diff options
Diffstat (limited to 'drivers/block/loop.c')
| -rw-r--r-- | drivers/block/loop.c | 132 |
1 files changed, 117 insertions, 15 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 91797bbbe702..6c48b3545f84 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -67,16 +67,18 @@ #include <linux/compat.h> #include <linux/suspend.h> #include <linux/freezer.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <linux/writeback.h> #include <linux/buffer_head.h> /* for invalidate_bdev() */ #include <linux/completion.h> #include <linux/highmem.h> #include <linux/kthread.h> #include <linux/splice.h> +#include <linux/sysfs.h> #include <asm/uaccess.h> +static DEFINE_MUTEX(loop_mutex); static LIST_HEAD(loop_devices); static DEFINE_MUTEX(loop_devices_mutex); @@ -477,17 +479,17 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; if (bio_rw(bio) == WRITE) { - bool barrier = !!(bio->bi_rw & REQ_HARDBARRIER); struct file *file = lo->lo_backing_file; - if (barrier) { - if (unlikely(!file->f_op->fsync)) { - ret = -EOPNOTSUPP; - goto out; - } + /* REQ_HARDBARRIER is deprecated */ + if (bio->bi_rw & REQ_HARDBARRIER) { + ret = -EOPNOTSUPP; + goto out; + } + if (bio->bi_rw & REQ_FLUSH) { ret = vfs_fsync(file, 0); - if (unlikely(ret)) { + if (unlikely(ret && ret != -EINVAL)) { ret = -EIO; goto out; } @@ -495,9 +497,9 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) ret = lo_send(lo, bio, pos); - if (barrier && !ret) { + if ((bio->bi_rw & REQ_FUA) && !ret) { ret = vfs_fsync(file, 0); - if (unlikely(ret)) + if (unlikely(ret && ret != -EINVAL)) ret = -EIO; } } else @@ -737,6 +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) { @@ -832,10 +931,11 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, lo->lo_queue->unplug_fn = loop_unplug; if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) - blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN); + blk_queue_flush(lo->lo_queue, REQ_FLUSH); 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); @@ -854,6 +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; @@ -950,6 +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); } @@ -1409,11 +1511,11 @@ static int lo_open(struct block_device *bdev, fmode_t mode) { struct loop_device *lo = bdev->bd_disk->private_data; - lock_kernel(); + mutex_lock(&loop_mutex); mutex_lock(&lo->lo_ctl_mutex); lo->lo_refcnt++; mutex_unlock(&lo->lo_ctl_mutex); - unlock_kernel(); + mutex_unlock(&loop_mutex); return 0; } @@ -1423,7 +1525,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode) struct loop_device *lo = disk->private_data; int err; - lock_kernel(); + mutex_lock(&loop_mutex); mutex_lock(&lo->lo_ctl_mutex); if (--lo->lo_refcnt) @@ -1448,7 +1550,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode) out: mutex_unlock(&lo->lo_ctl_mutex); out_unlocked: - lock_kernel(); + mutex_unlock(&loop_mutex); return 0; } |