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* dm ioctl: suppress needless warning messagesMilan Broz2011-01-131-4/+4
| | | | | | | | | | | | The device-mapper should not send warning messages to syslog if a device is not found. This can be done by userspace according to the returned dm-ioctl error code. So move these messages to debug level and use rate limiting to not flood syslog. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: allow rename to fill empty uuidPeter Jones2011-01-131-25/+78
| | | | | | | | | | | | | | | | | | | | | Allow the uuid of a mapped device to be set after device creation. Previously the uuid (which is optional) could only be set by DM_DEV_CREATE. If no uuid was supplied it could not be set later. Sometimes it's necessary to create the device before the uuid is known, and in such cases the uuid must be filled in after the creation. This patch extends DM_DEV_RENAME to accept a uuid accompanied by a new flag DM_UUID_FLAG. This can only be done once and if no uuid was previously supplied. It cannot be used to change an existing uuid. DM_VERSION_MINOR is also bumped to 19 to indicate this interface extension is available. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* llseek: automatically add .llseek fopArnd Bergmann2010-10-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
* dm: allow autoloading of dm modPeter Rajnoha2010-08-121-2/+5
| | | | | | | | | Add devname:mapper/control and MAPPER_CTRL_MINOR module alias to support dm-mod module autoloading. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: refactor dm_table_completeWill Drewry2010-08-121-34/+0
| | | | | | | | | This change unifies the various checks and finalization that occurs on a table prior to use. By doing so, it allows table construction without traversing the dm-ioctl interface. Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: do not initialise full request queue when bio basedMike Snitzer2010-08-121-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change bio-based mapped devices no longer to have a fully initialized request_queue (request_fn, elevator, etc). This means bio-based DM devices no longer register elevator sysfs attributes ('iosched/' tree or 'scheduler' other than "none"). In contrast, a request-based DM device will continue to have a full request_queue and will register elevator sysfs attributes. Therefore a user can determine a DM device's type by checking if elevator sysfs attributes exist. First allocate a minimalist request_queue structure for a DM device (needed for both bio and request-based DM). Initialization of a full request_queue is deferred until it is known that the DM device is request-based, at the end of the table load sequence. Factor DM device's request_queue initialization: - common to both request-based and bio-based into dm_init_md_queue(). - specific to request-based into dm_init_request_based_queue(). The md->type_lock mutex is used to protect md->queue, in addition to md->type, during table_load(). A DM device's first table_load will establish the immutable md->type. But md->queue initialization, based on md->type, may fail at that time (because blk_init_allocated_queue cannot allocate memory). Therefore any subsequent table_load must (re)try dm_setup_md_queue independently of establishing md->type. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: make bio or request based device type immutableMike Snitzer2010-08-121-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Determine whether a mapped device is bio-based or request-based when loading its first (inactive) table and don't allow that to be changed later. This patch performs different device initialisation in each of the two cases. (We don't think it's necessary to add code to support changing between the two types.) Allowed md->type transitions: DM_TYPE_NONE to DM_TYPE_BIO_BASED DM_TYPE_NONE to DM_TYPE_REQUEST_BASED We now prevent table_load from replacing the inactive table with a conflicting type of table even after an explicit table_clear. Introduce 'type_lock' into the struct mapped_device to protect md->type and to prepare for the next patch that will change the queue initialization and allocate memory while md->type_lock is held. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> drivers/md/dm-ioctl.c | 15 +++++++++++++++ drivers/md/dm.c | 37 ++++++++++++++++++++++++++++++------- drivers/md/dm.h | 5 +++++ include/linux/dm-ioctl.h | 4 ++-- 4 files changed, 52 insertions(+), 9 deletions(-)
* dm ioctl: use nonseekable_openArnd Bergmann2010-08-121-0/+1
