diff options
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 1917 |
1 files changed, 793 insertions, 1124 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index ff3c5e6f87cf..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); -off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) +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; } @@ -331,23 +419,23 @@ COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned i } #endif -#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) +#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \ + defined(__ARCH_WANT_SYS_LLSEEK) SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, unsigned long, offset_low, loff_t __user *, result, 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; @@ -356,81 +444,108 @@ 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) { - struct inode *inode; - loff_t pos; - int retval = -EINVAL; + int mask = read_write == READ ? MAY_READ : MAY_WRITE; + int ret; - inode = file_inode(file); if (unlikely((ssize_t) count < 0)) - return retval; - pos = *ppos; - if (unlikely(pos < 0)) { - if (!unsigned_offsets(file)) - return retval; - if (count >= -pos) /* both values are in 0..LLONG_MAX */ - return -EOVERFLOW; - } else if (unlikely((loff_t) (pos + count) < 0)) { - if (!unsigned_offsets(file)) - return retval; - } + return -EINVAL; - if (unlikely(inode->i_flctx && mandatory_lock(inode))) { - retval = locks_mandatory_area(inode, file, pos, pos + count - 1, - read_write == READ ? F_RDLCK : F_WRLCK); - if (retval < 0) - return retval; + if (ppos) { + loff_t pos = *ppos; + + if (unlikely(pos < 0)) { + if (!unsigned_offsets(file)) + return -EINVAL; + if (count >= -pos) /* both values are in 0..LLONG_MAX */ + return -EOVERFLOW; + } else if (unlikely((loff_t) (pos + count) < 0)) { + if (!unsigned_offsets(file)) + return -EINVAL; + } } - 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; - iov_iter_init(&iter, READ, &iov, 1, len); + kiocb.ki_pos = (ppos ? *ppos : 0); + 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); - *ppos = kiocb.ki_pos; + if (ppos) + *ppos = kiocb.ki_pos; return ret; } -ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, - loff_t *pos) +static int warn_unsupported(struct file *file, const char *op) { - if (file->f_op->read) - return file->f_op->read(file, buf, count, pos); - else if (file->f_op->read_iter) - return new_sync_read(file, buf, count, pos); - else + pr_warn_ratelimited( + "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n", + op, file, current->pid, current->comm); + return -EINVAL; +} + +ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) +{ + struct kvec iov = { + .iov_base = 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_READ))) return -EINVAL; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + /* + * Also fail if ->read_iter and ->read are both wired up as that + * implies very convoluted semantics. + */ + if (unlikely(!file->f_op->read_iter || file->f_op->read)) + return warn_unsupported(file, "read"); + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = pos ? *pos : 0; + iov_iter_kvec(&iter, ITER_DEST, &iov, 1, iov.iov_len); + ret = file->f_op->read_iter(&kiocb, &iter); + if (ret > 0) { + if (pos) + *pos = kiocb.ki_pos; + fsnotify_access(file); + add_rchar(current, ret); + } + inc_syscr(current); + return ret; } ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { - mm_segment_t old_fs; - ssize_t result; + ssize_t ret; - old_fs = get_fs(); - set_fs(get_ds()); - /* The cast to a user pointer is valid due to the set_fs() */ - result = vfs_read(file, (void __user *)buf, count, pos); - set_fs(old_fs); - return result; + ret = rw_verify_area(READ, file, pos, count); + if (ret) + return ret; + return __kernel_read(file, buf, count, pos); } EXPORT_SYMBOL(kernel_read); @@ -446,87 +561,105 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) return -EFAULT; ret = rw_verify_area(READ, file, pos, count); - if (!ret) { - if (count > MAX_RW_COUNT) - count = MAX_RW_COUNT; - ret = __vfs_read(file, buf, count, pos); - if (ret > 0) { - fsnotify_access(file); - add_rchar(current, ret); - } - inc_syscr(current); - } + if (ret) + return ret; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + if (file->f_op->read) + ret = file->f_op->read(file, buf, count, pos); + else if (file->f_op->read_iter) + ret = new_sync_read(file, buf, count, pos); + else + ret = -EINVAL; + if (ret > 0) { + fsnotify_access(file); + add_rchar(current, ret); + } + inc_syscr(current); return ret; } 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; - iov_iter_init(&iter, WRITE, &iov, 1, len); + kiocb.ki_pos = (ppos ? *ppos : 0); + 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) + if (ret > 0 && ppos) *ppos = kiocb.ki_pos; return ret; } -ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, - loff_t *pos) -{ - if (file->f_op->write) - return