X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fopen.c;h=f53a5b9ffb7dce308f6e0e05d4982d343261564c;hb=02a78cdf425156b86abdb6883f837a70fb7106da;hp=2fac58c51910cf250607a8f7161edc608d8c18cc;hpb=abf914208a1e120446ea4f9bc26406bd3a4579e1;p=linux-2.6

diff --git a/fs/open.c b/fs/open.c
index 2fac58c519..f53a5b9ffb 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -194,7 +194,7 @@ out:
 	return error;
 }
 
-int do_truncate(struct dentry *dentry, loff_t length)
+int do_truncate(struct dentry *dentry, loff_t length, struct file *filp)
 {
 	int err;
 	struct iattr newattrs;
@@ -205,6 +205,10 @@ int do_truncate(struct dentry *dentry, loff_t length)
 
 	newattrs.ia_size = length;
 	newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
+	if (filp) {
+		newattrs.ia_file = filp;
+		newattrs.ia_valid |= ATTR_FILE;
+	}
 
 	down(&dentry->d_inode->i_sem);
 	err = notify_change(dentry, &newattrs);
@@ -236,7 +240,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length)
 	if (!S_ISREG(inode->i_mode))
 		goto dput_and_out;
 
-	error = permission(inode,MAY_WRITE,&nd);
+	error = vfs_permission(&nd, MAY_WRITE);
 	if (error)
 		goto dput_and_out;
 
@@ -262,7 +266,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length)
 	error = locks_verify_truncate(inode, NULL, length);
 	if (!error) {
 		DQUOT_INIT(inode);
-		error = do_truncate(nd.dentry, length);
+		error = do_truncate(nd.dentry, length, NULL);
 	}
 	put_write_access(inode);
 
@@ -314,7 +318,7 @@ static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 
 	error = locks_verify_truncate(inode, file, length);
 	if (!error)
-		error = do_truncate(dentry, length);
+		error = do_truncate(dentry, length, file);
 out_putf:
 	fput(file);
 out:
@@ -390,7 +394,7 @@ asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times)
                         goto dput_and_out;
 
 		if (current->fsuid != inode->i_uid &&
-		    (error = permission(inode,MAY_WRITE,&nd)) != 0)
+		    (error = vfs_permission(&nd, MAY_WRITE)) != 0)
 			goto dput_and_out;
 	}
 	down(&inode->i_sem);
@@ -443,7 +447,7 @@ long do_utimes(char __user * filename, struct timeval * times)
                         goto dput_and_out;
 
 		if (current->fsuid != inode->i_uid &&
-		    (error = permission(inode,MAY_WRITE,&nd)) != 0)
+		    (error = vfs_permission(&nd, MAY_WRITE)) != 0)
 			goto dput_and_out;
 	}
 	down(&inode->i_sem);
@@ -502,7 +506,7 @@ asmlinkage long sys_access(const char __user * filename, int mode)
 
 	res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
 	if (!res) {
-		res = permission(nd.dentry->d_inode, mode, &nd);
+		res = vfs_permission(&nd, mode);
 		/* SuS v2 requires we report a read only fs too */
 		if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode)
 		   && !special_file(nd.dentry->d_inode->i_mode))
@@ -526,7 +530,7 @@ asmlinkage long sys_chdir(const char __user * filename)
 	if (error)
 		goto out;
 
-	error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
+	error = vfs_permission(&nd, MAY_EXEC);
 	if (error)
 		goto dput_and_out;
 
@@ -559,7 +563,7 @@ asmlinkage long sys_fchdir(unsigned int fd)
 	if (!S_ISDIR(inode->i_mode))
 		goto out_putf;
 
-	error = permission(inode, MAY_EXEC, NULL);
+	error = file_permission(file, MAY_EXEC);
 	if (!error)
 		set_fs_pwd(current->fs, mnt, dentry);
 out_putf:
@@ -577,7 +581,7 @@ asmlinkage long sys_chroot(const char __user * filename)
 	if (error)
 		goto out;
 
-	error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
+	error = vfs_permission(&nd, MAY_EXEC);
 	if (error)
 		goto dput_and_out;
 
@@ -738,52 +742,16 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
 	return error;
 }
 
