kernel/linux.git/drivers/block/loop.c, branch linux-2.6.35.y

loop: handle on-demand devices correctly

2011-08-01T20:54:52+00:00

commit a1c15c59feee36267c43142a41152fbf7402afb6 upstream. When finding or allocating a loop device, loop_probe() did not take partition numbers into account so that it can result to a different device. Consider following example: $ sudo modprobe loop max_part=15 $ ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0 brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1 brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2 brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3 brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4 brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5 brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6 brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7 $ sudo mknod /dev/loop8 b 7 128 $ sudo losetup /dev/loop8 ~/temp/disk-with-3-parts.img $ sudo losetup -a /dev/loop128: [0805]:278201 (/home/namhyung/temp/disk-with-3-parts.img) $ ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0 brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1 brw-rw---- 1 root disk 7, 2048 2011-05-24 22:18 /dev/loop128 brw-rw---- 1 root disk 7, 2049 2011-05-24 22:18 /dev/loop128p1 brw-rw---- 1 root disk 7, 2050 2011-05-24 22:18 /dev/loop128p2 brw-rw---- 1 root disk 7, 2051 2011-05-24 22:18 /dev/loop128p3 brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2 brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3 brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4 brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5 brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6 brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7 brw-r--r-- 1 root root 7, 128 2011-05-24 22:17 /dev/loop8 After this patch, /dev/loop8 - instead of /dev/loop128 - was accessed correctly. In addition, 'range' passed to blk_register_region() should include all range of dev_t that LOOP_MAJOR can address. It does not need to be limited by partition numbers unless 'max_loop' param was specified. Signed-off-by: Namhyung Kim Cc: Laurent Vivier Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

loop: limit 'max_part' module param to DISK_MAX_PARTS

2011-08-01T20:54:52+00:00

commit 78f4bb367fd147a0e7e3998ba6e47109999d8814 upstream. The 'max_part' parameter controls the number of maximum partition a loop block device can have. However if a user specifies very large value it would exceed the limitation of device minor number and can cause a kernel panic (or, at least, produce invalid device nodes in some cases). On my desktop system, following command kills the kernel. On qemu, it triggers similar oops but the kernel was alive: $ sudo modprobe loop max_part0000 ------------[ cut here ]------------ kernel BUG at /media/Linux_Data/project/linux/fs/sysfs/group.c:65! invalid opcode: 0000 [#1] SMP last sysfs file: CPU 0 Modules linked in: loop(+) Pid: 43, comm: insmod Tainted: G W 2.6.39-qemu+ #155 Bochs Bochs RIP: 0010:[] [] internal_create_group= +0x2a/0x170 RSP: 0018:ffff880007b3fde8 EFLAGS: 00000246 RAX: 00000000ffffffef RBX: ffff880007b3d878 RCX: 00000000000007b4 RDX: ffffffff8152da50 RSI: 0000000000000000 RDI: ffff880007b3d878 RBP: ffff880007b3fe38 R08: ffff880007b3fde8 R09: 0000000000000000 R10: ffff88000783b4a8 R11: ffff880007b3d878 R12: ffffffff8152da50 R13: ffff880007b3d868 R14: 0000000000000000 R15: ffff880007b3d800 FS: 0000000002137880(0063) GS:ffff880007c00000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000422680 CR3: 0000000007b50000 CR4: 00000000000006b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000 Process insmod (pid: 43, threadinfo ffff880007b3e000, task ffff880007afb9c= 0) Stack: ffff880007b3fe58 ffffffff811e66dd ffff880007b3fe58 ffffffff811e570b 0000000000000010 ffff880007b3d800 ffff880007a7b390 ffff880007b3d868 0000000000400920 ffff880007b3d800 ffff880007b3fe48 ffffffff8113cfc8 Call Trace: [] ? device_add+0x4bc/0x5af [] ? dev_set_name+0x3c/0x3e [] sysfs_create_group+0xe/0x12 [] blk_trace_init_sysfs+0x14/0x16 [] blk_register_queue+0x47/0xf7 [] add_disk+0xdf/0x290 [] loop_init+0xeb/0x1b8 [loop] [] ? 0xffffffffa0005fff [] do_one_initcall+0x7a/0x12e [] sys_init_module+0x9c/0x1e0 [] system_call_fastpath+0x16/0x1b Code: c3 55 48 89 e5 41 57 41 56 41 89 f6 41 55 41 54 49 89 d4 53 48 89 fb= 48 83 ec 28 48 85 ff 74 0b 85 f6 75 0b 48 83 7f 30 00 75 14 <0f> 0b eb fe = 48 83 7f 30 00 b9 ea ff ff ff 0f 84 18 01 00 00 49 RIP [] internal_create_group+0x2a/0x170 RSP ---[ end trace a123eb592043acad ]--- Signed-off-by: Namhyung Kim Cc: Laurent Vivier Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

sanitize vfs_fsync calling conventions

2010-05-21T22:31:21+00:00

Now that the last user passing a NULL file pointer is gone we can remove the redundant dentry argument and associated hacks inside vfs_fsynmc_range. The next step will be removig the dentry argument from ->fsync, but given the luck with the last round of method prototype changes I'd rather defer this until after the main merge window. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

generate "change" uevent for loop device

2010-05-21T16:37:30+00:00

Recent udev versions probe loop devices for filesystems meaning that the /dev/disk hierarchy may contain useful entries such as $ ls -l /dev/disk/by-label/Fedora-12-x86_64-Live lrwxrwxrwx 1 root root 11 Mar 11 13:41 /dev/disk/by-label/Fedora-12-x86_64-Live -> ../../loop0 Unfortunately, no "change" uevent is generated when the loop device is detached so the symlink persists. Additionally, no "change" uevent is guaranteed to be generated when attaching an fd or changing capacity. For example, user space could open the loop device O_RDONLY (in fact, recent util-linux-ng does this) so udev's OPTIONS+="watch" machinery may not trigger the "change" uevent. This patch ensures that the "change" uevent is generated in all of these cases. As a result, the /dev/disk hierarchy works as expected for loop devices. Signed-off-by: David Zeuthen Acked-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2010-04-09T18:50:29+00:00

