diff options
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 871 |
1 files changed, 507 insertions, 364 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 0074afa7ecb3..833bae068770 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -28,30 +28,32 @@ const struct file_operations generic_ro_fops = { .llseek = generic_file_llseek, .read_iter = generic_file_read_iter, - .mmap = generic_file_readonly_mmap, - .splice_read = generic_file_splice_read, + .mmap_prepare = generic_file_readonly_mmap_prepare, + .splice_read = filemap_splice_read, }; EXPORT_SYMBOL(generic_ro_fops); static inline bool unsigned_offsets(struct file *file) { - return file->f_mode & FMODE_UNSIGNED_OFFSET; + return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET; } /** - * vfs_setpos - update the file offset for lseek + * vfs_setpos_cookie - update the file offset for lseek and reset cookie * @file: file structure in question * @offset: file offset to seek to * @maxsize: maximum file size + * @cookie: cookie to reset * - * This is a low-level filesystem helper for updating the file offset to - * the value specified by @offset if the given offset is valid and it is - * not equal to the current file offset. + * Update the file offset to the value specified by @offset if the given + * offset is valid and it is not equal to the current file offset and + * reset the specified cookie to indicate that a seek happened. * * Return the specified offset on success and -EINVAL on invalid offset. */ -loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) +static loff_t vfs_setpos_cookie(struct file *file, loff_t offset, + loff_t maxsize, u64 *cookie) { if (offset < 0 && !unsigned_offsets(file)) return -EINVAL; @@ -60,35 +62,48 @@ loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) if (offset != file->f_pos) { file->f_pos = offset; - file->f_version = 0; + if (cookie) + *cookie = 0; } return offset; } -EXPORT_SYMBOL(vfs_setpos); /** - * generic_file_llseek_size - generic llseek implementation for regular files - * @file: file structure to seek on + * vfs_setpos - update the file offset for lseek + * @file: file structure in question * @offset: file offset to seek to - * @whence: type of seek - * @size: max size of this file in file system - * @eof: offset used for SEEK_END position + * @maxsize: maximum file size * - * This is a variant of generic_file_llseek that allows passing in a custom - * maximum file size and a custom EOF position, for e.g. hashed directories + * This is a low-level filesystem helper for updating the file offset to + * the value specified by @offset if the given offset is valid and it is + * not equal to the current file offset. * - * Synchronization: - * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) - * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. - * read/writes behave like SEEK_SET against seeks. + * Return the specified offset on success and -EINVAL on invalid offset. */ -loff_t -generic_file_llseek_size(struct file *file, loff_t offset, int whence, - loff_t maxsize, loff_t eof) +loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) +{ + return vfs_setpos_cookie(file, offset, maxsize, NULL); +} +EXPORT_SYMBOL(vfs_setpos); + +/** + * must_set_pos - check whether f_pos has to be updated + * @file: file to seek on + * @offset: offset to use + * @whence: type of seek operation + * @eof: end of file + * + * Check whether f_pos needs to be updated and update @offset according + * to @whence. + * + * Return: 0 if f_pos doesn't need to be updated, 1 if f_pos has to be + * updated, and negative error code on failure. + */ +static int must_set_pos(struct file *file, loff_t *offset, int whence, loff_t eof) { switch (whence) { case SEEK_END: - offset += eof; + *offset += eof; break; case SEEK_CUR: /* @@ -97,23 +112,17 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, * f_pos value back to the file because a concurrent read(), * write() or lseek() might have altered it */ - if (offset == 0) - return file->f_pos; - /* - * f_lock protects against read/modify/write race with other - * SEEK_CURs. Note that parallel writes and reads behave - * like SEEK_SET. - */ - spin_lock(&file->f_lock); - offset = vfs_setpos(file, file->f_pos + offset, maxsize); - spin_unlock(&file->f_lock); - return offset; + if (*offset == 0) { + *offset = file->f_pos; + return 0; + } + break; case SEEK_DATA: /* * In the generic case the entire file is data, so as long as * offset isn't at the end of the file then the offset is data. */ - if ((unsigned long long)offset >= eof) + if ((unsigned long long)*offset >= eof) return -ENXIO; break; case SEEK_HOLE: @@ -121,23 +130,114 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, * There is a virtual hole at the end of the file, so as long as * offset isn't i_size or larger, return i_size. */ - if ((unsigned long long)offset >= eof) + if ((unsigned long long)*offset >= eof) return -ENXIO; - offset = eof; + *offset = eof; break; } + return 1; +} + +/** + * generic_file_llseek_size - generic llseek implementation for regular files + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @maxsize: max size of this file in file system + * @eof: offset used for SEEK_END position + * + * This is a variant of generic_file_llseek that allows passing in a custom + * maximum file size and a custom EOF position, for e.g. hashed directories + * + * Synchronization: + * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) + * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. + * read/writes behave like SEEK_SET against seeks. + */ +loff_t +generic_file_llseek_size(struct file *file, loff_t offset, int whence, + loff_t maxsize, loff_t eof) +{ + int ret; + + ret = must_set_pos(file, &offset, whence, eof); + if (ret < 0) + return ret; + if (ret == 0) + return offset; + + if (whence == SEEK_CUR) { + /* + * If the file requires locking via f_pos_lock we know + * that mutual exclusion for SEEK_CUR on the same file + * is guaranteed. If the file isn't locked, we take + * f_lock to protect against f_pos races with other + * SEEK_CURs. + */ + if (file_seek_cur_needs_f_lock(file)) { + guard(spinlock)(&file->f_lock); + return vfs_setpos(file, file->f_pos + offset, maxsize); + } + return vfs_setpos(file, file->f_pos + offset, maxsize); + } + return vfs_setpos(file, offset, maxsize); } EXPORT_SYMBOL(generic_file_llseek_size); /** + * generic_llseek_cookie - versioned llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @cookie: cookie to update + * + * See generic_file_llseek for a general description and locking assumptions. + * + * In contrast to generic_file_llseek, this function also resets a + * specified cookie to indicate a seek took place. + */ +loff_t generic_llseek_cookie(struct file *file, loff_t offset, int whence, + u64 *cookie) +{ + struct inode *inode = file->f_mapping->host; + loff_t maxsize = inode->i_sb->s_maxbytes; + loff_t eof = i_size_read(inode); + int ret; + + if (WARN_ON_ONCE(!cookie)) + return -EINVAL; + + /* + * Require that this is only used for directories that guarantee + * synchronization between readdir and seek so that an update to + * @cookie is correctly synchronized with concurrent readdir. + */ + if (WARN_ON_ONCE(!(file->f_mode & FMODE_ATOMIC_POS))) + return -EINVAL; + + ret = must_set_pos(file, &offset, whence, eof); + if (ret < 0) + return ret; + if (ret == 0) + return offset; + + /* No need to hold f_lock because we know that f_pos_lock is held. */ + if (whence == SEEK_CUR) + return vfs_setpos_cookie(file, file->f_pos + offset, maxsize, cookie); + + return vfs_setpos_cookie(file, offset, maxsize, cookie); +} +EXPORT_SYMBOL(generic_llseek_cookie); + +/** * generic_file_llseek - generic llseek implementation for regular files * @file: file structure to seek on * @offset: file offset to seek to * @whence: type of seek * - * This is a generic implemenation of ->llseek useable for all normal local + * This is a generic implementation of ->llseek useable for all normal local * filesystems. It just updates the file offset to the value specified by * @offset and @whence. */ @@ -227,18 +327,14 @@ loff_t noop_llseek(struct file *file, loff_t offset, int whence) } EXPORT_SYMBOL(noop_llseek); -loff_t no_llseek(struct file *file, loff_t offset, int whence) -{ - return -ESPIPE; -} -EXPORT_SYMBOL(no_llseek); - loff_t default_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file_inode(file); loff_t retval; - inode_lock(inode); + retval = inode_lock_killable(inode); + if (retval) + return retval; switch (whence) { case SEEK_END: offset += i_size_read(inode); @@ -276,10 +372,8 @@ loff_t default_llseek(struct file *file, loff_t offset, int whence) } retval = -EINVAL; if (offset >= 0 || unsigned_offsets(file)) { - if (offset != file->f_pos) { + if (offset != file->f_pos) file->f_pos = offset; - file->f_version = 0; - } retval = offset; } out: @@ -290,32 +384,26 @@ EXPORT_SYMBOL(default_llseek); loff_t vfs_llseek(struct file *file, loff_t offset, int whence) { - loff_t (*fn)(struct file *, loff_t, int); - - fn = no_llseek; - if (file->f_mode & FMODE_LSEEK) { - if (file->f_op->llseek) - fn = file->f_op->llseek; - } - return fn(file, offset, whence); + if (!