[RFC PATCH 00/68] VFS: Convert a bunch of filesystems to the new mount API

[RFC PATCH 00/68] VFS: Convert a bunch of filesystems to the new mount API

[David Howells]

Hi Al,

Here's a set of patches that converts a bunch (but not yet all!) to the new
mount API.  To this end, it makes the following changes:

 (1) Provides a convenience member in struct fs_context that is OR'd into
     sb->s_iflags by sget_fc().

 (2) Provides a convenience helper function, vfs_init_pseudo_fs_context(),
     for doing most of the work in mounting a pseudo filesystem.

 (3) Provides a convenience helper function, vfs_get_block_super(), for
     doing the work in setting up a block-based superblock.

 (4) Improves the handling of fd-type parameters.

 (5) Moves some of the subtype handling int fuse.

 (6) Provides a convenience helper function, vfs_get_mtd_super(), for
     doing the work in setting up an MTD device-based superblock.

 (7) Kills off mount_pseudo(), mount_pseudo_xattr(), mount_ns(),
     sget_userns(), mount_mtd(), mount_single().

 (8) Converts a slew of filesystems to use the mount API.

 (9) Fixes a bug in hypfs.

The patches can be found here also:

	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git

on branch:

	mount-api-viro

David
---
Andrew Price (1):
      gfs2: Convert gfs2 to fs_context

David Howells (66):
      vfs: Update mount API docs
      vfs: Fix refcounting of filenames in fs_parser
      vfs: Provide sb->s_iflags settings in fs_context struct
      vfs: Provide a mount_pseudo-replacement for the new mount API
      vfs: Convert aio to use the new mount API
      vfs: Convert anon_inodes to use the new mount API
      vfs: Convert bdev to use the new mount API
      vfs: Convert nsfs to use the new mount API
      vfs: Convert pipe to use the new mount API
      vfs: Convert zsmalloc to use the new mount API
      vfs: Convert sockfs to use the new mount API
      vfs: Convert dax to use the new mount API
      vfs: Convert drm to use the new mount API
      vfs: Convert ia64 perfmon to use the new mount API
      vfs: Convert cxl to use the new mount API
      vfs: Convert ocxlflash to use the new mount API
      vfs: Convert virtio_balloon to use the new mount API
      vfs: Convert btrfs_test to use the new mount API
      vfs: Kill off mount_pseudo() and mount_pseudo_xattr()
      vfs: Use sget_fc() for pseudo-filesystems
      vfs: Convert binderfs to use the new mount API
      vfs: Convert nfsctl to use the new mount API
      vfs: Convert rpc_pipefs to use the new mount API
      vfs: Kill mount_ns()
      vfs: Kill sget_userns()
      vfs: Convert binfmt_misc to use the new mount API
      vfs: Convert configfs to use the new mount API
      vfs: Convert efivarfs to use the new mount API
      vfs: Convert fusectl to use the new mount API
      vfs: Convert qib_fs/ipathfs to use the new mount API
      vfs: Convert ibmasmfs to use the new mount API
      vfs: Convert oprofilefs to use the new mount API
      vfs: Convert gadgetfs to use the new mount API
      vfs: Convert xenfs to use the new mount API
      vfs: Convert openpromfs to use the new mount API
      vfs: Convert apparmorfs to use the new mount API
      vfs: Convert securityfs to use the new mount API
      vfs: Convert selinuxfs to use the new mount API
      vfs: Convert smackfs to use the new mount API
      vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
      vfs: Create fs_context-aware mount_bdev() replacement
      vfs: Make fs_parse() handle fs_param_is_fd-type params better
      vfs: Convert fuse to use the new mount API
      vfs: Move the subtype parameter into fuse
      mtd: Provide fs_context-aware mount_mtd() replacement
      vfs: Convert romfs to use the new mount API
      vfs: Convert cramfs to use the new mount API
      vfs: Convert jffs2 to use the new mount API
      mtd: Kill mount_mtd()
      vfs: Convert squashfs to use the new mount API
      vfs: Convert ceph to use the new mount API
      vfs: Convert functionfs to use the new mount API
      vfs: Add a single-or-reconfig keying to vfs_get_super()
      vfs: Convert debugfs to use the new mount API
      vfs: Convert tracefs to use the new mount API
      vfs: Convert pstore to use the new mount API
      hypfs: Fix error number left in struct pointer member
      vfs: Convert hypfs to use the new mount API
      vfs: Convert spufs to use the new mount API
      vfs: Kill mount_single()
      vfs: Convert coda to use the new mount API
      vfs: Convert autofs to use the new mount API
      vfs: Convert devpts to use the new mount API
      vfs: Convert bpf to use the new mount API
      vfs: Convert ubifs to use the new mount API
      vfs: Convert orangefs to use the new mount API

Masahiro Yamada (1):
      kbuild: skip sub-make for in-tree build with GNU Make 4.x


 Documentation/filesystems/mount_api.txt   |  367 ++++++++-------
 Documentation/filesystems/vfs.txt         |    4 
 Makefile                                  |   31 +
 arch/ia64/kernel/perfmon.c                |   14 -
 arch/powerpc/platforms/cell/spufs/inode.c |  207 +++++----
 arch/s390/hypfs/inode.c                   |  137 +++---
 drivers/android/binderfs.c                |  173 ++++---
 drivers/base/devtmpfs.c                   |   16 -
 drivers/block/rbd.c                       |  363 ++++++++-------
 drivers/dax/super.c                       |   13 -
 drivers/gpu/drm/drm_drv.c                 |   14 -
 drivers/infiniband/hw/qib/qib_fs.c        |   26 +
 drivers/misc/cxl/api.c                    |   10 
 drivers/misc/ibmasm/ibmasmfs.c            |   21 +
 drivers/mtd/mtdcore.h                     |    1 
 drivers/mtd/mtdsuper.c                    |  181 ++++----
 drivers/oprofile/oprofilefs.c             |   20 +
 drivers/scsi/cxlflash/ocxl_hw.c           |   21 -
 drivers/usb/gadget/function/f_fs.c        |  233 +++++-----
 drivers/usb/gadget/legacy/inode.c         |   21 +
 drivers/virtio/virtio_balloon.c           |   19 -
 drivers/xen/xenfs/super.c                 |   21 +
 fs/aio.c                                  |   15 -
 fs/anon_inodes.c                          |   12 
 fs/autofs/autofs_i.h                      |   13 -
 fs/autofs/init.c                          |    9 
 fs/autofs/inode.c                         |  429 ++++++++++--------
 fs/binfmt_misc.c                          |   20 +
 fs/block_dev.c                            |   14 -
 fs/btrfs/tests/btrfs-tests.c              |   13 -
 fs/ceph/cache.c                           |    9 
 fs/ceph/cache.h                           |    5 
 fs/ceph/super.c                           |  697 ++++++++++++++---------------
 fs/ceph/super.h                           |    1 
 fs/coda/inode.c                           |  171 +++++--
 fs/configfs/mount.c                       |   20 +
 fs/cramfs/inode.c                         |   69 ++-
 fs/debugfs/inode.c                        |  186 ++++----
 fs/devpts/inode.c                         |  265 +++++------
 fs/efivarfs/super.c                       |   20 +
 fs/fs_context.c                           |   16 -
 fs/fs_parser.c                            |   18 +
 fs/fuse/control.c                         |   20 +
 fs/fuse/inode.c                           |  291 +++++++-----
 fs/gfs2/incore.h                          |    8 
 fs/gfs2/ops_fstype.c                      |  495 ++++++++++++++++-----
 fs/gfs2/super.c                           |  335 --------------
 fs/gfs2/super.h                           |    3 
 fs/jffs2/fs.c                             |   21 -
 fs/jffs2/os-linux.h                       |    4 
 fs/jffs2/super.c                          |  172 +++----
 fs/libfs.c                                |   91 +++-
 fs/nfsd/nfsctl.c                          |   33 +
 fs/nsfs.c                                 |   13 -
 fs/openpromfs/inode.c                     |   20 +
 fs/orangefs/orangefs-kernel.h             |    8 
 fs/orangefs/orangefs-mod.c                |    3 
 fs/orangefs/super.c                       |  186 ++++----
 fs/pipe.c                                 |   12 
 fs/pstore/inode.c                         |  109 +++--
 fs/ramfs/inode.c                          |  104 +++-
 fs/romfs/super.c                          |   46 +-
 fs/squashfs/super.c                       |  100 ++--
 fs/super.c                                |  301 ++++++-------
 fs/tracefs/inode.c                        |  180 +++----
 fs/ubifs/super.c                          |  447 ++++++++-----------
 include/linux/ceph/ceph_debug.h           |    1 
 include/linux/ceph/libceph.h              |   17 +
 include/linux/fs.h                        |   24 -
 include/linux/fs_context.h                |   20 +
 include/linux/mtd/super.h                 |    6 
 include/linux/ramfs.h                     |    6 
 include/linux/shmem_fs.h                  |    4 
 init/do_mounts.c                          |   12 
 kernel/bpf/inode.c                        |   92 ++--
 mm/shmem.c                                |  396 +++++++++++-----
 mm/zsmalloc.c                             |   19 -
 net/ceph/ceph_common.c                    |  410 +++++++----------
 net/socket.c                              |   14 -
 net/sunrpc/rpc_pipe.c                     |   34 +
 security/apparmor/apparmorfs.c            |   20 +
 security/inode.c                          |   21 +
 security/selinux/selinuxfs.c              |   20 +
 security/smack/smackfs.c                  |   34 +
 84 files changed, 4257 insertions(+), 3810 deletions(-)