| | | | | | | | | | | The dm control device does not implement read/write, so it has no use for seeking. Using no_llseek prevents falling back to default_llseek, which requires the BKL. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: separate device deletion from dm_putKiyoshi Ueda2010-08-121-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch separates the device deletion code from dm_put() to make sure the deletion happens in the process context. By this patch, device deletion always occurs in an ioctl (process) context and dm_put() can be called in interrupt context. As a result, the request-based dm's bad dm_put() usage pointed out by Mikulas below disappears. http://marc.info/?l=dm-devel&m=126699981019735&w=2 Without this patch, I confirmed there is a case to crash the system: dm_put() => dm_table_destroy() => vfree() => BUG_ON(in_interrupt()) Some more backgrounds and details: In request-based dm, a device opener can remove a mapped_device while the last request is still completing, because bios in the last request complete first and then the device opener can close and remove the mapped_device before the last request completes: CPU0 CPU1 ================================================================= <<INTERRUPT>> blk_end_request_all(clone_rq) blk_update_request(clone_rq) bio_endio(clone_bio) == end_clone_bio blk_update_request(orig_rq) bio_endio(orig_bio) <<I/O completed>> dm_blk_close() dev_remove() dm_put(md) <<Free md>> blk_finish_request(clone_rq) .... dm_end_request(clone_rq) free_rq_clone(clone_rq) blk_end_request_all(orig_rq) rq_completed(md) So request-based dm used dm_get()/dm_put() to hold md for each I/O until its request completion handling is fully done. However, the final dm_put() can call the device deletion code which must not be run in interrupt context and may cause kernel panic. To solve the problem, this patch moves the device deletion code, dm_destroy(), to predetermined places that is actually deleting the mapped_device in ioctl (process) context, and changes dm_put() just to decrement the reference count of the mapped_device. By this change, dm_put() can be used in any context and the symmetric model below is introduced: dm_create(): create a mapped_device dm_destroy(): destroy a mapped_device dm_get(): increment the reference count of a mapped_device dm_put(): decrement the reference count of a mapped_device dm_destroy() waits for all references of the mapped_device to disappear, then deletes the mapped_device. dm_destroy() uses active waiting with msleep(1), since deleting the mapped_device isn't performance-critical task. And since at this point, nobody opens the mapped_device and no new reference will be taken, the pending counts are just for racing completing activity and will eventually decrease to zero. For the unlikely case of the forced module unload, dm_destroy_immediate(), which doesn't wait and forcibly deletes the mapped_device, is also introduced and used in dm_hash_remove_all(). Otherwise, "rmmod -f" may be stuck and never return. And now, because the mapped_device is deleted at this point, subsequent accesses to the mapped_device may cause NULL pointer references. Cc: stable@kernel.org Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: release _hash_lock between devices in remove_allKiyoshi Ueda2010-08-121-19/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes dm_hash_remove_all() to release _hash_lock when removing a device. After removing the device, dm_hash_remove_all() takes _hash_lock and searches the hash from scratch again. This patch is a preparation for the next patch, which changes device deletion code to wait for md reference to be 0. Without this patch, the wait in the next patch may cause AB-BA deadlock: CPU0 CPU1 ----------------------------------------------------------------------- dm_hash_remove_all() down_write(_hash_lock) table_status() md = find_device() dm_get(md) <increment md->holders> dm_get_live_or_inactive_table() dm_get_inactive_table() down_write(_hash_lock) <in the md deletion code> <wait for md->holders to be 0> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: return uevent flag after renamePeter Rajnoha2010-08-121-17/+24
| | | | | | | | | | | | | All the dm ioctls that generate uevents set the DM_UEVENT_GENERATED flag so that userspace knows whether or not to wait for a uevent to be processed before continuing, The dm rename ioctl sets this flag but was not structured to return it to userspace. This patch restructures the rename ioctl processing to behave like the other ioctls that return data and so fix this. Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: make __dev_status voidAlasdair G Kergon2010-08-121-36/+31
| | | | | | __dev_status() cannot fail so make it void and simplify callers. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: remove __dev_status from geometry and target messagePeter Rajnoha2010-08-121-6/+0
| | | | | | | | | | | Remove useless __dev_status call while processing an ioctl that sets up device geometry and target message. The data is not returned to userspace so there is no point collecting it and in the case of target_message it is collected before processing the message so if it did return it might be stale. Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: introduce flag indicating uevent was generatedPeter Rajnoha2010-03-061-7/+12
