4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Jiang <dave.jiang@xxxxxxxxx> commit 80660f20252d6f76c9f203874ad7c7a4a8508cf8 upstream. The function return values are confusing with the way the function is named. We expect a true or false return value but it actually returns 0/-errno. This makes the code very confusing. Changing the return values to return a bool where if DAX is supported then return true and no DAX support returns false. Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx> Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/dax/super.c | 14 +++++++------- fs/ext2/super.c | 3 +-- fs/ext4/super.c | 3 +-- fs/xfs/xfs_ioctl.c | 4 ++-- fs/xfs/xfs_super.c | 12 ++++++------ include/linux/dax.h | 8 ++++---- 6 files changed, 21 insertions(+), 23 deletions(-) --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -79,9 +79,9 @@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); * This is a library function for filesystems to check if the block device * can be mounted with dax option. * - * Return: negative errno if unsupported, 0 if supported. + * Return: true if supported, false if unsupported */ -int __bdev_dax_supported(struct block_device *bdev, int blocksize) +bool __bdev_dax_supported(struct block_device *bdev, int blocksize) { struct dax_device *dax_dev; pgoff_t pgoff; @@ -94,21 +94,21 @@ int __bdev_dax_supported(struct block_de if (blocksize != PAGE_SIZE) { pr_debug("%s: error: unsupported blocksize for dax\n", bdevname(bdev, buf)); - return -EINVAL; + return false; } err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); if (err) { pr_debug("%s: error: unaligned partition for dax\n", bdevname(bdev, buf)); - return err; + return false; } dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); if (!dax_dev) { pr_debug("%s: error: device does not support dax\n", bdevname(bdev, buf)); - return -EOPNOTSUPP; + return false; } id = dax_read_lock(); @@ -120,10 +120,10 @@ int __bdev_dax_supported(struct block_de if (len < 1) { pr_debug("%s: error: dax access failed (%ld)\n", bdevname(bdev, buf), len); - return len < 0 ? len : -EIO; + return false; } - return 0; + return true; } EXPORT_SYMBOL_GPL(__bdev_dax_supported); #endif --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -953,8 +953,7 @@ static int ext2_fill_super(struct super_ blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); if (sbi->s_mount_opt & EXT2_MOUNT_DAX) { - err = bdev_dax_supported(sb->s_bdev, blocksize); - if (err) + if (!bdev_dax_supported(sb->s_bdev, blocksize)) goto failed_mount; } --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3770,8 +3770,7 @@ static int ext4_fill_super(struct super_ " that may contain inline data"); goto failed_mount; } - err = bdev_dax_supported(sb->s_bdev, blocksize); - if (err) + if (!bdev_dax_supported(sb->s_bdev, blocksize)) goto failed_mount; } --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1101,8 +1101,8 @@ xfs_ioctl_setattr_dax_invalidate( if (fa->fsx_xflags & FS_XFLAG_DAX) { if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) return -EINVAL; - if (bdev_dax_supported(xfs_find_bdev_for_inode(VFS_I(ip)), - sb->s_blocksize) < 0) + if (!bdev_dax_supported(xfs_find_bdev_for_inode(VFS_I(ip)), + sb->s_blocksize)) return -EINVAL; } --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1640,17 +1640,17 @@ xfs_fs_fill_super( sb->s_flags |= SB_I_VERSION; if (mp->m_flags & XFS_MOUNT_DAX) { - int error2 = 0; + bool rtdev_is_dax = false, datadev_is_dax; xfs_warn(mp, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); - error = bdev_dax_supported(mp->m_ddev_targp->bt_bdev, - sb->s_blocksize); + datadev_is_dax = bdev_dax_supported(mp->m_ddev_targp->bt_bdev, + sb->s_blocksize); if (mp->m_rtdev_targp) - error2 = bdev_dax_supported(mp->m_rtdev_targp->bt_bdev, - sb->s_blocksize); - if (error && error2) { + rtdev_is_dax = bdev_dax_supported( + mp->m_rtdev_targp->bt_bdev, sb->s_blocksize); + if (!rtdev_is_dax && !datadev_is_dax) { xfs_alert(mp, "DAX unsupported by block device. Turning off DAX."); mp->m_flags &= ~XFS_MOUNT_DAX; --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -40,8 +40,8 @@ static inline void put_dax(struct dax_de int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff); #if IS_ENABLED(CONFIG_FS_DAX) -int __bdev_dax_supported(struct block_device *bdev, int blocksize); -static inline int bdev_dax_supported(struct block_device *bdev, int blocksize) +bool __bdev_dax_supported(struct block_device *bdev, int blocksize); +static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize) { return __bdev_dax_supported(bdev, blocksize); } @@ -58,10 +58,10 @@ static inline void fs_put_dax(struct dax struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); #else -static inline int bdev_dax_supported(struct block_device *bdev, +static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize) { - return -EOPNOTSUPP; + return false; } static inline struct dax_device *fs_dax_get_by_host(const char *host)