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[RFC PATCH 46/68] mtd: Provide fs_context-aware mount_mtd() replacement

[David Howells]

Provide a function, vfs_get_mtd_super(), to replace mount_mtd(), using an
fs_context struct to hold the parameters.  The mtd device pointer is cached
in the struct, along with a destructor pointer as the mtd core may be in a
module and, as such, unreachable by the core code that would release the
fs_context.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---

 drivers/mtd/mtdcore.h      |    1 
 drivers/mtd/mtdsuper.c     |  192 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fs_context.h |    3 -
 include/linux/mtd/super.h  |    3 +
 4 files changed, 196 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index b31c868019ad..b5eefeabf310 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -5,6 +5,7 @@
  */
 
 extern struct mutex mtd_table_mutex;
+extern struct backing_dev_info *mtd_bdi;
 
 struct mtd_info *__mtd_next_device(int i);
 int __must_check add_mtd_device(struct mtd_info *mtd);
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index d58a61c09304..cf165f7c8632 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -19,6 +19,196 @@
 #include <linux/slab.h>
 #include <linux/major.h>
 #include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include "mtdcore.h"
+
+static void mtd_fc_destructor(struct fs_context *fc)
+{
+	if (fc->mtd)
+		put_mtd_device(fc->mtd);
+}
+
+/*
+ * compare superblocks to see if they're equivalent
+ * - they are if the underlying MTD device is the same
+ */
+static int mtd_test_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct mtd_info *mtd = fc->mtd;
+
+	if (sb->s_mtd == mtd) {
+		pr_debug("MTDSB: Match on device %d (\"%s\")\n",
+			 mtd->index, mtd->name);
+		return 1;
+	}
+
+	pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
+		 sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
+	return 0;
+}
+
+/*
+ * mark the superblock by the MTD device it is using
+ * - set the device number to be the correct MTD block device for pesuperstence
+ *   of NFS exports
+ */
+static int mtd_set_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct mtd_info *mtd = fc->mtd;
+
+	sb->s_mtd = mtd;
+	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
+	sb->s_bdi = bdi_get(mtd_bdi);
+	fc->mtd = NULL;
+	return 0;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem
+ */
+static int mtd_get_sb(struct fs_context *fc,
+		      int (*fill_super)(struct super_block *,
+					struct fs_context *))
+{
+	struct super_block *sb;
+	struct mtd_info *mtd = fc->mtd;
+	int ret;
+
+	sb = sget_fc(fc, mtd_test_super, mtd_set_super);
+	if (IS_ERR(sb))
+		return PTR_ERR(sb);
+
+	if (sb->s_root) {
+		/* new mountpoint for an already mounted superblock */
+		pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
+			 mtd->index, mtd->name);
+		put_mtd_device(mtd);
+	} else {
+		/* fresh new superblock */
+		pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
+			 mtd->index, mtd->name);
+
+		ret = fill_super(sb, fc);
+		if (ret < 0)
+			goto error_sb;
+
+		sb->s_flags |= SB_ACTIVE;
+	}
+
+	BUG_ON(fc->root);
+	fc->root = dget(sb->s_root);
+	return 0;
+
+error_sb:
+	deactivate_locked_super(sb);
+	return ret;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem by MTD device number
+ */
+static int mtd_get_sb_by_nr(struct fs_context *fc, int mtdnr,
+			    int (*fill_super)(struct super_block *,
+					      struct fs_context *))
+{
+	struct mtd_info *mtd;
+
+	mtd = get_mtd_device(NULL, mtdnr);
+	if (IS_ERR(mtd)) {
+		errorf(fc, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
+		return PTR_ERR(mtd);
+	}
+
+	fc->mtd = mtd;
+	fc->dev_destructor = mtd_fc_destructor;
+	return mtd_get_sb(fc, fill_super);
+}
+
+/**
+ * vfs_get_mtd_super - Get a superblock based on a single MTD device
+ * @fc: The filesystem context holding the parameters
+ * @fill_super: Helper to initialise a new superblock
+ */
+int vfs_get_mtd_super(struct fs_context *fc,
+		      int (*fill_super)(struct super_block *sb,
+					struct fs_context *fc))
+{
+#ifdef CONFIG_BLOCK
+	struct block_device *bdev;
+	int ret, major;
+#endif
+	int mtdnr;
+
+	if (!fc->source)
+		return invalf(fc, "No source specified");
+
+	pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);
+
+	/* the preferred way of mounting in future; especially when
+	 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
+	 * by name, so that we don't require block device support to be present
+	 * in the kernel.
+	 */
+	if (fc->source[0] == 'm' &&
+	    fc->source[1] == 't' &&
+	    fc->source[2] == 'd') {
+		if (fc->source[3] == ':') {
+			struct mtd_info *mtd;
+
+			/* mount by MTD device name */
+			pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
+				 fc->source + 4);
+
+			mtd = get_mtd_device_nm(fc->source + 4);
+			if (!IS_ERR(mtd)) {
+				fc->mtd = mtd;
+				fc->dev_destructor = mtd_fc_destructor;
+				return mtd_get_sb(fc, fill_super);
+			}
+
+			errorf(fc, "MTD: MTD device with name \"%s\" not found",
+			       fc->source + 4);
+
+		} else if (isdigit(fc->source[3])) {
+			/* mount by MTD device number name */
+			char *endptr;
+
+			mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);
+			if (!*endptr) {
+				/* It was a valid number */
+				pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);
+				return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+			}
+		}
+	}
+
+#ifdef CONFIG_BLOCK
+	/* try the old way - the hack where we allowed users to mount
+	 * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
+	 */
+	bdev = lookup_bdev(fc->source);
+	if (IS_ERR(bdev)) {
+		ret = PTR_ERR(bdev);
+		errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);
+		return ret;
+	}
+	pr_debug("MTDSB: lookup_bdev() returned 0\n");
+
+	major = MAJOR(bdev->bd_dev);
+	mtdnr = MINOR(bdev->bd_dev);
+	bdput(bdev);
+
+	if (major == MTD_BLOCK_MAJOR)
+		return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+
+#endif /* CONFIG_BLOCK */
+
+	if (!(fc->sb_flags & SB_SILENT))
+		errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",
+		       fc->source);
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
 
 /*
  * compare superblocks to see if they're equivalent
@@ -39,8 +229,6 @@ static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
 	return 0;
 }
 
-extern struct backing_dev_info *mtd_bdi;
-
 /*
  * mark the superblock by the MTD device it is using
  * - set the device number to be the correct MTD block device for pesuperstence
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 70fdebf1dc85..7c7eefb35cc3 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -77,7 +77,8 @@ struct fs_context {
 	struct file_system_type	*fs_type;
 	void			*fs_private;	/* The filesystem's context */
 	union {
-		struct block_device *bdev;	/* The backing blockdev (if applicable) */
+		struct block_device	*bdev;	/* The backing blockdev (if applicable) */
+		struct mtd_info		*mtd;	/* The backing mtd (if applicable) */
 	};
 	struct dentry		*root;		/* The root and superblock */
 	struct user_namespace	*user_ns;	/* The user namespace for this mount */
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index f456230f9330..7ebd69e5c640 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -18,6 +18,9 @@
 #include <linux/fs.h>
 #include <linux/mount.h>
 
+extern int vfs_get_mtd_super(struct fs_context *fc,
+			     int (*fill_super)(struct super_block *sb,
+					       struct fs_context *fc));
 extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
 		      const char *dev_name, void *data,
 		      int (*fill_super)(struct super_block *, void *, int));


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[RFC PATCH 47/68] vfs: Convert romfs to use the new mount API

[David Howells]

Convert the romfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
---

 fs/romfs/super.c |   46 ++++++++++++++++++++++++++++------------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 6ccb51993a76..627c2b64ff03 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -65,7 +65,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/statfs.h>
@@ -430,10 +430,10 @@ static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 /*
  * remounting must involve read-only
  */
-static int romfs_remount(struct super_block *sb, int *flags, char *data)
+static int romfs_reconfigure(struct fs_context *fc)
 {
-	sync_filesystem(sb);
-	*flags |= SB_RDONLY;
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= SB_RDONLY;
 	return 0;
 }
 
@@ -441,7 +441,6 @@ static const struct super_operations romfs_super_ops = {
 	.alloc_inode	= romfs_alloc_inode,
 	.destroy_inode	= romfs_destroy_inode,
 	.statfs		= romfs_statfs,
-	.remount_fs	= romfs_remount,
 };
 
 /*
@@ -464,7 +463,7 @@ static __u32 romfs_checksum(const void *data, int size)
 /*
  * fill in the superblock
  */
-static int romfs_fill_super(struct super_block *sb, void *data, int silent)
+static int romfs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct romfs_super_block *rsb;
 	struct inode *root;
@@ -511,8 +510,8 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
 	    img_size < ROMFH_SIZE) {
-		if (!silent)
-			pr_warn("VFS: Can't find a romfs filesystem on dev %s.\n",
+		if (!(fc->sb_flags & SB_SILENT))
+			errorf(fc, "VFS: Can't find a romfs filesystem on dev %s.\n",
 			       sb->s_id);
 		goto error_rsb_inval;
 	}
@@ -525,7 +524,7 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
 	storage = sb->s_mtd ? "MTD" : "the block layer";
 
 	len = strnlen(rsb->name, ROMFS_MAXFN);
-	if (!silent)
+	if (!(fc->sb_flags & SB_SILENT))
 		pr_notice("Mounting image '%*.*s' through %s\n",
 			  (unsigned) len, (unsigned) len, rsb->name, storage);
 