file->f_op->write(file, p, count, pos); - else if (file->f_op->write_iter) - return new_sync_write(file, p, count, pos); - else - return -EINVAL; -} - -ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) +/* caller is responsible for file_start_write/file_end_write */ +ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos) { - mm_segment_t old_fs; - const char __user *p; + struct kiocb kiocb; ssize_t ret; + if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) + return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; + /* + * Also fail if ->write_iter and ->write are both wired up as that + * implies very convoluted semantics. + */ + if (unlikely(!file->f_op->write_iter || file->f_op->write)) + return warn_unsupported(file, "write"); - old_fs = get_fs(); - set_fs(get_ds()); - p = (__force const char __user *)buf; - if (count > MAX_RW_COUNT) - count = MAX_RW_COUNT; - ret = __vfs_write(file, p, count, pos); - set_fs(old_fs); + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = pos ? *pos : 0; + ret = file->f_op->write_iter(&kiocb, from); if (ret > 0) { + if (pos) + *pos = kiocb.ki_pos; fsnotify_modify(file); add_wchar(current, ret); } inc_syscw(current); return ret; } -EXPORT_SYMBOL(__kernel_write); + +/* 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 + * wants this _and_ can be built as a module. So we need to export + * this symbol for autofs, even though it really isn't appropriate + * for any other kernel modules. + */ +EXPORT_SYMBOL_GPL(__kernel_write); ssize_t kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) { - mm_segment_t old_fs; - ssize_t res; + ssize_t ret; - old_fs = get_fs(); - set_fs(get_ds()); - /* The cast to a user pointer is valid due to the set_fs() */ - res = vfs_write(file, (__force const char __user *)buf, count, pos); - set_fs(old_fs); + ret = rw_verify_area(WRITE, file, pos, count); + if (ret) + return ret; - return res; + file_start_write(file); + ret = __kernel_write(file, buf, count, pos); + file_end_write(file); + return ret; } EXPORT_SYMBOL(kernel_write); @@ -542,43 +675,46 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_ return -EFAULT; ret = rw_verify_area(WRITE, file, pos, count); - if (!ret) { - if (count > MAX_RW_COUNT) - count = MAX_RW_COUNT; - file_start_write(file); - ret = __vfs_write(file, buf, count, pos); - if (ret > 0) { - fsnotify_modify(file); - add_wchar(current, ret); - } - inc_syscw(current); - file_end_write(file); + if (ret) + return ret; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + file_start_write(file); + if (file->f_op->write) + ret = file->f_op->write(file, buf, count, pos); + else if (file->f_op->write_iter) + ret = new_sync_write(file, buf, count, pos); + else + ret = -EINVAL; + if (ret > 0) { + fsnotify_modify(file); + add_wchar(current, ret); } - + inc_syscw(current); + file_end_write(file); return ret; } -static inline loff_t file_pos_read(struct file *file) +/* file_ppos returns &file->f_pos or NULL if file is stream */ +static inline loff_t *file_ppos(struct file *file) { - return file->f_pos; -} - -static inline void file_pos_write(struct file *file, loff_t pos) -{ - file->f_pos = pos; + return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; } 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 = file_pos_read(f.file); - ret = vfs_read(f.file, buf, count, &pos); - if (ret >= 0) - file_pos_write(f.file, pos); - fdput_pos(f); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_read(fd_file(f), buf, count, ppos); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; } return ret; } @@ -590,15 +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 = file_pos_read(f.file); - ret = vfs_write(f.file, buf, count, &pos); - if (ret >= 0) - file_pos_write(f.file, pos); - fdput_pos(f); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_write(fd_file(f), buf, count, ppos); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; } return ret; @@ -613,21 +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, @@ -636,24 +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, @@ -662,6 +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) { @@ -669,17 +816,18 @@ 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; + 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); - *ppos = kiocb.ki_pos; + if (ppos) + *ppos = kiocb.ki_pos; return ret; } @@ -693,15 +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) { @@ -710,7 +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); } @@ -718,191 +865,42 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, return ret; } -/** - * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace - * into the kernel and check that it is valid. - * - * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE. - * @uvector: Pointer to the userspace array. - * @nr_segs: Number of elements in userspace array. - * @fast_segs: Number of