On Tue, Feb 20, 2024 at 03:05:38PM -0600, Eric Sandeen wrote:
> On 2/20/24 8:45 AM, Bill O'Donnell wrote:
> > Convert the efs filesystem to use the new mount API.
> >
> > Signed-off-by: Bill O'Donnell <bodonnel@xxxxxxxxxx>
> > ---
> >
> > Changelog:
> > v2: Remove efs_param_spec and efs_parse_param, since no mount options.
>
> A few more items below
>
> > ---
> > fs/efs/super.c | 91 +++++++++++++++++++++++++++++++++-----------------
> > 1 file changed, 61 insertions(+), 30 deletions(-)
> >
> > diff --git a/fs/efs/super.c b/fs/efs/super.c
> > index f17fdac76b2e..d86c84e9e497 100644
> > --- a/fs/efs/super.c
> > +++ b/fs/efs/super.c
> > @@ -14,19 +14,13 @@
> > #include <linux/buffer_head.h>
> > #include <linux/vfs.h>
> > #include <linux/blkdev.h>
> > -
> > +#include <linux/fs_context.h>
> > #include "efs.h"
> > #include <linux/efs_vh.h>
> > #include <linux/efs_fs_sb.h>
> >
> > static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
> > -static int efs_fill_super(struct super_block *s, void *d, int silent);
> > -
> > -static struct dentry *efs_mount(struct file_system_type *fs_type,
> > - int flags, const char *dev_name, void *data)
> > -{
> > - return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
> > -}
> > +static int efs_init_fs_context(struct fs_context *fc);
> >
> > static void efs_kill_sb(struct super_block *s)
> > {
> > @@ -35,15 +29,6 @@ static void efs_kill_sb(struct super_block *s)
> > kfree(sbi);
> > }
> >
> > -static struct file_system_type efs_fs_type = {
> > - .owner = THIS_MODULE,
> > - .name = "efs",
> > - .mount = efs_mount,
> > - .kill_sb = efs_kill_sb,
> > - .fs_flags = FS_REQUIRES_DEV,
> > -};
> > -MODULE_ALIAS_FS("efs");
> > -
> > static struct pt_types sgi_pt_types[] = {
> > {0x00, "SGI vh"},
> > {0x01, "SGI trkrepl"},
> > @@ -63,6 +48,17 @@ static struct pt_types sgi_pt_types[] = {
> > {0, NULL}
> > };
> >
> > +/*
> > + * File system definition and registration.
> > + */
> > +static struct file_system_type efs_fs_type = {
> > + .owner = THIS_MODULE,
> > + .name = "efs",
> > + .kill_sb = efs_kill_sb,
> > + .fs_flags = FS_REQUIRES_DEV,
> > + .init_fs_context = efs_init_fs_context,
> > +};
> > +MODULE_ALIAS_FS("efs");
> >
> > static struct kmem_cache * efs_inode_cachep;
> >
> > @@ -108,18 +104,10 @@ static void destroy_inodecache(void)
> > kmem_cache_destroy(efs_inode_cachep);
> > }
> >
> > -static int efs_remount(struct super_block *sb, int *flags, char *data)
> > -{
> > - sync_filesystem(sb);
> > - *flags |= SB_RDONLY;
> > - return 0;
> > -}
> > -
> > static const struct super_operations efs_superblock_operations = {
> > .alloc_inode = efs_alloc_inode,
> > .free_inode = efs_free_inode,
> > .statfs = efs_statfs,
> > - .remount_fs = efs_remount,
> > };
> >
> > static const struct export_operations efs_export_ops = {
> > @@ -249,26 +237,26 @@ static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
> > return 0;
> > }
> >
> > -static int efs_fill_super(struct super_block *s, void *d, int silent)
> > +static int efs_fill_super(struct super_block *s, struct fs_context *fc)
> > {
> > struct efs_sb_info *sb;
> > struct buffer_head *bh;
> > struct inode *root;
> >
> > - sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
> > + sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
>
> Ok, I guess this and elsewhere is fixing up whitespace oddities,
> not adding them. :)
Yeah, I fixed some tabs to spaces whitespace, when I was in that area of code.
>
> > if (!sb)
> > return -ENOMEM;
> > s->s_fs_info = sb;
> > s->s_time_min = 0;
> > s->s_time_max = U32_MAX;
> > -
> > +
> > s->s_magic = EFS_SUPER_MAGIC;
> > if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
> > pr_err("device does not support %d byte blocks\n",
> > EFS_BLOCKSIZE);
> > return -EINVAL;
>
> I think this can (should?) be converted to:
>
> return invalf(fc,
> "device does not support %d byte blocks",
> EFS_BLOCKSIZE);
>
> and similarly for other error printing failures along the fill_super path,
> with appropriate variants of invalf()/errorf()/warnf()/etc
>
> (dhowells - am I right about this?)
I'm still looking at this.
>
> > }
> > -
> > +
> > /* read the vh (volume header) block */
> > bh = sb_bread(s, 0);
> >
> > @@ -294,7 +282,7 @@ static int efs_fill_super(struct super_block *s, void *d, int silent)
> > pr_err("cannot read superblock\n");
> > return -EIO;
> > }
> > -
> > +
> > if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
> > #ifdef DEBUG
> > pr_warn("invalid superblock at block %u\n",
> > @@ -328,6 +316,49 @@ static int efs_fill_super(struct super_block *s, void *d, int silent)
> > return 0;
> > }
> >
> > +static void efs_free_fc(struct fs_context *fc)
> > +{
> > + kfree(fc->fs_private);
> > +}
>
> unneeded; see below
Agreed.
>
> > +static int efs_get_tree(struct fs_context *fc)
> > +{
> > + return get_tree_bdev(fc, efs_fill_super);
> > +}
> > +
> > +static int efs_reconfigure(struct fs_context *fc)
> > +{
> > + sync_filesystem(fc->root->d_sb);
>
> I think you need:
>
> fc->sb_flags |= SB_RDONLY;
>
> here to preserve the original behavior in efs_remount()
Good catch. I had noticed that /proc/mounts changed the permission to rw,
but not behaving as rw.
>
> > +
> > + return 0;
> > +}
> > +
> > +struct efs_context {
> > + unsigned long s_mount_opts;
> > +};
>
> This looks unused, and probably also copied from zonefs, which used it
> to store mount options - something efs doesn't have.
Agreed.
>
> > +
> > +static const struct fs_context_operations efs_context_opts = {
> > + .get_tree = efs_get_tree,
> > + .reconfigure = efs_reconfigure,
> > + .free = efs_free_fc,
> > +};
> > +
> > +/*
> > + * Set up the filesystem mount context.
> > + */
> > +static int efs_init_fs_context(struct fs_context *fc)
> > +{
> > + struct efs_context *ctx;
> > +
> > + ctx = kzalloc(sizeof(struct efs_context), GFP_KERNEL);
> > + if (!ctx)
> > + return -ENOMEM;
> > + fc->fs_private = ctx;
>
> so there's no reason to allocate and assign it here.
> which means efs_free_fc() doesn't need to exist either.
Agreed.
>
> > + fc->ops = &efs_context_opts;
> > +
> > + return 0;
> > +}
> > +
> > static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
> > struct super_block *sb = dentry->d_sb;
> > struct efs_sb_info *sbi = SUPER_INFO(sb);
>