@@ -555,23 +554,34 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
 /*
  * get a superblock for mounting
  */
-static struct dentry *romfs_mount(struct file_system_type *fs_type,
-			int flags, const char *dev_name,
-			void *data)
+static int romfs_get_tree(struct fs_context *fc)
 {
-	struct dentry *ret = ERR_PTR(-EINVAL);
+	int ret = -EINVAL;
 
 #ifdef CONFIG_ROMFS_ON_MTD
-	ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super);
+	ret = vfs_get_mtd_super(fc, romfs_fill_super);
 #endif
 #ifdef CONFIG_ROMFS_ON_BLOCK
-	if (ret == ERR_PTR(-EINVAL))
-		ret = mount_bdev(fs_type, flags, dev_name, data,
-				  romfs_fill_super);
+	if (ret == -EINVAL)
+		ret = vfs_get_block_super(fc, romfs_fill_super);
 #endif
 	return ret;
 }
 
+static const struct fs_context_operations romfs_context_ops = {
+	.get_tree	= romfs_get_tree,
+	.reconfigure	= romfs_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int romfs_init_fs_context(struct fs_context *fc)
+{
+	fc->ops = &romfs_context_ops;
+	return 0;
+}
+
 /*
  * destroy a romfs superblock in the appropriate manner
  */
@@ -594,7 +604,7 @@ static void romfs_kill_sb(struct super_block *sb)
 static struct file_system_type romfs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "romfs",
-	.mount		= romfs_mount,
+	.init_fs_context = romfs_init_fs_context,
 	.kill_sb	= romfs_kill_sb,
 	.fs_flags	= FS_REQUIRES_DEV,
 };


______________________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-mtd/

[RFC PATCH 48/68] vfs: Convert cramfs to use the new mount API

[David Howells]

Convert the cramfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Nicolas Pitre <nico@linaro.org>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
---

 fs/cramfs/inode.c |   69 ++++++++++++++++++++++++++++++-----------------------
 1 file changed, 39 insertions(+), 30 deletions(-)

diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 9352487bd0fc..2ee89a353d64 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -24,6 +24,7 @@
 #include <linux/blkdev.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/super.h>
+#include <linux/fs_context.h>
 #include <linux/slab.h>
 #include <linux/vfs.h>
 #include <linux/mutex.h>
@@ -506,18 +507,19 @@ static void cramfs_kill_sb(struct super_block *sb)
 	kfree(sbi);
 }
 
-static int cramfs_remount(struct super_block *sb, int *flags, char *data)
+static int cramfs_reconfigure(struct fs_context *fc)
 {
-	sync_filesystem(sb);
-	*flags |= SB_RDONLY;
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= SB_RDONLY;
 	return 0;
 }
 
-static int cramfs_read_super(struct super_block *sb,
-			     struct cramfs_super *super, int silent)
+static int cramfs_read_super(struct super_block *sb, struct fs_context *fc,
+			     struct cramfs_super *super)
 {
 	struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
 	unsigned long root_offset;
+	bool silent = fc->sb_flags & SB_SILENT;
 
 	/* We don't know the real size yet */
 	sbi->size = PAGE_SIZE;
@@ -532,7 +534,7 @@ static int cramfs_read_super(struct super_block *sb,
 		/* check for wrong endianness */
 		if (super->magic == CRAMFS_MAGIC_WEND) {
 			if (!silent)
-				pr_err("wrong endianness\n");
+				errorf(fc, "cramfs: wrong endianness");
 			return -EINVAL;
 		}
 
@@ -544,22 +546,22 @@ static int cramfs_read_super(struct super_block *sb,
 		mutex_unlock(&read_mutex);
 		if (super->magic != CRAMFS_MAGIC) {
 			if (super->magic == CRAMFS_MAGIC_WEND && !silent)
-				pr_err("wrong endianness\n");
+				errorf(fc, "cramfs: wrong endianness");
 			else if (!silent)
-				pr_err("wrong magic\n");
+				errorf(fc, "cramfs: wrong magic");
 			return -EINVAL;
 		}
 	}
 
 	/* get feature flags first */
 	if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) {
-		pr_err("unsupported filesystem features\n");
+		errorf(fc, "cramfs: unsupported filesystem features");
 		return -EINVAL;
 	}
 
 	/* Check that the root inode is in a sane state */
 	if (!S_ISDIR(super->root.mode)) {
-		pr_err("root is not a directory\n");
+		errorf(fc, "cramfs: root is not a directory");
 		return -EINVAL;
 	}
 	/* correct strange, hard-coded permissions of mkcramfs */
@@ -578,12 +580,12 @@ static int cramfs_read_super(struct super_block *sb,
 	sbi->magic = super->magic;
 	sbi->flags = super->flags;
 	if (root_offset == 0)
-		pr_info("empty filesystem");
+		infof(fc, "cramfs: empty filesystem");
 	else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
 		 ((root_offset != sizeof(struct cramfs_super)) &&
 		  (root_offset != 512 + sizeof(struct cramfs_super))))
 	{
-		pr_err("bad root offset %lu\n", root_offset);
+		errorf(fc, "cramfs: bad root offset %lu", root_offset);
 		return -EINVAL;
 	}
 
@@ -607,8 +609,7 @@ static int cramfs_finalize_super(struct super_block *sb,
 	return 0;
 }
 
-static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
-				    int silent)
+static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct cramfs_sb_info *sbi;
 	struct cramfs_super super;
@@ -623,14 +624,13 @@ static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
 	for (i = 0; i < READ_BUFFERS; i++)
 		buffer_blocknr[i] = -1;
 
-	err = cramfs_read_super(sb, &super, silent);
+	err = cramfs_read_super(sb, fc, &super);
 	if (err)
 		return err;
 	return cramfs_finalize_super(sb, &super.root);
 }
 
-static int cramfs_mtd_fill_super(struct super_block *sb, void *data,
-				 int silent)
+static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct cramfs_sb_info *sbi;
 	struct cramfs_super super;
@@ -652,7 +652,7 @@ static int cramfs_mtd_fill_super(struct super_block *sb, void *data,
 
 	pr_info("checking physical address %pap for linear cramfs image\n",
 		&sbi->linear_phys_addr);
-	err = cramfs_read_super(sb, &super, silent);
+	err = cramfs_read_super(sb, fc, &super);
 	if (err)
 		return err;
 
@@ -947,32 +947,41 @@ static const struct inode_operations cramfs_dir_inode_operations = {
 };
 
 static const struct super_operations cramfs_ops = {
-	.remount_fs	= cramfs_remount,
 	.statfs		= cramfs_statfs,
 };
 
-static struct dentry *cramfs_mount(struct file_system_type *fs_type, int flags,
-				   const char *dev_name, void *data)
+static int cramfs_get_tree(struct fs_context *fc)
 {
-	struct dentry *ret = ERR_PTR(-ENOPROTOOPT);
+	int ret = -ENOPROTOOPT;
 
 	if (IS_ENABLED(CONFIG_CRAMFS_MTD)) {
-		ret = mount_mtd(fs_type, flags, dev_name, data,
-				cramfs_mtd_fill_super);
-		if (!IS_ERR(ret))
+		ret = vfs_get_mtd_super(fc, cramfs_mtd_fill_super);
+		if (ret < 0)
 			return ret;
 	}
-	if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) {
-		ret = mount_bdev(fs_type, flags, dev_name, data,
-				 cramfs_blkdev_fill_super);
-	}
+	if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
+		ret = vfs_get_block_super(fc, cramfs_blkdev_fill_super);
 	return ret;
 }
 
+static const struct fs_context_operations cramfs_context_ops = {
+	.get_tree	= cramfs_get_tree,
+	.reconfigure	= cramfs_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int cramfs_init_fs_context(struct fs_context *fc)
+{
+	fc->ops = &cramfs_context_ops;
+	return 0;
+}
+
 static struct file_system_type cramfs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "cramfs",
-	.mount		= cramfs_mount,
+	.init_fs_context = cramfs_init_fs_context,
 	.kill_sb	= cramfs_kill_sb,
 	.fs_flags	= FS_REQUIRES_DEV,
 };


______________________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-mtd/

[RFC PATCH 49/68] vfs: Convert jffs2 to use the new mount API

[David Howells]

Convert the jffs2 filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: linux-mtd@lists.infradead.org
---

 fs/jffs2/fs.c       |   21 +++---
 fs/jffs2/os-linux.h |    4 +
 fs/jffs2/super.c    |  172 +++++++++++++++++++++++++--------------------------
 3 files changed, 96 insertions(+), 101 deletions(-)

diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index eab04eca95a3..d79734bd7650 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -17,6 +17,7 @@
 #include <linux/sched.h>
 #include <linux/cred.h>
 #include <linux/fs.h>
+#include <linux/fs_context.h>
 #include <linux/list.h>
 #include <linux/mtd/mtd.h>
 #include <linux/pagemap.h>
@@ -184,7 +185,7 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
 		truncate_setsize(inode, iattr->ia_size);
 		inode->i_blocks = (inode->i_size + 511) >> 9;
-	}	
+	}
 
 	return 0;
 }
@@ -390,7 +391,7 @@ void jffs2_dirty_inode(struct inode *inode, int flags)
 	jffs2_do_setattr(inode, &iattr);
 }
 
