user/sven/linux.git/include/linux/loop.h, branch v3.3-rc6

Merge branch 'for-3.2/drivers' of git://git.kernel.dk/linux-block

2011-11-05T00:22:14Z

* 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits) virtio-blk: use ida to allocate disk index hpsa: add small delay when using PCI Power Management to reset for kump cciss: add small delay when using PCI Power Management to reset for kump xen/blkback: Fix two races in the handling of barrier requests. xen/blkback: Check for proper operation. xen/blkback: Fix the inhibition to map pages when discarding sector ranges. xen/blkback: Report VBD_WSECT (wr_sect) properly. xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests. xen-blkfront: plug device number leak in xlblk_init() error path xen-blkfront: If no barrier or flush is supported, use invalid operation. xen-blkback: use kzalloc() in favor of kmalloc()+memset() xen-blkback: fixed indentation and comments xen-blkfront: fix a deadlock while handling discard response xen-blkfront: Handle discard requests. xen-blkback: Implement discard requests ('feature-discard') xen-blkfront: add BLKIF_OP_DISCARD and discard request struct drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd() drivers/block/loop.c: emit uevent on auto release drivers/block/cpqarray.c: use pci_dev->revision loop: always allow userspace partitions and optionally support automatic scanning ... Fic up trivial header file includsion conflict in drivers/block/loop.c

loop: remove the incorrect write_begin/write_end shortcut

2011-10-17T10:57:20Z

Currently the loop device tries to call directly into write_begin/write_end instead of going through ->write if it can. This is a fairly nasty shortcut as write_begin and write_end are only callbacks for the generic write code and expect to be called with filesystem specific locks held. This code currently causes various issues for clustered filesystems as it doesn't take the required cluster locks, and it also causes issues for XFS as it doesn't properly lock against the swapext ioctl as called by the defragmentation tools. This in case causes data corruption if defragmentation hits a busy loop device in the wrong time window, as reported by RH QA. The reason why we have this shortcut is that it saves a data copy when doing a transformation on the loop device, which is the technical term for using cryptoloop (or an XOR transformation). Given that cryptoloop has been deprecated in favour of dm-crypt my opinion is that we should simply drop this shortcut instead of finding complicated ways to to introduce a formal interface for this shortcut. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

loop: always allow userspace partitions and optionally support automatic scanning

2011-08-23T18:12:04Z

Automatic partition scanning can be requested individually per loop device during its setup by setting LO_FLAGS_PARTSCAN. By default, no partition tables are scanned. Userspace can now always add and remove partitions from all loop devices, regardless if the in-kernel partition scanner is enabled or not. The needed partition minor numbers are allocated from the extended minors space, the main loop device numbers will continue to match the loop minors, regardless of the number of partitions used. # grep . /sys/class/block/loop1/loop/* /sys/block/loop1/loop/autoclear:0 /sys/block/loop1/loop/backing_file:/home/kay/data/stuff/part.img /sys/block/loop1/loop/offset:0 /sys/block/loop1/loop/partscan:1 /sys/block/loop1/loop/sizelimit:0 # ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 Aug 14 20:22 /dev/loop0 brw-rw---- 1 root disk 7, 1 Aug 14 20:23 /dev/loop1 brw-rw---- 1 root disk 259, 0 Aug 14 20:23 /dev/loop1p1 brw-rw---- 1 root disk 259, 1 Aug 14 20:23 /dev/loop1p2 brw-rw---- 1 root disk 7, 99 Aug 14 20:23 /dev/loop99 brw-rw---- 1 root disk 259, 2 Aug 14 20:23 /dev/loop99p1 brw-rw---- 1 root disk 259, 3 Aug 14 20:23 /dev/loop99p2 crw------T 1 root root 10, 237 Aug 14 20:22 /dev/loop-control Cc: Karel Zak Cc: Davidlohr Bueso Acked-By: Tejun Heo Signed-off-by: Kay Sievers Signed-off-by: Jens Axboe

loop: add management interface for on-demand device allocation

2011-07-31T20:08:04Z

Loop devices today have a fixed pre-allocated number of usually 8. The number can only be changed at module init time. To find a free device to use, /dev/loop%i needs to be scanned, and all devices need to be opened until a free one is possibly found. This adds a new /dev/loop-control device node, that allows to dynamically find or allocate a free device, and to add and remove loop devices from the running system: LOOP_CTL_ADD adds a specific device. Arg is the number of the device. It returns the device i or a negative error code. LOOP_CTL_REMOVE removes a specific device, Arg is the number the device. It returns the device i or a negative error code. LOOP_CTL_GET_FREE finds the next unbound device or allocates a new one. No arg is given. It returns the device i or a negative error code. The loop kernel module gets automatically loaded when /dev/loop-control is accessed the first time. The alias specified in the module, instructs udev to create this 'dead' device node, even when the module is not loaded. Example: cfd = open("/dev/loop-control", O_RDWR); # add a new specific loop device err = ioctl(cfd, LOOP_CTL_ADD, devnr); # remove a specific loop device err = ioctl(cfd, LOOP_CTL_REMOVE, devnr); # find or allocate a free loop device to use devnr = ioctl(cfd, LOOP_CTL_GET_FREE); sprintf(loopname, "/dev/loop%i", devnr); ffd = open("backing-file", O_RDWR); lfd = open(loopname, O_RDWR); err = ioctl(lfd, LOOP_SET_FD, ffd); Cc: Tejun Heo Cc: Karel Zak Signed-off-by: Kay Sievers Signed-off-by: Jens Axboe

loop: replace linked list of allocated devices with an idr index

2011-07-31T20:08:04Z

Replace the linked list, that keeps track of allocated devices, with an idr index to allow a more efficient lookup of devices. Cc: Tejun Heo Signed-off-by: Kay Sievers Signed-off-by: Jens Axboe

loop: use BIO list management functions

2009-04-28T05:37:28Z

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 Cc: Christoph Hellwig Signed-off-by: Akinobu Mita Signed-off-by: Jens Axboe

loop: add ioctl to resize a loop device

2009-04-01T15:59:17Z

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 #include #include #include #include #include #include #include #include #include #include #define _GNU_SOURCE #include 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 Signed-off-by: Tomas Matejicek Cc: Cc: Karel Zak Cc: Jens Axboe Cc: Al Viro Cc: Christoph Hellwig Cc: Akinobu Mita Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include of is preferred over

2009-01-16T00:39:41Z

Impact: fix 15 make headers_check warnings: include of is preferred over Signed-off-by: Jaswinder Singh Rajput Cc: Ingo Molnar Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Allow auto-destruction of loop devices

2008-02-06T18:41:01Z

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 Cc: Bernardo Innocenti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

loop.h build fix

2007-07-24T19:24:59Z

include/linux/loop.h:66: error: expected specifier-qualifier-list before 'request_queue_t' Cc: Sebastian Siewior Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds