f2fs: Fix use of number of devices

commit 0916878da355650d7e77104a7ac0fa1784eca852 upstream.

For a single device mount using a zoned block device, the zone
information for the device is stored in the sbi->devs single entry
array and sbi->s_ndevs is set to 1. This differs from a single device
mount using a regular block device which does not allocate sbi->devs
and sets sbi->s_ndevs to 0.

However, sbi->s_devs == 0 condition is used throughout the code to
differentiate a single device mount from a multi-device mount where
sbi->s_ndevs is always larger than 1. This results in problems with
single zoned block device volumes as these are treated as multi-device
mounts but do not have the start_blk and end_blk information set. One
of the problem observed is skipping of zone discard issuing resulting in
write commands being issued to full zones or unaligned to a zone write
pointer.

Fix this problem by simply treating the cases sbi->s_ndevs == 0 (single
regular block device mount) and sbi->s_ndevs == 1 (single zoned block
device mount) in the same manner. This is done by introducing the
helper function f2fs_is_multi_device() and using this helper in place
of direct tests of sbi->s_ndevs value, improving code readability.

Fixes: 7bb3a371d199 ("f2fs: Fix zoned block device support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 08314fb..4d02e76 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -197,12 +197,14 @@ struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
        struct block_device *bdev = sbi->sb->s_bdev;
        int i;
 
-       for (i = 0; i < sbi->s_ndevs; i++) {
-               if (FDEV(i).start_blk <= blk_addr &&
-                                       FDEV(i).end_blk >= blk_addr) {
-                       blk_addr -= FDEV(i).start_blk;
-                       bdev = FDEV(i).bdev;
-                       break;
+       if (f2fs_is_multi_device(sbi)) {
+               for (i = 0; i < sbi->s_ndevs; i++) {
+                       if (FDEV(i).start_blk <= blk_addr &&
+                           FDEV(i).end_blk >= blk_addr) {
+                               blk_addr -= FDEV(i).start_blk;
+                               bdev = FDEV(i).bdev;
+                               break;
+                       }
                }
        }
        if (bio) {
@@ -216,6 +218,9 @@ int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
        int i;
 
+       if (!f2fs_is_multi_device(sbi))
+               return 0;
+
        for (i = 0; i < sbi->s_ndevs; i++)
                if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
                        return i;

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 1f5d5f6..a4b6eac 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1336,6 +1336,17 @@ static inline bool time_to_inject(struct f2fs_sb_info *sbi, int type)
 }
 #endif
 
+/*
+ * Test if the mounted volume is a multi-device volume.
+ *   - For a single regular disk volume, sbi->s_ndevs is 0.
+ *   - For a single zoned disk volume, sbi->s_ndevs is 1.
+ *   - For a multi-device volume, sbi->s_ndevs is always 2 or more.
+ */
+static inline bool f2fs_is_multi_device(struct f2fs_sb_info *sbi)
+{
+       return sbi->s_ndevs > 1;
+}
+
 /* For write statistics. Suppose sector size is 512 bytes,
  * and the return value is in kbytes. s is of struct f2fs_sb_info.
  */
@@ -3455,7 +3466,7 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)
 {
        return (f2fs_post_read_required(inode) ||
                        (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
-                       F2FS_I_SB(inode)->s_ndevs);
+                       f2fs_is_multi_device(F2FS_I_SB(inode)));
 }
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b3f46e3..8d1eb8d 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2539,7 +2539,7 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
                                                        sizeof(range)))
                return -EFAULT;
 
-       if (sbi->s_ndevs <= 1 || sbi->s_ndevs - 1 <= range.dev_num ||
+       if (!f2fs_is_multi_device(sbi) || sbi->s_ndevs - 1 <= range.dev_num ||
                        sbi->segs_per_sec != 1) {
                f2fs_msg(sbi->sb, KERN_WARNING,
                        "Can't flush %u in %d for segs_per_sec %u != 1\n",

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 5c8d004..d44b57a 100644 (file)
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1256,7 +1256,7 @@ void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
        sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
 
        /* give warm/cold data area from slower device */
-       if (sbi->s_ndevs && sbi->segs_per_sec == 1)
+       if (f2fs_is_multi_device(sbi) && sbi->segs_per_sec == 1)
                SIT_I(sbi)->last_victim[ALLOC_NEXT] =
                                GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
 }

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index ac03856..03fa2c4 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -574,7 +574,7 @@ static int submit_flush_wait(struct f2fs_sb_info *sbi, nid_t ino)
        int ret = 0;
        int i;
 
-       if (!sbi->s_ndevs)
+       if (!f2fs_is_multi_device(sbi))
                return __submit_flush_wait(sbi, sbi->sb->s_bdev);
 
        for (i = 0; i < sbi->s_ndevs; i++) {
@@ -640,7 +640,8 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
                return ret;
        }
 
-       if (atomic_inc_return(&fcc->issing_flush) == 1 || sbi->s_ndevs > 1) {
+       if (atomic_inc_return(&fcc->issing_flush) == 1 ||
+           f2fs_is_multi_device(sbi)) {
                ret = submit_flush_wait(sbi, ino);
                atomic_dec(&fcc->issing_flush);
 
@@ -746,7 +747,7 @@ int f2fs_flush_device_cache(struct f2fs_sb_info *sbi)
 {
        int ret = 0, i;
 
-       if (!sbi->s_ndevs)
+       if (!f2fs_is_multi_device(sbi))
                return 0;
 
        for (i = 1; i < sbi->s_ndevs; i++) {
@@ -1289,7 +1290,7 @@ static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
 
        trace_f2fs_queue_discard(bdev, blkstart, blklen);
 
-       if (sbi->s_ndevs) {
+       if (f2fs_is_multi_device(sbi)) {
                int devi = f2fs_target_device_index(sbi, blkstart);
 
                blkstart -= FDEV(devi).start_blk;
@@ -1638,7 +1639,7 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
        block_t lblkstart = blkstart;
        int devi = 0;
 
-       if (sbi->s_ndevs) {
+       if (f2fs_is_multi_device(sbi)) {
                devi = f2fs_target_device_index(sbi, blkstart);
                blkstart -= FDEV(devi).start_blk;
        }
@@ -2971,7 +2972,7 @@ static void update_device_state(struct f2fs_io_info *fio)
        struct f2fs_sb_info *sbi = fio->sbi;
        unsigned int devidx;
 
-       if (!sbi->s_ndevs)
+       if (!f2fs_is_multi_device(sbi))
                return;
 
        devidx = f2fs_target_device_index(sbi, fio->new_blkaddr);