The patch titled
mount options: add generic_show_options()
has been added to the -mm tree. Its filename is
mount-options-add-generic_show_options.patch
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------------------------------------------------------
Subject: mount options: add generic_show_options()
From: Miklos Szeredi <mszeredi@xxxxxxx>
Add a new s_options field to struct super_block. Filesystems can save
mount options passed to them in mount or remount. It is automatically
freed when the superblock is destroyed.
A new helper function, generic_show_options() is introduced, which uses
this field to display the mount options in /proc/mounts.
Another helper function, save_mount_options() may be used by
filesystems to save the options in the super block.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 49 ++++++++++++++++++++++++++++++++++++++-----
fs/super.c | 1
include/linux/fs.h | 9 +++++++
3 files changed, 54 insertions(+), 5 deletions(-)
diff -puN fs/namespace.c~mount-options-add-generic_show_options fs/namespace.c
--- a/fs/namespace.c~mount-options-add-generic_show_options
+++ a/fs/namespace.c
@@ -575,6 +575,50 @@ void mnt_unpin(struct vfsmount *mnt)
EXPORT_SYMBOL(mnt_unpin);
+static inline void mangle(struct seq_file *m, const char *s)
+{
+ seq_escape(m, s, " \t\n\\");
+}
+
+/*
+ * Simple .show_options callback for filesystems which don't want to
+ * implement more complex mount option showing.
+ *
+ * See also save_mount_options().
+ */
+int generic_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+ const char *options = mnt->mnt_sb->s_options;
+
+ if (options != NULL && options[0]) {
+ seq_putc(m, ',');
+ mangle(m, options);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(generic_show_options);
+
+/*
+ * If filesystem uses generic_show_options(), this function should be
+ * called from the fill_super() callback.
+ *
+ * The .remount_fs callback usually needs to be handled in a special
+ * way, to make sure, that previous options are not overwritten if the
+ * remount fails.
+ *
+ * Also note, that if the filesystem's .remount_fs function doesn't
+ * reset all options to their default value, but changes only newly
+ * given options, then the displayed options will not reflect reality
+ * any more.
+ */
+void save_mount_options(struct super_block *sb, char *options)
+{
+ kfree(sb->s_options);
+ sb->s_options = kstrdup(options, GFP_KERNEL);
+}
+EXPORT_SYMBOL(save_mount_options);
+
/* iterator */
static void *m_start(struct seq_file *m, loff_t *pos)
{
@@ -596,11 +640,6 @@ static void m_stop(struct seq_file *m, v
up_read(&namespace_sem);
}
-static inline void mangle(struct seq_file *m, const char *s)
-{
- seq_escape(m, s, " \t\n\\");
-}
-
static int show_vfsmnt(struct seq_file *m, void *v)
{
struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list);
diff -puN fs/super.c~mount-options-add-generic_show_options fs/super.c
--- a/fs/super.c~mount-options-add-generic_show_options
+++ a/fs/super.c
@@ -106,6 +106,7 @@ static inline void destroy_super(struct
{
security_sb_free(s);
kfree(s->s_subtype);
+ kfree(s->s_options);
kfree(s);
}
diff -puN include/linux/fs.h~mount-options-add-generic_show_options include/linux/fs.h
--- a/include/linux/fs.h~mount-options-add-generic_show_options
+++ a/include/linux/fs.h
@@ -1042,6 +1042,12 @@ struct super_block {
* in /proc/mounts will be "type.subtype"
*/
char *s_subtype;
+
+ /*
+ * Saved mount options for lazy filesystems using
+ * generic_show_options()
+ */
+ char *s_options;
};
extern struct timespec current_fs_time(struct super_block *sb);
@@ -1973,6 +1979,9 @@ extern int __must_check inode_setattr(st
extern void file_update_time(struct file *file);
+extern int generic_show_options(struct seq_file *m, struct vfsmount *mnt);
+extern void save_mount_options(struct super_block *sb, char *options);
+
static inline ino_t parent_ino(struct dentry *dentry)
{
ino_t res;
_
Patches currently in -mm which might be from mszeredi@xxxxxxx are
origin.patch
git-x86.patch
fuse-fix-attribute-caching-after-create.patch
fuse-save-space-in-struct-fuse_req.patch
fuse-limit-queued-background-requests.patch
mount-options-add-documentation.patch
mount-options-add-generic_show_options.patch
mount-options-fix-adfs.patch
mount-options-fix-affs.patch
mount-options-fix-afs.patch
mount-options-fix-autofs4.patch
mount-options-fix-autofs.patch
mount-options-fix-befs.patch
mount-options-fix-capifs.patch
mount-options-fix-devpts.patch
mount-options-fix-ext2.patch
mount-options-fix-fat.patch
mount-options-fix-fuse.patch
mount-options-fix-hostfs.patch
mount-options-fix-hpfs.patch
mount-options-fix-hugetlbfs.patch
mount-options-fix-isofs.patch
mount-options-fix-ncpfs.patch
mount-options-fix-reiserfs.patch
mount-options-fix-spufs.patch
mount-options-fix-tmpfs.patch
mount-options-fix-udf.patch
-
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