-int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
+int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc)
 {
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 
@@ -408,10 +409,10 @@ int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
 		mutex_unlock(&c->alloc_sem);
 	}
 
-	if (!(*flags & SB_RDONLY))
+	if (!(fc->sb_flags & SB_RDONLY))
 		jffs2_start_garbage_collect_thread(c);
 
-	*flags |= SB_NOATIME;
+	fc->sb_flags |= SB_NOATIME;
 	return 0;
 }
 
@@ -508,7 +509,7 @@ static int calculate_inocache_hashsize(uint32_t flash_size)
 	return hashsize;
 }
 
-int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
+int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct jffs2_sb_info *c;
 	struct inode *root_i;
@@ -523,11 +524,11 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
 
 #ifndef CONFIG_JFFS2_FS_WRITEBUFFER
 	if (c->mtd->type == MTD_NANDFLASH) {
-		pr_err("Cannot operate on NAND flash unless jffs2 NAND support is compiled in\n");
+		errorf(fc, "Cannot operate on NAND flash unless jffs2 NAND support is compiled in");
 		return -EINVAL;
 	}
 	if (c->mtd->type == MTD_DATAFLASH) {
-		pr_err("Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in\n");
+		errorf(fc, "Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in");
 		return -EINVAL;
 	}
 #endif
@@ -541,12 +542,12 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
 	 */
 	if ((c->sector_size * blocks) != c->flash_size) {
 		c->flash_size = c->sector_size * blocks;
-		pr_info("Flash size not aligned to erasesize, reducing to %dKiB\n",
-			c->flash_size / 1024);
+		infof(fc, "Flash size not aligned to erasesize, reducing to %dKiB",
+		      c->flash_size / 1024);
 	}
 
 	if (c->flash_size < 5*c->sector_size) {
-		pr_err("Too few erase blocks (%d)\n",
+		errorf(fc, "Too few erase blocks (%d)",
 		       c->flash_size / c->sector_size);
 		return -EINVAL;
 	}
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index a2dbbb3f4c74..ac23ae5cdb54 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -172,8 +172,8 @@ void jffs2_dirty_inode(struct inode *inode, int flags);
 struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode,
 			       struct jffs2_raw_inode *ri);
 int jffs2_statfs (struct dentry *, struct kstatfs *);
-int jffs2_do_remount_fs(struct super_block *, int *, char *);
-int jffs2_do_fill_super(struct super_block *sb, void *data, int silent);
+int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc);
+int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc);
 void jffs2_gc_release_inode(struct jffs2_sb_info *c,
 			    struct jffs2_inode_info *f);
 struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index bb6ae387469f..69dcc4e0b243 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -19,7 +19,8 @@
 #include <linux/fs.h>
 #include <linux/err.h>
 #include <linux/mount.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/jffs2.h>
 #include <linux/pagemap.h>
 #include <linux/mtd/super.h>
@@ -160,96 +161,77 @@ static const struct export_operations jffs2_export_ops = {
 /*
  * JFFS2 mount options.
  *
+ * Opt_source: The source device
  * Opt_override_compr: override default compressor
  * Opt_rp_size: size of reserved pool in KiB
- * Opt_err: just end of array marker
  */
 enum {
+	Opt_source,
 	Opt_override_compr,
 	Opt_rp_size,
-	Opt_err,
 };
 
-static const match_table_t tokens = {
-	{Opt_override_compr, "compr=%s"},
-	{Opt_rp_size, "rp_size=%u"},
-	{Opt_err, NULL},
+static const struct fs_parameter_spec jffs2_param_specs[] = {
+	fsparam_string	("source",	Opt_source),
+	fsparam_enum	("compr",	Opt_override_compr),
+	fsparam_u32	("rp_size",	Opt_rp_size),
+	{}
 };
 
-static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
-{
-	substring_t args[MAX_OPT_ARGS];
-	char *p, *name;
-	unsigned int opt;
-
-	if (!data)
-		return 0;
-
-	while ((p = strsep(&data, ","))) {
-		int token;
-
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_override_compr:
-			name = match_strdup(&args[0]);
-
-			if (!name)
-				return -ENOMEM;
-			if (!strcmp(name, "none"))
-				c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
+static const struct fs_parameter_enum jffs2_param_enums[] = {
+	{ Opt_override_compr,	"none",	JFFS2_COMPR_MODE_NONE },
 #ifdef CONFIG_JFFS2_LZO
-			else if (!strcmp(name, "lzo"))
-				c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
+	{ Opt_override_compr,	"lzo",	JFFS2_COMPR_MODE_FORCELZO },
 #endif
 #ifdef CONFIG_JFFS2_ZLIB
-			else if (!strcmp(name, "zlib"))
-				c->mount_opts.compr =
-						JFFS2_COMPR_MODE_FORCEZLIB;
+	{ Opt_override_compr,	"zlib",	JFFS2_COMPR_MODE_FORCEZLIB },
 #endif
-			else {
-				pr_err("Error: unknown compressor \"%s\"\n",
-				       name);
-				kfree(name);
-				return -EINVAL;
-			}
-			kfree(name);
-			c->mount_opts.override_compr = true;
-			break;
-		case Opt_rp_size:
-			if (match_int(&args[0], &opt))
-				return -EINVAL;
-			opt *= 1024;
-			if (opt > c->mtd->size) {
-				pr_warn("Too large reserve pool specified, max "
-					"is %llu KB\n", c->mtd->size / 1024);
-				return -EINVAL;
-			}
-			c->mount_opts.rp_size = opt;
-			break;
-		default:
-			pr_err("Error: unrecognized mount option '%s' or missing value\n",
-			       p);
-			return -EINVAL;
-		}
+	{}
+};
+
+const struct fs_parameter_description jffs2_fs_parameters = {
+	.name		= "jffs2",
+	.specs		= jffs2_param_specs,
+	.enums		= jffs2_param_enums,
+};
+
+static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct fs_parse_result result;
+	struct jffs2_sb_info *c = fc->s_fs_info;
+	int opt;
+
+	opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_override_compr:
+		c->mount_opts.compr = result.uint_32;
+		c->mount_opts.override_compr = true;
+		break;
+	case Opt_rp_size:
+		if (result.uint_32 > UINT_MAX / 1024)
+			return invalf(fc, "jffs2: rp_size unrepresentable");
+		opt = result.uint_32 * 1024;
+		if (opt > c->mtd->size)
+			return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
+				      c->mtd->size / 1024);
+		c->mount_opts.rp_size = opt;
+		break;
+	default:
+		return -EINVAL;
 	}
 
 	return 0;
 }
 
-static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
+static int jffs2_reconfigure(struct fs_context *fc)
 {
-	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
-	int err;
+	struct super_block *sb = fc->root->d_sb;
 
 	sync_filesystem(sb);
-	err = jffs2_parse_options(c, data);
-	if (err)
-		return -EINVAL;
-
-	return jffs2_do_remount_fs(sb, flags, data);
+	return jffs2_do_remount_fs(sb, fc);
 }
 
 static const struct super_operations jffs2_super_operations =
@@ -258,7 +240,6 @@ static const struct super_operations jffs2_super_operations =
 	.destroy_inode =jffs2_destroy_inode,
 	.put_super =	jffs2_put_super,
 	.statfs =	jffs2_statfs,
-	.remount_fs =	jffs2_remount_fs,
 	.evict_inode =	jffs2_evict_inode,
 	.dirty_inode =	jffs2_dirty_inode,
 	.show_options =	jffs2_show_options,
@@ -268,26 +249,16 @@ static const struct super_operations jffs2_super_operations =
 /*
  * fill in the superblock
  */
-static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
+static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
 {
-	struct jffs2_sb_info *c;
-	int ret;
+	struct jffs2_sb_info *c = sb->s_fs_info;
 
 	jffs2_dbg(1, "jffs2_get_sb_mtd():"
 		  " New superblock for device %d (\"%s\")\n",
 		  sb->s_mtd->index, sb->s_mtd->name);
 
-	c = kzalloc(sizeof(*c), GFP_KERNEL);
-	if (!c)
-		return -ENOMEM;
-
 	c->mtd = sb->s_mtd;
 	c->os_priv = sb;
-	sb->s_fs_info = c;
-
-	ret = jffs2_parse_options(c, data);
-	if (ret)
-		return -EINVAL;
 
 	/* Initialize JFFS2 superblock locks, the further initialization will
 	 * be done later */
@@ -305,15 +276,37 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 	sb->s_flags |= SB_POSIXACL;
 #endif
-	ret = jffs2_do_fill_super(sb, data, silent);
-	return ret;
+	return jffs2_do_fill_super(sb, fc);
 }
 
-static struct dentry *jffs2_mount(struct file_system_type *fs_type,
-			int flags, const char *dev_name,
-			void *data)
+static int jffs2_get_tree(struct fs_context *fc)
 {
-	return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
+	return vfs_get_mtd_super(fc, jffs2_fill_super);
+}
+
+static void jffs2_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations jffs2_context_ops = {
+	.free		= jffs2_free_fc,
+	.parse_param	= jffs2_parse_param,
+	.get_tree	= jffs2_get_tree,
+	.reconfigure	= jffs2_reconfigure,
+};
+
+static int jffs2_init_fs_context(struct fs_context *fc)
+{
+	struct jffs2_sb_info *ctx;
+
+	ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	fc->s_fs_info = ctx;
+	fc->ops = &jffs2_context_ops;
+	return 0;
 }
 
 static void jffs2_put_super (struct super_block *sb)
@@ -350,7 +343,8 @@ static void jffs2_kill_sb(struct super_block *sb)
 static struct file_system_type jffs2_fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"jffs2",
-	.mount =	jffs2_mount,
+	.init_fs_context = jffs2_init_fs_context,
+	.parameters =	&jffs2_fs_parameters,
 	.kill_sb =	jffs2_kill_sb,
 };
 MODULE_ALIAS_FS("jffs2");


