[PATCH v6 2/3] dax: change bdev_dax_supported() to support boolean returns
From: Dave Jiang <dave.jiang@intel.com>
Date: 2018-02-16 17:04:21
Also in:
linux-ext4, nvdimm
Subsystem:
device direct access (dax), ext2 file system, ext4 file system, filesystem direct access (dax), filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Dan Williams, Vishal Verma, Dave Jiang, Alison Schofield, Jan Kara, "Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
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@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> --- drivers/dax/super.c | 16 ++++++++-------- 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 | 6 +++--- 6 files changed, 21 insertions(+), 23 deletions(-)
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index f037458600aa..a7a30d3794f6 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c@@ -80,9 +80,9 @@ 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;
@@ -95,21 +95,21 @@ int bdev_dax_supported(struct block_device *bdev, int blocksize) 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();
@@ -121,7 +121,7 @@ int bdev_dax_supported(struct block_device *bdev, int blocksize) if (len < 1) { pr_debug("%s: error: dax access failed (%ld)\n", bdevname(bdev, buf), len); - return len < 0 ? len : -EIO; + return false; } if ((IS_ENABLED(CONFIG_FS_DAX_LIMITED) && pfn_t_special(pfn))
@@ -130,10 +130,10 @@ int bdev_dax_supported(struct block_device *bdev, int blocksize) else { pr_debug("%s: error: dax support not enabled\n", bdevname(bdev, buf)); - return -EOPNOTSUPP; + return false; } - return 0; + return true; } EXPORT_SYMBOL_GPL(bdev_dax_supported); #endif
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index b8063b640ec1..5e19e1a886b7 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c@@ -961,8 +961,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) 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)) { ext2_msg(sb, KERN_ERR, "DAX unsupported by block device. Turning off DAX."); sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 911eca771853..23debb8313e5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c@@ -3714,8 +3714,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) " that may contain inline data"); sbi->s_mount_opt &= ~EXT4_MOUNT_DAX; } - err = bdev_dax_supported(sb->s_bdev, blocksize); - if (err) { + if (!bdev_dax_supported(sb->s_bdev, blocksize)) { ext4_msg(sb, KERN_ERR, "DAX unsupported by block device. Turning off DAX."); sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 0effd46b965f..2c70a0a4f59f 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c@@ -1103,8 +1103,8 @@ 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; }
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index aaaba6e604c4..3634e7eb362c 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c@@ -1657,17 +1657,17 @@ 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;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 8eb3a359df95..dd77b0ed2283 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h@@ -40,7 +40,7 @@ static inline void put_dax(struct dax_device *dax_dev) 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); +bool bdev_dax_supported(struct block_device *bdev, int blocksize); static inline struct dax_device *fs_dax_get_by_host(const char *host) { return dax_get_by_host(host);
@@ -53,10 +53,10 @@ static inline void fs_put_dax(struct dax_device *dax_dev) 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)