[PATCH 4.10 148/167] f2fs: Fix zoned block device support

From: Greg Kroah-Hartman
Date: Fri Mar 10 2017 - 04:46:49 EST


4.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Masato Suzuki <masato.suzuki@xxxxxxx>

commit 7bb3a371d199156cb6a863feab377146b80942c5 upstream.

The introduction of the multi-device feature partially broke the support
for zoned block devices. In the function f2fs_scan_devices, sbi->devs
allocation and initialization is skipped in the case of a single device
mount. This result in no device information structure being allocated
for the device. This is fine if the device is a regular device, but in
the case of a zoned block device, the device zone type array is not
initialized, which causes the function __f2fs_issue_discard_zone to fail
as get_blkz_type is unable to determine the zone type of a section.

Fix this by always allocating and initializing the sbi->devs device
information array even in the case of a single device if that device is
zoned. For this particular case, make sure to obtain a reference on the
single device so that the call to blkdev_put() in destroy_device_list
operates as expected.

Fixes: 3c62be17d4f562f4 ("f2fs: support multiple devices")
Signed-off-by: Masato Suzuki <masato.suzuki@xxxxxxx>
Acked-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/f2fs/super.c | 69 ++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 45 insertions(+), 24 deletions(-)

--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1698,36 +1698,55 @@ int f2fs_commit_super(struct f2fs_sb_inf
static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
{
struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+ unsigned int max_devices = MAX_DEVICES;
int i;

- for (i = 0; i < MAX_DEVICES; i++) {
- if (!RDEV(i).path[0])
+ /* Initialize single device information */
+ if (!RDEV(0).path[0]) {
+ if (!bdev_is_zoned(sbi->sb->s_bdev))
return 0;
+ max_devices = 1;
+ }

- if (i == 0) {
- sbi->devs = kzalloc(sizeof(struct f2fs_dev_info) *
- MAX_DEVICES, GFP_KERNEL);
- if (!sbi->devs)
- return -ENOMEM;
- }
-
- memcpy(FDEV(i).path, RDEV(i).path, MAX_PATH_LEN);
- FDEV(i).total_segments = le32_to_cpu(RDEV(i).total_segments);
- if (i == 0) {
- FDEV(i).start_blk = 0;
- FDEV(i).end_blk = FDEV(i).start_blk +
- (FDEV(i).total_segments <<
- sbi->log_blocks_per_seg) - 1 +
- le32_to_cpu(raw_super->segment0_blkaddr);
+ /*
+ * Initialize multiple devices information, or single
+ * zoned block device information.
+ */
+ sbi->devs = kcalloc(max_devices, sizeof(struct f2fs_dev_info),
+ GFP_KERNEL);
+ if (!sbi->devs)
+ return -ENOMEM;
+
+ for (i = 0; i < max_devices; i++) {
+
+ if (i > 0 && !RDEV(i).path[0])
+ break;
+
+ if (max_devices == 1) {
+ /* Single zoned block device mount */
+ FDEV(0).bdev =
+ blkdev_get_by_dev(sbi->sb->s_bdev->bd_dev,
+ sbi->sb->s_mode, sbi->sb->s_type);
} else {
- FDEV(i).start_blk = FDEV(i - 1).end_blk + 1;
- FDEV(i).end_blk = FDEV(i).start_blk +
- (FDEV(i).total_segments <<
- sbi->log_blocks_per_seg) - 1;
- }
-
- FDEV(i).bdev = blkdev_get_by_path(FDEV(i).path,
+ /* Multi-device mount */
+ memcpy(FDEV(i).path, RDEV(i).path, MAX_PATH_LEN);
+ FDEV(i).total_segments =
+ le32_to_cpu(RDEV(i).total_segments);
+ if (i == 0) {
+ FDEV(i).start_blk = 0;
+ FDEV(i).end_blk = FDEV(i).start_blk +
+ (FDEV(i).total_segments <<
+ sbi->log_blocks_per_seg) - 1 +
+ le32_to_cpu(raw_super->segment0_blkaddr);
+ } else {
+ FDEV(i).start_blk = FDEV(i - 1).end_blk + 1;
+ FDEV(i).end_blk = FDEV(i).start_blk +
+ (FDEV(i).total_segments <<
+ sbi->log_blocks_per_seg) - 1;
+ }
+ FDEV(i).bdev = blkdev_get_by_path(FDEV(i).path,
sbi->sb->s_mode, sbi->sb->s_type);
+ }
if (IS_ERR(FDEV(i).bdev))
return PTR_ERR(FDEV(i).bdev);

@@ -1747,6 +1766,8 @@ static int f2fs_scan_devices(struct f2fs
"Failed to initialize F2FS blkzone information");
return -EINVAL;
}
+ if (max_devices == 1)
+ break;
f2fs_msg(sbi->sb, KERN_INFO,
"Mount Device [%2d]: %20s, %8u, %8x - %8x (zone: %s)",
i, FDEV(i).path,