elements in @fast_pointer. - * @fast_pointer: Pointer to (usually small on-stack) kernel array. - * @ret_pointer: (output parameter) Pointer to a variable that will point to - * either @fast_pointer, a newly allocated kernel array, or NULL, - * depending on which array was used. - * - * This function copies an array of &struct iovec of @nr_segs from - * userspace into the kernel and checks that each element is valid (e.g. - * it does not point to a kernel address or cause overflow by being too - * large, etc.). - * - * As an optimization, the caller may provide a pointer to a small - * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long - * (the size of this array, or 0 if unused, should be given in @fast_segs). - * - * @ret_pointer will always point to the array that was used, so the - * caller must take care not to call kfree() on it e.g. in case the - * @fast_pointer array was used and it was allocated on the stack. - * - * Return: The total number of bytes covered by the iovec array on success - * or a negative error code on error. - */ -ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, - unsigned long nr_segs, unsigned long fast_segs, - struct iovec *fast_pointer, - struct iovec **ret_pointer) -{ - unsigned long seg; - ssize_t ret; - struct iovec *iov = fast_pointer; - - /* - * SuS says "The readv() function *may* fail if the iovcnt argument - * was less than or equal to 0, or greater than {IOV_MAX}. Linux has - * traditionally returned zero for zero segments, so... - */ - if (nr_segs == 0) { - ret = 0; - goto out; - } - - /* - * First get the "struct iovec" from user memory and - * verify all the pointers - */ - if (nr_segs > UIO_MAXIOV) { - ret = -EINVAL; - goto out; - } - if (nr_segs > fast_segs) { - iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); - if (iov == NULL) { - ret = -ENOMEM; - goto out; - } - } - if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { - ret = -EFAULT; - goto out; - } - - /* - * According to the Single Unix Specification we should return EINVAL - * if an element length is < 0 when cast to ssize_t or if the - * total length would overflow the ssize_t return value of the - * system call. - * - * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the - * overflow case. - */ - ret = 0; - for (seg = 0; seg < nr_segs; seg++) { - void __user *buf = iov[seg].iov_base; - ssize_t len = (ssize_t)iov[seg].iov_len; - - /* see if we we're about to use an invalid len or if - * it's about to overflow ssize_t */ - if (len < 0) { - ret = -EINVAL; - goto out; - } - if (type >= 0 - && unlikely(!access_ok(buf, len))) { - ret = -EFAULT; - goto out; - } - if (len > MAX_RW_COUNT - ret) { - len = MAX_RW_COUNT - ret; - iov[seg].iov_len = len; - } - ret += len; - } -out: - *ret_pointer = iov; - return ret; -} - -#ifdef CONFIG_COMPAT -ssize_t compat_rw_copy_check_uvector(int type, - const struct compat_iovec __user *uvector, unsigned long nr_segs, - unsigned long fast_segs, struct iovec *fast_pointer, - struct iovec **ret_pointer) +ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, + struct iov_iter *iter) { - compat_ssize_t tot_len; - struct iovec *iov = *ret_pointer = fast_pointer; + size_t tot_len; ssize_t ret = 0; - int seg; - - /* - * SuS says "The readv() function *may* fail if the iovcnt argument - * was less than or equal to 0, or greater than {IOV_MAX}. Linux has - * traditionally returned zero for zero segments, so... - */ - if (nr_segs == 0) - goto out; - ret = -EINVAL; - if (nr_segs > UIO_MAXIOV) - goto out; - if (nr_segs > fast_segs) { - ret = -ENOMEM; - iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); - if (iov == NULL) - goto out; - } - *ret_pointer = iov; + if (!file->f_op->read_iter) + return -EINVAL; + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; - ret = -EFAULT; - if (!access_ok(uvector, nr_segs*sizeof(*uvector))) + tot_len = iov_iter_count(iter); + if (!tot_len) goto out; + ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); + if (ret < 0) + return ret; - /* - * Single unix specification: - * We should -EINVAL if an element length is not >= 0 and fitting an - * ssize_t. - * - * In Linux, the total length is limited to MAX_RW_COUNT, there is - * no overflow possibility. - */ - tot_len = 0; - ret = -EINVAL; - for (seg = 0; seg < nr_segs; seg++) { - compat_uptr_t buf; - compat_ssize_t len; - - if (__get_user(len, &uvector->iov_len) || - __get_user(buf, &uvector->iov_base)) { - ret = -EFAULT; - goto out; - } - if (len < 0) /* size_t not fitting in compat_ssize_t .. */ - goto out; - if (type >= 0 && - !access_ok(compat_ptr(buf), len)) { - ret = -EFAULT; - goto out; - } - if (len > MAX_RW_COUNT - tot_len) - len = MAX_RW_COUNT - tot_len; - tot_len += len; - iov->iov_base = compat_ptr(buf); - iov->iov_len = (compat_size_t) len; - uvector++; - iov++; - } - ret = tot_len; - + ret = file->f_op->read_iter(iocb, iter); out: + if (ret >= 0) + fsnotify_access(file); return ret; } -#endif +EXPORT_SYMBOL(vfs_iocb_iter_read); -static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, - loff_t *pos, rwf_t flags) +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; + if (!file->f_op->read_iter) + return -EINVAL; if (!