISS driver, where it produce OOPS here BUG_ON(creq->nr_phys_segments > MAXSGENTRIES); (MAXSEGENTRIES is 31 by default.) Sometimes even this command is enough to cause oops: dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10 This command generates bios with 250 sectors, allocated in 32 4k-pages (last page uses only 1024 bytes). For LVM layer, it allocates bio with 31 segments (still OK for CCISS), unfortunatelly on lower layer it is recalculated to 32 segments and this violates CCISS restriction and triggers BUG_ON(). The patch tries to fix it by: * initializing attributes above in queue request constructor blk_queue_make_request() * make sure that blk_queue_stack_limits() inherits setting (DM uses its own function to set the limits because it blk_queue_stack_limits() was introduced later. It should probably switch to use generic stack limit function too.) * sets the default seg_boundary value in one place (blkdev.h) * use this mask as default in DM (instead of -1, which differs in 64bit) Bugs related to this: https://bugzilla.redhat.com/show_bug.cgi?id=471639 http://bugzilla.kernel.org/show_bug.cgi?id=8672 Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits) [PATCH] kill the rest of struct file propagation in block ioctls [PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET [PATCH] get rid of blkdev_locked_ioctl() [PATCH] get rid of blkdev_driver_ioctl() [PATCH] sanitize blkdev_get() and friends [PATCH] remember mode of reiserfs journal [PATCH] propagate mode through swsusp_close() [PATCH] propagate mode through open_bdev_excl/close_bdev_excl [PATCH] pass fmode_t to blkdev_put() [PATCH] kill the unused bsize on the send side of /dev/loop [PATCH] trim file propagation in block/compat_ioctl.c [PATCH] end of methods switch: remove the old ones [PATCH] switch sr [PATCH] switch sd [PATCH] switch ide-scsi [PATCH] switch tape_block [PATCH] switch dcssblk [PATCH] switch dasd [PATCH] switch mtd_blkdevs [PATCH] switch mmc ...
2008-10-23[PATCH] dm: kill lookup_device wrapperChristoph Hellwig
Now that lookup_bdev is exported and used by dm just use it directly instead of through a trivial wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] pass fmode_t to blkdev_put()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] introduce fmode_t, do annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-10dm: detect lost queueAlasdair G Kergon
Detect and report buggy drivers that destroy their request_queue. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Stefan Raspl <raspl@linux.vnet.ibm.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org>
2008-10-10dm: export struct dm_devMikulas Patocka
Split struct dm_dev in two and publish the part that other targets need in include/linux/device-mapper.h. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-08-01[PATCH] switch mtd and dm-table to lookup_bdev()Al Viro
No need to open-code it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-21dm table: remove merge_bvec sector restrictionMilan Broz
Remove max_sector restriction - merge function replaced it. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-04-29dm: use unlocked variants of queue flag check/setJens Axboe
dm.c already provides mutual exclusion through ->map_lock. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29block: make queue flags non-atomicNick Piggin
We can save some atomic ops in the IO path, if we clearly define the rules of how to modify the queue flags. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-25dm table: remove unused dm_create_error_tableAdrian Bunk
dm_create_error_table() was added in kernel 2.6.18 and never used... Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-04-25dm table: drop void suspend_targets returnAdrian Bunk
void returning functions returned the return value of another void returning function... Spotted by sparse. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-14Introduce path_put()Jan Blunck
* Add path_put() functions for releasing a reference to the dentry and vfsmount of a struct path in the right order * Switch from path_release(nd) to path_put(&nd->path) * Rename dput_path() to path_put_conditional() [akpm@linux-foundation.org: fix cifs] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14Embed a struct path into struct nameidata instead of nd->{dentry,mnt}Jan Blunck
This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on <dentry,vfsmount> pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08dm: table use uninitialized_varAndrew Morton
drivers/md/dm-table.c: In function 'dm_get_device': drivers/md/dm-table.c:478: warning: 'dev' may be used uninitialized in this function Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: table remove unused totalJun'ichi Nomura
"total = 0" does nothing. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: table use list_for_eachPaul Jimenez
This patch is some minor janitorish cleanup, using some macros from linux/list.h (already #included via dm.h) to improve readability. Signed-off-by: Paul Jimenez <pj@place.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-12-20dm: merge max_hw_sectorNeil Brown
Make sure dm honours max_hw_sectors of underlying devices We still have no firm testing evidence in support of this patch but believe it may help to resolve some bug reports. - agk Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-12-20dm: table detect io beyond deviceJun'ichi Nomura
This patch fixes a panic on shrinking a DM device if there is outstanding I/O to the part of the device that is being removed. (Normally this doesn't happen - a filesystem would be resized first, for example.) The bug is that __clone_and_map() assumes dm_table_find_target() always returns a valid pointer. It may fail if a bio arrives from the block layer but its target sector is no longer included in the DM btree. This patch appends an empty entry to table->targets[] which will be returned by a lookup beyond the end of the device. After calling dm_table_find_target(), __clone_and_map() and target_message() check for this condition using dm_target_is_valid(). Sample test script to trigger oops:
