From: Tony Solomonik <[email protected]> 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 <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> (cherry picked from commit 5f0d594c602f870e3a3872f7ea42bf846a1d26cf) https://virtuozzo.atlassian.net/browse/VSTOR-123292 Signed-off-by: Vasileios Almpanis <[email protected]> Feature: dm-ploop: ploop target driver --- 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 d4f05a3aa34a..2fbfd5863397 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -138,6 +138,7 @@ 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, diff --git a/fs/open.c b/fs/open.c index 8d30f25f3a59..b82f5fc333d7 100644 --- a/fs/open.c +++ b/fs/open.c @@ -153,49 +153,52 @@ 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; - 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_path_truncate(&f.file->f_path); + error = security_path_truncate(&file->f_path); if (!error) - error = do_truncate(file_mnt_user_ns(f.file), dentry, length, - ATTR_MTIME | ATTR_CTIME, f.file); + error = do_truncate(file_mnt_user_ns(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 = do_ftruncate(f.file, length, small); + fdput(f); -out: return error; } -- 2.43.0 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
