Re: [PATCH 03/14] omfs: Implement show_options

[Bob Copeland]

On Wed, Jul 05, 2017 at 04:24:27PM +0100, David Howells wrote:
> Implement the show_options superblock op for omfs as part of a bid to get
> rid of s_options and generic_show_options() to make it easier to implement
> a context-based mount where the mount options can be passed individually
> over a file descriptor.
> 
> Note that the uid and gid should possibly be displayed relative to the
> viewer's user namespace.
> 
> Signed-off-by: David Howells 
> cc: Bob Copeland 

Acked-by: Bob Copeland 

-- 
Bob Copeland %% https://bobcopeland.com/

Re: [PATCH 03/14] omfs: Implement show_options

[Bob Copeland]

On Wed, Jul 05, 2017 at 04:24:27PM +0100, David Howells wrote:
> Implement the show_options superblock op for omfs as part of a bid to get
> rid of s_options and generic_show_options() to make it easier to implement
> a context-based mount where the mount options can be passed individually
> over a file descriptor.
> 
> Note that the uid and gid should possibly be displayed relative to the
> viewer's user namespace.
> 
> Signed-off-by: David Howells 
> cc: Bob Copeland 

Acked-by: Bob Copeland 

-- 
Bob Copeland %% https://bobcopeland.com/

[PATCH 03/14] omfs: Implement show_options

[David Howells]

Implement the show_options superblock op for omfs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Note that the uid and gid should possibly be displayed relative to the
viewer's user namespace.

Signed-off-by: David Howells 
cc: Bob Copeland 
cc: linux-karma-de...@lists.sourceforge.net
---

 fs/omfs/inode.c |   33 ++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index 8c9034ee7383..ee14af9e26f2 100644
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include "omfs.h"
 
@@ -290,12 +291,40 @@ static int omfs_statfs(struct dentry *dentry, struct 
kstatfs *buf)
return 0;
 }
 
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int omfs_show_options(struct seq_file *m, struct dentry *root)
+{
+   struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
+   umode_t cur_umask = current_umask();
+
+   if (!uid_eq(sbi->s_uid, current_uid()))
+   seq_printf(m, ",uid=%u",
+  from_kuid_munged(_user_ns, sbi->s_uid));
+   if (!gid_eq(sbi->s_gid, current_gid()))
+   seq_printf(m, ",gid=%u",
+  from_kgid_munged(_user_ns, sbi->s_gid));
+
+   if (sbi->s_dmask == sbi->s_fmask) {
+   if (sbi->s_fmask != cur_umask)
+   seq_printf(m, ",umask=%o", sbi->s_fmask);
+   } else {
+   if (sbi->s_dmask != cur_umask)
+   seq_printf(m, ",dmask=%o", sbi->s_dmask);
+   if (sbi->s_fmask != cur_umask)
+   seq_printf(m, ",fmask=%o", sbi->s_fmask);
+   }
+
+   return 0;
+}
+
 static const struct super_operations omfs_sops = {
.write_inode= omfs_write_inode,
.evict_inode= omfs_evict_inode,
.put_super  = omfs_put_super,
.statfs = omfs_statfs,
-   .show_options   = generic_show_options,
+   .show_options   = omfs_show_options,
 };
 
 /*
@@ -434,8 +463,6 @@ static int omfs_fill_super(struct super_block *sb, void 
*data, int silent)
struct inode *root;
int ret = -EINVAL;
 
-   save_mount_options(sb, (char *) data);
-
sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;

[PATCH 03/14] omfs: Implement show_options

[David Howells]

Implement the show_options superblock op for omfs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Note that the uid and gid should possibly be displayed relative to the
viewer's user namespace.

Signed-off-by: David Howells 
cc: Bob Copeland 
cc: linux-karma-de...@lists.sourceforge.net
---

 fs/omfs/inode.c |   33 ++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index 8c9034ee7383..ee14af9e26f2 100644
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include "omfs.h"
 
@@ -290,12 +291,40 @@ static int omfs_statfs(struct dentry *dentry, struct 
kstatfs *buf)
return 0;
 }
 
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int omfs_show_options(struct seq_file *m, struct dentry *root)
+{
+   struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
+   umode_t cur_umask = current_umask();
+
+   if (!uid_eq(sbi->s_uid, current_uid()))
+   seq_printf(m, ",uid=%u",
+  from_kuid_munged(_user_ns, sbi->s_uid));
+   if (!gid_eq(sbi->s_gid, current_gid()))
+   seq_printf(m, ",gid=%u",
+  from_kgid_munged(_user_ns, sbi->s_gid));
+
+   if (sbi->s_dmask == sbi->s_fmask) {
+   if (sbi->s_fmask != cur_umask)
+   seq_printf(m, ",umask=%o", sbi->s_fmask);
+   } else {
+   if (sbi->s_dmask != cur_umask)
+   seq_printf(m, ",dmask=%o", sbi->s_dmask);
+   if (sbi->s_fmask != cur_umask)
+   seq_printf(m, ",fmask=%o", sbi->s_fmask);
+   }
+
+   return 0;
+}
+
 static const struct super_operations omfs_sops = {
.write_inode= omfs_write_inode,
.evict_inode= omfs_evict_inode,
.put_super  = omfs_put_super,
.statfs = omfs_statfs,
-   .show_options   = generic_show_options,
+   .show_options   = omfs_show_options,
 };
 
 /*
@@ -434,8 +463,6 @@ static int omfs_fill_super(struct super_block *sb, void 
*data, int silent)
struct inode *root;
int ret = -EINVAL;
 
-   save_mount_options(sb, (char *) data);
-
sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;