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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.c97
1 files changed, 65 insertions, 32 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e2b1f377f585..053a086d547e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -137,20 +137,35 @@ static void loop_global_unlock(struct loop_device *lo, bool global)
static int max_part;
static int part_shift;
-static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file)
+static loff_t lo_calculate_size(struct loop_device *lo, struct file *file)
{
loff_t loopsize;
+ int ret;
+
+ if (S_ISBLK(file_inode(file)->i_mode)) {
+ loopsize = i_size_read(file->f_mapping->host);
+ } else {
+ struct kstat stat;
+
+ /*
+ * Get the accurate file size. This provides better results than
+ * cached inode data, particularly for network filesystems where
+ * metadata may be stale.
+ */
+ ret = vfs_getattr_nosec(&file->f_path, &stat, STATX_SIZE, 0);
+ if (ret)
+ return 0;
- /* Compute loopsize in bytes */
- loopsize = i_size_read(file->f_mapping->host);
- if (offset > 0)
- loopsize -= offset;
+ loopsize = stat.size;
+ }
+
+ if (lo->lo_offset > 0)
+ loopsize -= lo->lo_offset;
/* offset is beyond i_size, weird but possible */
if (loopsize < 0)
return 0;
-
- if (sizelimit > 0 && sizelimit < loopsize)
- loopsize = sizelimit;
+ if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize)
+ loopsize = lo->lo_sizelimit;
/*
* Unfortunately, if we want to do I/O on the device,
* the number of 512-byte sectors has to fit into a sector_t.
@@ -158,11 +173,6 @@ static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file)
return loopsize >> 9;
}
-static loff_t get_loop_size(struct loop_device *lo, struct file *file)
-{
- return get_size(lo->lo_offset, lo->lo_sizelimit, file);
-}
-
/*
* We support direct I/O only if lo_offset is aligned with the logical I/O size
* of backing device, and the logical block size of loop is bigger than that of
@@ -313,6 +323,8 @@ static void lo_rw_aio_do_completion(struct loop_cmd *cmd)
return;
kfree(cmd->bvec);
cmd->bvec = NULL;
+ if (req_op(rq) == REQ_OP_WRITE)
+ kiocb_end_write(&cmd->iocb);
if (likely(!blk_should_fake_timeout(rq->q)))
blk_mq_complete_request(rq);
}
@@ -387,9 +399,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
cmd->iocb.ki_flags = 0;
}
- if (rw == ITER_SOURCE)
+ if (rw == ITER_SOURCE) {
+ kiocb_start_write(&cmd->iocb);
ret = file->f_op->write_iter(&cmd->iocb, &iter);
- else
+ } else
ret = file->f_op->read_iter(&cmd->iocb, &iter);
lo_rw_aio_do_completion(cmd);
@@ -566,7 +579,7 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
error = -EINVAL;
/* size of the new backing store needs to be the same */
- if (get_loop_size(lo, file) != get_loop_size(lo, old_file))
+ if (lo_calculate_size(lo, file) != lo_calculate_size(lo, old_file))
goto out_err;
/*
@@ -1060,7 +1073,7 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode,
loop_update_dio(lo);
loop_sysfs_init(lo);
- size = get_loop_size(lo, file);
+ size = lo_calculate_size(lo, file);
loop_set_size(lo, size);
/* Order wrt reading lo_state in loop_validate_file(). */
@@ -1244,12 +1257,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
lo->lo_flags &= ~LOOP_SET_STATUS_CLEARABLE_FLAGS;
lo->lo_flags |= (info->lo_flags & LOOP_SET_STATUS_SETTABLE_FLAGS);
- if (size_changed) {
- loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit,
- lo->lo_backing_file);
- loop_set_size(lo, new_size);
- }
-
/* update the direct I/O flag if lo_offset changed */
loop_update_dio(lo);
@@ -1257,6 +1264,10 @@ out_unfreeze:
blk_mq_unfreeze_queue(lo->lo_queue, memflags);
if (partscan)
clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state);
+ if (!err && size_changed) {
+ loff_t new_size = lo_calculate_size(lo, lo->lo_backing_file);
+ loop_set_size(lo, new_size);
+ }
out_unlock:
mutex_unlock(&lo->lo_mutex);
if (partscan)
@@ -1397,7 +1408,7 @@ static int loop_set_capacity(struct loop_device *lo)
if (unlikely(lo->lo_state != Lo_bound))
return -ENXIO;
- size = get_loop_size(lo, lo->lo_backing_file);
+ size = lo_calculate_size(lo, lo->lo_backing_file);
loop_set_size(lo, size);
return 0;
@@ -1429,17 +1440,34 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg)
return 0;
}
-static int loop_set_block_size(struct loop_device *lo, unsigned long arg)
+static int loop_set_block_size(struct loop_device *lo, blk_mode_t mode,
+ struct block_device *bdev, unsigned long arg)
{
struct queue_limits lim;
unsigned int memflags;
int err = 0;
- if (lo->lo_state != Lo_bound)
- return -ENXIO;
+ /*
+ * If we don't hold exclusive handle for the device, upgrade to it
+ * here to avoid changing device under exclusive owner.
+ */
+ if (!(mode & BLK_OPEN_EXCL)) {
+ err = bd_prepare_to_claim(bdev, loop_set_block_size, NULL);
+ if (err)
+ return err;
+ }
+
+ err = mutex_lock_killable(&lo->lo_mutex);
+ if (err)
+ goto abort_claim;
+
+ if (lo->lo_state != Lo_bound) {
+ err = -ENXIO;
+ goto unlock;
+ }
if (lo->lo_queue->limits.logical_block_size == arg)
- return 0;
+ goto unlock;
sync_blockdev(lo->lo_device);
invalidate_bdev(lo->lo_device);
@@ -1452,6 +1480,11 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg)
loop_update_dio(lo);
blk_mq_unfreeze_queue(lo->lo_queue, memflags);
+unlock:
+ mutex_unlock(&lo->lo_mutex);
+abort_claim:
+ if (!(mode & BLK_OPEN_EXCL))
+ bd_abort_claiming(bdev, loop_set_block_size);
return err;
}
@@ -1470,9 +1503,6 @@ static int lo_simple_ioctl(struct loop_device *lo, unsigned int cmd,
case LOOP_SET_DIRECT_IO:
err = loop_set_dio(lo, arg);
break;
- case LOOP_SET_BLOCK_SIZE:
- err = loop_set_block_size(lo, arg);
- break;
default:
err = -EINVAL;
}
@@ -1527,9 +1557,12 @@ static int lo_ioctl(struct block_device *bdev, blk_mode_t mode,
break;
case LOOP_GET_STATUS64:
return loop_get_status64(lo, argp);
+ case LOOP_SET_BLOCK_SIZE:
+ if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ return loop_set_block_size(lo, mode, bdev, arg);
case LOOP_SET_CAPACITY:
case LOOP_SET_DIRECT_IO:
- case LOOP_SET_BLOCK_SIZE:
if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN))
return -EPERM;
fallthrough;
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-03 22:27:32 +0300