2007-11-09Add UNPLUG traces to all appropriate placesAlan D. Brunelle
Added blk_unplug interface, allowing all invocations of unplugs to result in a generated blktrace UNPLUG. Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02dm: bounce_pfn limit addedVasily Averin
Device mapper uses its own bounce_pfn that may differ from one on underlying device. In that way dm can build incorrect requests that contain sg elements greater than underlying device is able to handle. This is the cause of slab corruption in i2o layer, occurred on i386 arch when very long direct IO requests are addressed to dm-over-i2o device. Signed-off-by: Vasily Averin <vvs@sw.ru> Cc: <stable@kernel.org> Cc: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-20dm: use kzallocDmitry Monakhov
Convert kmalloc() + memset() to kzalloc(). Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-16block: convert blkdev_issue_flush() to use empty barriersJens Axboe
Then we can get rid of ->issue_flush_fn() and all the driver private implementations of that. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-24[BLOCK] Get rid of request_queue_t typedefJens Axboe
Some of the code has been gradually transitioned to using the proper struct request_queue, but there's lots left. So do a full sweet of the kernel and get rid of this typedef and replace its uses with the proper type. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-05-09dm: allow offline devicesMike Anderson
Allow check_device_area to succeed if a device has an i_size of zero. This addresses an issue seen on DASD devices setting up a multipath table for paths in online and offline state. Signed-off-by: Mike Anderson <andmike@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-03[PATCH] dm table: add target flushBryn Reeves
This patch adds support for a per-target dm_flush_fn method. This is needed to allow dm-loop to invalidate page cache mappings in response to BLKFLSBUF ioctl commands. Signed-off-by: Bryn Reeves <breeves@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm: extract device limit settingBryn Reeves
Separate the setting of device I/O limits from dm_get_device(). dm-loop will use this. Signed-off-by: Bryn Reeves <breeves@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm table: add target preresumeMilan Broz
This patch adds a target preresume hook. It is called before the targets are resumed and if it returns an error the resume gets cancelled. The crypt target will use this to indicate that it is unable to process I/O because no encryption key has been supplied. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] dm: improve error message consistencyAlasdair G Kergon
Tidy device-mapper error messages to include context information automatically. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] dm: create error tableDavid Teigland
Add a library function dm_create_error_table() to create a table that rejects any I/O sent to a device with EIO. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] dm table split_args: handle no inputDavid Teigland
Return sense if dm_split_args is called with a NULL input parameter. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] dm table: get_target: fix last indexMilan Broz
The table is indexed from 0, so an index equal to t->num_targets should be rejected. (There is no code in the current tree that would exercise this bug.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] sem2mutex: drivers/mdArjan van de Ven
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] dm/md dependency tree in sysfs: dm to use bd_claim_by_diskJun'ichi Nomura
Use bd_claim_by_disk. Following symlinks are created if dm-0 maps to sda: /sys/block/dm-0/slaves/sda --> /sys/block/sda /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] dm table: store mdMike Anderson
Store an up-pointer to the owning struct mapped_device in every table when it is created. Access it with: struct mapped_device *dm_table_get_md(struct dm_table *t) Tables linked to md must be destroyed before the md itself. Signed-off-by: Mike Anderson <andmike@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] dm: make sure QUEUE_FLAG_CLUSTER is set properlyNeilBrown
This flag should be set for a virtual device iff it is set for all underlying devices. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26BUG_ON() Conversion in md/dm-table.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner and can better optimized away Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-02-01[PATCH] dm: dm-table warning fixAlasdair G Kergon
drivers/md/dm-table.c:500: warning: comparison of distinct pointer types lacks a cast Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-15[SCSI] seperate max_sectors from max_hw_sectorsMike Christie
- export __blk_put_request and blk_execute_rq_nowait needed for async REQ_BLOCK_PC requests - seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was already testing against max_sectors and SCSI-ml was setting max_sectors and max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set a valid max_hw_sectors for all LLDs. Today if a LLD does not set it SCSI-ml sets it to a safe default and some LLDs set it to a artificial low value to overcome memory and feedback issues. Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024, drivers that used to call blk_queue_max_sectors with a large value of max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-07-28[PATCH] device-mapper: fix deadlocks in core (prep)Alasdair G Kergon
Some code tidy-ups in preparation for the next patches. Change dm_table_pre/postsuspend_targets to accept NULL. Use dm_suspended() throughout. Signed-Off-By: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12[PATCH] device-mapper snapshots: Handle origin extensionAlasdair G Kergon
Handle writes to a snapshot-origin device that has been extended since the snapshot was taken. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05[PATCH] device-mapper: Some missing staticsAlasdair G Kergon
This patch makes some needlessly global code static. Signed-Off-By: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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