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path: root/drivers/block/loop.c
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2010-04-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* '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 ...
2010-04-08loop: Update mtime when writing using aopsNikanth Karthikesan
Update mtime when writing to backing filesystem using the address space operations write_begin and write_end. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h 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 <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-10-29loop: fix NULL dereference if mount failsAlexey Dobriyan
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: [<ffffffff811486ee>] 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:[<ffffffff811486ee>] [<ffffffff811486ee>] 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: [<ffffffff812f95f5>] ? schedule_timeout+0x1f5/0x250 [<ffffffff811547d9>] ? rb_insert_color+0x109/0x140 [<ffffffff812fb754>] ? _spin_unlock_irq+0x14/0x40 [<ffffffff812f84c6>] ? wait_for_common+0x66/0x170 [<ffffffff8105a280>] ? default_wake_function+0x0/0x10 [<ffffffff810f8258>] ioctl_by_bdev+0x38/0x50 [<ffffffff811d2481>] loop_clr_fd+0x1e1/0x210 [<ffffffff811d2522>] lo_release+0x72/0x80 [<ffffffff810f934c>] __blkdev_put+0x1ac/0x1d0 [<ffffffff810f937b>] blkdev_put+0xb/0x10 [<ffffffff810f93b9>] blkdev_close+0x39/0x60 [<ffffffff810ccef3>] __fput+0xd3/0x230 [<ffffffff810cd06d>] fput+0x1d/0x30 [<ffffffff810c9680>] filp_close+0x50/0x80 [<ffffffff81061f11>] put_files_struct+0x81/0x100 [<ffffffff81061fde>] exit_files+0x4e/0x60 [<ffffffff81063ec5>] do_exit+0x6b5/0x730 [<ffffffff8107b279>] ? up_read+0x9/0x10 [<ffffffff8104c86e>] ? do_page_fault+0x18e/0x2a0 [<ffffffff81063f81>] do_group_exit+0x41/0xc0 [<ffffffff81064012>] sys_exit_group+0x12/0x20 [<ffffffff81030deb>] 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 [<ffffffff811486ee>] blkdev_ioctl+0x2e/0xa30 RSP <ffff88003b3d5bb8> CR2: 00000000000000b8 ---[ end trace c0b4d3c3118d1427 ]--- Fixing recursive fault but reboot is needed! Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22const: make block_device_operations constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-11bio: first step in sanitizing the bio->bi_rw flag testingJens Axboe
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 <jens.axboe@oracle.com>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-11splice: implement default splice_read methodMiklos Szeredi
If f_op->splice_read() is not implemented, fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-28loop: use BIO list management functionsAkinobu Mita
Now that the bio list management stuff is generic, convert loop to use bio lists instead of its own private bio list implementation. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-07loop: mutex already unlocked in loop_clr_fd()Alexander Beregalov
mount/1865 is trying to release lock (&lo->lo_ctl_mutex) at: but there are no more locks to release! mutex is already unlocked in loop_clr_fd(), we should not try to unlock it in lo_release() again. Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-01loop: add ioctl to resize a loop deviceJ. R. Okajima
Add the ability to 'resize' the loop device on the fly. One practical application is a loop file with XFS filesystem, already mounted: You can easily enlarge the file (append some bytes) and then call ioctl(fd, LOOP_SET_CAPACITY, new); The loop driver will learn about the new size and you can use xfs_growfs later on, which will allow you to use full capacity of the loop file without the need to unmount. Test app: #include <linux/fs.h> #include <linux/loop.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/types.h> #include <assert.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #define _GNU_SOURCE #include <getopt.h> char *me; void usage(FILE *f) { fprintf(f, "%s [options] loop_dev [backend_file]\n" "-s, --set new_size_in_bytes\n" "\twhen backend_file is given, " "it will be expanded too while keeping the original contents\n", me); } struct option opts[] = { { .name = "set", .has_arg = 1, .flag = NULL, .val = 's' }, { .name = "help", .has_arg = 0, .flag = NULL, .val = 'h' } }; void err_size(char *name, __u64 old) { fprintf(stderr, "size must be larger than current %s (%llu)\n", name, old); } int main(int argc, char *argv[]) { int fd, err, c, i, bfd; ssize_t ssz; size_t sz; __u64 old, new, append; char a[BUFSIZ]; struct stat st; FILE *out; char *backend, *dev; err = EINVAL; out = stderr; me = argv[0]; new = 0; while ((c = getopt_long(argc, argv, "s:h", opts, &i)) != -1) { switch (c) { case 's': errno = 0; new = strtoull(optarg, NULL, 0); if (errno) { err = errno; perror(argv[i]); goto out; } break; case 'h': err = 0; out = stdout; goto err; default: perror(argv[i]); goto err; } } if (optind < argc) dev = argv[optind++]; else goto err; fd = open(dev, O_RDONLY); if (fd < 0) { err = errno; perror(dev); goto out; } err = ioctl(fd, BLKGETSIZE64, &old); if (err) { err = errno; perror("ioctl BLKGETSIZE64"); goto out; } if (!new) { printf("%llu\n", old); goto out; } if (new < old) { err = EINVAL; err_size(dev, old); goto out; } if (optind < argc) { backend = argv[optind++]; bfd = open(backend, O_WRONLY|O_APPEND); if (bfd < 0) { err = errno; perror(backend); goto out; } err = fstat(bfd, &st); if (err) { err = errno; perror(backend); goto out; } if (new < st.st_size) { err = EINVAL; err_size(backend, st.st_size); goto out; } append = new - st.st_size; sz = sizeof(a); while (append > 0) { if (append < sz) sz = append; ssz = write(bfd, a, sz); if (ssz != sz) { err = errno; perror(backend); goto out; } append -= sz; } err = fsync(bfd); if (err) { err = errno; perror(backend); goto out; } } err = ioctl(fd, LOOP_SET_CAPACITY, new); if (err) { err = errno; perror("ioctl LOOP_SET_CAPACITY"); } goto out; err: usage(out); out: return err; } Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Tomas Matejicek <tomas@slax.org> Cc: <util-linux-ng@vger.kernel.org> Cc: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26loop: fix circular locking in loop_clr_fd()Nikanth Karthikesan
With CONFIG_PROVE_LOCKING enabled $ losetup /dev/loop0 file $ losetup -o 32256 /dev/loop1 /dev/loop0 $ losetup -d /dev/loop1 $ losetup -d /dev/loop0 triggers a [ INFO: possible circular locking dependency detected ] I think this warning is a false positive. Open/close on a loop device acquires bd_mutex of the device before acquiring lo_ctl_mutex of the same device. For ioctl(LOOP_CLR_FD) after acquiring lo_ctl_mutex, fput on the backing_file might acquire the bd_mutex of a device, if backing file is a device and this is the last reference to the file being dropped . But it is guaranteed that it is impossible to have a circular list of backing devices.(say loop2->loop1->loop0->loop2 is not possible), which guarantees that this can never deadlock. So this warning should be suppressed. It is very difficult to annotate lockdep not to warn here in the correct way. A simple way to silence lockdep could be to mark the lo_ctl_mutex in ioctl to be a sub class, but this might mask some other real bugs. @@ -1164,7 +1164,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, struct loop_device *lo = bdev->bd_disk->private_data; int err; - mutex_lock(&lo->lo_ctl_mutex); + mutex_lock_nested(&lo->lo_ctl_mutex, 1); switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, mode, bdev, arg); Or actually marking the bd_mutex after lo_ctl_mutex as a sub class could be a better solution. Luckily it is easy to avoid calling fput on backing file with lo_ctl_mutex held, so no lockdep annotation is required. If you do not like the special handling of the lo_ctl_mutex just for the LOOP_CLR_FD ioctl in lo_ioctl(), the mutex handling could be moved inside each of the individual ioctl handlers and I could send you another patch. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-24loop: support barrier writesNikanth Karthikesan
Honour barrier requests in the loop back block device driver. In case of barrier bios, flush the backing file once before processing the barrier and once after to guarantee ordering. In case of filesystems that does not support fsync, barrier bios would be failed with -EOPNOTSUPP. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-05loop: don't increment p->offset with (size_t) -EINVALRoel Kluin
Upon a 'transfer error block' size is set to -EINVAL, but this becomes positive since size is unsigned: p->offset still gets incremented. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29loop: Do not call loop_unplug for not configured loop device.Milan Broz
In loop_unplug() function is expected that mapping is set and lo->lo_backing_file is not NULL. Unfortunately loop_set_fd() set the request queue unplug function, but loop_clr_fd() doesn't clear that. Loop device allows open of non-configured loop in some situations. If the unplug on request queue is called, loop module oopses because of missing lo_backing_file. Simple reproducer: losetup /dev/loop0 /xxx losetup -d /dev/loop0 dmsetup create x --table "0 1 linear /dev/loop0 0" EIP is at loop_unplug+0x1d/0x3b ... Call Trace: blk_unplug+0x57/0x5e dm_table_unplug_all+0x34/0x77 [dm_mod] destroy_inode+0x27/0x38 generic_delete_inode+0xd5/0xd9 iput+0x4b/0x4e dm_resume+0xca/0xfe [dm_mod] dev_suspend+0x143/0x165 [dm_mod] dm_ctl_ioctl+0x18e/0x1cf [dm_mod] dev_suspend+0x0/0x165 [dm_mod] dm_ctl_ioctl+0x0/0x1cf [dm_mod] vfs_ioctl+0x22/0x69 do_vfs_ioctl+0x39d/0x3c7 trace_hardirqs_on+0xb/0xd remove_vma+0x50/0x56 do_munmap+0x21c/0x237 sys_ioctl+0x2c/0x45 sysenter_do_call+0x12/0x31 Several reports here http://www.kerneloops.org/search.php?search=loop_unplug Fix it by simply clear unplug function together with removing of backing file. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29loop: Flush possible running bios when loop device is released.Milan Broz
