diff options
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/loop.c | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 1b6ee91f8eb9..57263c273f0f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -137,20 +137,29 @@ 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) { + struct kstat stat; loff_t loopsize; + int ret; - /* Compute loopsize in bytes */ - loopsize = i_size_read(file->f_mapping->host); - if (offset > 0) - loopsize -= offset; + /* + * 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; + + 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 +167,6 @@ 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 @@ -569,7 +573,7 @@ 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; /* @@ -1063,7 +1067,7 @@ 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(). */ @@ -1255,8 +1259,7 @@ out_unfreeze: if (partscan) clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); if (!err && size_changed) { - loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit, - lo->lo_backing_file); + loff_t new_size = lo_calculate_size(lo, lo->lo_backing_file); loop_set_size(lo, new_size); } out_unlock: @@ -1399,7 +1402,7 @@ 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; |