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[RFC PATCH 50/68] mtd: Kill mount_mtd()

[David Howells]

Kill mount_mtd() as it has now been replaced by vfs_get_mtd_super() in the
new mount API and nothing now uses it.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---

 drivers/mtd/mtdsuper.c    |  189 ---------------------------------------------
 include/linux/mtd/super.h |    3 -
 2 files changed, 192 deletions(-)

diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index cf165f7c8632..428beb766166 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -210,195 +210,6 @@ int vfs_get_mtd_super(struct fs_context *fc,
 }
 EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
 
-/*
- * compare superblocks to see if they're equivalent
- * - they are if the underlying MTD device is the same
- */
-static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
-{
-	struct mtd_info *mtd = _mtd;
-
-	if (sb->s_mtd == mtd) {
-		pr_debug("MTDSB: Match on device %d (\"%s\")\n",
-		      mtd->index, mtd->name);
-		return 1;
-	}
-
-	pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
-	      sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
-	return 0;
-}
-
-/*
- * mark the superblock by the MTD device it is using
- * - set the device number to be the correct MTD block device for pesuperstence
- *   of NFS exports
- */
-static int get_sb_mtd_set(struct super_block *sb, void *_mtd)
-{
-	struct mtd_info *mtd = _mtd;
-
-	sb->s_mtd = mtd;
-	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
-	sb->s_bdi = bdi_get(mtd_bdi);
-
-	return 0;
-}
-
-/*
- * get a superblock on an MTD-backed filesystem
- */
-static struct dentry *mount_mtd_aux(struct file_system_type *fs_type, int flags,
-			  const char *dev_name, void *data,
-			  struct mtd_info *mtd,
-			  int (*fill_super)(struct super_block *, void *, int))
-{
-	struct super_block *sb;
-	int ret;
-
-	sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, flags, mtd);
-	if (IS_ERR(sb))
-		goto out_error;
-
-	if (sb->s_root)
-		goto already_mounted;
-
-	/* fresh new superblock */
-	pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
-	      mtd->index, mtd->name);
-
-	ret = fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
-	if (ret < 0) {
-		deactivate_locked_super(sb);
-		return ERR_PTR(ret);
-	}
-
-	/* go */
-	sb->s_flags |= SB_ACTIVE;
-	return dget(sb->s_root);
-
-	/* new mountpoint for an already mounted superblock */
-already_mounted:
-	pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
-	      mtd->index, mtd->name);
-	put_mtd_device(mtd);
-	return dget(sb->s_root);
-
-out_error:
-	put_mtd_device(mtd);
-	return ERR_CAST(sb);
-}
-
-/*
- * get a superblock on an MTD-backed filesystem by MTD device number
- */
-static struct dentry *mount_mtd_nr(struct file_system_type *fs_type, int flags,
-			 const char *dev_name, void *data, int mtdnr,
-			 int (*fill_super)(struct super_block *, void *, int))
-{
-	struct mtd_info *mtd;
-
-	mtd = get_mtd_device(NULL, mtdnr);
-	if (IS_ERR(mtd)) {
-		pr_debug("MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
-		return ERR_CAST(mtd);
-	}
-
-	return mount_mtd_aux(fs_type, flags, dev_name, data, mtd, fill_super);
-}
-
-/*
- * set up an MTD-based superblock
- */
-struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
-	       const char *dev_name, void *data,
-	       int (*fill_super)(struct super_block *, void *, int))
-{
-#ifdef CONFIG_BLOCK
-	struct block_device *bdev;
-	int ret, major;
-#endif
-	int mtdnr;
-
-	if (!dev_name)
-		return ERR_PTR(-EINVAL);
-
-	pr_debug("MTDSB: dev_name \"%s\"\n", dev_name);
-
-	/* the preferred way of mounting in future; especially when
-	 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
-	 * by name, so that we don't require block device support to be present
-	 * in the kernel. */
-	if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
-		if (dev_name[3] == ':') {
-			struct mtd_info *mtd;
-
-			/* mount by MTD device name */
-			pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
-			      dev_name + 4);
-
-			mtd = get_mtd_device_nm(dev_name + 4);
-			if (!IS_ERR(mtd))
-				return mount_mtd_aux(
-					fs_type, flags,
-					dev_name, data, mtd,
-					fill_super);
-
-			printk(KERN_NOTICE "MTD:"
-			       " MTD device with name \"%s\" not found.\n",
-			       dev_name + 4);
-
-		} else if (isdigit(dev_name[3])) {
-			/* mount by MTD device number name */
-			char *endptr;
-
-			mtdnr = simple_strtoul(dev_name + 3, &endptr, 0);
-			if (!*endptr) {
-				/* It was a valid number */
-				pr_debug("MTDSB: mtd%%d, mtdnr %d\n",
-				      mtdnr);
-				return mount_mtd_nr(fs_type, flags,
-						     dev_name, data,
-						     mtdnr, fill_super);
-			}
-		}
-	}
-
-#ifdef CONFIG_BLOCK
-	/* try the old way - the hack where we allowed users to mount
-	 * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
-	 */
-	bdev = lookup_bdev(dev_name);
-	if (IS_ERR(bdev)) {
-		ret = PTR_ERR(bdev);
-		pr_debug("MTDSB: lookup_bdev() returned %d\n", ret);
-		return ERR_PTR(ret);
-	}
-	pr_debug("MTDSB: lookup_bdev() returned 0\n");
-
-	ret = -EINVAL;
-
-	major = MAJOR(bdev->bd_dev);
-	mtdnr = MINOR(bdev->bd_dev);
-	bdput(bdev);
-
-	if (major != MTD_BLOCK_MAJOR)
-		goto not_an_MTD_device;
-
-	return mount_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super);
-
-not_an_MTD_device:
-#endif /* CONFIG_BLOCK */
-
-	if (!(flags & SB_SILENT))
-		printk(KERN_NOTICE
-		       "MTD: Attempt to mount non-MTD device \"%s\"\n",
-		       dev_name);
-	return ERR_PTR(-EINVAL);
-}
-
-EXPORT_SYMBOL_GPL(mount_mtd);
-
 /*
  * destroy an MTD-based superblock
  */
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index 7ebd69e5c640..c8bfaf0b8fe7 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -21,9 +21,6 @@
 extern int vfs_get_mtd_super(struct fs_context *fc,
 			     int (*fill_super)(struct super_block *sb,
 					       struct fs_context *fc));
-extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
-		      const char *dev_name, void *data,
-		      int (*fill_super)(struct super_block *, void *, int));
 extern void kill_mtd_super(struct super_block *sb);
 
 


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

[RFC PATCH 66/68] vfs: Convert ubifs to use the new mount API

[David Howells]

Convert the ubifs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Richard Weinberger <richard@nod.at>
cc: Artem Bityutskiy <dedekind1@gmail.com>
cc: Adrian Hunter <adrian.hunter@intel.com>
cc: linux-mtd@lists.infradead.org
---

 fs/ubifs/super.c |  447 ++++++++++++++++++++++++------------------------------
 1 file changed, 200 insertions(+), 247 deletions(-)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 8dc2818fdd84..e77ad4dd2665 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -31,9 +31,9 @@
 #include <linux/module.h>
 #include <linux/ctype.h>
 #include <linux/kthread.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/seq_file.h>
-#include <linux/mount.h>
 #include <linux/math64.h>
 #include <linux/writeback.h>
 #include "ubifs.h"
@@ -935,7 +935,7 @@ static int check_volume_empty(struct ubifs_info *c)
  * Opt_no_bulk_read: disable bulk-reads
  * Opt_chk_data_crc: check CRCs when reading data nodes
  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
- * Opt_override_compr: override default compressor
+ * Opt_compr: override default compressor
  * Opt_assert: set ubifs_assert() action
  * Opt_auth_key: The key name used for authentication
  * Opt_auth_hash_name: The hash type used for authentication
@@ -948,54 +948,47 @@ enum {
 	Opt_no_bulk_read,
 	Opt_chk_data_crc,
 	Opt_no_chk_data_crc,
-	Opt_override_compr,
+	Opt_compr,
 	Opt_assert,
 	Opt_auth_key,
 	Opt_auth_hash_name,
 	Opt_ignore,
-	Opt_err,
 };
 
-static const match_table_t tokens = {
-	{Opt_fast_unmount, "fast_unmount"},
-	{Opt_norm_unmount, "norm_unmount"},
-	{Opt_bulk_read, "bulk_read"},
-	{Opt_no_bulk_read, "no_bulk_read"},
-	{Opt_chk_data_crc, "chk_data_crc"},
-	{Opt_no_chk_data_crc, "no_chk_data_crc"},
-	{Opt_override_compr, "compr=%s"},
-	{Opt_auth_key, "auth_key=%s"},
-	{Opt_auth_hash_name, "auth_hash_name=%s"},
-	{Opt_ignore, "ubi=%s"},
-	{Opt_ignore, "vol=%s"},
-	{Opt_assert, "assert=%s"},
-	{Opt_err, NULL},
+static const struct fs_parameter_spec ubifs_param_specs[] = {
+	fsparam_flag	("fast_unmount",		Opt_fast_unmount),
+	fsparam_flag	("norm_unmount",		Opt_norm_unmount),
+	fsparam_flag	("bulk_read",			Opt_bulk_read),
+	fsparam_flag	("no_bulk_read",		Opt_no_bulk_read),
+	fsparam_flag	("chk_data_crc",		Opt_chk_data_crc),
+	fsparam_flag	("no_chk_data_crc",		Opt_no_chk_data_crc),
+	fsparam_enum	("compr",			Opt_compr),
+	fsparam_enum	("assert",			Opt_assert),
+	fsparam_string	("auth_key",			Opt_auth_key),
+	fsparam_string	("auth_hash_name",		Opt_auth_hash_name),
+	fsparam_string	("ubi",				Opt_ignore),
+	fsparam_string	("vol",				Opt_ignore),
+	{}
 };
 