-/*
- * Note that while the flag value (low two bits) for sys_open means:
- *	00 - read-only
- *	01 - write-only
- *	10 - read-write
- *	11 - special
- * it is changed into
- *	00 - no permissions needed
- *	01 - read-permission
- *	10 - write-permission
- *	11 - read-write
- * for the internal routines (ie open_namei()/follow_link() etc). 00 is
- * used by symlinks.
- */
-struct file *filp_open(const char * filename, int flags, int mode)
-{
-	int namei_flags, error;
-	struct nameidata nd;
-
-	namei_flags = flags;
-	if ((namei_flags+1) & O_ACCMODE)
-		namei_flags++;
-	if (namei_flags & O_TRUNC)
-		namei_flags |= 2;
-
-	error = open_namei(filename, namei_flags, mode, &nd);
-	if (!error)
-		return dentry_open(nd.dentry, nd.mnt, flags);
-
-	return ERR_PTR(error);
-}
-
-EXPORT_SYMBOL(filp_open);
-
-struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+					int flags, struct file *f,
+					int (*open)(struct inode *, struct file *))
 {
-	struct file * f;
 	struct inode *inode;
 	int error;
 
-	error = -ENFILE;
-	f = get_empty_filp();
-	if (!f)
-		goto cleanup_dentry;
 	f->f_flags = flags;
-	f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
+	f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
+				FMODE_PREAD | FMODE_PWRITE;
 	inode = dentry->d_inode;
 	if (f->f_mode & FMODE_WRITE) {
 		error = get_write_access(inode);
@@ -798,11 +766,14 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
 	f->f_op = fops_get(inode->i_fop);
 	file_move(f, &inode->i_sb->s_files);
 
-	if (f->f_op && f->f_op->open) {
-		error = f->f_op->open(inode,f);
+	if (!open && f->f_op)
+		open = f->f_op->open;
+	if (open) {
+		error = open(inode, f);
 		if (error)
 			goto cleanup_all;
 	}
+
 	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 
 	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
@@ -828,12 +799,117 @@ cleanup_all:
 	f->f_vfsmnt = NULL;
 cleanup_file:
 	put_filp(f);
-cleanup_dentry:
 	dput(dentry);
 	mntput(mnt);
 	return ERR_PTR(error);
 }
 
+/*
+ * Note that while the flag value (low two bits) for sys_open means:
+ *	00 - read-only
+ *	01 - write-only
+ *	10 - read-write
+ *	11 - special
+ * it is changed into
+ *	00 - no permissions needed
+ *	01 - read-permission
+ *	10 - write-permission
+ *	11 - read-write
+ * for the internal routines (ie open_namei()/follow_link() etc). 00 is
+ * used by symlinks.
+ */
+struct file *filp_open(const char * filename, int flags, int mode)
+{
+	int namei_flags, error;
+	struct nameidata nd;
+
+	namei_flags = flags;
+	if ((namei_flags+1) & O_ACCMODE)
+		namei_flags++;
+
+	error = open_namei(filename, namei_flags, mode, &nd);
+	if (!error)
+		return nameidata_to_filp(&nd, flags);
+
+	return ERR_PTR(error);
+}
+EXPORT_SYMBOL(filp_open);
+
+/**
+ * lookup_instantiate_filp - instantiates the open intent filp
+ * @nd: pointer to nameidata
+ * @dentry: pointer to dentry
+ * @open: open callback
+ *
+ * Helper for filesystems that want to use lookup open intents and pass back
+ * a fully instantiated struct file to the caller.
+ * This function is meant to be called from within a filesystem's
+ * lookup method.
+ * Note that in case of error, nd->intent.open.file is destroyed, but the
+ * path information remains valid.
+ * If the open callback is set to NULL, then the standard f_op->open()
+ * filesystem callback is substituted.
+ */
+struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
+		int (*open)(struct inode *, struct file *))
+{
+	if (IS_ERR(nd->intent.open.file))
+		goto out;
+	if (IS_ERR(dentry))
+		goto out_err;
+	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt),
+					     nd->intent.open.flags - 1,
+					     nd->intent.open.file,
+					     open);
+out:
+	return nd->intent.open.file;
+out_err:
+	release_open_intent(nd);
+	nd->intent.open.file = (struct file *)dentry;
+	goto out;
+}
+EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
+
+/**
+ * nameidata_to_filp - convert a nameidata to an open filp.
+ * @nd: pointer to nameidata
+ * @flags: open flags
+ *
+ * Note that this function destroys the original nameidata
+ */
+struct file *nameidata_to_filp(struct nameidata *nd, int flags)
+{
+	struct file *filp;
+
+	/* Pick up the filp from the open intent */
+	filp = nd->intent.open.file;
+	/* Has the filesystem initialised the file for us? */
+	if (filp->f_dentry == NULL)
+		filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL);
+	else
+		path_release(nd);
+	return filp;
+}
+
+/*
+ * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
+ * error.
+ */
+struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+{
+	int error;
+	struct file *f;
+
+	error = -ENFILE;
+	f = get_empty_filp();
+	if (f == NULL) {
+		dput(dentry);
+		mntput(mnt);
+		return ERR_PTR(error);
+	}
+
+	return __dentry_open(dentry, mnt, flags, f, NULL);
+}
 EXPORT_SYMBOL(dentry_open);
 
 /*