(file->f_mode & FMODE_READ)) return -EBADF; if (!(file->f_mode & FMODE_CAN_READ)) @@ -911,35 +909,30 @@ 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, ppos, 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 = do_iter_readv_writev(file, iter, ppos, READ, flags); out: if (ret >= 0) fsnotify_access(file); return ret; } - -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)) @@ -948,75 +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_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, - rwf_t flags) + rwf_t flags) { + size_t tot_len; + ssize_t ret; + + 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; - return do_iter_write(file, iter, ppos, flags); + + tot_len = iov_iter_count(iter); + if (!tot_len) + return 0; + + ret = rw_verify_area(WRITE, file, ppos, tot_len); + if (ret < 0) + return ret; + + 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_iter_write); -ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, - unsigned long vlen, loff_t *pos, rwf_t flags) +static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, + 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 = file_pos_read(f.file); - ret = vfs_readv(f.file, vec, vlen, &pos, flags); - if (ret >= 0) - file_pos_write(f.file, pos); - fdput_pos(f); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_readv(fd_file(f), vec, vlen, ppos, flags); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; } if (ret > 0) @@ -1028,15 +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 = file_pos_read(f.file); - ret = vfs_writev(f.file, vec, vlen, &pos, flags); - if (ret >= 0) - file_pos_write(f.file, pos); - fdput_pos(f); + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_writev(fd_file(f), vec, vlen, ppos, flags); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; } if (ret > 0) @@ -1054,18 +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) @@ -1077,18 +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) @@ -1149,224 +1211,99 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, return do_pwritev(fd, vec, vlen, pos, flags); } +/* + * Various compat syscalls. Note that they all pretend to take a native + * iovec - import_iovec will properly treat those as compat_iovecs based on + * in_compat_syscall(). + */ #ifdef CONFIG_COMPAT -static size_t compat_readv(struct file *file, - const struct compat_iovec __user *vec, - 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; - - ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter); - if (ret >= 0) { - ret = do_iter_read(file, &iter, pos, flags); - kfree(iov); - } - if (ret > 0) - add_rchar(current, ret); - inc_syscr(current); - return ret; -} - -static size_t do_compat_readv(compat_ulong_t fd, - const struct compat_iovec __user *vec, - compat_ulong_t vlen, rwf_t flags) -{ - struct fd f = fdget_pos(fd); - ssize_t ret; - loff_t pos; - - if (!f.file) - return -EBADF; - pos = f.file->f_pos; - ret = compat_readv(f.file, vec, vlen, &pos, flags); - if (ret >= 0) - f.file->f_pos = pos; - fdput_pos(f); - return ret; - -} - -COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, - const struct compat_iovec __user *,vec, - compat_ulong_t, vlen) -{ - return do_compat_readv(fd, vec, vlen, 0); -} - -static long do_compat_preadv64(unsigned long fd, - const struct compat_iovec __user *vec, - unsigned long vlen, loff_t pos, rwf_t flags) -{ - struct fd f; - ssize_t ret; - - if (pos < 0) - return -EINVAL; - f = fdget(fd); - if (!f.file) - return -EBADF; - ret = -ESPIPE; - if (f.file->f_mode & FMODE_PREAD) - ret = compat_readv(f.file, vec, vlen, &pos, flags); - fdput(f); - return ret; -} - #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, unsigned long, vlen, loff_t, pos) { - return do_compat_preadv64(fd, vec, vlen, pos, 0); + return do_preadv(fd, vec, vlen, pos, 0); } #endif COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, compat_ulong_t, vlen, u32, pos_low, u32, pos_high) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; - return do_compat_preadv64(fd, vec, vlen, pos, 0); + return do_preadv(fd, vec, vlen, pos, 0); } #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { - return do_compat_preadv64(fd, vec, vlen, pos, flags); + if (pos == -1) + return do_readv(fd, vec, vlen, flags); + return do_preadv(fd, vec, vlen, pos, flags); } #endif COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; if (pos == -1) - return do_compat_readv(fd, vec, vlen, flags); - - return do_compat_preadv64(fd, vec, vlen, pos, flags); -} - -static size_t compat_writev(struct file *file, - const struct compat_iovec __user *vec, - 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; - - ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter); - if (ret >= 0) { - file_start_write(file); - ret = do_iter_write(file, &iter, pos, flags); - file_end_write(file); - kfree(iov); - } - if (ret > 0) - add_wchar(current, ret); - inc_syscw(current); - return ret; -} - -static size_t do_compat_writev(compat_ulong_t fd, - const struct compat_iovec __user* vec, - compat_ulong_t vlen, rwf_t flags) -{ - struct fd f = fdget_pos(fd); - ssize_t ret; - loff_t pos; - - if (!f.file) - return -EBADF; - pos = f.file->f_pos; - ret = compat_writev(f.file, vec, vlen, &pos, flags); - if (ret >= 0) - f.file->f_pos = pos; - fdput_pos(f); - return ret; -} - -COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, - const struct compat_iovec __user *, vec, - compat_ulong_t, vlen) -{ - return do_compat_writev(fd, vec, vlen, 0); -} - -static long do_compat_pwritev64(unsigned long fd, - const struct compat_iovec __user *vec, - unsigned long vlen, loff_t pos, rwf_t flags) -{ - struct fd f; - ssize_t ret; - - if (pos < 0) - return -EINVAL; - f = fdget(fd); - if (!f.file) - return -EBADF; - ret = -ESPIPE; - if (f.file->f_mode & FMODE_PWRITE) - ret = compat_writev(f.file, vec, vlen, &pos, flags); - fdput(f); - return ret; + return do_readv(fd, vec, vlen, flags); + return do_preadv(fd, vec, vlen, pos, flags); } #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, unsigned long, vlen, loff_t, pos) { - return do_compat_pwritev64(fd, vec, vlen, pos, 0); + return do_pwritev(fd, vec, vlen, pos, 0); } #endif COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *,vec, compat_ulong_t, vlen, u32, pos_low, u32, pos_high) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; - return do_compat_pwritev64(fd, vec, vlen, pos, 0); + return do_pwritev(fd, vec, vlen, pos, 0); } #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *, vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { - return do_compat_pwritev64(fd, vec, vlen, pos, flags); + if (pos == -1) + return do_writev(fd, vec, vlen, flags); + return do_pwritev(fd, vec, vlen, pos, flags); } #endif COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, - const struct compat_iovec __user *,vec, + const struct iovec __user *,vec, compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; if (pos == -1) - return do_compat_writev(fd, vec, vlen, flags); - - return do_compat_pwritev64(fd, vec, vlen, pos, flags); + return do_writev(fd, vec, vlen, flags); + return do_pwritev(fd, vec, vlen, pos, flags); } - -#endif +#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; loff_t out_pos; ssize_t retval; @@ -1375,49 +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; - retval = rw_verify_area(WRITE, out.file, &out_pos, count); - if (retval < 0) - goto fput_out; + 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; } @@ -1429,35 +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 - file_start_write(out.file); - retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); - file_end_write(out.file); + opipe = get_pipe_info(fd_file(out), true); + if (!opipe) { + retval = rw_verify_area(WRITE, fd_file(out), &out_pos, count); + if (retval < 0) + return retval; + retval = do_splice_direct(fd_file(in), &pos, fd_file(out), &out_pos, + count, fl); + } else { + 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; } @@ -1538,6 +1472,79 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, #endif /* + * Performs necessary checks before doing a file copy + * + * Can adjust amount of bytes to copy via @req_count argument. + * Returns appropriate error code that caller should return or + * zero in case the copy should be allowed. + */ +static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + size_t *req_count, unsigned int flags) +{ + struct inode *inode_in = file_inode(file_in); + struct inode *inode_out = file_inode(file_out); + uint64_t count = *req_count; + loff_t size_in; + int ret; + + ret = generic_file_rw_checks(file_in, file_out); + 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; + + if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) + return -ETXTBSY; + + /* Ensure offsets don't wrap. */ + if (pos_in + count < pos_in || pos_out + count < pos_out) + return -EOVERFLOW; + + /* Shorten the copy to EOF */ + size_in = i_size_read(inode_in); + if (pos_in >= size_in) + count = 0; + else + count = min(count, size_in - (uint64_t)pos_in); + + ret = generic_write_check_limits(file_out, pos_out, &count); + if (ret) + return ret; + + /* Don't allow overlapped copying within the same file. */ + if (inode_in == inode_out && + pos_out + count > pos_in && + pos_out < pos_in + count) + return -EINVAL; + + *req_count = count; + return 0; +} + +/* * copy_file_range() differs from regular file read and write in that it * specifically allows return partial success. When it does so is up to * the copy_file_range method. @@ -1546,17 +1553,17 @@ ssize_t vfs_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) { - struct inode *inode_in = file_inode(file_in); - struct inode *inode_out = file_inode(file_out); 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; - if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) - return -EISDIR; - if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) - return -EINVAL; + ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, + flags); + if (unlikely(ret)) + return ret; ret = rw_verify_area(READ, file_in, &pos_in, len); if (unlikely(ret)) @@ -1566,47 +1573,63 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (unlikely(ret)) return ret; - if (!