sysv: convert sysv to use the new mount api

Commit Message

Eric Sandeen Feb. 5, 2025, 10:30 p.m. UTC

Convert the sysv filesystem to use the new mount API.

Tested by mounting some old sysv & v7 images I found in archives;
there are no mount options, and no remount op, so this conversion
is trivial.

Signed-off-by: Eric Sandeen <[e-mail]>
---
 fs/sysv/super.c | 57 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 39 insertions(+), 18 deletions(-)

I understand that sysv has been discussed for removal, and that's fine.

There seemed to be a little pushback so I figured I'd throw this
out there just in case removal gets deferred. Feel free to take it or
leave it, there's minimal time investment here.

With sysv done (or removed) we'll be down to just ext2, f2fs, bfs,
9p and omfs for remaining (un-sent) conversions. (orangefs seems to
be in a black hole for now though.)

Comments

Christian Brauner Feb. 6, 2025, 2:27 p.m. UTC | #1

On Wed, 05 Feb 2025 16:30:09 -0600, Eric Sandeen wrote:
> Convert the sysv filesystem to use the new mount API.
> 
> Tested by mounting some old sysv & v7 images I found in archives;
> there are no mount options, and no remount op, so this conversion
> is trivial.
> 
> 
> [...]

I think it's fine to convert and then drop. It's also fine to drop and
thus not convert. Whatever happens to happen first. If Jan gets around
to the removal during this cycle we can always drop this. If it happens
next it's also fine. If we need to add it back we at least have the work
done already.

---

Applied to the vfs-6.15.mount.api branch of the vfs/vfs.git tree.
Patches in the vfs-6.15.mount.api branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.15.mount.api

[1/1] sysv: convert sysv to use the new mount api
      https://git.kernel.org/vfs/vfs/c/00dac020ca2a

Patch

diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index 5c0d07ddbda2..03be9f1b7802 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -25,6 +25,7 @@ 
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/buffer_head.h>
+#include <linux/fs_context.h>
 #include "sysv.h"
 
 /*
@@ -349,12 +350,13 @@  static int complete_read_super(struct super_block *sb, int silent, int size)
 	return 1;
 }
 
-static int sysv_fill_super(struct super_block *sb, void *data, int silent)
+static int sysv_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct buffer_head *bh1, *bh = NULL;
 	struct sysv_sb_info *sbi;
 	unsigned long blocknr;
 	int size = 0, i;
+	int silent = fc->sb_flags & SB_SILENT;
 	
 	BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block));
 	BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block));
@@ -471,10 +473,11 @@  static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh)
 	return 1;
 }
 
-static int v7_fill_super(struct super_block *sb, void *data, int silent)
+static int v7_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct sysv_sb_info *sbi;
 	struct buffer_head *bh;
+	int silent = fc->sb_flags & SB_SILENT;
 
 	BUILD_BUG_ON(sizeof(struct v7_super_block) != 440);
 	BUILD_BUG_ON(sizeof(struct sysv_inode) != 64);
@@ -528,33 +531,51 @@  static int v7_fill_super(struct super_block *sb, void *data, int silent)
 
 /* Every kernel module contains stuff like this. */
 
-static struct dentry *sysv_mount(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int sysv_get_tree(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super);
+	return get_tree_bdev(fc, sysv_fill_super);
 }
 
-static struct dentry *v7_mount(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int v7_get_tree(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super);
+	return get_tree_bdev(fc, v7_fill_super);
+}
+
+static const struct fs_context_operations sysv_context_ops = {
+	.get_tree	= sysv_get_tree,
+};
+
+static const struct fs_context_operations v7_context_ops = {
+	.get_tree	= v7_get_tree,
+};
+
+static int sysv_init_fs_context(struct fs_context *fc)
+{
+	fc->ops = &sysv_context_ops;
+	return 0;
+}
+
+static int v7_init_fs_context(struct fs_context *fc)
+{
+	fc->ops = &v7_context_ops;
+	return 0;
 }
 
 static struct file_system_type sysv_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "sysv",
-	.mount		= sysv_mount,
-	.kill_sb	= kill_block_super,
-	.fs_flags	= FS_REQUIRES_DEV,
+	.owner			= THIS_MODULE,
+	.name			= "sysv",
+	.kill_sb		= kill_block_super,
+	.fs_flags		= FS_REQUIRES_DEV,
+	.init_fs_context	= sysv_init_fs_context,
 };
 MODULE_ALIAS_FS("sysv");
 
 static struct file_system_type v7_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "v7",
-	.mount		= v7_mount,
-	.kill_sb	= kill_block_super,
-	.fs_flags	= FS_REQUIRES_DEV,
+	.owner			= THIS_MODULE,
+	.name			= "v7",
+	.kill_sb		= kill_block_super,
+	.fs_flags		= FS_REQUIRES_DEV,
+	.init_fs_context	= v7_init_fs_context,
 };
 MODULE_ALIAS_FS("v7");
 MODULE_ALIAS("v7");