| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Al Viro | 2285 | 23.17% | 30 | 13.70% |
| Christoph Hellwig | 1511 | 15.32% | 25 | 11.42% |
| Darrick J. Wong | 1491 | 15.12% | 18 | 8.22% |
| Linus Torvalds (pre-git) | 606 | 6.14% | 29 | 13.24% |
| Milosz Tanski | 553 | 5.61% | 1 | 0.46% |
| Zach Brown | 525 | 5.32% | 1 | 0.46% |
| Linus Torvalds | 520 | 5.27% | 20 | 9.13% |
| Miklos Szeredi | 368 | 3.73% | 9 | 4.11% |
| Gerd Hoffmann | 221 | 2.24% | 1 | 0.46% |
| Dominik Brodowski | 217 | 2.20% | 4 | 1.83% |
| Heiko Carstens | 204 | 2.07% | 5 | 2.28% |
| Badari Pulavarty | 202 | 2.05% | 4 | 1.83% |
| Andi Kleen | 147 | 1.49% | 3 | 1.37% |
| H. J. Lu | 88 | 0.89% | 1 | 0.46% |
| Neil Brown | 84 | 0.85% | 2 | 0.91% |
| Mark Fasheh | 73 | 0.74% | 2 | 0.91% |
| Dmitry Kasatkin | 68 | 0.69% | 1 | 0.46% |
| Amir Goldstein | 63 | 0.64% | 4 | 1.83% |
| Andrew Morton | 62 | 0.63% | 10 | 4.57% |
| Jay Lan | 54 | 0.55% | 1 | 0.46% |
| Josef Bacik | 48 | 0.49% | 1 | 0.46% |
| Anna Schumaker | 45 | 0.46% | 1 | 0.46% |
| Alexey Dobriyan | 44 | 0.45% | 1 | 0.46% |
| Kamezawa Hiroyuki | 37 | 0.38% | 1 | 0.46% |
| Robert Love | 32 | 0.32% | 2 | 0.91% |
| Jens Axboe | 31 | 0.31% | 4 | 1.83% |
| James Morris | 26 | 0.26% | 1 | 0.46% |
| Jan Blunck | 25 | 0.25% | 1 | 0.46% |
| David Chinner | 24 | 0.24% | 1 | 0.46% |
| Arnaldo Carvalho de Melo | 21 | 0.21% | 1 | 0.46% |
| Alain Knaff | 19 | 0.19% | 1 | 0.46% |
| Arnd Bergmann | 19 | 0.19% | 3 | 1.37% |
| Stephen D. Smalley | 17 | 0.17% | 1 | 0.46% |
| Dan Carpenter | 16 | 0.16% | 1 | 0.46% |
| Scott Wolchok | 14 | 0.14% | 1 | 0.46% |
| Eric Sandeen | 12 | 0.12% | 1 | 0.46% |
| Andreas Gruenbacher | 10 | 0.10% | 1 | 0.46% |
| Goldwyn Rodrigues | 10 | 0.10% | 1 | 0.46% |
| Dave Hansen | 9 | 0.09% | 1 | 0.46% |
| Jie Liu | 9 | 0.09% | 1 | 0.46% |
| Art Haas | 7 | 0.07% | 1 | 0.46% |
| Benjamin LaHaise | 7 | 0.07% | 2 | 0.91% |
| Eric Dumazet | 4 | 0.04% | 1 | 0.46% |
| Christopher Yeoh | 4 | 0.04% | 2 | 0.91% |
| Alan Cox | 4 | 0.04% | 1 | 0.46% |
| Chris Snook | 4 | 0.04% | 2 | 0.91% |
| Wouter van Kesteren | 4 | 0.04% | 1 | 0.46% |
| Kees Cook | 4 | 0.04% | 1 | 0.46% |
| Ingo Molnar | 3 | 0.03% | 1 | 0.46% |
| Zev Weiss | 3 | 0.03% | 1 | 0.46% |
| Eric Biggers | 2 | 0.02% | 1 | 0.46% |
| Greg Kroah-Hartman | 1 | 0.01% | 1 | 0.46% |
| Jeff Layton | 1 | 0.01% | 1 | 0.46% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.46% |
| Vegard Nossum | 1 | 0.01% | 1 | 0.46% |
| Pavel Emelyanov | 1 | 0.01% | 1 | 0.46% |
| David Sterba | 1 | 0.01% | 1 | 0.46% |
| Lei Ming | 1 | 0.01% | 1 | 0.46% |
| Paul Gortmaker | 1 | 0.01% | 1 | 0.46% |
| Total | 9864 | 219 |
// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/read_write.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/slab.h> #include <linux/stat.h> #include <linux/sched/xacct.h> #include <linux/fcntl.h> #include <linux/file.h> #include <linux/uio.h> #include <linux/fsnotify.h> #include <linux/security.h> #include <linux/export.h> #include <linux/syscalls.h> #include <linux/pagemap.h> #include <linux/splice.h> #include <linux/compat.h> #include <linux/mount.h> #include <linux/fs.h> #include "internal.h" #include <linux/uaccess.h> #include <asm/unistd.h> 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, }; EXPORT_SYMBOL(generic_ro_fops); static inline bool unsigned_offsets(struct file *file) { return file->f_mode & FMODE_UNSIGNED_OFFSET; } /** * vfs_setpos - update the file offset for lseek * @file: file structure in question * @offset: file offset to seek to * @maxsize: maximum file size * * 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. * * Return the specified offset on success and -EINVAL on invalid offset. */ loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) { if (offset < 0 && !unsigned_offsets(file)) return -EINVAL; if (offset > maxsize) return -EINVAL; if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; } return offset; } EXPORT_SYMBOL(vfs_setpos); /** * 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 * @size: 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) { switch (whence) { case SEEK_END: offset += eof; break; case SEEK_CUR: /* * Here we special-case the lseek(fd, 0, SEEK_CUR) * position-querying operation. Avoid rewriting the "same" * 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; 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) return -ENXIO; break; case SEEK_HOLE: /* * 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) return -ENXIO; offset = eof; break; } return vfs_setpos(file, offset, maxsize); } EXPORT_SYMBOL(generic_file_llseek_size); /** * 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 * filesystems. It just updates the file offset to the value specified by * @offset and @whence. */ loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file->f_mapping->host; return generic_file_llseek_size(file, offset, whence, inode->i_sb->s_maxbytes, i_size_read(inode)); } EXPORT_SYMBOL(generic_file_llseek); /** * fixed_size_llseek - llseek implementation for fixed-sized devices * @file: file structure to seek on * @offset: file offset to seek to * @whence: type of seek * @size: size of the file * */ loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) { switch (whence) { case SEEK_SET: case SEEK_CUR: case SEEK_END: return generic_file_llseek_size(file, offset, whence, size, size); default: return -EINVAL; } } EXPORT_SYMBOL(fixed_size_llseek); /** * no_seek_end_llseek - llseek implementation for fixed-sized devices * @file: file structure to seek on * @offset: file offset to seek to * @whence: type of seek * */ loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) { switch (whence) { case SEEK_SET: case SEEK_CUR: return generic_file_llseek_size(file, offset, whence, OFFSET_MAX, 0); default: return -EINVAL; } } EXPORT_SYMBOL(no_seek_end_llseek); /** * no_seek_end_llseek_size - llseek implementation for fixed-sized devices * @file: file structure to seek on * @offset: file offset to seek to * @whence: type of seek * @size: maximal offset allowed * */ loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size) { switch (whence) { case SEEK_SET: case SEEK_CUR: return generic_file_llseek_size(file, offset, whence, size, 0); default: return -EINVAL; } } EXPORT_SYMBOL(no_seek_end_llseek_size); /** * noop_llseek - No Operation Performed llseek implementation * @file: file structure to seek on * @offset: file offset to seek to * @whence: type of seek * * This is an implementation of ->llseek useable for the rare special case when * userspace expects the seek to succeed but the (device) file is actually not * able to perform the seek. In this case you use noop_llseek() instead of * falling back to the default implementation of ->llseek. */ loff_t noop_llseek(struct file *file, loff_t offset, int whence) { return file->f_pos; } 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); switch (whence) { case SEEK_END: offset += i_size_read(inode); break; case SEEK_CUR: if (offset == 0) { retval = file->f_pos; goto out; } offset += file->f_pos; 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 (offset >= inode->i_size) { retval = -ENXIO; goto out; } break; case SEEK_HOLE: /* * 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 (offset >= inode->i_size) { retval = -ENXIO; goto out; } offset = inode->i_size; break; } retval = -EINVAL; if (offset >= 0 || unsigned_offsets(file)) { if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; } retval = offset; } out: inode_unlock(inode); return retval; } 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); } EXPORT_SYMBOL(vfs_llseek); 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) return -EBADF; retval = -EINVAL; if (whence <= SEEK_MAX) { loff_t res = vfs_llseek(f.file, offset, whence); retval = res; if (res != (loff_t)retval) retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ } fdput_pos(f); return retval; } SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) { return ksys_lseek(fd, offset, whence); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) { return ksys_lseek(fd, offset, whence); } #endif #if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) 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); loff_t offset; if (!f.file) return -EBADF; retval = -EINVAL; if (whence > SEEK_MAX) goto out_putf; offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, whence); retval = (int)offset; if (offset >= 0) { retval = -EFAULT; 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; 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; } 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; } return security_file_permission(file, read_write == READ ? MAY_READ : MAY_WRITE); } 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); ret = call_read_iter(filp, &kiocb, &iter); BUG_ON(ret == -EIOCBQUEUED); *ppos = kiocb.ki_pos; return ret; } ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { 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 return -EINVAL; } ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { mm_segment_t old_fs; ssize_t result; 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; } EXPORT_SYMBOL(kernel_read); ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { ssize_t ret; if (!