(file_in->f_mode & FMODE_READ) || - !(file_out->f_mode & FMODE_WRITE) || - (file_out->f_flags & O_APPEND)) - return -EBADF; - - /* this could be relaxed once a method supports cross-fs copies */ - if (inode_in->i_sb != inode_out->i_sb) - return -EXDEV; - 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) { - 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; } - if (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); - if (ret != -EOPNOTSUPP) - goto done; - } + file_end_write(file_out); - ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + 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); @@ -1618,8 +1641,6 @@ done: inc_syscr(current); inc_syscw(current); - file_end_write(file_out); - return ret; } EXPORT_SYMBOL(vfs_copy_file_range); @@ -1630,34 +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; @@ -1667,486 +1688,134 @@ 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; } -static int remap_verify_area(struct file *file, loff_t pos, loff_t len, - bool write) -{ - struct inode *inode = file_inode(file); - - if (unlikely(pos < 0 || len < 0)) - return -EINVAL; - - if (unlikely((loff_t) (pos + len) < 0)) - return -EINVAL; - - if (unlikely(inode->i_flctx && mandatory_lock(inode))) { - loff_t end = len ? pos + len - 1 : OFFSET_MAX; - int retval; - - retval = locks_mandatory_area(inode, file, pos, end, - write ? F_WRLCK : F_RDLCK); - if (retval < 0) - return retval; - } - - return security_file_permission(file, write ? MAY_WRITE : MAY_READ); -} /* - * Ensure that we don't remap a partial EOF block in the middle of something - * else. Assume that the offsets have already been checked for block - * alignment. - * - * For deduplication we always scale down to the previous block because we - * can't meaningfully compare post-EOF contents. - * - * For clone we only link a partial EOF block above the destination file's EOF. - * - * Shorten the request if possible. + * Don't operate on ranges the page cache doesn't support, and don't exceed the + * LFS limits. If pos is under the limit it becomes a short access. If it + * exceeds the limit we return -EFBIG. */ -static int generic_remap_check_len(struct inode *inode_in, - struct inode *inode_out, - loff_t pos_out, - loff_t *len, - unsigned int remap_flags) +int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) { - u64 blkmask = i_blocksize(inode_in) - 1; - loff_t new_len = *len; + struct inode *inode = file->f_mapping->host; + loff_t max_size = inode->i_sb->s_maxbytes; + loff_t limit = rlimit(RLIMIT_FSIZE); - if ((*len & blkmask) == 0) - return 0; + if (limit != RLIM_INFINITY) { + if (pos >= limit) { + send_sig(SIGXFSZ, current, 0); + return -EFBIG; + } + *count = min(*count, limit - pos); + } - if ((remap_flags & REMAP_FILE_DEDUP) || - pos_out + *len < i_size_read(inode_out)) - new_len &= ~blkmask; + if (!(file->f_flags & O_LARGEFILE)) + max_size = MAX_NON_LFS; - if (new_len == *len) - return 0; + if (unlikely(pos >= max_size)) + return -EFBIG; - if (remap_flags & REMAP_FILE_CAN_SHORTEN) { - *len = new_len; - return 0; - } + *count = min(*count, max_size - pos); - return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL; + return 0; } +EXPORT_SYMBOL_GPL(generic_write_check_limits); -/* - * Read a page's worth of file data into the page cache. Return the page - * locked. - */ -static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset) +/* Like generic_write_checks(), but takes size of write instead of iter. */ +int generic_write_checks_count(struct kiocb *iocb, loff_t *count) { - struct page *page; - - page = read_mapping_page(inode->i_mapping, offset >> PAGE_SHIFT, NULL); - if (IS_ERR(page)) - return page; - if (!PageUptodate(page)) { - put_page(page); - return ERR_PTR(-EIO); - } - lock_page(page); - return page; -} - -/* - * Compare extents of two files to see if they are the same. - * Caller must have locked both inodes to prevent write races. - */ -static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, - struct inode *dest, loff_t destoff, - loff_t len, bool *is_same) -{ - loff_t src_poff; - loff_t dest_poff; - void *src_addr; - void *dest_addr; - struct page *src_page; - struct page *dest_page; - loff_t cmp_len; - bool same; - int error; - - error = -EINVAL; - same = true; - while (len) { - src_poff = srcoff & (PAGE_SIZE - 1); - dest_poff = destoff & (PAGE_SIZE - 1); - cmp_len = min(PAGE_SIZE - src_poff, - PAGE_SIZE - dest_poff); - cmp_len = min(cmp_len, len); - if (cmp_len <= 0) - goto out_error; - - src_page = vfs_dedupe_get_page(src, srcoff); - if (IS_ERR(src_page)) { - error = PTR_ERR(src_page); - goto out_error; - } - dest_page = vfs_dedupe_get_page(dest, destoff); - if (IS_ERR(dest_page)) { - error = PTR_ERR(dest_page); - unlock_page(src_page); - put_page(src_page); - goto out_error; - } - src_addr = kmap_atomic(src_page); - dest_addr = kmap_atomic(dest_page); - - flush_dcache_page(src_page); - flush_dcache_page(dest_page); + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; - if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) - same = false; + if (IS_SWAPFILE(inode)) + return -ETXTBSY; - kunmap_atomic(dest_addr); - kunmap_atomic(src_addr); - unlock_page(dest_page); - unlock_page(src_page); - put_page(dest_page); - put_page(src_page); + if (!*count) + return 0; - if (!same) - break; + if (iocb->ki_flags & IOCB_APPEND) + iocb->ki_pos = i_size_read(inode); - srcoff += cmp_len; - destoff += cmp_len; - len -= cmp_len; - } - - *is_same = same; - return 0; + if ((iocb->ki_flags & IOCB_NOWAIT) && + !((iocb->ki_flags & IOCB_DIRECT) || + (file->f_op->fop_flags & FOP_BUFFER_WASYNC))) + return -EINVAL; -out_error: - return error; + return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); } +EXPORT_SYMBOL(generic_write_checks_count); /* - * Check that the two inodes are eligible for cloning, the ranges make - * sense, and then flush all dirty data. Caller must ensure that the - * inodes have been locked against any other modifications. + * Performs necessary checks before doing a write * - * If there's an error, then the usual negative error code is returned. - * Otherwise returns 0 with *len set to the request length. + * 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. */ -int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t *len, unsigned int remap_flags) +ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) { - struct inode *inode_in = file_inode(file_in); - struct inode *inode_out = file_inode(file_out); - bool same_inode = (inode_in == inode_out); + loff_t count = iov_iter_count(from); int ret; - /* Don't touch certain kinds of inodes */ - if (IS_IMMUTABLE(inode_out)) - return -EPERM; - - if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) - return -ETXTBSY; - - /* Don't reflink dirs, pipes, sockets... */ - if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) - return -EISDIR; - if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) - return -EINVAL; - - /* Zero length dedupe exits immediately; reflink goes to EOF. */ - if (*len == 0) { - loff_t isize = i_size_read(inode_in); - - if ((remap_flags & REMAP_FILE_DEDUP) || pos_in == isize) - return 0; - if (pos_in > isize) - return -EINVAL; - *len = isize - pos_in; - if (*len == 0) - return 0; - } - - /* Check that we don't violate system file offset limits. */ - ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len, - remap_flags); - if (ret) - return ret; - - /* Wait for the completion of any pending IOs on both files */ - inode_dio_wait(inode_in); - if (!same_inode) - inode_dio_wait(inode_out); - - ret = filemap_write_and_wait_range(inode_in->i_mapping, - pos_in, pos_in + *len - 1); - if (ret) - return ret; - - ret = filemap_write_and_wait_range(inode_out->i_mapping, - pos_out, pos_out + *len - 1); - if (ret) - return ret; - - /* - * Check that the extents are the same. - */ - if (remap_flags & REMAP_FILE_DEDUP) { - bool is_same = false; - - ret = vfs_dedupe_file_range_compare(inode_in, pos_in, - inode_out, pos_out, *len, &is_same); - if (ret) - return ret; - if (!is_same) - return -EBADE; - } - - ret = generic_remap_check_len(inode_in, inode_out, pos_out, len, - remap_flags); + ret = generic_write_checks_count(iocb, &count); if (ret) return ret; - /* If can't alter the file contents, we're done. */ - if (!(remap_flags & REMAP_FILE_DEDUP)) { - /* Update the timestamps, since we can alter file contents. */ - if (!