cregit-Linux how code gets into the kernel

Release 4.13 fs/read_write.c

Directory: fs
/*
 *  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 int unsigned_offsets(struct file *file) { return file->f_mode & FMODE_UNSIGNED_OFFSET; }

Contributors

PersonTokensPropCommitsCommitProp
Kamezawa Hiroyuki1789.47%150.00%
Al Viro210.53%150.00%
Total19100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds3755.22%112.50%
Kamezawa Hiroyuki1116.42%112.50%
Andi Kleen710.45%112.50%
Christoph Hellwig710.45%112.50%
Al Viro22.99%112.50%
Jie Liu11.49%112.50%
Andrew Morton11.49%112.50%
Josef Bacik11.49%112.50%
Total67100.00%8100.00%

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 (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 (offset >= eof) return -ENXIO; offset = eof; break; } return vfs_setpos(file, offset, maxsize); }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen9573.08%342.86%
Robert Love2418.46%114.29%
Eric Sandeen75.38%114.29%
Andrew Morton21.54%114.29%
Jie Liu21.54%114.29%
Total130100.00%7100.00%

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)); }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen3981.25%240.00%
Eric Sandeen510.42%120.00%
Andrew Morton24.17%120.00%
Robert Love24.17%120.00%
Total48100.00%5100.00%

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; } }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro53100.00%1100.00%
Total53100.00%1100.00%

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; } }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro4697.87%150.00%
Wouter van Kesteren12.13%150.00%
Total47100.00%2100.00%

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; } }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro50100.00%1100.00%
Total50100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Jan Blunck2095.24%150.00%
Andrew Morton14.76%150.00%
Total21100.00%2100.00%

EXPORT_SYMBOL(noop_llseek);
loff_t no_llseek(struct file *file, loff_t offset, int whence) { return -ESPIPE; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds1995.00%150.00%
Andrew Morton15.00%150.00%
Total20100.00%2100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7741.85%422.22%
Josef Bacik4725.54%15.56%
Alain Knaff1910.33%15.56%
Dan Carpenter168.70%15.56%
Al Viro63.26%316.67%
Andrew Morton63.26%316.67%
Kamezawa Hiroyuki42.17%15.56%
Arnd Bergmann42.17%15.56%
Chris Snook21.09%15.56%
Linus Torvalds21.09%15.56%
David Sterba10.54%15.56%
Total184100.00%18100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5577.46%555.56%
Linus Torvalds1318.31%222.22%
Andrew Morton22.82%111.11%
Neil Brown11.41%111.11%
Total71100.00%9100.00%

EXPORT_SYMBOL(vfs_llseek); SYSCALL_DEFINE3(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; } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) { return sys_lseek(fd, offset, whence); } #endif #ifdef __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); 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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds9650.53%426.67%
Al Viro4121.58%426.67%
James Morris2613.68%16.67%
Christoph Hellwig126.32%16.67%
Kamezawa Hiroyuki63.16%16.67%
Eric Dumazet42.11%16.67%
Jens Axboe31.58%16.67%
Pavel Emelyanov10.53%16.67%
Jeff Layton10.53%16.67%
Total190100.00%15100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro10493.69%250.00%
Christoph Hellwig43.60%125.00%
Miklos Szeredi32.70%125.00%
Total111100.00%4100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kasatkin6793.06%150.00%
Al Viro56.94%150.00%
Total72100.00%2100.00%

EXPORT_SYMBOL(__vfs_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(VERIFY_WRITE, 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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig3826.21%15.26%
Linus Torvalds (pre-git)3624.83%631.58%
Al Viro2819.31%315.79%
Linus Torvalds2517.24%421.05%
Jay Lan74.83%15.26%
Alexey Dobriyan74.83%15.26%
Stephen D. Smalley21.38%15.26%
Robert Love10.69%15.26%
Dmitry Kasatkin10.69%15.26%
Total145100.00%19100.00%

