[PATCH v6 13/27] nfs: get rid of mount_info ->fill_super()

From: Scott Mayhew
Date: Tue Dec 10 2019 - 07:32:38 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

The only possible values are nfs_fill_super and nfs_clone_super. The
latter is used only when crossing into a submount and it is almost
identical to the former; the only differences are
* ->s_time_gran unconditionally set to 1 (even for v2 mounts).
Regression dating back to 2012, actually.
* ->s_blocksize/->s_blocksize_bits set to that of parent.

Rather than messing with the method, stash ->s_blocksize_bits in
mount_info in submount case and after the (now unconditional)
call of nfs_fill_super() override ->s_blocksize/->s_blocksize_bits
if that has been set.

Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/nfs/internal.h | 4 +--
fs/nfs/namespace.c | 2 +-
fs/nfs/nfs4super.c | 1 -
fs/nfs/super.c | 75 ++++++++++------------------------------------
4 files changed, 18 insertions(+), 64 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 0bb0493785fc..65c8e353cb6b 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -136,7 +136,7 @@ struct nfs_mount_request {
};

struct nfs_mount_info {
- void (*fill_super)(struct super_block *, struct nfs_mount_info *);
+ unsigned int inherited_bsize;
int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
struct nfs_parsed_mount_data *parsed;
struct nfs_clone_mount *cloned;
@@ -395,8 +395,6 @@ int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_
int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
void nfs_kill_super(struct super_block *);
-void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
-void nfs_clone_super(struct super_block *, struct nfs_mount_info *);

extern struct rpc_stat nfs_rpcstat;

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index e5f4f2d760af..30331558bd8e 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -232,7 +232,7 @@ struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
.authflavor = authflavor,
};
struct nfs_mount_info mount_info = {
- .fill_super = nfs_clone_super,
+ .inherited_bsize = sb->s_blocksize_bits,
.set_security = nfs_clone_sb_security,
.cloned = &mountdata,
.mntfh = fh,
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index e5d8a76bd144..5020a43b31c9 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -224,7 +224,6 @@ static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
{
struct nfs_clone_mount *data = raw_data;
struct nfs_mount_info mount_info = {
- .fill_super = nfs_fill_super,
.set_security = nfs_clone_sb_security,
.cloned = data,
.nfs_mod = &nfs_v4,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6239c78d8f54..2bcf0f8295e0 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2339,29 +2339,9 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
EXPORT_SYMBOL_GPL(nfs_remount);

/*
- * Initialise the common bits of the superblock
+ * Finish setting up an NFS superblock
*/
-static void nfs_initialise_sb(struct super_block *sb)
-{
- struct nfs_server *server = NFS_SB(sb);
-
- sb->s_magic = NFS_SUPER_MAGIC;
-
- /* We probably want something more informative here */
- snprintf(sb->s_id, sizeof(sb->s_id),
- "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
-
- if (sb->s_blocksize == 0)
- sb->s_blocksize = nfs_block_bits(server->wsize,
- &sb->s_blocksize_bits);
-
- nfs_super_set_maxbytes(sb, server->maxfilesize);
-}
-
-/*
- * Finish setting up an NFS2/3 superblock
- */
-void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
+static void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
{
struct nfs_parsed_mount_data *data = mount_info->parsed;
struct nfs_server *server = NFS_SB(sb);
@@ -2391,44 +2371,17 @@ void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
sb->s_time_max = S64_MAX;
}

- nfs_initialise_sb(sb);
-}
-EXPORT_SYMBOL_GPL(nfs_fill_super);
-
-/*
- * Finish setting up a cloned NFS2/3/4 superblock
- */
-void nfs_clone_super(struct super_block *sb,
- struct nfs_mount_info *mount_info)
-{
- const struct super_block *old_sb = mount_info->cloned->sb;
- struct nfs_server *server = NFS_SB(sb);
-
- sb->s_blocksize_bits = old_sb->s_blocksize_bits;
- sb->s_blocksize = old_sb->s_blocksize;
- sb->s_maxbytes = old_sb->s_maxbytes;
- sb->s_xattr = old_sb->s_xattr;
- sb->s_op = old_sb->s_op;
- sb->s_export_op = old_sb->s_export_op;
+ sb->s_magic = NFS_SUPER_MAGIC;

- if (server->nfs_client->rpc_ops->version != 2) {
- /* The VFS shouldn't apply the umask to mode bits. We will do
- * so ourselves when necessary.
- */
- sb->s_flags |= SB_POSIXACL;
- sb->s_time_gran = 1;
- } else
- sb->s_time_gran = 1000;
+ /* We probably want something more informative here */
+ snprintf(sb->s_id, sizeof(sb->s_id),
+ "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));

- if (server->nfs_client->rpc_ops->version != 4) {
- sb->s_time_min = 0;
- sb->s_time_max = U32_MAX;
- } else {
- sb->s_time_min = S64_MIN;
- sb->s_time_max = S64_MAX;
- }
+ if (sb->s_blocksize == 0)
+ sb->s_blocksize = nfs_block_bits(server->wsize,
+ &sb->s_blocksize_bits);

- nfs_initialise_sb(sb);
+ nfs_super_set_maxbytes(sb, server->maxfilesize);
}

static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
@@ -2701,8 +2654,13 @@ static struct dentry *nfs_fs_mount_common(int flags, const char *dev_name,
}

if (!s->s_root) {
+ unsigned bsize = mount_info->inherited_bsize;
/* initial superblock/root creation */
- mount_info->fill_super(s, mount_info);
+ nfs_fill_super(s, mount_info);
+ if (bsize) {
+ s->s_blocksize_bits = bsize;
+ s->s_blocksize = 1U << bsize;
+ }
nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
if (!(server->flags & NFS_MOUNT_UNSHARED))
s->s_iflags |= SB_I_MULTIROOT;
@@ -2737,7 +2695,6 @@ struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data)
{
struct nfs_mount_info mount_info = {
- .fill_super = nfs_fill_super,
.set_security = nfs_set_sb_security,
};
struct dentry *mntroot = ERR_PTR(-ENOMEM);
--
2.17.2