-/**
- * parse_standard_option - parse a standard mount option.
- * @option: the option to parse
- *
- * Normally, standard mount options like "sync" are passed to file-systems as
- * flags. However, when a "rootflags=" kernel boot parameter is used, they may
- * be present in the options string. This function tries to deal with this
- * situation and parse standard options. Returns 0 if the option was not
- * recognized, and the corresponding integer flag if it was.
- *
- * UBIFS is only interested in the "sync" option, so do not check for anything
- * else.
- */
-static int parse_standard_option(const char *option)
-{
+static const struct fs_parameter_enum ubifs_param_enums[] = {
+	{ Opt_compr,	"none",		UBIFS_COMPR_NONE },
+	{ Opt_compr,	"lzo",		UBIFS_COMPR_LZO },
+	{ Opt_compr,	"zlib",		UBIFS_COMPR_ZLIB },
+	{ Opt_assert,	"report",	ASSACT_REPORT },
+	{ Opt_assert,	"read-only",	ASSACT_RO },
+	{ Opt_assert,	"panic",	ASSACT_PANIC },
+	{}
+};
 
-	pr_notice("UBIFS: parse %s\n", option);
-	if (!strcmp(option, "sync"))
-		return SB_SYNCHRONOUS;
-	return 0;
-}
+static const struct fs_parameter_description ubifs_fs_parameters = {
+	.name		= "ubifs",
+	.specs		= ubifs_param_specs,
+	.enums		= ubifs_param_enums,
+};
 
 /**
- * ubifs_parse_options - parse mount parameters.
+ * ubifs_parse_param - parse a parameter.
  * @c: UBIFS file-system description object
  * @options: parameters to parse
  * @is_remount: non-zero if this is FS re-mount
@@ -1003,119 +996,64 @@ static int parse_standard_option(const char *option)
  * This function parses UBIFS mount options and returns zero in case success
  * and a negative error code in case of failure.
  */
-static int ubifs_parse_options(struct ubifs_info *c, char *options,
-			       int is_remount)
+static int ubifs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-
-	if (!options)
-		return 0;
-
-	while ((p = strsep(&options, ","))) {
-		int token;
+	struct ubifs_info *c = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
 
-		if (!*p)
-			continue;
+	opt = fs_parse(fc, &ubifs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
 
-		token = match_token(p, tokens, args);
-		switch (token) {
+	switch (opt) {
 		/*
 		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
 		 * We accept them in order to be backward-compatible. But this
 		 * should be removed at some point.
 		 */
-		case Opt_fast_unmount:
-			c->mount_opts.unmount_mode = 2;
-			break;
-		case Opt_norm_unmount:
-			c->mount_opts.unmount_mode = 1;
-			break;
-		case Opt_bulk_read:
-			c->mount_opts.bulk_read = 2;
-			c->bulk_read = 1;
-			break;
-		case Opt_no_bulk_read:
-			c->mount_opts.bulk_read = 1;
-			c->bulk_read = 0;
-			break;
-		case Opt_chk_data_crc:
-			c->mount_opts.chk_data_crc = 2;
-			c->no_chk_data_crc = 0;
-			break;
-		case Opt_no_chk_data_crc:
-			c->mount_opts.chk_data_crc = 1;
-			c->no_chk_data_crc = 1;
-			break;
-		case Opt_override_compr:
-		{
-			char *name = match_strdup(&args[0]);
-
-			if (!name)
-				return -ENOMEM;
-			if (!strcmp(name, "none"))
-				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
-			else if (!strcmp(name, "lzo"))
-				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
-			else if (!strcmp(name, "zlib"))
-				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
-			else {
-				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
-				kfree(name);
-				return -EINVAL;
-			}
-			kfree(name);
-			c->mount_opts.override_compr = 1;
-			c->default_compr = c->mount_opts.compr_type;
-			break;
-		}
-		case Opt_assert:
-		{
-			char *act = match_strdup(&args[0]);
-
-			if (!act)
-				return -ENOMEM;
-			if (!strcmp(act, "report"))
-				c->assert_action = ASSACT_REPORT;
-			else if (!strcmp(act, "read-only"))
-				c->assert_action = ASSACT_RO;
-			else if (!strcmp(act, "panic"))
-				c->assert_action = ASSACT_PANIC;
-			else {
-				ubifs_err(c, "unknown assert action \"%s\"", act);
-				kfree(act);
-				return -EINVAL;
-			}
-			kfree(act);
-			break;
-		}
-		case Opt_auth_key:
-			c->auth_key_name = kstrdup(args[0].from, GFP_KERNEL);
-			if (!c->auth_key_name)
-				return -ENOMEM;
-			break;
-		case Opt_auth_hash_name:
-			c->auth_hash_name = kstrdup(args[0].from, GFP_KERNEL);
-			if (!c->auth_hash_name)
-				return -ENOMEM;
-			break;
-		case Opt_ignore:
-			break;
-		default:
-		{
-			unsigned long flag;
-			struct super_block *sb = c->vfs_sb;
-
-			flag = parse_standard_option(p);
-			if (!flag) {
-				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
-					  p);
-				return -EINVAL;
-			}
-			sb->s_flags |= flag;
-			break;
-		}
-		}
+	case Opt_fast_unmount:
+		c->mount_opts.unmount_mode = 2;
+		break;
+	case Opt_norm_unmount:
+		c->mount_opts.unmount_mode = 1;
+		break;
+	case Opt_bulk_read:
+		c->mount_opts.bulk_read = 2;
+		c->bulk_read = 1;
+		break;
+	case Opt_no_bulk_read:
+		c->mount_opts.bulk_read = 1;
+		c->bulk_read = 0;
+		break;
+	case Opt_chk_data_crc:
+		c->mount_opts.chk_data_crc = 2;
+		c->no_chk_data_crc = 0;
+		break;
+	case Opt_no_chk_data_crc:
+		c->mount_opts.chk_data_crc = 1;
+		c->no_chk_data_crc = 1;
+		break;
+	case Opt_compr:
+		c->mount_opts.compr_type = result.uint_32;
+		c->mount_opts.override_compr = 1;
+		c->default_compr = c->mount_opts.compr_type;
+		break;
+	case Opt_assert:
+		c->assert_action = result.uint_32;
+		break;
+	case Opt_auth_key:
+		kfree(c->auth_key_name);
+		c->auth_key_name = param->string;
+		param->string = NULL;
+		break;
+	case Opt_auth_hash_name:
+		kfree(c->auth_hash_name);
+		c->auth_hash_name = param->string;
+		param->string = NULL;
+		break;
+	case Opt_ignore:
+		break;
 	}
 
 	return 0;
@@ -1927,21 +1865,30 @@ static void ubifs_put_super(struct super_block *sb)
 	mutex_unlock(&c->umount_mutex);
 }
 
-static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
+static int ubifs_reconfigure(struct fs_context *fc)
 {
+	struct super_block *sb = fc->root->d_sb;
 	int err;
 	struct ubifs_info *c = sb->s_fs_info;
+	struct ubifs_info *reconf = fc->s_fs_info;
 
 	sync_filesystem(sb);
-	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
+	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, fc->sb_flags);
 
-	err = ubifs_parse_options(c, data, 1);
-	if (err) {
-		ubifs_err(c, "invalid or unknown remount parameter");
-		return err;
-	}
+	/* Apply the mount option changes.
+	 *
+	 * [!] NOTE Replacing the auth_key_name and auth_hash_name is
+	 *     very dodgy without locking.  Previously it just leaked
+	 *     the old strings.  The strings only seem to be used
+	 *     during mounting, so don't reconfigure those.
+	 */
+	c->mount_opts		= reconf->mount_opts;
+	c->bulk_read		= reconf->bulk_read;
+	c->no_chk_data_crc	= reconf->no_chk_data_crc;
+	c->default_compr	= reconf->default_compr;
+	c->assert_action	= reconf->assert_action;
 
-	if (c->ro_mount && !(*flags & SB_RDONLY)) {
+	if (c->ro_mount && !(fc->sb_flags & SB_RDONLY)) {
 		if (c->ro_error) {
 			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
 			return -EROFS;
@@ -1953,7 +1900,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
 		err = ubifs_remount_rw(c);
 		if (err)
 			return err;
-	} else if (!c->ro_mount && (*flags & SB_RDONLY)) {
+	} else if (!c->ro_mount && (fc->sb_flags & SB_RDONLY)) {
 		if (c->ro_error) {
 			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
 			return -EROFS;
@@ -1985,14 +1932,13 @@ const struct super_operations ubifs_super_operations = {
 	.evict_inode   = ubifs_evict_inode,
 	.statfs        = ubifs_statfs,
 	.dirty_inode   = ubifs_dirty_inode,
-	.remount_fs    = ubifs_remount_fs,
 	.show_options  = ubifs_show_options,
 	.sync_fs       = ubifs_sync_fs,
 };
 