When there are still queued bios and reference count drops to zero, loop device must flush all queued bios. Otherwise it can lead to situation that caller closes the device, but some bios are still running and endio() function call later OOpses when uses unallocated mempool. This happens for example when running dm-crypt over loop, here is typical oops backtrace: Oops: 0000 [#1] PREEMPT SMP EIP is at mempool_free+0x12/0x6b ... crypt_dec_pending+0x50/0x54 [dm_crypt] crypt_endio+0x9f/0xa7 [dm_crypt] crypt_endio+0x0/0xa7 [dm_crypt] bio_endio+0x2b/0x2e loop_thread+0x37a/0x3b1 do_lo_send_aops+0x0/0x165 autoremove_wake_function+0x0/0x33 loop_thread+0x0/0x3b1 kthread+0x3b/0x61 kthread+0x0/0x61 kernel_thread_helper+0x7/0x10 (But crash is reproducible with different dm targets running over loop device too.) Patch fixes it by flushing the bios in release call, reusing the flush mechanism for switching backing store. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-14CRED: Wrap task credential accesses in the block loopback driverDavid Howells
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-30fs: remove prepare_write/commit_writeNick Piggin
Nothing uses prepare_write or commit_write. Remove them from the tree completely. [akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-21[PATCH] kill the unused bsize on the send side of /dev/loopAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] switch loopAl Viro
ioctl doesn't need BKL here Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] beginning of methods conversionAl Viro
To keep the size of changesets sane we split the switch by drivers; to keep the damn thing bisectable we do the following: 1) rename the affected methods, add ones with correct prototypes, make (few) callers handle both. That's this changeset. 2) for each driver convert to new methods. *ALL* drivers are converted in this series. 3) kill the old (renamed) methods. Note that it _is_ a flagday; all in-tree drivers are converted and by the end of this series no trace of old methods remain. The only reason why we do that this way is to keep the damn thing bisectable and allow per-driver debugging if anything goes wrong. New methods: open(bdev, mode) release(disk, mode) ioctl(bdev, mode, cmd, arg) /* Called without BKL */ compat_ioctl(bdev, mode, cmd, arg) locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
2008-04-21loop: manage partitions in disk imageLaurent Vivier
This patch allows to use loop device with partitionned disk image. Original behavior of loop is not modified. A new parameter is introduced to define how many partition we want to be able to manage per loop device. This parameter is "max_part". For instance, to manage 63 partitions / loop device, we will do: # modprobe loop max_part=63 # ls -l /dev/loop?* brw-rw---- 1 root disk 7, 0 2008-03-05 14:55 /dev/loop0 brw-rw---- 1 root disk 7, 64 2008-03-05 14:55 /dev/loop1 brw-rw---- 1 root disk 7, 128 2008-03-05 14:55 /dev/loop2 brw-rw---- 1 root disk 7, 192 2008-03-05 14:55 /dev/loop3 brw-rw---- 1 root disk 7, 256 2008-03-05 14:55 /dev/loop4 brw-rw---- 1 root disk 7, 320 2008-03-05 14:55 /dev/loop5 brw-rw---- 1 root disk 7, 384 2008-03-05 14:55 /dev/loop6 brw-rw---- 1 root disk 7, 448 2008-03-05 14:55 /dev/loop7 And to attach a raw partitionned disk image, the original losetup is used: # losetup -f etch.img # ls -l /dev/loop?* brw-rw---- 1 root disk 7, 0 2008-03-05 14:55 /dev/loop0 brw-rw---- 1 root disk 7, 1 2008-03-05 14:57 /dev/loop0p1 brw-rw---- 1 root disk 7, 2 2008-03-05 14:57 /dev/loop0p2 brw-rw---- 1 root disk 7, 5 2008-03-05 14:57 /dev/loop0p5 brw-rw---- 1 root disk 7, 64 2008-03-05 14:55 /dev/loop1 brw-rw---- 1 root disk 7, 128 2008-03-05 14:55 /dev/loop2 brw-rw---- 1 root disk 7, 192 2008-03-05 14:55 /dev/loop3 brw-rw---- 1 root disk 7, 256 2008-03-05 14:55 /dev/loop4 brw-rw---- 1 root disk 7, 320 2008-03-05 14:55 /dev/loop5 brw-rw---- 1 root disk 7, 384 2008-03-05 14:55 /dev/loop6 brw-rw---- 1 root disk 7, 448 2008-03-05 14:55 /dev/loop7 # mount /dev/loop0p1 /mnt # ls /mnt bench cdrom home lib mnt root srv usr bin dev initrd lost+found opt sbin sys var boot etc initrd.img media proc selinux tmp vmlinuz # umount /mnt # losetup -d /dev/loop0 Of course, the same behavior can be done using kpartx on a loop device, but modifying loop avoids to stack several layers of block device (loop + device mapper), this is a very light modification (40% of modifications are to manage the new parameter). Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-02-06Allow auto-destruction of loop devicesDavid Woodhouse
