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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c136
1 files changed, 119 insertions, 17 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 91797bbbe70..1e5284ef65f 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);
@@ -99,8 +101,8 @@ static int transfer_none(struct loop_device *lo, int cmd,
else
memcpy(raw_buf, loop_buf, size);
- kunmap_atomic(raw_buf, KM_USER0);
kunmap_atomic(loop_buf, KM_USER1);
+ kunmap_atomic(raw_buf, KM_USER0);
cond_resched();
return 0;
}
@@ -128,8 +130,8 @@ static int transfer_xor(struct loop_device *lo, int cmd,
for (i = 0; i < size; i++)
*out++ = *in++ ^ key[(i & 511) % keysize];
- kunmap_atomic(raw_buf, KM_USER0);
kunmap_atomic(loop_buf, KM_USER1);
+ kunmap_atomic(raw_buf, KM_USER0);
cond_resched();
return 0;
}
@@ -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;
@@ -948,6 +1049,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
if (bdev)
invalidate_bdev(bdev);
set_capacity(lo->lo_disk, 0);
+ loop_sysfs_exit(lo);
if (bdev) {
bd_set_size(bdev, 0);
/* let user-space know about this 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;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-25 18:52:44 +0000