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits) cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch loop: Update mtime when writing using aops block: expose the statistics in blkio.time and blkio.sectors for the root cgroup backing-dev: Handle class_create() failure Block: Fix block/elevator.c elevator_get() off-by-one error drbd: lc_element_by_index() never returns NULL cciss: unlock on error path cfq-iosched: Do not merge queues of BE and IDLE classes cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging i2o: Remove the dangerous kobj_to_i2o_device macro block: remove 16 bytes of padding from struct request on 64bits cfq-iosched: fix a kbuild regression block: make CONFIG_BLK_CGROUP visible Remove GENHD_FL_DRIVERFS block: Export max number of segments and max segment size in sysfs block: Finalize conversion of block limits functions block: Fix overrun in lcm() and move it to lib vfs: improve writeback_inodes_wb() paride: fix off-by-one test drbd: fix al-to-on-disk-bitmap for 4k logical_block_size ...

loop: Update mtime when writing using aops

2010-04-08T19:39:31+00:00

Update mtime when writing to backing filesystem using the address space operations write_begin and write_end. Signed-off-by: Nikanth Karthikesan Signed-off-by: Jens Axboe

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

loop: fix NULL dereference if mount fails

2009-10-29T14:39:27+00:00

Commit bb21488482bd36eae6b30b014d93619063773fd4 ("[PATCH] switch loop") started to pass NULL bdev to ioctl hook. Steps to reproduce: [boot with loop.max_part=1] [mount -o loop something so mount fails] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b8 IP: [] blkdev_ioctl+0x2e/0xa30 PGD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:35/ACPI0003:00/power_supply/ACAD/online CPU 0 Modules linked in: zfs nvidia(P) [last unloaded: zfs] Pid: 15177, comm: mount Tainted: P 2.6.32-rc4-zfs #2 Satellite X200 RIP: 0010:[] [] blkdev_ioctl+0x2e/0xa30 RSP: 0018:ffff88003b3d5bb8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000125f RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88003b3d5ce8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffffffff000 R13: 0000000000000000 R14: ffff880071cef280 R15: 00000000000200da FS: 00007fd77cfe7740(0000) GS:ffff880001600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000000b8 CR3: 0000000001001000 CR4: 00000000000026f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process mount (pid: 15177, threadinfo ffff88003b3d4000, task ffff88007572f920) Stack: ffff88003b3d5c38 ffffffff812f95f5 ffff88007eeb6600 0000000000000000 <0> 0000000000000000 ffff88003b3d5c18 ffffffff811547d9 ffff88001bf11ef0 <0> 7fffffffffffffff ffff88001bf11ee8 ffff88001bf11ef0 0000000000000000 Call Trace: [] ? schedule_timeout+0x1f5/0x250 [] ? rb_insert_color+0x109/0x140 [] ? _spin_unlock_irq+0x14/0x40 [] ? wait_for_common+0x66/0x170 [] ? default_wake_function+0x0/0x10 [] ioctl_by_bdev+0x38/0x50 [] loop_clr_fd+0x1e1/0x210 [] lo_release+0x72/0x80 [] __blkdev_put+0x1ac/0x1d0 [] blkdev_put+0xb/0x10 [] blkdev_close+0x39/0x60 [] __fput+0xd3/0x230 [] fput+0x1d/0x30 [] filp_close+0x50/0x80 [] put_files_struct+0x81/0x100 [] exit_files+0x4e/0x60 [] do_exit+0x6b5/0x730 [] ? up_read+0x9/0x10 [] ? do_page_fault+0x18e/0x2a0 [] do_group_exit+0x41/0xc0 [] sys_exit_group+0x12/0x20 [] system_call_fastpath+0x16/0x1b Code: f8 48 89 e5 48 81 ec 30 01 00 00 48 89 5d d8 4c 89 6d e8 4c 89 65 e0 4c 89 75 f0 4c 89 7d f8 48 89 bd e8 fe ff ff 49 89 cd 89 f3 <49> 8b 88 b8 00 00 00 81 fa 68 12 00 00 0f 84 57 05 00 00 0f 86 RIP [] blkdev_ioctl+0x2e/0xa30 RSP CR2: 00000000000000b8 ---[ end trace c0b4d3c3118d1427 ]--- Fixing recursive fault but reboot is needed! Signed-off-by: Alexey Dobriyan Cc: Jens Axboe Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

const: make block_device_operations const

2009-09-22T14:17:25+00:00

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bio: first step in sanitizing the bio->bi_rw flag testing

2009-09-11T12:33:31+00:00

Get rid of any functions that test for these bits and make callers use bio_rw_flagged() directly. Then it is at least directly apparent what variable and flag they check. Signed-off-by: Jens Axboe