This allows a flag to be set on loop devices so that when they are closed for the last time, they'll self-destruct. In general, so that we can automatically allocate loop devices (as with losetup -f) and have them disappear when we're done with them. In particular, right now, so that we can stop relying on the hackish special-case in umount(8) which kills off loop devices which were set up by 'mount -oloop'. That means we can stop putting crap in /etc/mtab which doesn't belong there, which means it can be a symlink to /proc/mounts, which means yet another writable file on the root filesystem is eliminated and the 'stateless' folks get happier... and OLPC trac #356 can be closed. The mount(8) side of that is at http://marc.info/?l=util-linux-ng&m=119362955431694&w=2 [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: David Woodhouse <dwmw2@infradead.org> Cc: Bernardo Innocenti <bernie@codewiz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-11loop: fix bad bio_alloc() nr_iovec requestJens Axboe
Don't allocate room for an iovec when it is not needed. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-19Convert files to UTF-8 and some cleanupsJan Engelhardt
* Convert files to UTF-8. * Also correct some people's names (one example is Eißfeldt, which was found in a source file. Given that the author used an ß at all in a source file indicates that the real name has in fact a 'ß' and not an 'ss', which is commonly used as a substitute for 'ß' when limited to 7bit.) * Correct town names (Goettingen -> Göttingen) * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313) Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-17Remove unneeded lock_kernel() in driver/block/loop.cDiego Woitasen
Signed-off-by: Diego Woitasen <diego@woitasen.com.ar> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16deny partial write for loop dev fdDmitry Monakhov
Partial write can be easily supported by LO_CRYPT_NONE mode, but it is not easy in LO_CRYPT_CRYPTOAPI case, because of its block nature. I don't know who still used cryptoapi, but theoretically it is possible. So let's leave things as they are. Loop device doesn't support partial write before Nick's "write_begin/write_end" patch set, and let's it behave the same way after. Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16fs: introduce write_begin, write_end, and perform_write aopsNick Piggin
These are intended to replace prepare_write and commit_write with more flexible alternatives that are also able to avoid the buffered write deadlock problems efficiently (which prepare_write is unable to do). [mark.fasheh@oracle.com: API design contributions, code review and fixes] [akpm@linux-foundation.org: various fixes] [dmonakhov@sw.ru: new aop block_write_begin fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> 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>
2007-07-17unregister_blkdev() delete redundant messages in callersAkinobu Mita
No need to warn unregister_blkdev() failure by the callers. (The previous patch makes unregister_blkdev() print error message in error case) 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>
2007-07-17Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki
Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-10pipe: change the ->pin() operation to ->confirm()Jens Axboe
The name 'pin' was badly chosen, it doesn't pin a pipe buffer in the most commonly used sense in the kernel. So change the name to 'confirm', after debating this issue with Hugh Dickins a bit. A good return from ->confirm() means that the buffer is really there, and that the contents are good. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10splice: divorce the splice structure/function definitions from the pipe headerJens Axboe
We need to move even more stuff into the header so that folks can use the splice_to_pipe() implementation instead of open-coding a lot of pipe knowledge (see relay implementation), so move to our own header file finally. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10loop: convert to using splice_direct_to_actor() instead of sendfile()Jens Axboe
This gets rid of the dependency on ->sendfile() for receiving data and converts loop to ->splice_read() instead. Also includes an IV offset fix from Hugh Dickins. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-06-08loop: preallocate eight loop devicesKen Chen
The kernel on-demand loop device instantiation breaks several user space tools as the tools are not ready to cope with the "on-demand feature". Fix it by instantiate default 8 loop devices and also reinstate max_loop module parameter. Signed-off-by: Ken Chen <kenchen@google.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-13fix deadlock in loop.cAl Viro
