summaryrefslogtreecommitdiffstats
path: root/fs/open.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/open.c')
-rw-r--r--fs/open.c112
1 files changed, 87 insertions, 25 deletions
diff --git a/fs/open.c b/fs/open.c
index f0d90cf0495..f53a5b9ffb7 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;
@@ -739,7 +743,8 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
}
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
- int flags, struct file *f)
+ int flags, struct file *f,
+ int (*open)(struct inode *, struct file *))
{
struct inode *inode;
int error;
@@ -761,11 +766,14 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
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);
@@ -814,28 +822,79 @@ struct file *filp_open(const char * filename, int flags, int mode)
{
int namei_flags, error;
struct nameidata nd;
- struct file *f;
namei_flags = flags;
if ((namei_flags+1) & O_ACCMODE)
namei_flags++;
- if (namei_flags & O_TRUNC)
- namei_flags |= 2;
-
- error = -ENFILE;
- f = get_empty_filp();
- if (f == NULL)
- return ERR_PTR(error);
error = open_namei(filename, namei_flags, mode, &nd);
if (!error)
- return __dentry_open(nd.dentry, nd.mnt, flags, f);
+ return nameidata_to_filp(&nd, flags);
- put_filp(f);
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;
@@ -843,10 +902,13 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
error = -ENFILE;
f = get_empty_filp();
- if (f == NULL)
+ if (f == NULL) {
+ dput(dentry);
+ mntput(mnt);
return ERR_PTR(error);
+ }
- return __dentry_open(dentry, mnt, flags, f);
+ return __dentry_open(dentry, mnt, flags, f, NULL);
}
EXPORT_SYMBOL(dentry_open);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-10 14:50:33 +0000