Message ID | 20240124083301.8661-2-tony.solomonik@gmail.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | io_uring: add support for ftruncate | expand |
On Wed, Jan 24, 2024 at 10:33:00AM +0200, Tony Solomonik wrote: > do_sys_ftruncate receives a file descriptor, fgets the struct file, and > finally actually truncates the file. > > ftruncate_file 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 | 53 +++++++++++++++++++++++++++------------------------ > 2 files changed, 29 insertions(+), 25 deletions(-) > > diff --git a/fs/internal.h b/fs/internal.h > index 58e43341aebf..78a641ebd16e 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -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 ftruncate_file(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, > diff --git a/fs/open.c b/fs/open.c > index 02dc608d40d8..649d38eecfe4 100644 > --- a/fs/open.c > +++ b/fs/open.c > @@ -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 ftruncate_file(struct file *file, loff_t length, int small) All internal functions that io_uring currently calls are called do_*(): * do_rmdir() * do_unlinkat() * do_mkdirat() * do_symlinkat() * do_statx() So I'd follow that pattern and just call that thing do_ftruncate(). Otherwise looks good to me, Acked-by: Christian Brauner <brauner@kernel.org>
On Wed, Jan 24, 2024 at 10:33:00AM +0200, Tony Solomonik wrote: > /* explicitly opened as large or we are on 64-bit box */ > - if (f.file->f_flags & O_LARGEFILE) > + if (file->f_flags & O_LARGEFILE) > small = 0; > [...] > /* Cannot ftruncate over 2^31 bytes without large file support */ > if (small && length > MAX_NON_LFS) > - goto out_putf; > + return -EINVAL; I'd leave this in do_sys_truncate(). No need for ioring to care about this ancient problem.
diff --git a/fs/internal.h b/fs/internal.h index 58e43341aebf..78a641ebd16e 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -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 ftruncate_file(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, diff --git a/fs/open.c b/fs/open.c index 02dc608d40d8..649d38eecfe4 100644 --- a/fs/open.c +++ b/fs/open.c @@ -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 ftruncate_file(struct file *file, loff_t length, int small) { struct inode *inode; struct dentry *dentry; - struct fd f; int error; - error = -EINVAL; - if (length < 0) - goto out; - error = -EBADF; - f = fdget(fd); - if (!f.file) - goto out; - /* explicitly opened as large or we are on 64-bit box */ - if (f.file->f_flags & O_LARGEFILE) + if (file->f_flags & O_LARGEFILE) small = 0; - dentry = f.file->f_path.dentry; + dentry = 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; + if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) + return -EINVAL; - error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) - goto out_putf; + return -EINVAL; - error = -EPERM; /* Check IS_APPEND on real upper inode */ - if (IS_APPEND(file_inode(f.file))) - goto out_putf; + if (IS_APPEND(file_inode(file))) + return -EPERM; sb_start_write(inode->i_sb); - error = security_file_truncate(f.file); + error = security_file_truncate(file); if (!error) - error = do_truncate(file_mnt_idmap(f.file), dentry, length, - ATTR_MTIME | ATTR_CTIME, f.file); + error = do_truncate(file_mnt_idmap(file), dentry, length, + ATTR_MTIME | ATTR_CTIME, file); sb_end_write(inode->i_sb); -out_putf: + + return error; +} + +long do_sys_ftruncate(unsigned int fd, loff_t length, int small) +{ + struct fd f; + int error; + + if (length < 0) + return -EINVAL; + f = fdget(fd); + if (!f.file) + return -EBADF; + + error = ftruncate_file(f.file, length, small); + fdput(f); -out: return error; }
do_sys_ftruncate receives a file descriptor, fgets the struct file, and finally actually truncates the file. ftruncate_file 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 | 53 +++++++++++++++++++++++++++------------------------ 2 files changed, 29 insertions(+), 25 deletions(-)