(file->f_mode & FMODE_READ)) return -EBADF; if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; if (unlikely(!access_ok(buf, count))) 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); } 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); ret = call_write_iter(filp, &kiocb, &iter); BUG_ON(ret == -EIOCBQUEUED); if (ret > 0) *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) { mm_segment_t old_fs; const char __user *p; ssize_t ret; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; 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); if (ret > 0) { fsnotify_modify(file); add_wchar(current, ret); } inc_syscw(current); return ret; } EXPORT_SYMBOL(__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; 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); return res; } EXPORT_SYMBOL(kernel_write); ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) { ssize_t ret; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; if (unlikely(!access_ok(buf, count))) 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); } return ret; } static inline loff_t file_pos_read(struct file *file) { return file->f_pos; } static inline void file_pos_write(struct file *file, loff_t pos) { file->f_pos = pos; } ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) { struct fd f = fdget_pos(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); } return ret; } SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) { return ksys_read(fd, buf, count); } ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) { struct fd f = fdget_pos(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); } return ret; } SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, size_t, count) { return ksys_write(fd, buf, count); } 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); } return ret; } SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, size_t, count, loff_t, pos) { return ksys_pread64(fd, buf, count, pos); } 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); } return ret; } SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, size_t, count, loff_t, pos) { return ksys_pwrite64(fd, buf, count, pos); } static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, loff_t *ppos, int type, rwf_t flags) { struct kiocb kiocb; ssize_t ret; init_sync_kiocb(&kiocb, filp); ret = kiocb_set_rw_flags(&kiocb, flags); if (ret) return ret; kiocb.ki_pos = *ppos; if (type == READ) ret = call_read_iter(filp, &kiocb, iter); else ret = call_write_iter(filp, &kiocb, iter); BUG_ON(ret == -EIOCBQUEUED); *ppos = kiocb.ki_pos; return ret; } /* Do it by hand, with file-ops */ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, loff_t *ppos, int type, rwf_t flags) { ssize_t ret = 0; if (flags & ~RWF_HIPRI) 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); } else { nr = filp->f_op->write(filp, iovec.iov_base, iovec.iov_len, ppos); } if (nr < 0) { if (!ret) ret = nr; break; } ret += nr; if (nr != iovec.iov_len) break; iov_iter_advance(iter, nr); } 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) { compat_ssize_t tot_len; struct iovec *iov = *ret_pointer = fast_pointer; 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; ret = -EFAULT; if (!access_ok(uvector, nr_segs*sizeof(*uvector))) goto out; /* * 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; out: return ret; } #endif static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, loff_t *pos, rwf_t flags) { size_t tot_len; ssize_t ret = 0; if (!(file->f_mode & FMODE_READ)) return -EBADF; if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; tot_len = iov_iter_count(iter); if (!tot_len) goto out; ret = rw_verify_area(READ, file, 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); 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) { size_t tot_len; ssize_t ret = 0; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; tot_len = iov_iter_count(iter); if (!tot_len) return 0; ret = rw_verify_area(WRITE, file, 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); if (ret > 0) fsnotify_modify(file); return ret; } 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); 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; ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); if (ret >= 0) { ret = do_iter_read(file, &iter, pos, flags); 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) { struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; ssize_t ret; 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); } 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); 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 (ret > 0) add_rchar(current, ret); inc_syscr(current); return ret; } 