 /**
  * open_ubi - parse UBI device name string and open the UBI device.
- * @name: UBI volume name
+ * @fc: The filesystem parameters
  * @mode: UBI volume open mode
  *
  * The primary method of mounting UBIFS is by specifying the UBI volume
@@ -2009,15 +1955,13 @@ const struct super_operations ubifs_super_operations = {
  * returns UBI volume description object in case of success and a negative
  * error code in case of failure.
  */
-static struct ubi_volume_desc *open_ubi(const char *name, int mode)
+static struct ubi_volume_desc *open_ubi(struct fs_context *fc, int mode)
 {
 	struct ubi_volume_desc *ubi;
+	const char *name = fc->source;
 	int dev, vol;
 	char *endptr;
 
-	if (!name || !*name)
-		return ERR_PTR(-EINVAL);
-
 	/* First, try to open using the device node path method */
 	ubi = ubi_open_volume_path(name, mode);
 	if (!IS_ERR(ubi))
@@ -2025,14 +1969,14 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
 
 	/* Try the "nodev" method */
 	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
-		return ERR_PTR(-EINVAL);
+		goto invalid_source;
 
 	/* ubi:NAME method */
 	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
 		return ubi_open_volume_nm(0, name + 4, mode);
 
 	if (!isdigit(name[3]))
-		return ERR_PTR(-EINVAL);
+		goto invalid_source;
 
 	dev = simple_strtoul(name + 3, &endptr, 0);
 
@@ -2044,7 +1988,7 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
 	if (*endptr == '_' && isdigit(endptr[1])) {
 		vol = simple_strtoul(endptr + 1, &endptr, 0);
 		if (*endptr != '\0')
-			return ERR_PTR(-EINVAL);
+			goto invalid_source;
 		return ubi_open_volume(dev, vol, mode);
 	}
 
@@ -2052,57 +1996,11 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
 	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
 		return ubi_open_volume_nm(dev, ++endptr, mode);
 
-	return ERR_PTR(-EINVAL);
-}
-
-static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
-{
-	struct ubifs_info *c;
-
-	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
-	if (c) {
-		spin_lock_init(&c->cnt_lock);
-		spin_lock_init(&c->cs_lock);
-		spin_lock_init(&c->buds_lock);
-		spin_lock_init(&c->space_lock);
-		spin_lock_init(&c->orphan_lock);
-		init_rwsem(&c->commit_sem);
-		mutex_init(&c->lp_mutex);
-		mutex_init(&c->tnc_mutex);
-		mutex_init(&c->log_mutex);
-		mutex_init(&c->umount_mutex);
-		mutex_init(&c->bu_mutex);
-		mutex_init(&c->write_reserve_mutex);
-		init_waitqueue_head(&c->cmt_wq);
-		c->buds = RB_ROOT;
-		c->old_idx = RB_ROOT;
-		c->size_tree = RB_ROOT;
-		c->orph_tree = RB_ROOT;
-		INIT_LIST_HEAD(&c->infos_list);
-		INIT_LIST_HEAD(&c->idx_gc);
-		INIT_LIST_HEAD(&c->replay_list);
-		INIT_LIST_HEAD(&c->replay_buds);
-		INIT_LIST_HEAD(&c->uncat_list);
-		INIT_LIST_HEAD(&c->empty_list);
-		INIT_LIST_HEAD(&c->freeable_list);
-		INIT_LIST_HEAD(&c->frdi_idx_list);
-		INIT_LIST_HEAD(&c->unclean_leb_list);
-		INIT_LIST_HEAD(&c->old_buds);
-		INIT_LIST_HEAD(&c->orph_list);
-		INIT_LIST_HEAD(&c->orph_new);
-		c->no_chk_data_crc = 1;
-		c->assert_action = ASSACT_RO;
-
-		c->highest_inum = UBIFS_FIRST_INO;
-		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
-
-		ubi_get_volume_info(ubi, &c->vi);
-		ubi_get_device_info(c->vi.ubi_num, &c->di);
-	}
-	return c;
+invalid_source:
+	return ERR_PTR(invalf(fc, "Invalid source name"));
 }
 
-static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
+static int ubifs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct ubifs_info *c = sb->s_fs_info;
 	struct inode *root;
@@ -2116,10 +2014,6 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 		goto out;
 	}
 
-	err = ubifs_parse_options(c, data, 0);
-	if (err)
-		goto out_close;
-
 	/*
 	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
 	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
@@ -2183,69 +2077,61 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 	return err;
 }
 
-static int sb_test(struct super_block *sb, void *data)
+static int sb_test(struct super_block *sb, struct fs_context *fc)
 {
-	struct ubifs_info *c1 = data;
+	struct ubifs_info *c1 = fc->s_fs_info;
 	struct ubifs_info *c = sb->s_fs_info;
 
 	return c->vi.cdev == c1->vi.cdev;
 }
 
-static int sb_set(struct super_block *sb, void *data)
-{
-	sb->s_fs_info = data;
-	return set_anon_super(sb, NULL);
-}
-
-static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
-			const char *name, void *data)
+static int ubifs_get_tree(struct fs_context *fc)
 {
 	struct ubi_volume_desc *ubi;
-	struct ubifs_info *c;
+	struct ubifs_info *c = fc->s_fs_info;
 	struct super_block *sb;
 	int err;
 
-	dbg_gen("name %s, flags %#x", name, flags);
+	if (!fc->source || !*fc->source)
+		return invalf(fc, "No source specified");
+
+	dbg_gen("name %s, flags %#x", fc->source, fc->sb_flags);
 
 	/*
 	 * Get UBI device number and volume ID. Mount it read-only so far
 	 * because this might be a new mount point, and UBI allows only one
 	 * read-write user at a time.
 	 */
-	ubi = open_ubi(name, UBI_READONLY);
+	ubi = open_ubi(fc, UBI_READONLY);
 	if (IS_ERR(ubi)) {
-		if (!(flags & SB_SILENT))
-			pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
-			       current->pid, name, (int)PTR_ERR(ubi));
-		return ERR_CAST(ubi);
+		err = PTR_ERR(ubi);
+		if (!(fc->sb_flags & SB_SILENT))
+			errorf(fc, "UBIFS error (pid: %d): cannot open \"%s\", error %d",
+			       current->pid, fc->source, err);
+		return err;
 	}
 
-	c = alloc_ubifs_info(ubi);
-	if (!c) {
-		err = -ENOMEM;
-		goto out_close;
-	}
+	ubi_get_volume_info(ubi, &c->vi);
+	ubi_get_device_info(c->vi.ubi_num, &c->di);
 
 	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
 
-	sb = sget(fs_type, sb_test, sb_set, flags, c);
+	sb = sget_fc(fc, sb_test, set_anon_super_fc);
 	if (IS_ERR(sb)) {
 		err = PTR_ERR(sb);
-		kfree(c);
 		goto out_close;
 	}
 
 	if (sb->s_root) {
-		struct ubifs_info *c1 = sb->s_fs_info;
-		kfree(c);
 		/* A new mount point for already mounted UBIFS */
+		c = sb->s_fs_info;
 		dbg_gen("this ubi volume is already mounted");
-		if (!!(flags & SB_RDONLY) != c1->ro_mount) {
+		if (!!(fc->sb_flags & SB_RDONLY) != c->ro_mount) {
 			err = -EBUSY;
 			goto out_deact;
 		}
 	} else {
-		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
+		err = ubifs_fill_super(sb, fc);
 		if (err)
 			goto out_deact;
 		/* We do not support atime */
@@ -2260,13 +2146,79 @@ static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
 	/* 'fill_super()' opens ubi again so we must close it here */
 	ubi_close_volume(ubi);
 
-	return dget(sb->s_root);
+	fc->root = dget(sb->s_root);
+	return 0;
 
 out_deact:
 	deactivate_locked_super(sb);
 out_close:
 	ubi_close_volume(ubi);
-	return ERR_PTR(err);
+	return err;
+}
+
+static void ubifs_free_fc(struct fs_context *fc)
+{
+	struct ubifs_info *c = fc->s_fs_info;
+
+	if (c) {
+		kfree(c->auth_key_name);
+		kfree(c->auth_hash_name);
+		kfree(c);
+	}
+}
+
+static const struct fs_context_operations ubifs_context_ops = {
+	.free		= ubifs_free_fc,
+	.parse_param	= ubifs_parse_param,
+	.get_tree	= ubifs_get_tree,
+	.reconfigure	= ubifs_reconfigure,
+};
+
+static int ubifs_init_fs_context(struct fs_context *fc)
+{
+	struct ubifs_info *c;
+
+	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
+	if (!c)
+		return -ENOMEM;
+
+	spin_lock_init(&c->cnt_lock);
+	spin_lock_init(&c->cs_lock);
+	spin_lock_init(&c->buds_lock);
+	spin_lock_init(&c->space_lock);
+	spin_lock_init(&c->orphan_lock);
+	init_rwsem(&c->commit_sem);
+	mutex_init(&c->lp_mutex);
+	mutex_init(&c->tnc_mutex);
+	mutex_init(&c->log_mutex);
+	mutex_init(&c->umount_mutex);
+	mutex_init(&c->bu_mutex);
+	mutex_init(&c->write_reserve_mutex);
+	init_waitqueue_head(&c->cmt_wq);
+	c->buds = RB_ROOT;
+	c->old_idx = RB_ROOT;
+	c->size_tree = RB_ROOT;
+	c->orph_tree = RB_ROOT;
+	INIT_LIST_HEAD(&c->infos_list);
+	INIT_LIST_HEAD(&c->idx_gc);
+	INIT_LIST_HEAD(&c->replay_list);
+	INIT_LIST_HEAD(&c->replay_buds);
+	INIT_LIST_HEAD(&c->uncat_list);
+	INIT_LIST_HEAD(&c->empty_list);
+	INIT_LIST_HEAD(&c->freeable_list);
+	INIT_LIST_HEAD(&c->frdi_idx_list);
+	INIT_LIST_HEAD(&c->unclean_leb_list);
+	INIT_LIST_HEAD(&c->old_buds);
+	INIT_LIST_HEAD(&c->orph_list);
+	INIT_LIST_HEAD(&c->orph_new);
+	c->no_chk_data_crc = 1;
+	c->assert_action = ASSACT_RO;
+	c->highest_inum = UBIFS_FIRST_INO;
+	c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
+
+	fc->s_fs_info = c;
+	fc->ops = &ubifs_context_ops;
+	return 0;
 }
 