| | | | | | | | | Set a new DM_UEVENT_GENERATED_FLAG when returning from ioctls to indicate that a uevent was actually generated. This tells the userspace caller that it may need to wait for the event to be processed. Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: only issue uevent on resume if state changedMike Snitzer2010-03-061-4/+5
| | | | | | | | | | Only issue a uevent on a resume if the state of the device changed, i.e. if it was suspended and/or its table was replaced. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename dm_suspended to dm_suspended_mdKiyoshi Ueda2009-12-111-4/+4
| | | | | | | | | | | This patch renames dm_suspended() to dm_suspended_md() and keeps it internal to dm. No functional change. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: keep old table until after resume succeededAlasdair G Kergon2009-12-111-4/+6
| | | | | | | | | | | | When swapping a new table into place, retain the old table until its replacement is in place. An old check for an empty table is removed because this is enforced in populate_table(). __unbind() becomes redundant when followed by __bind(). Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: retrieve status from inactive tableMike Snitzer2009-12-111-13/+57
| | | | | | | | | | | | | Add the flag DM_QUERY_INACTIVE_TABLE_FLAG to the ioctls to return infomation about the loaded-but-not-yet-active table instead of the live table. Prior to this patch it was impossible to obtain this information until the device had been 'resumed'. Userspace dmsetup and libdevmapper support the flag as of version 1.02.40. e.g. dmsetup info --inactive vg1-lv1 Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: forbid messages to devices being deletedMike Anderson2009-12-111-0/+6
| | | | | | | | Once we begin deleting a device, prevent any further messages being sent to targets of its table (to avoid races). Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename dm_get_table to dm_get_live_tableAlasdair G Kergon2009-12-111-7/+7
| | | | | | Rename dm_get_table to dm_get_live_table. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: prefer strlcpy over strncpyRoel Kluin2009-12-111-2/+2
| | | | | | | | | | | | | | strlcpy() will always null terminate the string. The code should already guarantee this as the last bytes are already NULs and the string lengths were restricted before being stored in hc. Removing the '-1' becomes necessary so strlcpy() doesn't lose the last character of a maximum-length string. - agk Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: avoid _hash_lock deadlockMikulas Patocka2009-12-111-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a reported deadlock if there are still unprocessed multipath events on a device that is being removed. _hash_lock is held during dev_remove while trying to send the outstanding events. Sending the events requests the _hash_lock again in dm_copy_name_and_uuid. This patch introduces a separate lock around regions that modify the link to the hash table (dm_set_mdptr) or the name or uuid so that dm_copy_name_and_uuid no longer needs _hash_lock. Additionally, dm_copy_name_and_uuid can only be called if md exists so we can drop the dm_get() and dm_put() which can lead to a BUG() while md is being freed. The deadlock: #0 [ffff8106298dfb48] schedule at ffffffff80063035 #1 [ffff8106298dfc20] __down_read at ffffffff8006475d #2 [ffff8106298dfc60] dm_copy_name_and_uuid at ffffffff8824f740 #3 [ffff8106298dfc90] dm_send_uevents at ffffffff88252685 #4 [ffff8106298dfcd0] event_callback at ffffffff8824c678 #5 [ffff8106298dfd00] dm_table_event at ffffffff8824dd01 #6 [ffff8106298dfd10] __hash_remove at ffffffff882507ad #7 [ffff8106298dfd30] dev_remove at ffffffff88250865 #8 [ffff8106298dfd60] ctl_ioctl at ffffffff88250d80 #9 [ffff8106298dfee0] do_ioctl at ffffffff800418c4 #10 [ffff8106298dff00] vfs_ioctl at ffffffff8002fab9 #11 [ffff8106298dff40] sys_ioctl at ffffffff8004bdaf #12 [ffff8106298dff80] tracesys at ffffffff8005d28d (via system_call) Cc: stable@kernel.org Reported-by: guy keren <choo@actcom.co.il> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Driver-Core: extend devnode callbacks to provide permissionsKay Sievers2009-09-191-1/+1