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); 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 (ret > 0) add_wchar(current, ret); inc_syscw(current); return ret; } static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) { #define HALF_LONG_BITS (BITS_PER_LONG / 2) return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | 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) { ret = -ESPIPE; if (f.file->f_mode & FMODE_PREAD) ret = vfs_readv(f.file, vec, vlen, &pos, flags); fdput(f); } if (ret > 0) add_rchar(current, ret); inc_syscr(current); return ret; } 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) { ret = -ESPIPE; if (f.file->f_mode & FMODE_PWRITE) ret = vfs_writev(f.file, vec, vlen, &pos, flags); fdput(f); } if (ret > 0) add_wchar(current, ret); inc_syscw(current); return ret; } SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { return do_readv(fd, vec, vlen, 0); } SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { return do_writev(fd, vec, vlen, 0); } SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) { loff_t pos = pos_from_hilo(pos_h, pos_l); return do_preadv(fd, vec, vlen, pos, 0); } SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, rwf_t, flags) { loff_t pos = pos_from_hilo(pos_h, pos_l); if (pos == -1) return do_readv(fd, vec, vlen, flags); return do_preadv(fd, vec, vlen, pos, flags); } SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) { loff_t pos = pos_from_hilo(pos_h, pos_l); return do_pwritev(fd, vec, vlen, pos, 0); } SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, rwf_t, flags) { loff_t pos = pos_from_hilo(pos_h, pos_l); if (pos == -1) return do_writev(fd, vec, vlen, flags); return do_pwritev(fd, vec, vlen, pos, flags); } #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, unsigned long, vlen, loff_t, pos) { return do_compat_preadv64(fd, vec, vlen, pos, 0); } #endif COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, const struct compat_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); } #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, const struct compat_iovec __user *,vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { return do_compat_preadv64(fd, vec, vlen, pos, flags); } #endif COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, const struct compat_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; } #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, const struct compat_iovec __user *,vec, unsigned long, vlen, loff_t, pos) { return do_compat_pwritev64(fd, vec, vlen, pos, 0); } #endif COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, const struct compat_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); } #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, const struct compat_iovec __user *,vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { return do_compat_pwritev64(fd, vec, vlen, pos, flags); } #endif COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, const struct compat_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); } #endif static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, size_t count, loff_t max) { struct fd in, out; struct inode *in_inode, *out_inode; loff_t pos; loff_t out_pos; ssize_t retval; int fl; /* * 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; if (!ppos) { pos = in.file->f_pos; } else { pos = *ppos; if (!(in.file->f_mode & FMODE_PREAD)) goto fput_in; } retval = rw_verify_area(READ, in.file, &pos, count); if (retval < 0) goto fput_in; 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; 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; count = max - pos; } fl = 0; #if 0 /* * We need to debate whether we can enable this or not. The * man page documents EAGAIN return for the output at least, * 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) 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); 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; if (ppos) *ppos = pos; else in.file->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; } SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) { loff_t pos; off_t off; ssize_t ret; if (offset) { if (unlikely(get_user(off, offset))) return -EFAULT; pos = off; ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); if (unlikely(put_user(pos, offset))) return -EFAULT; return ret; } return do_sendfile(out_fd, in_fd, NULL, count, 0); } SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) { loff_t pos; ssize_t ret; if (offset) { if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) return -EFAULT; ret = do_sendfile(out_fd, in_fd, &pos, count, 0); if (unlikely(put_user(pos, offset))) return -EFAULT; return