... doh Jeremy Fitzhardinge noted that the recent loop.c cleanups worked, but cause lockdep to complain. Ouch. OK, the deadlock is real and yes, I'm an idiot. Speaking of which, we probably want to s/lock/pin/ in drivers/base/map.c to avoid such brainos again. And yes, this stuff needs clear documentation. Will try to put one together once I get some sleep... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-12fix the dynamic allocation and probe in loop.cAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Ken Chen <kenchen@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09fs: convert core functions to zero_user_pageNate Diller
It's very common for file systems to need to zero part or all of a page, the simplist way is just to use kmap_atomic() and memset(). There's actually a library function in include/linux/highmem.h that does exactly that, but it's confusingly named memclear_highpage_flush(), which is descriptive of *how* it does the work rather than what the *purpose* is. So this patchset renames the function to zero_user_page(), and calls it from the various places that currently open code it. This first patch introduces the new function call, and converts all the core kernel callsites, both the open-coded ones and the old memclear_highpage_flush() ones. Following this patch is a series of conversions for each file system individually, per AKPM, and finally a patch deprecating the old call. The diffstat below shows the entire patchset. [akpm@linux-foundation.org: fix a few things] Signed-off-by: Nate Diller <nate.diller@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08remove artificial software max_loop limitKen Chen
Remove artificial maximum 256 loop device that can be created due to a legacy device number limit. Searching through lkml archive, there are several instances where users complained about the artificial limit that the loop driver impose. There is no reason to have such limit. This patch rid the limit entirely and make loop device and associated block queue instantiation on demand. With on-demand instantiation, it also gives the benefit of not wasting memory if these devices are not in use (compare to current implementation that always create 8 loop devices), a net improvement in both areas. This version is both tested with creation of large number of loop devices and is compatible with existing losetup/mount user land tools. There are a number of people who worked on this and provided valuable suggestions, in no particular order, by: Jens Axboe Jan Engelhardt Christoph Hellwig Thomas M Signed-off-by: Ken Chen <kenchen@google.com> Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07mm: remove destroy_dirty_buffers from invalidate_bdev()Peter Zijlstra
Remove the destroy_dirty_buffers argument from invalidate_bdev(), it hasn't been used in 6 years (so akpm says). find * -name \*.[ch] | xargs grep -l invalidate_bdev | while read file; do quilt add $file; sed -ie 's/invalidate_bdev(\([^,]*\),[^)]*)/invalidate_bdev(\1)/g' $file; done Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] struct path: convert block_driversJosef Sipek
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-10[PATCH] __user annotations: loop.cAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-10[PATCH] fix misannotations in loop.cAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-30[PATCH] BLOCK: Move the loop device ioctl compat stuff to the loop driver ↵David Howells
[try #6] Move the loop device ioctl compat stuff from fs/compat_ioctl.c to the loop driver so that the loop header file doesn't need to be included. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-29[PATCH] loop: forward-port resource leak checks from SolarSerge E. Hallyn
Forward port of the patch by Solar and ported by Julio. Compiles, boots, and passes my looptorturetest.sh. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Julio Auto <mindvortex@gmail.com> Cc: Solar Designer <solar@openwall.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] kthread: convert loop.c to kthreadSerge E. Hallyn
Convert loop.c from the deprecated kernel_thread to kthread. This patch simplifies the code quite a bit and passes similar testing to the previous submission on both emulated x86 and s390. Changes since last submission: switched to using a rather simple loop based on wait_event_interruptible. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27[PATCH] inode-diet: Eliminate i_blksize from the inode structureTheodore Ts'o
This eliminates the i_blksize field from struct inode. Filesystems that want to provide a per-inode st_blksize can do so by providing their own getattr routine instead of using the generic_fillattr() function. Note that some filesystems were providing pretty much random (and incorrect) values for i_blksize. [bunk@stusta.de: cleanup] [akpm@osdl.org: generic_fillattr() fix] Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Adrian Bunk <bunk@stusta.de> 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>