(file->f_mode & FMODE_LSEEK)) + return -ESPIPE; + return file->f_op->llseek(file, offset, whence); } EXPORT_SYMBOL(vfs_llseek); static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) { off_t retval; - struct fd f = fdget_pos(fd); - if (!f.file) + CLASS(fd_pos, f)(fd); + if (fd_empty(f)) return -EBADF; retval = -EINVAL; if (whence <= SEEK_MAX) { - loff_t res = vfs_llseek(f.file, offset, whence); + loff_t res = vfs_llseek(fd_file(f), offset, whence); retval = res; if (res != (loff_t)retval) retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ } - fdput_pos(f); return retval; } @@ -338,17 +426,16 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, unsigned int, whence) { int retval; - struct fd f = fdget_pos(fd); + CLASS(fd_pos, f)(fd); loff_t offset; - if (!f.file) + if (fd_empty(f)) return -EBADF; - retval = -EINVAL; if (whence > SEEK_MAX) - goto out_putf; + return -EINVAL; - offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, + offset = vfs_llseek(fd_file(f), ((loff_t) offset_high << 32) | offset_low, whence); retval = (int)offset; @@ -357,14 +444,15 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, if (!copy_to_user(result, &offset, sizeof(offset))) retval = 0; } -out_putf: - fdput_pos(f); return retval; } #endif int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) { + int mask = read_write == READ ? MAY_READ : MAY_WRITE; + int ret; + if (unlikely((ssize_t) count < 0)) return -EINVAL; @@ -382,22 +470,25 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t } } - return security_file_permission(file, - read_write == READ ? MAY_READ : MAY_WRITE); + ret = security_file_permission(file, mask); + if (ret) + return ret; + + return fsnotify_file_area_perm(file, mask, ppos, count); } +EXPORT_SYMBOL(rw_verify_area); static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) { - struct iovec iov = { .iov_base = buf, .iov_len = len }; struct kiocb kiocb; struct iov_iter iter; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = (ppos ? *ppos : 0); - iov_iter_init(&iter, READ, &iov, 1, len); + iov_iter_ubuf(&iter, ITER_DEST, buf, len); - ret = call_read_iter(filp, &kiocb, &iter); + ret = filp->f_op->read_iter(&kiocb, &iter); BUG_ON(ret == -EIOCBQUEUED); if (ppos) *ppos = kiocb.ki_pos; @@ -435,7 +526,7 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) init_sync_kiocb(&kiocb, file); kiocb.ki_pos = pos ? *pos : 0; - iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len); + iov_iter_kvec(&iter, ITER_DEST, &iov, 1, iov.iov_len); ret = file->f_op->read_iter(&kiocb, &iter); if (ret > 0) { if (pos) @@ -491,16 +582,15 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) { - struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; struct kiocb kiocb; struct iov_iter iter; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = (ppos ? *ppos : 0); - iov_iter_init(&iter, WRITE, &iov, 1, len); + iov_iter_ubuf(&iter, ITER_SOURCE, (void __user *)buf, len); - ret = call_write_iter(filp, &kiocb, &iter); + ret = filp->f_op->write_iter(&kiocb, &iter); BUG_ON(ret == -EIOCBQUEUED); if (ret > 0 && ppos) *ppos = kiocb.ki_pos; @@ -508,14 +598,9 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t } /* caller is responsible for file_start_write/file_end_write */ -ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) +ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos) { - struct kvec iov = { - .iov_base = (void *)buf, - .iov_len = min_t(size_t, count, MAX_RW_COUNT), - }; struct kiocb kiocb; - struct iov_iter iter; ssize_t ret; if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) @@ -531,8 +616,7 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t init_sync_kiocb(&kiocb, file); kiocb.ki_pos = pos ? *pos : 0; - iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len); - ret = file->f_op->write_iter(&kiocb, &iter); + ret = file->f_op->write_iter(&kiocb, from); if (ret > 0) { if (pos) *pos = kiocb.ki_pos; @@ -542,6 +626,18 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t inc_syscw(current); return ret; } + +/* caller is responsible for file_start_write/file_end_write */ +ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) +{ + struct kvec iov = { + .iov_base = (void *)buf, + .iov_len = min_t(size_t, count, MAX_RW_COUNT), + }; + struct iov_iter iter; + iov_iter_kvec(&iter, ITER_SOURCE, &iov, 1, iov.iov_len); + return __kernel_write_iter(file, &iter, pos); +} /* * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()", * but autofs is one of the few internal kernel users that actually @@ -607,19 +703,18 @@ static inline loff_t *file_ppos(struct file *file) ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) { - struct fd f = fdget_pos(fd); + CLASS(fd_pos, f)(fd); ssize_t ret = -EBADF; - if (f.file) { - loff_t pos, *ppos = file_ppos(f.file); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); if (ppos) { pos = *ppos; ppos = &pos; } - ret = vfs_read(f.file, buf, count, ppos); + ret = vfs_read(fd_file(f), buf, count, ppos); if (ret >= 0 && ppos) - f.file->f_pos = pos; - fdput_pos(f); + fd_file(f)->f_pos = pos; } return ret; } @@ -631,19 +726,18 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) { - struct fd f = fdget_pos(fd); + CLASS(fd_pos, f)(fd); ssize_t ret = -EBADF; - if (f.file) { - loff_t pos, *ppos = file_ppos(f.file); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); if (ppos) { pos = *ppos; ppos = &pos; } - ret = vfs_write(f.file, buf, count, ppos); + ret = vfs_write(fd_file(f), buf, count, ppos); if (ret >= 0 && ppos) - f.file->f_pos = pos; - fdput_pos(f); + fd_file(f)->f_pos = pos; } return ret; @@ -658,21 +752,17 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, loff_t pos) { - struct fd f; - ssize_t ret = -EBADF; - if (pos < 0) return -EINVAL; - f = fdget(fd); - if (f.file) { - ret = -ESPIPE; - if (f.file->f_mode & FMODE_PREAD) - ret = vfs_read(f.file, buf, count, &pos); - fdput(f); - } + CLASS(fd, f)(fd); + if (fd_empty(f)) + return -EBADF; - return ret; + if (fd_file(f)->f_mode & FMODE_PREAD) + return vfs_read(fd_file(f), buf, count, &pos); + + return -ESPIPE; } SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, @@ -681,24 +771,28 @@ SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, return ksys_pread64(fd, buf, count, pos); } +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64) +COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf, + size_t, count, compat_arg_u64_dual(pos)) +{ + return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos)); +} +#endif + ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, size_t count, loff_t pos) { - struct fd f; - ssize_t ret = -EBADF; - if (pos < 0) return -EINVAL; - f = fdget(fd); - if (f.file) { - ret = -ESPIPE; - if (f.file->f_mode & FMODE_PWRITE) - ret = vfs_write(f.file, buf, count, &pos); - fdput(f); - } + CLASS(fd, f)(fd); + if (fd_empty(f)) + return -EBADF; - return ret; + if (fd_file(f)->f_mode & FMODE_PWRITE) + return vfs_write(fd_file(f), buf, count, &pos); + + return -ESPIPE; } SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, @@ -707,6 +801,14 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, return ksys_pwrite64(fd, buf, count, pos); } +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64) +COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf, + size_t, count, compat_arg_u64_dual(pos)) +{ + return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos)); +} +#endif + static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, loff_t *ppos, int type, rwf_t flags) { @@ -714,15 +816,15 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, ssize_t ret; init_sync_kiocb(&kiocb, filp); - ret = kiocb_set_rw_flags(&kiocb, flags); + ret = kiocb_set_rw_flags(&kiocb, flags, type); if (ret) return ret; kiocb.ki_pos = (ppos ? *ppos : 0); if (type == READ) - ret = call_read_iter(filp, &kiocb, iter); + ret = filp->f_op->read_iter(&kiocb, iter); else - ret = call_write_iter(filp, &kiocb, iter); + ret = filp->f_op->write_iter(&kiocb, iter); BUG_ON(ret == -EIOCBQUEUED); if (ppos) *ppos = kiocb.ki_pos; @@ -739,15 +841,14 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, return -EOPNOTSUPP; while (iov_iter_count(iter)) { - struct iovec iovec = iov_iter_iovec(iter); ssize_t nr; if (type == READ) { - nr = filp->f_op->read(filp, iovec.iov_base, - iovec.iov_len, ppos); + nr = filp->f_op->read(filp, iter_iov_addr(iter), + iter_iov_len(iter), ppos); } else { - nr = filp->f_op->write(filp, iovec.iov_base, - iovec.iov_len, ppos); + nr = filp->f_op->write(filp, iter_iov_addr(iter), + iter_iov_len(iter), ppos); } if (nr < 0) { @@ -756,7 +857,7 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, break; } ret += nr; - if (nr != iovec.iov_len) + if (nr != iter_iov_len(iter)) break; iov_iter_advance(iter, nr); } @@ -764,12 +865,14 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, return ret; } -static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, - loff_t *pos, rwf_t flags) +ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, + struct iov_iter *iter) { size_t tot_len; ssize_t ret = 0; + if (!file->f_op->read_iter) + return -EINVAL; if (!(file->f_mode & FMODE_READ)) return -EBADF; if (!(file->f_mode & FMODE_CAN_READ)) @@ -778,22 +881,20 @@ static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, tot_len = iov_iter_count(iter); if (!tot_len) goto out; - ret = rw_verify_area(READ, file, pos, tot_len); + ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); if (ret < 0) return ret; - if (file->f_op->read_iter) - ret = do_iter_readv_writev(file, iter, pos, READ, flags); - else - ret = do_loop_readv_writev(file, iter, pos, READ, flags); + ret = file->f_op->read_iter(iocb, iter); out: if (ret >= 0) fsnotify_access(file); return ret; } +EXPORT_SYMBOL(vfs_iocb_iter_read); -ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, - struct iov_iter *iter) +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags) { size_t tot_len; ssize_t ret = 0; @@ -808,33 +909,30 @@ ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, tot_len = iov_iter_count(iter); if (!tot_len) goto out; - ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); + ret = rw_verify_area(READ, file, ppos, tot_len); if (ret < 0) return ret; - ret = call_read_iter(file, iocb, iter); + ret = do_iter_readv_writev(file, iter, ppos, READ, flags); out: if (ret >= 0) fsnotify_access(file); return ret; } -EXPORT_SYMBOL(vfs_iocb_iter_read); - -ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, - rwf_t flags) -{ - if (!file->f_op->read_iter) - return -EINVAL; - return do_iter_read(file, iter, ppos, flags); -} EXPORT_SYMBOL(vfs_iter_read); -static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, - loff_t *pos, rwf_t flags) +/* + * Caller is responsible for calling kiocb_end_write() on completion + * if async iocb was queued. + */ +ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, + struct iov_iter *iter) { size_t tot_len; ssize_t ret = 0; + if (!file->f_op->write_iter) + return -EINVAL; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) @@ -843,107 +941,145 @@ static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, tot_len = iov_iter_count(iter); if (!tot_len) return 0; - ret = rw_verify_area(WRITE, file, pos, tot_len); + ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); if (ret < 0) return ret; - if (file->f_op->write_iter) - ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); - else - ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); + kiocb_start_write(iocb); + ret = file->f_op->write_iter(iocb, iter); + if (ret != -EIOCBQUEUED) + kiocb_end_write(iocb); if (ret > 0) fsnotify_modify(file); + return ret; } +EXPORT_SYMBOL(vfs_iocb_iter_write); -ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, - struct iov_iter *iter) +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags) { size_t tot_len; - ssize_t ret = 0; + ssize_t ret; - if (!file->f_op->write_iter) - return -EINVAL; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; + if (!file->f_op->write_iter) + return -EINVAL; tot_len = iov_iter_count(iter); if (!tot_len) return 0; - ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); + + ret = rw_verify_area(WRITE, file, ppos, tot_len); if (ret < 0) return ret; - ret = call_write_iter(file, iocb, iter); + file_start_write(file); + ret = do_iter_readv_writev(file, iter, ppos, WRITE, flags); if (ret > 0) fsnotify_modify(file); + file_end_write(file); return ret; } -EXPORT_SYMBOL(vfs_iocb_iter_write); - -ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, - rwf_t flags) -{ - if (!file->f_op->write_iter) - return -EINVAL; - return do_iter_write(file, iter, ppos, flags); -} EXPORT_SYMBOL(vfs_iter_write); static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, - unsigned long vlen, loff_t *pos, rwf_t flags) + unsigned long vlen, loff_t *pos, rwf_t flags) { struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; - ssize_t ret; + size_t tot_len; + ssize_t ret = 0; - ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); - if (ret >= 0) { - ret = do_iter_read(file, &iter, pos, flags); - kfree(iov); - } + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + + ret = import_iovec(ITER_DEST, vec, vlen, ARRAY_SIZE(iovstack), &iov, + &iter); + if (ret < 0) + return ret; + + tot_len = iov_iter_count(&iter); + if (!tot_len) + goto out; + + ret = rw_verify_area(READ, file, pos, tot_len); + if (ret < 0) + goto out; + if (file->f_op->read_iter) + ret = do_iter_readv_writev(file, &iter, pos, READ, flags); + else + ret = do_loop_readv_writev(file, &iter, pos, READ, flags); +out: + if (ret >= 0) + fsnotify_access(file); + kfree(iov); return ret; } static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, - unsigned long vlen, loff_t *pos, rwf_t flags) + unsigned long vlen, loff_t *pos, rwf_t flags) { struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; - ssize_t ret; + size_t tot_len; + ssize_t ret = 0; - ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); - if (ret >= 0) { - file_start_write(file); - ret = do_iter_write(file, &iter, pos, flags); - file_end_write(file); - kfree(iov); - } + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + + ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, + &iter); + if (ret < 0) + return ret; + + tot_len = iov_iter_count(&iter); + if (!tot_len) + goto out; + + ret = rw_verify_area(WRITE, file, pos, tot_len); + if (ret < 0) + goto out; + + file_start_write(file); + if (file->f_op->write_iter) + ret = do_iter_readv_writev(file, &iter, pos, WRITE, flags); + else + ret = do_loop_readv_writev(file, &iter, pos, WRITE, flags); + if (ret > 0) + fsnotify_modify(file); + file_end_write(file); +out: + kfree(iov); return ret; } static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, rwf_t flags) { - struct fd f = fdget_pos(fd); + CLASS(fd_pos, f)(fd); ssize_t ret = -EBADF; - if (f.file) { - loff_t pos, *ppos = file_ppos(f.file); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); if (ppos) { pos = *ppos; ppos = &pos; } - ret = vfs_readv(f.file, vec, vlen, ppos, flags); + ret = vfs_readv(fd_file(f), vec, vlen, ppos, flags); if (ret >= 0 && ppos) - f.file->f_pos = pos; - fdput_pos(f); + fd_file(f)->f_pos = pos; } if (ret > 0) @@ -955,19 +1091,18 @@ static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, rwf_t flags) { - struct fd f = fdget_pos(fd); + CLASS(fd_pos, f)(fd); ssize_t ret = -EBADF; - if (f.file) { - loff_t pos, *ppos = file_ppos(f.file); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); if (ppos) { pos = *ppos; ppos = &pos; } - ret = vfs_writev(f.file, vec, vlen, ppos, flags); + ret = vfs_writev(fd_file(f), vec, vlen, ppos, flags); if (ret >= 0 && ppos) - f.file->f_pos = pos; - fdput_pos(f); + fd_file(f)->f_pos = pos; } if (ret > 0) @@ -985,18 +1120,16 @@ static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, loff_t pos, rwf_t flags) { - struct fd f; ssize_t ret = -EBADF; if (pos < 0) return -EINVAL; - f = fdget(fd); - if (f.file) { + CLASS(fd, f)(fd); + if (!fd_empty(f)) { ret = -ESPIPE; - if (f.file->f_mode & FMODE_PREAD) - ret = vfs_readv(f.file, vec, vlen, &pos, flags); - fdput(f); + if (fd_file(f)->f_mode & FMODE_PREAD) + ret = vfs_readv(fd_file(f), vec, vlen, &pos, flags); } if (ret > 0) @@ -1008,18 +1141,16 @@ static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, loff_t pos, rwf_t flags) { - struct fd f; ssize_t ret = -EBADF; if (pos < 0) return -EINVAL; - f = fdget(fd); - if (f.file) { + CLASS(fd, f)(fd); + if (!fd_empty(f)) { ret = -ESPIPE; - if (f.file->f_mode & FMODE_PWRITE) - ret = vfs_writev(f.file, vec, vlen, &pos, flags); - fdput(f); + if (fd_file(f)->f_mode & FMODE_PWRITE) + ret = vfs_writev(fd_file(f), vec, vlen, &pos, flags); } if (ret > 0) @@ -1169,9 +1300,8 @@ COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, #endif /* CONFIG_COMPAT */ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, - size_t count, loff_t max) + size_t count, loff_t max) { - struct fd in, out; struct inode *in_inode, *out_inode; struct pipe_inode_info *opipe; loff_t pos; @@ -1182,46 +1312,42 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, /* * Get input file, and verify that it is ok.. */ - retval = -EBADF; - in = fdget(in_fd); - if (!in.file) - goto out; - if (!(in.file->f_mode & FMODE_READ)) - goto fput_in; - retval = -ESPIPE; + CLASS(fd, in)(in_fd); + if (fd_empty(in)) + return -EBADF; + if (!(fd_file(in)->f_mode & FMODE_READ)) + return -EBADF; if (!ppos) { - pos = in.file->f_pos; + pos = fd_file(in)->f_pos; } else { pos = *ppos; - if (!(in.file->f_mode & FMODE_PREAD)) - goto fput_in; + if (!(fd_file(in)->f_mode & FMODE_PREAD)) + return -ESPIPE; } - retval = rw_verify_area(READ, in.file, &pos, count); + retval = rw_verify_area(READ, fd_file(in), &pos, count); if (retval < 0) - goto fput_in; + return retval; if (count > MAX_RW_COUNT) count = MAX_RW_COUNT; /* * Get output file, and verify that it is ok.. */ - retval = -EBADF; - out = fdget(out_fd); - if (!out.file) - goto fput_in; - if (!(out.file->f_mode & FMODE_WRITE)) - goto fput_out; - in_inode = file_inode(in.file); - out_inode = file_inode(out.file); - out_pos = out.file->f_pos; + CLASS(fd, out)(out_fd); + if (fd_empty(out)) + return -EBADF; + if (!(fd_file(out)->f_mode & FMODE_WRITE)) + return -EBADF; + in_inode = file_inode(fd_file(in)); + out_inode = file_inode(fd_file(out)); + out_pos = fd_file(out)->f_pos; if (!max) max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); if (unlikely(pos + count > max)) { - retval = -EOVERFLOW; if (pos >= max) - goto fput_out; + return -EOVERFLOW; count = max - pos; } @@ -1233,44 +1359,39 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, * and the application is arguably buggy if it doesn't expect * EAGAIN on a non-blocking file descriptor. */ - if (in.file->f_flags & O_NONBLOCK) + if (fd_file(in)->f_flags & O_NONBLOCK) fl = SPLICE_F_NONBLOCK; #endif - opipe = get_pipe_info(out.file, true); + opipe = get_pipe_info(fd_file(out), true); if (!opipe) { - retval = rw_verify_area(WRITE, out.file, &out_pos, count); + retval = rw_verify_area(WRITE, fd_file(out), &out_pos, count); if (retval < 0) - goto fput_out; - file_start_write(out.file); - retval = do_splice_direct(in.file, &pos, out.file, &out_pos, + return retval; + retval = do_splice_direct(fd_file(in), &pos, fd_file(out), &out_pos, count, fl); - file_end_write(out.file); } else { - retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); + if (fd_file(out)->f_flags & O_NONBLOCK) + fl |= SPLICE_F_NONBLOCK; + + retval = splice_file_to_pipe(fd_file(in), opipe, &pos, count, fl); } if (retval > 0) { add_rchar(current, retval); add_wchar(current, retval); - fsnotify_access(in.file); - fsnotify_modify(out.file); - out.file->f_pos = out_pos; + fsnotify_access(fd_file(in)); + fsnotify_modify(fd_file(out)); + fd_file(out)->f_pos = out_pos; if (ppos) *ppos = pos; else - in.file->f_pos = pos; + fd_file(in)->f_pos = pos; } inc_syscr(current); inc_syscw(current); if (pos > max) retval = -EOVERFLOW; - -fput_out: - fdput(out); -fput_in: - fdput(in); -out: return retval; } @@ -1350,58 +1471,6 