Commit 726c3342 authored by David Howells's avatar David Howells Committed by Linus Torvalds
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[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 



Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.

This complements the get_sb() patch.  That reduced the significance of
sb->s_root, allowing NFS to place a fake root there.  However, NFS does
require a dentry to use as a target for the statfs operation.  This permits
the root in the vfsmount to be used instead.

linux/mount.h has been added where necessary to make allyesconfig build
successfully.

Interest has also been expressed for use with the FUSE and XFS filesystems.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 454e2398

Documentation/filesystems/Locking

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ prototypes: 
	int (*sync_fs)(struct super_block *sb, int wait);

	void (*write_super_lockfs) (struct super_block *);

	void (*unlockfs) (struct super_block *);

	int (*statfs) (struct super_block *, struct kstatfs *);

	int (*statfs) (struct dentry *, struct kstatfs *);

	int (*remount_fs) (struct super_block *, int *, char *);

	void (*clear_inode) (struct inode *);

	void (*umount_begin) (struct super_block *);

Documentation/filesystems/vfs.txt

+1 −1
Original line number Diff line number Diff line
@@ -211,7 +211,7 @@ struct super_operations { 
        int (*sync_fs)(struct super_block *sb, int wait);

        void (*write_super_lockfs) (struct super_block *);

        void (*unlockfs) (struct super_block *);

        int (*statfs) (struct super_block *, struct kstatfs *);

        int (*statfs) (struct dentry *, struct kstatfs *);

        int (*remount_fs) (struct super_block *, int *, char *);

        void (*clear_inode) (struct inode *);

        void (*umount_begin) (struct super_block *);

arch/alpha/kernel/osf_sys.c

+1 −1
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ do_osf_statfs(struct dentry * dentry, struct osf_statfs __user *buffer, 
	      unsigned long bufsiz)

{

	struct kstatfs linux_stat;

	int error = vfs_statfs(dentry->d_inode->i_sb, &linux_stat);

	int error = vfs_statfs(dentry, &linux_stat);

	if (!error)

		error = linux_to_osf_statfs(&linux_stat, buffer, bufsiz);

	return error;

arch/mips/kernel/sysirix.c

+6 −6
Original line number Diff line number Diff line
@@ -694,7 +694,7 @@ asmlinkage int irix_statfs(const char __user *path, 
	if (error)

		goto out;



	error = vfs_statfs(nd.dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(nd.dentry, &kbuf);

	if (error)

		goto dput_and_out;
@@ -732,7 +732,7 @@ asmlinkage int irix_fstatfs(unsigned int fd, struct irix_statfs __user *buf) 
		goto out;

	}



	error = vfs_statfs(file->f_dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(file->f_dentry, &kbuf);

	if (error)

		goto out_f;
@@ -1360,7 +1360,7 @@ asmlinkage int irix_statvfs(char __user *fname, struct irix_statvfs __user *buf) 
	error = user_path_walk(fname, &nd);

	if (error)

		goto out;

	error = vfs_statfs(nd.dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(nd.dentry, &kbuf);

	if (error)

		goto dput_and_out;
@@ -1406,7 +1406,7 @@ asmlinkage int irix_fstatvfs(int fd, struct irix_statvfs __user *buf) 
		error = -EBADF;

		goto out;

	}

	error = vfs_statfs(file->f_dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(file->f_dentry, &kbuf);

	if (error)

		goto out_f;
@@ -1611,7 +1611,7 @@ asmlinkage int irix_statvfs64(char __user *fname, struct irix_statvfs64 __user * 
	error = user_path_walk(fname, &nd);

	if (error)

		goto out;

	error = vfs_statfs(nd.dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(nd.dentry, &kbuf);

	if (error)

		goto dput_and_out;
@@ -1658,7 +1658,7 @@ asmlinkage int irix_fstatvfs64(int fd, struct irix_statvfs __user *buf) 
		error = -EBADF;

		goto out;

	}

	error = vfs_statfs(file->f_dentry->d_inode->i_sb, &kbuf);

	error = vfs_statfs(file->f_dentry, &kbuf);

	if (error)

		goto out_f;

arch/parisc/hpux/sys_hpux.c

+5 −5
Original line number Diff line number Diff line
@@ -145,7 +145,7 @@ static int hpux_ustat(dev_t dev, struct hpux_ustat __user *ubuf) 
	s = user_get_super(dev);

	if (s == NULL)

		goto out;

	err = vfs_statfs(s, &sbuf);

	err = vfs_statfs(s->s_root, &sbuf);

	drop_super(s);

	if (err)

		goto out;
@@ -186,12 +186,12 @@ struct hpux_statfs { 
     int16_t f_pad;

};



static int vfs_statfs_hpux(struct super_block *sb, struct hpux_statfs *buf)

static int vfs_statfs_hpux(struct dentry *dentry, struct hpux_statfs *buf)

{

	struct kstatfs st;

	int retval;

	

	retval = vfs_statfs(sb, &st);

	retval = vfs_statfs(dentry, &st);

	if (retval)

		return retval;
@@ -219,7 +219,7 @@ asmlinkage long hpux_statfs(const char __user *path, 
	error = user_path_walk(path, &nd);

	if (!error) {

		struct hpux_statfs tmp;

		error = vfs_statfs_hpux(nd.dentry->d_inode->i_sb, &tmp);

		error = vfs_statfs_hpux(nd.dentry, &tmp);

		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))

			error = -EFAULT;

		path_release(&nd);
@@ -237,7 +237,7 @@ asmlinkage long hpux_fstatfs(unsigned int fd, struct hpux_statfs __user * buf) 
	file = fget(fd);

	if (!file)

		goto out;

	error = vfs_statfs_hpux(file->f_dentry->d_inode->i_sb, &tmp);

	error = vfs_statfs_hpux(file->f_dentry, &tmp);

	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))

		error = -EFAULT;

	fput(file);

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