| | | | | | | | | | | | | This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* dm: enable request based optionKiyoshi Ueda2009-06-221-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables request-based dm. o Request-based dm and bio-based dm coexist, since there are some target drivers which are more fitting to bio-based dm. Also, there are other bio-based devices in the kernel (e.g. md, loop). Since bio-based device can't receive struct request, there are some limitations on device stacking between bio-based and request-based. type of underlying device bio-based request-based ---------------------------------------------- bio-based OK OK request-based -- OK The device type is recognized by the queue flag in the kernel, so dm follows that. o The type of a dm device is decided at the first table binding time. Once the type of a dm device is decided, the type can't be changed. o Mempool allocations are deferred to at the table loading time, since mempools for request-based dm are different from those for bio-based dm and needed mempool type is fixed by the type of table. o Currently, request-based dm supports only tables that have a single target. To support multiple targets, we need to support request splitting or prevent bio/request from spanning multiple targets. The former needs lots of changes in the block layer, and the latter needs that all target drivers support merge() function. Both will take a time. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: support cookies for udevMilan Broz2009-06-221-4/+10
| | | | | | | | | | | | | | | | | | | | Add support for passing a 32 bit "cookie" into the kernel with the DM_SUSPEND, DM_DEV_RENAME and DM_DEV_REMOVE ioctls. The (unsigned) value of this cookie is returned to userspace alongside the uevents issued by these ioctls in the variable DM_COOKIE. This means the userspace process issuing these ioctls can be notified by udev after udev has completed any actions triggered. To minimise the interface extension, we pass the cookie into the kernel in the event_nr field which is otherwise unused when calling these ioctls. Incrementing the version number allows userspace to determine in advance whether or not the kernel supports the cookie. If the kernel does support this but userspace does not, there should be no impact as the new variable will just get ignored. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Driver Core: misc: add nodename support for misc devices.Kay Sievers2009-06-161-0/+1
| | | | | | | | | | | This adds support for misc devices to report their requested nodename to userspace. It also updates a number of misc drivers to provide the needed subdirectory and device name to be used for them. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* dm: add integrity supportMartin K. Petersen2009-04-091-0/+21
| | | | | | | | | | | | | | | | This patch provides support for data integrity passthrough in the device mapper. - If one or more component devices support integrity an integrity profile is preallocated for the DM device. - If all component devices have compatible profiles the DM device is flagged as capable. - Handle integrity metadata when splitting and cloning bios. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: rework reference counting fixMikulas Patocka2009-03-161-2/+2
| | | | | | | | | | | | | | | Fix an error introduced in dm-table-rework-reference-counting.patch. When there is failure after table initialization, we need to use dm_table_destroy, not dm_table_put, to free the table. dm_table_put may be used only after dm_table_get. Cc: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: validate name length when renamingMilan Broz2009-03-161-1/+2
| | | | | | | | | | | | | | | | | | When renaming a mapped device validate the length of the new name. The rename ioctl accepted any correctly-terminated string enclosed within the data passed from userspace. The other ioctls enforce a size limit of DM_NAME_LEN. If the name is changed and becomes longer than that, the device can no longer be addressed by name. Fix it by properly checking for device name length (including terminating zero). Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: rework reference countingMikulas Patocka2009-01-061-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm ioctl: allow dm_copy_name_and_uuid to return only one fieldMilan Broz2009-01-061-2/+4
| | | | | | | | | | | Allow NULL buffer in dm_copy_name_and_uuid if you only want to return one of the fields. (Required by a following patch that adds these fields to sysfs.) Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* [PATCH] introduce fmode_t, do annotationsAl Viro2008-10-211-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds2008-10-101-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: dm: detect lost queue dm: publish dm_vcalloc dm: publish dm_table_unplug_all dm: publish dm_get_mapinfo dm: export struct dm_dev dm crypt: avoid unnecessary wait when splitting bio dm crypt: tidy ctx pending dm crypt: fix async inc_pending dm crypt: move dec_pending on error into write_io_submit dm crypt: remove inc_pending from write_io_submit dm crypt: tidy write loop pending dm crypt: tidy crypt alloc dm crypt: tidy inc pending dm exception store: use chunk_t for_areas dm exception store: introduce area_location function dm raid1: kcopyd should stop on error if errors handled dm mpath: remove is_active from struct dm_path dm mpath: use more error codes Fixed up trivial conflict in drivers/md/dm-mpath.c manually.