(file_out->f_mode & FMODE_NOCMTIME)) { - ret = file_update_time(file_out); - if (ret) - return ret; - } - - /* - * Clear the security bits if the process is not being run by - * root. This keeps people from modifying setuid and setgid - * binaries. - */ - ret = file_remove_privs(file_out); - if (ret) - return ret; - } - - return 0; + iov_iter_truncate(from, count); + return iov_iter_count(from); } -EXPORT_SYMBOL(generic_remap_file_range_prep); +EXPORT_SYMBOL(generic_write_checks); -loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags) +/* + * Performs common checks before doing a file copy/clone + * from @file_in to @file_out. + */ +int generic_file_rw_checks(struct file *file_in, struct file *file_out) { struct inode *inode_in = file_inode(file_in); struct inode *inode_out = file_inode(file_out); - loff_t ret; - - WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP); + /* Don't copy dirs, pipes, sockets... */ if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) return -EISDIR; if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) return -EINVAL; - /* - * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on - * the same mount. Practically, they only need to be on the same file - * system. - */ - if (inode_in->i_sb != inode_out->i_sb) - return -EXDEV; - if (!(file_in->f_mode & FMODE_READ) || !(file_out->f_mode & FMODE_WRITE) || (file_out->f_flags & O_APPEND)) return -EBADF; - if (!file_in->f_op->remap_file_range) - return -EOPNOTSUPP; - - ret = remap_verify_area(file_in, pos_in, len, false); - if (ret) - return ret; - - ret = remap_verify_area(file_out, pos_out, len, true); - if (ret) - return ret; - - ret = file_in->f_op->remap_file_range(file_in, pos_in, - file_out, pos_out, len, remap_flags); - if (ret < 0) - return ret; - - fsnotify_access(file_in); - fsnotify_modify(file_out); - return ret; -} -EXPORT_SYMBOL(do_clone_file_range); - -loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags) -{ - loff_t ret; - - file_start_write(file_out); - ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len, - remap_flags); - file_end_write(file_out); - - return ret; -} -EXPORT_SYMBOL(vfs_clone_file_range); - -/* Check whether we are allowed to dedupe the destination file */ -static bool allow_file_dedupe(struct file *file) -{ - if (capable(CAP_SYS_ADMIN)) - return true; - if (file->f_mode & FMODE_WRITE) - return true; - if (uid_eq(current_fsuid(), file_inode(file)->i_uid)) - return true; - if (!inode_permission(file_inode(file), MAY_WRITE)) - return true; - return false; -} - -loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, - struct file *dst_file, loff_t dst_pos, - loff_t len, unsigned int remap_flags) -{ - loff_t ret; - - WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP | - REMAP_FILE_CAN_SHORTEN)); - - ret = mnt_want_write_file(dst_file); - if (ret) - return ret; - - ret = remap_verify_area(dst_file, dst_pos, len, true); - if (ret < 0) - goto out_drop_write; - - ret = -EPERM; - if (!allow_file_dedupe(dst_file)) - goto out_drop_write; - - ret = -EXDEV; - if (src_file->f_path.mnt != dst_file->f_path.mnt) - goto out_drop_write; - - ret = -EISDIR; - if (S_ISDIR(file_inode(dst_file)->i_mode)) - goto out_drop_write; - - ret = -EINVAL; - if (!dst_file->f_op->remap_file_range) - goto out_drop_write; - - if (len == 0) { - ret = 0; - goto out_drop_write; - } - - ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file, - dst_pos, len, remap_flags | REMAP_FILE_DEDUP); -out_drop_write: - mnt_drop_write_file(dst_file); - - return ret; + return 0; } -EXPORT_SYMBOL(vfs_dedupe_file_range_one); -int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter) { - struct file_dedupe_range_info *info; - struct inode *src = file_inode(file); - u64 off; - u64 len; - int i; - int ret; - u16 count = same->dest_count; - loff_t deduped; + size_t len = iov_iter_count(iter); - if (!(file->f_mode & FMODE_READ)) + if (!iter_is_ubuf(iter)) return -EINVAL; - if (same->reserved1 || same->reserved2) + if (!is_power_of_2(len)) return -EINVAL; - off = same->src_offset; - len = same->src_length; - - if (S_ISDIR(src->i_mode)) - return -EISDIR; - - if (!S_ISREG(src->i_mode)) + if (!IS_ALIGNED(iocb->ki_pos, len)) return -EINVAL; - if (!file->f_op->remap_file_range) + if (!(iocb->ki_flags & IOCB_DIRECT)) return -EOPNOTSUPP; - ret = remap_verify_area(file, off, len, false); - if (ret < 0) - return ret; - ret = 0; - - if (off + len > i_size_read(src)) - return -EINVAL; - - /* Arbitrary 1G limit on a single dedupe request, can be raised. */ - len = min_t(u64, len, 1 << 30); - - /* pre-format output fields to sane values */ - for (i = 0; i < count; i++) { - same->info[i].bytes_deduped = 0ULL; - same->info[i].status = FILE_DEDUPE_RANGE_SAME; - } - - for (i = 0, info = same->info; i < count; i++, info++) { - struct fd dst_fd = fdget(info->dest_fd); - struct file *dst_file = dst_fd.file; - - if (!dst_file) { - info->status = -EBADF; - goto next_loop; - } - - if (info->reserved) { - info->status = -EINVAL; - goto next_fdput; - } - - deduped = vfs_dedupe_file_range_one(file, off, dst_file, - info->dest_offset, len, - REMAP_FILE_CAN_SHORTEN); - if (deduped == -EBADE) - info->status = FILE_DEDUPE_RANGE_DIFFERS; - else if (deduped < 0) - info->status = deduped; - else - info->bytes_deduped = len; - -next_fdput: - fdput(dst_fd); -next_loop: - if (fatal_signal_pending(current)) - break; - } - return ret; + return 0; } -EXPORT_SYMBOL(vfs_dedupe_file_range); +EXPORT_SYMBOL_GPL(generic_atomic_write_valid); |