EXPORT_SYMBOL(vfs_read);
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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig6149.59%222.22%
Al Viro2822.76%333.33%
Badari Pulavarty2318.70%111.11%
Neil Brown75.69%111.11%
Miklos Szeredi32.44%111.11%
Linus Torvalds10.81%111.11%
Total123100.00%9100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro73100.00%1100.00%
Total73100.00%1100.00%

EXPORT_SYMBOL(__vfs_write);
ssize_t __kernel_write(struct file *file, const char *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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro127100.00%5100.00%
Total127100.00%5100.00%

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(VERIFY_READ, 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; }

Contributors

PersonTokensPropCommitsCommitProp
Neil Brown6944.23%17.14%
Al Viro3623.08%535.71%
Linus Torvalds2516.03%428.57%
Christoph Hellwig117.05%17.14%
Jay Lan74.49%17.14%
Alexey Dobriyan74.49%17.14%
Robert Love10.64%17.14%
Total156100.00%14100.00%

EXPORT_SYMBOL(vfs_write);
static inline loff_t file_pos_read(struct file *file) { return file->f_pos; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds17100.00%1100.00%
Total17100.00%1100.00%


static inline void file_pos_write(struct file *file, loff_t pos) { file->f_pos = pos; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds21100.00%1100.00%
Total21100.00%1100.00%

SYSCALL_DEFINE3(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(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_DEFINE4(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(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; } /* * Reduce an iovec's length in-place. Return the resulting number of segments */
unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) { unsigned long seg = 0; size_t len = 0; while (seg < nr_segs) { seg++; if (len + iov->iov_len >= to) { iov->iov_len = to - len; break; } len += iov->iov_len; iov++; } return seg; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton73100.00%1100.00%
Total73100.00%1100.00%

EXPORT_SYMBOL(iov_shorten);
static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, loff_t *ppos, int type, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro6859.65%222.22%
Miklos Szeredi2421.05%222.22%
Christoph Hellwig1210.53%444.44%
Goldwyn Rodrigues108.77%111.11%
Total114100.00%9100.00%

/* 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, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Badari Pulavarty6239.49%112.50%
Miklos Szeredi3924.84%112.50%
Al Viro3119.75%225.00%
Christoph Hellwig148.92%225.00%
Linus Torvalds (pre-git)117.01%225.00%
Total157100.00%8100.00%

/* A write operation does a read from user space and vice versa */ #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) /** * 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(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(vrfy_dir(type), 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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9935.36%738.89%
Badari Pulavarty8831.43%211.11%
Linus Torvalds6021.43%316.67%
Andrew Morton165.71%211.11%
Dave Hansen93.21%15.56%
Christopher Yeoh41.43%211.11%
Alan Cox41.43%15.56%
Total280100.00%18100.00%

#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(nr_segs*sizeof(struct iovec), GFP_KERNEL); if (iov == NULL) goto out; } *ret_pointer = iov; ret = -EFAULT; if (!access_ok(VERIFY_READ, 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(vrfy_dir(type), 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro303100.00%1100.00%
Total303100.00%1100.00%

#endif
static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, loff_t *pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig5535.95%418.18%
Al Viro3522.88%418.18%
Badari Pulavarty2415.69%29.09%
Linus Torvalds (pre-git)2315.03%627.27%
Andrew Morton74.58%29.09%
Miklos Szeredi63.92%29.09%
Linus Torvalds31.96%29.09%
Total153100.00%22100.00%


ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, int flags) { if (!file->f_op->read_iter) return -EINVAL; return do_iter_read(file, iter, ppos, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig4085.11%133.33%
Al Viro510.64%133.33%
Miklos Szeredi24.26%133.33%
Total47100.00%3100.00%

EXPORT_SYMBOL(vfs_iter_read);
static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, loff_t *pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig11576.16%433.33%
Al Viro1912.58%216.67%
Linus Torvalds (pre-git)85.30%216.67%
Badari Pulavarty31.99%18.33%
Robert Love31.99%18.33%
Miklos Szeredi21.32%18.33%
Andrew Morton10.66%18.33%
Total151100.00%12100.00%


ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, int flags) { if (!file->f_op->write_iter) return -EINVAL; return do_iter_write(file, iter, ppos, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig4493.62%150.00%
Miklos Szeredi36.38%150.00%
Total47100.00%2100.00%

EXPORT_SYMBOL(vfs_iter_write);
ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, unsigned long vlen, loff_t *pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Miklos Szeredi8988.12%120.00%
Christoph Hellwig1211.88%480.00%
Total101100.00%5100.00%

EXPORT_SYMBOL(vfs_readv);
ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, unsigned long vlen, loff_t *pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig9081.08%555.56%
Linus Torvalds (pre-git)109.01%222.22%
Al Viro109.01%111.11%
Linus Torvalds10.90%111.11%
Total111100.00%9100.00%

EXPORT_SYMBOL(vfs_writev);
static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Milosz Tanski2319.83%17.14%
Al Viro2118.10%214.29%
Linus Torvalds (pre-git)2118.10%321.43%
Linus Torvalds1714.66%214.29%
Jay Lan119.48%17.14%
Christoph Hellwig108.62%321.43%
Alexey Dobriyan76.03%17.14%
Stephen D. Smalley65.17%17.14%
Total116100.00%14100.00%


static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Gerd Hoffmann2521.55%17.69%
Milosz Tanski2319.83%17.69%
Al Viro2118.10%215.38%
Linus Torvalds1714.66%215.38%
Linus Torvalds (pre-git)1512.93%323.08%
Christoph Hellwig97.76%323.08%
Stephen D. Smalley65.17%17.69%
Total116100.00%13100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds35100.00%1100.00%
Total35100.00%1100.00%


static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, loff_t pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Gerd Hoffmann8469.42%133.33%
Milosz Tanski2520.66%133.33%
Al Viro129.92%133.33%
Total121100.00%3100.00%


static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, loff_t pos, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Gerd Hoffmann5948.76%110.00%
Milosz Tanski2419.83%110.00%
Al Viro129.92%110.00%
Jay Lan119.09%110.00%
Alexey Dobriyan75.79%110.00%
Linus Torvalds (pre-git)64.96%330.00%
Christoph Hellwig21.65%220.00%
Total121100.00%10100.00%

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, int, 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, int, 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, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro10690.60%450.00%
Christoph Hellwig119.40%450.00%
Total117100.00%8100.00%


static size_t do_compat_readv(compat_ulong_t fd, const struct compat_iovec __user *vec, compat_ulong_t vlen, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro7275.00%250.00%
Milosz Tanski2222.92%125.00%
Linus Torvalds22.08%125.00%
Total96100.00%4100.00%

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, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro7673.79%133.33%
Heiko Carstens2120.39%133.33%
Milosz Tanski65.83%133.33%
Total103100.00%3100.00%

#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, int, 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, int, 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, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro8264.57%225.00%
Christoph Hellwig4233.07%562.50%
Milosz Tanski32.36%112.50%
Total127100.00%8100.00%


static size_t do_compat_writev(compat_ulong_t fd, const struct compat_iovec __user* vec, compat_ulong_t vlen, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro7275.00%250.00%
Milosz Tanski2222.92%125.00%
Linus Torvalds22.08%125.00%
Total96100.00%4100.00%

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, int 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; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro7673.79%133.33%
Heiko Carstens2120.39%133.33%
Milosz Tanski65.83%133.33%
Total103100.00%3100.00%

#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, int, 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, int, 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; retval = -EINVAL; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig22347.85%15.56%
Al Viro13328.54%633.33%
Linus Torvalds275.79%316.67%
Jens Axboe234.94%211.11%
Jay Lan183.86%15.56%
Scott Wolchok143.00%15.56%
Alexey Dobriyan143.00%15.56%
Andrew Morton112.36%211.11%
Miklos Szeredi30.64%15.56%
Total466100.00%18100.00%