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, } #endif -/** - * generic_copy_file_range - copy data between two files - * @file_in: file structure to read from - * @pos_in: file offset to read from - * @file_out: file structure to write data to - * @pos_out: file offset to write data to - * @len: amount of data to copy - * @flags: copy flags - * - * This is a generic filesystem helper to copy data from one file to another. - * It has no constraints on the source or destination file owners - the files - * can belong to different superblocks and different filesystem types. Short - * copies are allowed. - * - * This should be called from the @file_out filesystem, as per the - * ->copy_file_range() method. - * - * Returns the number of bytes copied or a negative error indicating the - * failure. - */ - -ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - size_t len, unsigned int flags) -{ - return do_splice_direct(file_in, &pos_in, file_out, &pos_out, - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); -} -EXPORT_SYMBOL(generic_copy_file_range); - -static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - size_t len, unsigned int flags) -{ - /* - * Although we now allow filesystems to handle cross sb copy, passing - * a file of the wrong filesystem type to filesystem driver can result - * in an attempt to dereference the wrong type of ->private_data, so - * avoid doing that until we really have a good reason. NFS defines - * several different file_system_type structures, but they all end up - * using the same ->copy_file_range() function pointer. - */ - if (file_out->f_op->copy_file_range && - file_out->f_op->copy_file_range == file_in->f_op->copy_file_range) - return file_out->f_op->copy_file_range(file_in, pos_in, - file_out, pos_out, - len, flags); - - return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, - flags); -} - /* * Performs necessary checks before doing a file copy * @@ -1423,6 +1492,26 @@ static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, if (ret) return ret; + /* + * We allow some filesystems to handle cross sb copy, but passing + * a file of the wrong filesystem type to filesystem driver can result + * in an attempt to dereference the wrong type of ->private_data, so + * avoid doing that until we really have a good reason. + * + * nfs and cifs define several different file_system_type structures + * and several different sets of file_operations, but they all end up + * using the same ->copy_file_range() function pointer. + */ + if (flags & COPY_FILE_SPLICE) { + /* cross sb splice is allowed */ + } else if (file_out->f_op->copy_file_range) { + if (file_in->f_op->copy_file_range != + file_out->f_op->copy_file_range) + return -EXDEV; + } else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) { + return -EXDEV; + } + /* Don't touch certain kinds of inodes */ if (IS_IMMUTABLE(inode_out)) return -EPERM; @@ -1465,8 +1554,10 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, size_t len, unsigned int flags) { ssize_t ret; + bool splice = flags & COPY_FILE_SPLICE; + bool samesb = file_inode(file_in)->i_sb == file_inode(file_out)->i_sb; - if (flags != 0) + if (flags & ~COPY_FILE_SPLICE) return -EINVAL; ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, @@ -1485,29 +1576,60 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (len == 0) return 0; + /* + * Make sure return value doesn't overflow in 32bit compat mode. Also + * limit the size for all cases except when calling ->copy_file_range(). + */ + if (splice || !file_out->f_op->copy_file_range || in_compat_syscall()) + len = min_t(size_t, MAX_RW_COUNT, len); + file_start_write(file_out); /* - * Try cloning first, this is supported by more file systems, and - * more efficient if both clone and copy are supported (e.g. NFS). + * Cloning is supported by more file systems, so we implement copy on + * same sb using clone, but for filesystems where both clone and copy + * are supported (e.g. nfs,cifs), we only call the copy method. */ - if (file_in->f_op->remap_file_range && - file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) { - loff_t cloned; - - cloned = file_in->f_op->remap_file_range(file_in, pos_in, - file_out, pos_out, - min_t(loff_t, MAX_RW_COUNT, len), - REMAP_FILE_CAN_SHORTEN); - if (cloned > 0) { - ret = cloned; - goto done; - } + if (!splice && file_out->f_op->copy_file_range) { + ret = file_out->f_op->copy_file_range(file_in, pos_in, + file_out, pos_out, + len, flags); + } else if (!splice && file_in->f_op->remap_file_range && samesb) { + ret = file_in->f_op->remap_file_range(file_in, pos_in, + file_out, pos_out, len, REMAP_FILE_CAN_SHORTEN); + /* fallback to splice */ + if (ret <= 0) + splice = true; + } else if (samesb) { + /* Fallback to splice for same sb copy for backward compat */ + splice = true; } - ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len, - flags); - WARN_ON_ONCE(ret == -EOPNOTSUPP); + file_end_write(file_out); + + if (!splice) + goto done; + + /* + * We can get here for same sb copy of filesystems that do not implement + * ->copy_file_range() in case filesystem does not support clone or in + * case filesystem supports clone but rejected the clone request (e.g. + * because it was not block aligned). + * + * In both cases, fall back to kernel copy so we are able to maintain a + * consistent story about which filesystems support copy_file_range() + * and which filesystems do not, that will allow userspace tools to + * make consistent desicions w.r.t using copy_file_range(). + * + * We also get here if caller (e.g. nfsd) requested COPY_FILE_SPLICE + * for server-side-copy between any two sb. + * + * In any case, we call do_splice_direct() and not splice_file_range(), + * without file_start_write() held, to avoid possible deadlocks related + * to splicing from input file, while file_start_write() is held on + * the output file on a different sb. + */ + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, len, 0); done: if (ret > 0) { fsnotify_access(file_in); @@ -1519,8 +1641,6 @@ done: inc_syscr(current); inc_syscw(current); - file_end_write(file_out); - return ret; } EXPORT_SYMBOL(vfs_copy_file_range); @@ -1531,34 +1651,34 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, { loff_t pos_in; loff_t pos_out; - struct fd f_in; - struct fd f_out; ssize_t ret = -EBADF; - f_in = fdget(fd_in); - if (!f_in.file) - goto out2; + CLASS(fd, f_in)(fd_in); + if (fd_empty(f_in)) + return -EBADF; - f_out = fdget(fd_out); - if (!f_out.file) - goto out1; + CLASS(fd, f_out)(fd_out); + if (fd_empty(f_out)) + return -EBADF; - ret = -EFAULT; if (off_in) { if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) - goto out; + return -EFAULT; } else { - pos_in = f_in.file->f_pos; + pos_in = fd_file(f_in)->f_pos; } if (off_out) { if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) - goto out; + return -EFAULT; } else { - pos_out = f_out.file->f_pos; + pos_out = fd_file(f_out)->f_pos; } - ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, + if (flags != 0) + return -EINVAL; + + ret = vfs_copy_file_range(fd_file(f_in), pos_in, fd_file(f_out), pos_out, len, flags); if (ret > 0) { pos_in += ret; @@ -1568,22 +1688,16 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) ret = -EFAULT; } else { - f_in.file->f_pos = pos_in; + fd_file(f_in)->f_pos = pos_in; } if (off_out) { if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) ret = -EFAULT; } else { - f_out.file->f_pos = pos_out; + fd_file(f_out)->f_pos = pos_out; } } - -out: - fdput(f_out); -out1: - fdput(f_in); -out2: return ret; } @@ -1616,36 +1730,45 @@ int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) return 0; } +EXPORT_SYMBOL_GPL(generic_write_check_limits); -/* - * Performs necessary checks before doing a write - * - * Can adjust writing position or amount of bytes to write. - * Returns appropriate error code that caller should return or - * zero in case that write should be allowed. - */ -ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) +/* Like generic_write_checks(), but takes size of write instead of iter. */ +int generic_write_checks_count(struct kiocb *iocb, loff_t *count) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; - loff_t count; - int ret; if (IS_SWAPFILE(inode)) return -ETXTBSY; - if (!iov_iter_count(from)) + if (!*count) return 0; - /* FIXME: this is for backwards compatibility with 2.4 */ if (iocb->ki_flags & IOCB_APPEND) iocb->ki_pos = i_size_read(inode); - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) + if ((iocb->ki_flags & IOCB_NOWAIT) && + !((iocb->ki_flags & IOCB_DIRECT) || + (file->f_op->fop_flags & FOP_BUFFER_WASYNC))) return -EINVAL; - count = iov_iter_count(from); - ret = generic_write_check_limits(file, iocb->ki_pos, &count); + return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); +} +EXPORT_SYMBOL(generic_write_checks_count); + +/* + * Performs necessary checks before doing a write + * + * Can adjust writing position or amount of bytes to write. + * Returns appropriate error code that caller should return or + * zero in case that write should be allowed. + */ +ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) +{ + loff_t count = iov_iter_count(from); + int ret; + + ret = generic_write_checks_count(iocb, &count); if (ret) return ret; @@ -1676,3 +1799,23 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out) return 0; } + +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter) +{ + size_t len = iov_iter_count(iter); + + if (!iter_is_ubuf(iter)) + return -EINVAL; + + if (!is_power_of_2(len)) + return -EINVAL; + + if (!IS_ALIGNED(iocb->ki_pos, len)) + return -EINVAL; + + if (!(iocb->ki_flags & IOCB_DIRECT)) + return -EOPNOTSUPP; + + return 0; +} +EXPORT_SYMBOL_GPL(generic_atomic_write_valid); |