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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-22 17:03:12 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-22 17:03:12 -0700 |
commit | 8abfc6e7a45eb74e51904bbae676fae008b11366 (patch) | |
tree | 57d0a24558c0693e3a52e8e756616f6c72def1e9 /drivers/block/loop.c | |
parent | e9dd2b6837e26fe202708cce5ea4bb4ee3e3482e (diff) | |
parent | 6362beea8914cbd4630ccde3617d944aeca2d48f (diff) |
Merge branch 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
cciss: fix PCI IDs for new Smart Array controllers
drbd: add race-breaker to drbd_go_diskless
drbd: use dynamic_dev_dbg to optionally log uuid changes
dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
drbd: cleanup: change "<= 0" to "== 0"
drbd: relax the grace period of the md_sync timer again
drbd: add some more explicit drbd_md_sync
drbd: drop wrong debug asserts, fix recently introduced race
drbd: cleanup useless leftover warn/error printk's
drbd: add explicit drbd_md_sync to drbd_resync_finished
drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
drbd: fix for possible deadlock on IO error during resync
drbd: fix unlikely access after free and list corruption
drbd: fix for spurious fullsync (uuids rotated too fast)
drbd: allow for explicit resync-finished notifications
drbd: preparation commit, using full state in receive_state()
drbd: drbd_send_ack_dp must not rely on header information
drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
drbd: Fixed a stupid copy and paste error
drbd: Allow larger values for c-fill-target.
...
Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r-- | drivers/block/loop.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index a10c8c9b6b7..de3083b0a4f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -74,6 +74,7 @@ #include <linux/highmem.h> #include <linux/kthread.h> #include <linux/splice.h> +#include <linux/sysfs.h> #include <asm/uaccess.h> @@ -738,6 +739,103 @@ static inline int is_loop_device(struct file *file) return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; } +/* loop sysfs attributes */ + +static ssize_t loop_attr_show(struct device *dev, char *page, + ssize_t (*callback)(struct loop_device *, char *)) +{ + struct loop_device *l, *lo = NULL; + + mutex_lock(&loop_devices_mutex); + list_for_each_entry(l, &loop_devices, lo_list) + if (disk_to_dev(l->lo_disk) == dev) { + lo = l; + break; + } + mutex_unlock(&loop_devices_mutex); + + return lo ? callback(lo, page) : -EIO; +} + +#define LOOP_ATTR_RO(_name) \ +static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ +static ssize_t loop_attr_do_show_##_name(struct device *d, \ + struct device_attribute *attr, char *b) \ +{ \ + return loop_attr_show(d, b, loop_attr_##_name##_show); \ +} \ +static struct device_attribute loop_attr_##_name = \ + __ATTR(_name, S_IRUGO, loop_attr_do_show_##_name, NULL); + +static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) +{ + ssize_t ret; + char *p = NULL; + + mutex_lock(&lo->lo_ctl_mutex); + if (lo->lo_backing_file) + p = d_path(&lo->lo_backing_file->f_path, buf, PAGE_SIZE - 1); + mutex_unlock(&lo->lo_ctl_mutex); + + if (IS_ERR_OR_NULL(p)) + ret = PTR_ERR(p); + else { + ret = strlen(p); + memmove(buf, p, ret); + buf[ret++] = '\n'; + buf[ret] = 0; + } + + return ret; +} + +static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); +} + +static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); +} + +static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) +{ + int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); + + return sprintf(buf, "%s\n", autoclear ? "1" : "0"); +} + +LOOP_ATTR_RO(backing_file); +LOOP_ATTR_RO(offset); +LOOP_ATTR_RO(sizelimit); +LOOP_ATTR_RO(autoclear); + +static struct attribute *loop_attrs[] = { + &loop_attr_backing_file.attr, + &loop_attr_offset.attr, + &loop_attr_sizelimit.attr, + &loop_attr_autoclear.attr, + NULL, +}; + +static struct attribute_group loop_attribute_group = { + .name = "loop", + .attrs= loop_attrs, +}; + +static int loop_sysfs_init(struct loop_device *lo) +{ + return sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, + &loop_attribute_group); +} + +static void loop_sysfs_exit(struct loop_device *lo) +{ + sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, + &loop_attribute_group); +} + static int loop_set_fd(struct loop_device *lo, fmode_t mode, struct block_device *bdev, unsigned int arg) { @@ -837,6 +935,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, set_capacity(lo->lo_disk, size); bd_set_size(bdev, size << 9); + loop_sysfs_init(lo); /* let user-space know about the new size */ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); @@ -855,6 +954,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, return 0; out_clr: + loop_sysfs_exit(lo); lo->lo_thread = NULL; lo->lo_device = NULL; lo->lo_backing_file = NULL; @@ -951,6 +1051,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) set_capacity(lo->lo_disk, 0); if (bdev) { bd_set_size(bdev, 0); + loop_sysfs_exit(lo); /* let user-space know about this change */ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } |