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path: root/block/genhd.c
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2008-07-21sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minorDan Williams
Why?: There are occasions where userspace would like to access sysfs attributes for a device but it may not know how sysfs has named the device or the path. For example what is the sysfs path for /dev/disk/by-id/ata-ST3160827AS_5MT004CK? With this change a call to stat(2) returns the major:minor then userspace can see that /sys/dev/block/8:32 links to /sys/block/sdc. What are the alternatives?: 1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce the need to proliferate ioctl interfaces into the kernel, so this seems counter productive. 2/ Use udev to create these symlinks: Also doable, but it adds a udev dependency to utilities that might be running in a limited environment like an initramfs. 3/ Do a full-tree search of sysfs. [kay.sievers@vrfy.org: fix duplicate registrations] [kay.sievers@vrfy.org: cleanup suggestions] Cc: Neil Brown <neilb@suse.de> Cc: Tejun Heo <htejun@gmail.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Reviewed-by: SL Baur <steve@xemacs.org> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Mark Lord <lkml@rtr.ca> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-03allow userspace to modify scsi command filter on per device basisAdel Gadllah
This patch exports the per-gendisk command filter to user space through sysfs, so it can be changed by the system administrator. All users of the old cmd filter have been converted to use the new one. Original patch from Peter Jones. Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com> Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03block: export "ro" attributeKay Sievers
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-09Fix invalid access errors in blk_lookup_devtLinus Torvalds
Commit 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 ("block: do_mounts - accept root=<non-existant partition>") extended blk_lookup_devt() to be able to look up partitions that had not yet been registered, but in the process made the assumption that the '&block_class.devices' list only contains disk devices and that you can do 'dev_to_disk(dev)' on them. That isn't actually true. The block_class device list also contains the partitions we've discovered so far, and you can't just do a 'dev_to_disk()' on those. So make sure to only work on devices that block/genhd.c has registered itself, something we can test by checking the 'dev->type' member. This makes the loop in blk_lookup_devt() match the other such loops in this file. [ We may want to do an alternate version that knows to handle _either_ whole-disk devices or partitions, but for now this is the minimal fix for a series of crashes reported by Mariusz Kozlowski in http://lkml.org/lkml/2008/5/25/25 and Ingo in http://lkml.org/lkml/2008/6/9/39 ] Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Reported-by: Ingo Molnar <mingo@elte.hu> Cc: Neil Brown <neilb@suse.de> Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14block: do_mounts - accept root=<non-existant partition>Kay Sievers
Some devices, like md, may create partitions only at first access, so allow root= to be set to a valid non-existant partition of an existing disk. This applies only to non-initramfs root mounting. This fixes a regression from 2.6.24 which did allow this to happen and broke some users machines :( Acked-by: Neil Brown <neilb@suse.de> Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br> Cc: stable <stable@kernel.org> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-30mm: bdi: export BDI attributes in sysfsPeter Zijlstra
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object. This allows us to see and set the various BDI specific variables. In particular this properly exposes the read-ahead window for all relevant users and /sys/block/<block>/queue/read_ahead_kb should be deprecated. With patient help from Kay Sievers and Greg KH [mszeredi@suse.cz] - split off NFS and FUSE changes into separate patches - document new sysfs attributes under Documentation/ABI - do bdi_class_init as a core_initcall, otherwise the "default" BDI won't be initialized - remove bdi_init_fmt macro, it's not used very much [akpm@linux-foundation.org: fix ia64 warning] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Greg KH <greg@kroah.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-12genhd must_check warning fixRoland McGrath
Fixes: block/genhd.c:361: warning: ignoring return value of ‘class_register’, declared with attribute warn_unused_result Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04block/genhd.c: cleanupsAdrian Bunk
This patch contains the following cleanups: - make the needlessly global struct disk_type static - #if 0 the unused genhd_media_change_notify() Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-03-04proper prototype for blk_dev_init()Adrian Bunk
This patch adds a proper prototye for blk_dev_init() in block/blk.h Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-02-08Enhanced partition statistics: procfsJerome Marchand
Reports enhanced partition statistics in /proc/diskstats. Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2008-01-29block: constify function pointer tablesJan Engelhardt
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-24Driver core: convert block from raw kobjects to core devicesKay Sievers
This moves the block devices to /sys/class/block. It will create a flat list of all block devices, with the disks and partitions in one directory. For compatibility /sys/block is created and contains symlinks to the disks. /sys/class/block |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1 |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10 |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5 |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6 |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7 |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8 |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9 `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 /sys/block/ |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kset: convert block_subsys to use kset_createGreg Kroah-Hartman
Dynamically create the kset instead of declaring it statically. We also rename block_subsys to block_kset to catch all users of this symbol with a build error instead of an easy-to-ignore build warning. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: remove struct kobj_type from struct ksetGreg Kroah-Hartman
We don't need a "default" ktype for a kset. We should set this explicitly every time for each kset. This change is needed so that we can make ksets dynamic, and cleans up one of the odd, undocumented assumption that the kset/kobject/ktype model has. This patch is based on a lot of help from Kay Sievers. Nasty bug in the block code was found by Dave Young <hidave.darkstar@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-11-27block: Fix memory leak in alloc_disk_node()Jerome Marchand
Fix a memory leak in alloc_disk_node(). Don't forget to free 'dkstats' when the allocation of 'part' failed. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-12Driver core: change add_uevent_var to use a structKay Sievers
This changes the uevent buffer functions to use a struct instead of a long list of parameters. It does no longer require the caller to do the proper buffer termination and size accounting, which is currently wrong in some places. It fixes a known bug where parts of the uevent environment are overwritten because of wrong index calculations. Many thanks to Mathieu Desnoyers for finding bugs and improving the error handling. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-17unregister_blkdev(): return voidAkinobu Mita
Put WARN_ON and fixed all callers of unregister_blkdev(). Now we can make unregister_blkdev return void. Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17unregister_blkdev(): do WARN_ON on failureAkinobu Mita
When unregister_blkdev() has failed, something wrong happened. This patch adds WARN_ON to notify of such badness. Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Slab allocators: Replace explicit zeroing with __GFP_ZEROChristoph Lameter
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing variant in the past. But with __GFP_ZERO it is possible now to do zeroing while allocating. Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever we can. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23genhd: send async notification on media changeKristen Carlson Accardi
Send an uevent to user space to indicate that a media change event has occurred. Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23genhd: expose AN to user spaceKristen Carlson Accardi
Allow user space to determine if a disk supports Asynchronous Notification of media changes. This is done by adding a new sysfs file "capability_flags", which is documented in (insert file name). This sysfs file will export all disk capabilities flags to user space. We also define a new flag to define the media change notification capability. Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Display all possible partitions when the root filesystem failed to mountDave Gilbert
Display all possible partitions when the root filesystem is not mounted. This helps to track spell'o's and missing drivers. Updated to work with newer kernels. Example output: VFS: Cannot open root device "foobar" or unknown-block(0,0) Please append a correct "root=" boot option; here are the available partitions: 0800 8388608 sda driver: sd 0801 192748 sda1 0802 8193150 sda2 0810 4194304 sdb driver: sd Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [akpm@linux-foundation.org: cleanups, fix printk warnings] Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Cc: Dave Gilbert <linux@treblig.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-02remove "struct subsystem" as it is no longer neededGreg Kroah-Hartman
We need to work on cleaning up the relationship between kobjects, ksets and ktypes. The removal of 'struct subsystem' is the first step of this, especially as it is not really needed at all. Thanks to Kay for fixing the bugs in this patch. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-04[PATCH] remove protection of LANANA-reserved majorsAndrew Morton
Revert all this. It can cause device-mapper to receive a different major from earlier kernels and it turns out that the Amanda backup program (via GNU tar, apparently) checks major numbers on files when performing incremental backups. Which is a bit broken of Amanda (or tar), but this feature isn't important enough to justify the churn. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] rework reserved major handlingAndrew Morton
Several people have reported failures in dynamic major device number handling due to the recent changes in there to avoid handing out the local/experimental majors. Rolf reports that this is due to a gcc-4.1.0 bug. The patch refactors that code a lot in an attempt to provoke the compiler into behaving. Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] register_blkdev(): don't hand out the LOCAL/EXPERIMENTAL majorsAndrew Morton
As pointed out in http://bugzilla.kernel.org/show_bug.cgi?id=7922, dynamic blockdev major allocation can hand out majors which LANANA has defined as being for local/experimental use. Cc: Torben Mathiasen <device@lanana.org> Cc: Greg KH <greg@kroah.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Tomas Klas <tomas.klas@mepatek.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] fault-injection capability for disk IOAkinobu Mita
This patch provides fault-injection capability for disk IO. Boot option: fail_make_request=<probability>,<interval>,<space>,<times> <interval> -- specifies the interval of failures. <probability> -- specifies how often it should fail in percent. <space> -- specifies the size of free space where disk IO can be issued safely in bytes. <times> -- specifies how many times failures may happen at most. Debugfs: /debug/fail_make_request/interval /debug/fail_make_request/probability /debug/fail_make_request/specifies /debug/fail_make_request/times Example: fail_make_request=10,100,0,-1 echo 1 > /sys/blocks/hda/hda1/make-it-fail generic_make_request() on /dev/hda1 fails once per 10 times. Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] block: handle subsystem_register() init errorsRandy Dunlap
Check and handle init errors. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-21[PATCH] Driver core: add generic "subsystem" link to all devicesKay Sievers
Like the SUBSYTEM= key we find in the environment of the uevent, this creates a generic "subsystem" link in sysfs for every device. Userspace usually doesn't care at all if its a "class" or a "bus" device. This provides an unified way to determine the subsytem of a device, regardless of the way the driver core has created it. Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-12Revert "[BLOCK] Fix oops on removal of SD/MMC card"Linus Torvalds
This reverts commit 56cf6504fc1c0c221b82cebc16a444b684140fb7. Both Erik Mouw and Andrew Vasquez independently pinpointed this commit as causing problems, where the slab cache for a driver is never released (most obviously causing problems when immediately re-loading that driver, resulting in a "kmem_cache_create: duplicate cache <xyz>" message, but it can also cause other trouble). James Bottomley dug into it, and reports: "OK, here's the scoop. The problem patch adds a get of driverfs_dev in add_disk(), but doesn't put it again until disk_release() (which occurs on final put_disk() of the gendisk). However, in SCSI, the driverfs_dev is the sdev_gendev. That means there's a reference held on sdev_gendev until final disk put. Unfortunately, we use the driver model driver_remove to trigger del_gendisk (which removes the gendisk from visibility and decrements the refcount), so we've introduced an unbreakable deadlock in the reference counting with this. I suggest simply reversing this patch at the moment. If Russell and Jens can tell me what they're trying to do I'll see if there's another way to do it." so hereby the patch gets reverted, waiting for a better fix. Cc: Jens Axboe <axboe@suse.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: James Bottomley <James.Bottomley@SteelEye.com> Cc: Erik Mouw <erik@harddisk-recovery.com> Cc: Andrew Vasquez <andrew.vasquez@qlogic.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-05[BLOCK] Fix oops on removal of SD/MMC cardRussell King
The block layer keeps a reference (driverfs_dev) to the struct device associated with the block device, and uses it internally for generating uevents in block_uevent. Block device uevents include umounting the partition, which can occur after the backing device has been removed. Unfortunately, this reference is not counted. This means that if the struct device is removed from the device tree, the block layers reference will become stale. Guard against this by holding a reference to the struct device in add_disk(), and only drop the reference when we're releasing the gendisk kobject - in other words when we can be sure that no further uevents will be generated for this block device. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Jens Axboe <axboe@suse.de>
2006-03-31[PATCH] Simplify proc/devices and fix early termination regressionJoe Korty
Make baby-simple the code for /proc/devices. Based on the proven design for /proc/interrupts. This also fixes the early-termination regression 2.6.16 introduced, as demonstrated by: # dd if=/proc/devices bs=1 Character devices: 1 mem 27+0 records in 27+0 records out This should also work (but is untested) when /proc/devices >4096 bytes, which I believe is what the original 2.6.16 rewrite fixed. [akpm@osdl.org: cleanups, simplifications] Signed-off-by: Joe Korty <joe.korty@ccur.com> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[BLOCK] increase size of disk stat countersBen Woodard
The kernel's representation of the disk statistics uses the type unsigned which is 32b on both 32b and 64b platforms. Unfortunately, most system tools that work with these numbers that are exported in /proc/diskstats including iostat read these numbers into unsigned longs. This works fine on 32b platforms and when the number of IO transactions are small on 64b platforms. However, when the numbers wrap on 64b platforms & you read the numbers into unsigned longs, and compare the numbers to previous readings, then you get an unsigned representation of a negative number. This looks like a very large 64b number & gives you bizarre readouts in iostat: ilc4: Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util ilc4: sda 5.50 0.00 143.96 0.00 307496983987862656.00 0.00 153748491993931328.00 0.00 2136028725038430.00 7.94 55.12 5.59 80.42 Though fixing iostat in user space is possible, and a quick survey indicates that several other similar tools also use unsigned longs when processing /proc/diskstats. Therefore, it seems like a better approach would be to extend the length of the disk_stats structure on 64b architectures to 64b. The following patch does that. It should not affect the operation on 32b platforms. Signed-off-by: Ben Woodard <woodard@redhat.com> Cc: Rick Lindsley <ricklind@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-03-20[PATCH] kobj_map semaphore to mutex conversionJes Sorensen
Convert the kobj_map code to use a mutex instead of a semaphore. It converts the single two users as well, genhd.c and char_dev.c. Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-14[PATCH] convert /proc/devices to use seq_file interfaceNeil Horman
A Christoph suggested that the /proc/devices file be converted to use the seq_file interface. This patch does that. I've obxerved one or two installation that had sufficiently large sans that they overran the 4k limit on /proc/devices. Signed-off-by: Neil Horman <nhorman@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-04[PATCH] driver core: replace "hotplug" by "uevent"Kay Sievers
Leave the overloaded "hotplug" word to susbsystems which are handling real devices. The driver core does not "plug" anything, it just exports the state to userspace and generates events. Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-12[BLOCK] Document the READ/WRITE splitup of the disk statsJens Axboe
Use the symbolic name where appropriate and add a comment to the disk_stats structure. Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-04[BLOCK] Move all core block layer code to new block/ directoryJens Axboe
drivers/block/ is right now a mix of core and driver parts. Lets move the core parts to a new top level directory. Al will move the fs/ related block parts to block/ next. Signed-off-by: Jens Axboe <axboe@suse.de>