ret; } return do_sendfile(out_fd, in_fd, NULL, count, 0); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, compat_off_t __user *, offset, compat_size_t, count) { loff_t pos; off_t off; ssize_t ret; if (offset) { if (unlikely(get_user(off, offset))) return -EFAULT; pos = off; ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); if (unlikely(put_user(pos, offset))) return -EFAULT; return ret; } return do_sendfile(out_fd, in_fd, NULL, count, 0); } COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, compat_loff_t __user *, offset, compat_size_t, count) { loff_t pos; ssize_t ret; if (offset) { if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) return -EFAULT; ret = do_sendfile(out_fd, in_fd, &pos, count, 0); if (unlikely(put_user(pos, offset))) return -EFAULT; return ret; } return do_sendfile(out_fd, in_fd, NULL, count, 0); } #endif /* * 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. */ 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; if (flags != 0) 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 = rw_verify_area(READ, file_in, &pos_in, len); if (unlikely(ret)) return ret; ret = rw_verify_area(WRITE, file_out, &pos_out, len); 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; 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). */ 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 (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; } ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); done: if (ret > 0) { fsnotify_access(file_in); add_rchar(current, ret); fsnotify_modify(file_out); add_wchar(current, ret); } inc_syscr(current); inc_syscw(current); file_end_write(file_out); return ret; } EXPORT_SYMBOL(vfs_copy_file_range); SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, int, fd_out, loff_t __user *, off_out, size_t, len, unsigned int, flags) { 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; f_out = fdget(fd_out); if (!f_out.file) goto out1; ret = -EFAULT; if (off_in) { if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) goto out; } else { pos_in = f_in.file->f_pos; } if (off_out) { if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) goto out; } else { pos_out = f_out.file->f_pos; } ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, flags); if (ret > 0) { pos_in += ret; pos_out += ret; if (off_in) { if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) ret = -EFAULT; } else { f_in.file->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; } } 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. */ 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) { u64 blkmask = i_blocksize(inode_in) - 1; loff_t new_len = *len; if ((*len & blkmask) == 0) return 0; if ((remap_flags & REMAP_FILE_DEDUP) || pos_out + *len < i_size_read(inode_out)) new_len &= ~blkmask; if (new_len == *len) return 0; if (remap_flags & REMAP_FILE_CAN_SHORTEN) { *len = new_len; return 0; } return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL; } /* * 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) { 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); if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) same = false; 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 (!same) break; srcoff += cmp_len; destoff += cmp_len; len -= cmp_len; } *is_same = same; return 0; out_error: return error; } /* * 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. * * If there's an error, then the usual negative error code is returned. * Otherwise returns 0 with *len set to the request length. */ 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) { struct inode *inode_in = file_inode(file_in); struct inode *inode_out = file_inode(file_out); bool same_inode = (inode_in == inode_out); 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); 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; } EXPORT_SYMBOL(generic_remap_file_range_prep); 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) { 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); 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; } EXPORT_SYMBOL(vfs_dedupe_file_range_one); int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) { 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; if (!(file->f_mode & FMODE_READ)) return -EINVAL; if (same->reserved1 || same->reserved2) return -EINVAL; off = same->src_offset; len = same->src_length; if (S_ISDIR(src->i_mode)) return -EISDIR; if (!S_ISREG(src->i_mode)) return -EINVAL; if (!file->f_op->remap_file_range) 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; } EXPORT_SYMBOL(vfs_dedupe_file_range);
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