| * dm: export struct dm_devMikulas Patocka2008-10-101-2/+2
| | | | | | | | | | | | | | | | 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>
* | block: move policy from disk to part0Tejun Heo2008-10-091-1/+1
| | | | | | | | | | | | | | Move disk->policy to part0->policy. Implement and use get_disk_ro(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: don't depend on consecutive minor spaceTejun Heo2008-10-091-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | * Implement disk_devt() and part_devt() and use them to directly access devt instead of computing it from ->major and ->first_minor. Note that all references to ->major and ->first_minor outside of block layer is used to determine devt of the disk (the part0) and as ->major and ->first_minor will continue to represent devt for the disk, converting these users aren't strictly necessary. However, convert them for consistency. * Implement disk_max_parts() to avoid directly deferencing genhd->minors. * Update bdget_disk() such that it doesn't assume consecutive minor space. * Move devt computation from register_disk() to add_disk() and make it the only one (all other usages use the initially determined value). These changes clean up the code and will help disk->part dereference fix and extended block device numbers. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* dm ioctl: use uninitialized_varAndrew Morton2008-02-081-1/+1
| | | | | | | drivers/md/dm-ioctl.c:1405: warning: 'param' 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>
* dm ioctl: move compat codeMilan Broz2008-02-081-2/+13
| | | | | | | Move compat_ioctl handling into dm-ioctl.c. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: remove lock_kernelAlasdair G Kergon2008-02-081-6/+9
| | | | | | | | | Remove lock_kernel() from the device-mapper ioctls - there should be sufficient internal locking already where required. Also remove some superfluous casts. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: trigger change uevent on renameAlasdair G Kergon2007-12-201-0/+2
| | | | | | | Insert a missing KOBJ_CHANGE notification when a device is renamed. Cc: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: table detect io beyond deviceJun'ichi Nomura2007-12-201-7/+3
| | | | | | | | | | | | | | | | | | | | | 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:
* dm: export name and uuidMike Anderson2007-10-201-0/+32
| | | | | | | This patch adds a function to obtain a copy of a mapped device's name and uuid. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io:ctl remove vmalloc void castJesper Juhl2007-10-201-1/+1
| | | | | | | | | In drivers/md/dm-ioctl.c::copy_params() there's a call to vmalloc() where we currently cast the return value, but that's pretty pointless given that vmalloc() returns "void *". Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io:ctl use constant struct sizeMilan Broz2007-10-201-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Make size of dm_ioctl struct always 312 bytes on all supported architectures. This change retains compatibility with already-compiled code because it uses an embedded offset to locate the payload that follows the structure. On 64-bit architectures there is no change at all; on 32-bit we are increasing the size of dm-ioctl from 308 to 312 bytes. Currently with 32-bit userspace / 64-bit kernel on x86_64 some ioctls (including rename, message) are incorrectly rejected by the comparison against 'param + 1'. This breaks userspace lvrename and multipath 'fail_if_no_path' changes, for example. (BTW Device-mapper uses its own versioning and ignores the ioctl size bits. Only the generic ioctl compat code on mixed arches checks them, and that will continue to accept both sizes for now, but we intend to list 308 as deprecated and eventually remove it.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Guido Guenther <agx@sigxcpu.org> Cc: Kevin Corry <kevcorry@us.ibm.com> Cc: stable@kernel.org
* [PATCH] mark struct file_operations const 4Arjan van de Ven2007-02-121-1/+1
| | | | | | | | | | | | Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. [akpm@sdl.org: dvb fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] dm: ioctl: add noflush suspendKiyoshi Ueda2006-12-081-0/+4
| | | | | | | | | | | | | | | | | | | Provide a dm ioctl option to request noflush suspending. (See next patch for what this is for.) As the interface is extended, the version number is incremented. Other than accepting the new option through the interface, There is no change to existing behaviour. Test results: Confirmed the option is given from user-space correctly. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm: suspend: parameter changeKiyoshi Ueda2006-12-081-6/+6
| | | | | | | | | | | | | | | | | | | Change the interface of dm_suspend() so that we can pass several options without increasing the number of parameters. The existing 'do_lockfs' integer parameter is replaced by a flag DM_SUSPEND_LOCKFS_FLAG. There is no functional change to the code. Test results: I have tested 'dmsetup suspend' command with/without the '--nolockfs' option and confirmed the do_lockfs value is correctly set. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm: fix find_device raceAlasdair G Kergon2006-11-091-2/+7
| | | | | | | | | | | | | | | | | | | | There is a race between dev_create() and find_device(). If the mdptr has not yet been stored against a device, find_device() needs to behave as though no device was found. It already returns NULL, but there is a dm_put() missing: it must drop the reference dm_get_md() took. The bug was introduced by dm-fix-mapped-device-ref-counting.patch. It manifests itself if another dm ioctl attempts to reference a newly-created device while the device creation ioctl is still running. The consequence is that the device cannot be removed until the machine is rebooted. Certain udev configurations can lead to this happening. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: <dm-devel@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer neededGreg Kroah-Hartman2006-06-261-1/+0
| | | | | | Also fixes all drivers that set this field. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] devfs: Remove the devfs_fs_kernel.h file from the treeGreg Kroah-Hartman2006-06-261-1/+0
| | | | | | Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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