| Message ID | 148559263442.11180.2158046423959539211.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Jan 28, 2017 at 12:37:14AM -0800, Dan Williams wrote: > This is in preparation for removing the ->direct_access() method from > block_device_operations. I don't think mount_bdev has any business knowing about DAX. Just call dax_get_by_host manually from the affected file systems for now, and in the future we can have a pure-DAX mount_dax helper. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jan 30, 2017 at 4:26 AM, Christoph Hellwig <hch@lst.de> wrote: > On Sat, Jan 28, 2017 at 12:37:14AM -0800, Dan Williams wrote: >> This is in preparation for removing the ->direct_access() method from >> block_device_operations. > > I don't think mount_bdev has any business knowing about DAX. > Just call dax_get_by_host manually from the affected file systems for > now, and in the future we can have a pure-DAX mount_dax helper. Ok, since we already need dax_get_by_host() in the blkdev_writepages() path I can sprinkle a few more of those calls and leave mount_bdev alone. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jan 30, 2017 at 10:29:12AM -0800, Dan Williams wrote: > On Mon, Jan 30, 2017 at 4:26 AM, Christoph Hellwig <hch@lst.de> wrote: > > On Sat, Jan 28, 2017 at 12:37:14AM -0800, Dan Williams wrote: > >> This is in preparation for removing the ->direct_access() method from > >> block_device_operations. > > > > I don't think mount_bdev has any business knowing about DAX. > > Just call dax_get_by_host manually from the affected file systems for > > now, and in the future we can have a pure-DAX mount_dax helper. > > Ok, since we already need dax_get_by_host() in the blkdev_writepages() > path I can sprinkle a few more of those calls and leave mount_bdev > alone. Huh? I thought we stopped using DAX I/O for the block device nodes a while ago? -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Feb 1, 2017 at 12:08 AM, Christoph Hellwig <hch@lst.de> wrote: > On Mon, Jan 30, 2017 at 10:29:12AM -0800, Dan Williams wrote: >> On Mon, Jan 30, 2017 at 4:26 AM, Christoph Hellwig <hch@lst.de> wrote: >> > On Sat, Jan 28, 2017 at 12:37:14AM -0800, Dan Williams wrote: >> >> This is in preparation for removing the ->direct_access() method from >> >> block_device_operations. >> > >> > I don't think mount_bdev has any business knowing about DAX. >> > Just call dax_get_by_host manually from the affected file systems for >> > now, and in the future we can have a pure-DAX mount_dax helper. >> >> Ok, since we already need dax_get_by_host() in the blkdev_writepages() >> path I can sprinkle a few more of those calls and leave mount_bdev >> alone. > > Huh? I thought we stopped using DAX I/O for the block device nodes > a while ago? Oh, yeah, you're right. The blkdev_writepages() call to dax_writeback_mapping_range() is likely leftover dead code. I'll clean it up. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/block_dev.c b/fs/block_dev.c index bf4b51a3a412..a73f2388c515 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -806,14 +806,16 @@ int bdev_dax_supported(struct super_block *sb, int blocksize) .sector = 0, .size = PAGE_SIZE, }; - int err; + int err, id; if (blocksize != PAGE_SIZE) { vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); return -EINVAL; } - err = bdev_direct_access(sb->s_bdev, &dax); + id = dax_read_lock(); + err = bdev_dax_direct_access(sb->s_bdev, sb->s_dax, &dax); + dax_read_unlock(id); if (err < 0) { switch (err) { case -EOPNOTSUPP: diff --git a/fs/super.c b/fs/super.c index ea662b0e5e78..5e64d11c46c1 100644 --- a/fs/super.c +++ b/fs/super.c @@ -26,6 +26,7 @@ #include <linux/mount.h> #include <linux/security.h> #include <linux/writeback.h> /* for the emergency remount stuff */ +#include <linux/dax.h> #include <linux/idr.h> #include <linux/mutex.h> #include <linux/backing-dev.h> @@ -1038,9 +1039,17 @@ struct dentry *mount_ns(struct file_system_type *fs_type, EXPORT_SYMBOL(mount_ns); #ifdef CONFIG_BLOCK +struct mount_bdev_data { + struct block_device *bdev; + struct dax_inode *dax_inode; +}; + static int set_bdev_super(struct super_block *s, void *data) { - s->s_bdev = data; + struct mount_bdev_data *mb_data = data; + + s->s_bdev = mb_data->bdev; + s->s_dax = mb_data->dax_inode; s->s_dev = s->s_bdev->bd_dev; /* @@ -1053,14 +1062,18 @@ static int set_bdev_super(struct super_block *s, void *data) static int test_bdev_super(struct super_block *s, void *data) { - return (void *)s->s_bdev == data; + struct mount_bdev_data *mb_data = data; + + return s->s_bdev == mb_data->bdev; } struct dentry *mount_bdev(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, int (*fill_super)(struct super_block *, void *, int)) { + struct mount_bdev_data mb_data; struct block_device *bdev; + struct dax_inode *dax_inode; struct super_block *s; fmode_t mode = FMODE_READ | FMODE_EXCL; int error = 0; @@ -1072,6 +1085,11 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, if (IS_ERR(bdev)) return ERR_CAST(bdev); + if (IS_ENABLED(CONFIG_FS_DAX)) + dax_inode = dax_get_by_host(bdev->bd_disk->disk_name); + else + dax_inode = NULL; + /* * once the super is inserted into the list by sget, s_umount * will protect the lockfs code from trying to start a snapshot @@ -1083,8 +1101,13 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, error = -EBUSY; goto error_bdev; } + + mb_data = (struct mount_bdev_data) { + .bdev = bdev, + .dax_inode = dax_inode, + }; s = sget(fs_type, test_bdev_super, set_bdev_super, flags | MS_NOSEC, - bdev); + &mb_data); mutex_unlock(&bdev->bd_fsfreeze_mutex); if (IS_ERR(s)) goto error_s; @@ -1126,6 +1149,7 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, error = PTR_ERR(s); error_bdev: blkdev_put(bdev, mode); + put_dax_inode(dax_inode); error: return ERR_PTR(error); } @@ -1133,6 +1157,7 @@ EXPORT_SYMBOL(mount_bdev); void kill_block_super(struct super_block *sb) { + struct dax_inode *dax_inode = sb->s_dax; struct block_device *bdev = sb->s_bdev; fmode_t mode = sb->s_mode; @@ -1141,6 +1166,7 @@ void kill_block_super(struct super_block *sb) sync_blockdev(bdev); WARN_ON_ONCE(!(mode & FMODE_EXCL)); blkdev_put(bdev, mode | FMODE_EXCL); + put_dax_inode(dax_inode); } EXPORT_SYMBOL(kill_block_super); diff --git a/include/linux/fs.h b/include/linux/fs.h index c930cbc19342..fdad43169146 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1313,6 +1313,7 @@ struct super_block { struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */ struct list_head s_mounts; /* list of mounts; _not_ for fs use */ struct block_device *s_bdev; + struct dax_inode *s_dax; struct backing_dev_info *s_bdi; struct mtd_info *s_mtd; struct hlist_node s_instances;
This is in preparation for removing the ->direct_access() method from block_device_operations. Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- fs/block_dev.c | 6 ++++-- fs/super.c | 32 +++++++++++++++++++++++++++++--- include/linux/fs.h | 1 + 3 files changed, 34 insertions(+), 5 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html