 static void kill_ubifs_super(struct super_block *s)
@@ -2279,7 +2231,8 @@ static void kill_ubifs_super(struct super_block *s)
 static struct file_system_type ubifs_fs_type = {
 	.name    = "ubifs",
 	.owner   = THIS_MODULE,
-	.mount   = ubifs_mount,
+	.init_fs_context = ubifs_init_fs_context,
+	.parameters	= &ubifs_fs_parameters,
 	.kill_sb = kill_ubifs_super,
 };
 MODULE_ALIAS_FS("ubifs");


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Re: [RFC PATCH 48/68] vfs: Convert cramfs to use the new mount API

[Nicolas Pitre]

On Wed, 27 Mar 2019, David Howells wrote:

> Convert the cramfs filesystem to the new internal mount API as the old
> one will be obsoleted and removed.  This allows greater flexibility in
> communication of mount parameters between userspace, the VFS and the
> filesystem.
> 
> See Documentation/filesystems/mount_api.txt for more information.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Nicolas Pitre <nico@linaro.org>
> cc: linux-mtd@lists.infradead.org
> cc: linux-block@vger.kernel.org

Tested-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>




> ---
> 
>  fs/cramfs/inode.c |   69 ++++++++++++++++++++++++++++++-----------------------
>  1 file changed, 39 insertions(+), 30 deletions(-)
> 
> diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
> index 9352487bd0fc..2ee89a353d64 100644
> --- a/fs/cramfs/inode.c
> +++ b/fs/cramfs/inode.c
> @@ -24,6 +24,7 @@
>  #include <linux/blkdev.h>
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/super.h>
> +#include <linux/fs_context.h>
>  #include <linux/slab.h>
>  #include <linux/vfs.h>
>  #include <linux/mutex.h>
> @@ -506,18 +507,19 @@ static void cramfs_kill_sb(struct super_block *sb)
>  	kfree(sbi);
>  }
>  
> -static int cramfs_remount(struct super_block *sb, int *flags, char *data)
> +static int cramfs_reconfigure(struct fs_context *fc)
>  {
> -	sync_filesystem(sb);
> -	*flags |= SB_RDONLY;
> +	sync_filesystem(fc->root->d_sb);
> +	fc->sb_flags |= SB_RDONLY;
>  	return 0;
>  }
>  
> -static int cramfs_read_super(struct super_block *sb,
> -			     struct cramfs_super *super, int silent)
> +static int cramfs_read_super(struct super_block *sb, struct fs_context *fc,
> +			     struct cramfs_super *super)
>  {
>  	struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
>  	unsigned long root_offset;
> +	bool silent = fc->sb_flags & SB_SILENT;
>  
>  	/* We don't know the real size yet */
>  	sbi->size = PAGE_SIZE;
> @@ -532,7 +534,7 @@ static int cramfs_read_super(struct super_block *sb,
>  		/* check for wrong endianness */
>  		if (super->magic == CRAMFS_MAGIC_WEND) {
>  			if (!silent)
> -				pr_err("wrong endianness\n");
> +				errorf(fc, "cramfs: wrong endianness");
>  			return -EINVAL;
>  		}
>  
> @@ -544,22 +546,22 @@ static int cramfs_read_super(struct super_block *sb,
>  		mutex_unlock(&read_mutex);
>  		if (super->magic != CRAMFS_MAGIC) {
>  			if (super->magic == CRAMFS_MAGIC_WEND && !silent)
> -				pr_err("wrong endianness\n");
> +				errorf(fc, "cramfs: wrong endianness");
>  			else if (!silent)
> -				pr_err("wrong magic\n");
> +				errorf(fc, "cramfs: wrong magic");
>  			return -EINVAL;
>  		}
>  	}
>  
>  	/* get feature flags first */
>  	if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) {
> -		pr_err("unsupported filesystem features\n");
> +		errorf(fc, "cramfs: unsupported filesystem features");
>  		return -EINVAL;
>  	}
>  
>  	/* Check that the root inode is in a sane state */
>  	if (!S_ISDIR(super->root.mode)) {
> -		pr_err("root is not a directory\n");
> +		errorf(fc, "cramfs: root is not a directory");
>  		return -EINVAL;
>  	}
>  	/* correct strange, hard-coded permissions of mkcramfs */
> @@ -578,12 +580,12 @@ static int cramfs_read_super(struct super_block *sb,
>  	sbi->magic = super->magic;
>  	sbi->flags = super->flags;
>  	if (root_offset == 0)
> -		pr_info("empty filesystem");
> +		infof(fc, "cramfs: empty filesystem");
>  	else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
>  		 ((root_offset != sizeof(struct cramfs_super)) &&
>  		  (root_offset != 512 + sizeof(struct cramfs_super))))
>  	{
> -		pr_err("bad root offset %lu\n", root_offset);
> +		errorf(fc, "cramfs: bad root offset %lu", root_offset);
>  		return -EINVAL;
>  	}
>  
> @@ -607,8 +609,7 @@ static int cramfs_finalize_super(struct super_block *sb,
>  	return 0;
>  }
>  
> -static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
> -				    int silent)
> +static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc)
>  {
>  	struct cramfs_sb_info *sbi;
>  	struct cramfs_super super;
> @@ -623,14 +624,13 @@ static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
>  	for (i = 0; i < READ_BUFFERS; i++)
>  		buffer_blocknr[i] = -1;
>  
> -	err = cramfs_read_super(sb, &super, silent);
> +	err = cramfs_read_super(sb, fc, &super);
>  	if (err)
>  		return err;
>  	return cramfs_finalize_super(sb, &super.root);
>  }
>  
> -static int cramfs_mtd_fill_super(struct super_block *sb, void *data,
> -				 int silent)
> +static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc)
>  {
>  	struct cramfs_sb_info *sbi;
>  	struct cramfs_super super;
> @@ -652,7 +652,7 @@ static int cramfs_mtd_fill_super(struct super_block *sb, void *data,
>  
>  	pr_info("checking physical address %pap for linear cramfs image\n",
>  		&sbi->linear_phys_addr);
> -	err = cramfs_read_super(sb, &super, silent);
> +	err = cramfs_read_super(sb, fc, &super);
>  	if (err)
>  		return err;
>  
> @@ -947,32 +947,41 @@ static const struct inode_operations cramfs_dir_inode_operations = {
>  };
>  
>  static const struct super_operations cramfs_ops = {
> -	.remount_fs	= cramfs_remount,
>  	.statfs		= cramfs_statfs,
>  };
>  
> -static struct dentry *cramfs_mount(struct file_system_type *fs_type, int flags,
> -				   const char *dev_name, void *data)
> +static int cramfs_get_tree(struct fs_context *fc)
>  {
> -	struct dentry *ret = ERR_PTR(-ENOPROTOOPT);
> +	int ret = -ENOPROTOOPT;
>  
>  	if (IS_ENABLED(CONFIG_CRAMFS_MTD)) {
> -		ret = mount_mtd(fs_type, flags, dev_name, data,
> -				cramfs_mtd_fill_super);
> -		if (!IS_ERR(ret))
> +		ret = vfs_get_mtd_super(fc, cramfs_mtd_fill_super);
> +		if (ret < 0)
>  			return ret;
>  	}
> -	if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) {
> -		ret = mount_bdev(fs_type, flags, dev_name, data,
> -				 cramfs_blkdev_fill_super);
> -	}
> +	if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
> +		ret = vfs_get_block_super(fc, cramfs_blkdev_fill_super);
>  	return ret;
>  }
>  
> +static const struct fs_context_operations cramfs_context_ops = {
> +	.get_tree	= cramfs_get_tree,
> +	.reconfigure	= cramfs_reconfigure,
> +};
> +
> +/*
> + * Set up the filesystem mount context.
> + */
> +static int cramfs_init_fs_context(struct fs_context *fc)
> +{
> +	fc->ops = &cramfs_context_ops;
> +	return 0;
> +}
> +
>  static struct file_system_type cramfs_fs_type = {
>  	.owner		= THIS_MODULE,
>  	.name		= "cramfs",
> -	.mount		= cramfs_mount,
> +	.init_fs_context = cramfs_init_fs_context,
>  	.kill_sb	= cramfs_kill_sb,
>  	.fs_flags	= FS_REQUIRES_DEV,
>  };
> 
> 

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