@@ -182,6 +182,7 @@ extern struct open_how build_open_how(int flags, umode_t mode);
extern int build_open_flags(const struct open_how *how, struct open_flags *op);
extern struct file *__close_fd_get_file(unsigned int fd);
+long do_ftruncate(struct file *file, loff_t length, int small);
long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
int chmod_common(const struct path *path, umode_t mode);
int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
@@ -154,49 +154,52 @@ COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length
}
#endif
-long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
+long do_ftruncate(struct file *file, loff_t length, int small)
{
struct inode *inode;
struct dentry *dentry;
+ int error;
+
+ dentry = file->f_path.dentry;
+ inode = dentry->d_inode;
+ if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
+ return -EINVAL;
+
+ /* Cannot ftruncate over 2^31 bytes without large file support */
+ if (small && length > MAX_NON_LFS)
+ return -EINVAL;
+
+ /* Check IS_APPEND on real upper inode */
+ if (IS_APPEND(file_inode(file)))
+ return -EPERM;
+ sb_start_write(inode->i_sb);
+ error = security_file_truncate(file);
+ if (!error)
+ error = do_truncate(file_mnt_idmap(file), dentry, length,
+ ATTR_MTIME | ATTR_CTIME, file);
+ sb_end_write(inode->i_sb);
+
+ return error;
+}
+
+long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
+{
struct fd f;
int error;
- error = -EINVAL;
if (length < 0)
- goto out;
- error = -EBADF;
+ return -EINVAL;
f = fdget(fd);
if (!f.file)
- goto out;
+ return -EBADF;
/* explicitly opened as large or we are on 64-bit box */
if (f.file->f_flags & O_LARGEFILE)
small = 0;
- dentry = f.file->f_path.dentry;
- inode = dentry->d_inode;
- error = -EINVAL;
- if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
- goto out_putf;
+ error = do_ftruncate(f.file, length, small);
- error = -EINVAL;
- /* Cannot ftruncate over 2^31 bytes without large file support */
- if (small && length > MAX_NON_LFS)
- goto out_putf;
-
- error = -EPERM;
- /* Check IS_APPEND on real upper inode */
- if (IS_APPEND(file_inode(f.file)))
- goto out_putf;
- sb_start_write(inode->i_sb);
- error = security_file_truncate(f.file);
- if (!error)
- error = do_truncate(file_mnt_idmap(f.file), dentry, length,
- ATTR_MTIME | ATTR_CTIME, f.file);
- sb_end_write(inode->i_sb);
-out_putf:
fdput(f);
-out:
return error;
}
do_sys_ftruncate receives a file descriptor, fgets the struct file, and finally actually truncates the file. do_ftruncate allows for passing in a file directly, with the caller already holding a reference to it. Signed-off-by: Tony Solomonik <tony.solomonik@gmail.com> --- fs/internal.h | 1 + fs/open.c | 57 +++++++++++++++++++++++++++------------------------ 2 files changed, 31 insertions(+), 27 deletions(-)