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->clone_file_range) { ret = file_in->f_op->clone_file_range(file_in, pos_in, file_out, pos_out, len); if (ret == 0) { ret = len; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Zach Brown22860.80%116.67%
Christoph Hellwig4712.53%116.67%
Amir Goldstein4612.27%233.33%
Anna Schumaker4512.00%116.67%
Al Viro92.40%116.67%
Total375100.00%6100.00%

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 clone_verify_area(struct file *file, loff_t pos, u64 len, bool write) { struct inode *inode = file_inode(file); if (unlikely(pos < 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); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig135100.00%1100.00%
Total135100.00%1100.00%

/* * 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. * * Returns: 0 for "nothing to clone", 1 for "something to clone", or * the usual negative error code. */
int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, struct inode *inode_out, loff_t pos_out, u64 *len, bool is_dedupe) { loff_t bs = inode_out->i_sb->s_blocksize; loff_t blen; loff_t isize; 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; /* Are we going all the way to the end? */ isize = i_size_read(inode_in); if (isize == 0) return 0; /* Zero length dedupe exits immediately; reflink goes to EOF. */ if (*len == 0) { if (is_dedupe || pos_in == isize) return 0; if (pos_in > isize) return -EINVAL; *len = isize - pos_in; } /* Ensure offsets don't wrap and the input is inside i_size */ if (pos_in + *len < pos_in || pos_out + *len < pos_out || pos_in + *len > isize) return -EINVAL; /* Don't allow dedupe past EOF in the dest file */ if (is_dedupe) { loff_t disize; disize = i_size_read(inode_out); if (pos_out >= disize || pos_out + *len > disize) return -EINVAL; } /* If we're linking to EOF, continue to the block boundary. */ if (pos_in + *len == isize) blen = ALIGN(isize, bs) - pos_in; else blen = *len; /* Only reflink if we're aligned to block boundaries */ if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) return -EINVAL; /* Don't allow overlapped reflink within the same file */ if (same_inode) { if (pos_out + blen > pos_in && pos_out < pos_in + blen) return -EINVAL; } /* 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 (is_dedupe) { 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; } return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Darrick J. Wong29965.86%350.00%
Christoph Hellwig15033.04%233.33%
Amir Goldstein51.10%116.67%
Total454100.00%6100.00%

EXPORT_SYMBOL(vfs_clone_file_prep_inodes);
int vfs_clone_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, u64 len) { struct inode *inode_in = file_inode(file_in); struct inode *inode_out = file_inode(file_out); int ret; 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->clone_file_range) return -EOPNOTSUPP; ret = clone_verify_area(file_in, pos_in, len, false); if (ret) return ret; ret = clone_verify_area(file_out, pos_out, len, true); if (ret) return ret; if (pos_in + len > i_size_read(inode_in)) return -EINVAL; ret = file_in->f_op->clone_file_range(file_in, pos_in, file_out, pos_out, len); if (!ret) { fsnotify_access(file_in); fsnotify_modify(file_out); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Darrick J. Wong22793.42%133.33%
Linus Torvalds156.17%133.33%
Christoph Hellwig10.41%133.33%
Total243100.00%3100.00%

EXPORT_SYMBOL(vfs_clone_file_range); /* * 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 address_space *mapping; struct page *page; pgoff_t n; n = offset >> PAGE_SHIFT; mapping = inode->i_mapping; page = read_mapping_page(mapping, n, NULL); if (IS_ERR(page)) return page; if (!PageUptodate(page)) { put_page(page); return ERR_PTR(-EIO); } lock_page(page); return page; }

Contributors

PersonTokensPropCommitsCommitProp
Darrick J. Wong92100.00%1100.00%
Total92100.00%1100.00%

/* * Compare extents of two files to see if they are the same. * Caller must have locked both inodes to prevent write races. */
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; }

Contributors

PersonTokensPropCommitsCommitProp
Darrick J. Wong297100.00%1100.00%
Total297100.00%1100.00%

EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
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; bool is_admin = capable(CAP_SYS_ADMIN); u16 count = same->dest_count; struct file *dst_file; loff_t dst_off; ssize_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; ret = -EISDIR; if (S_ISDIR(src->i_mode)) goto out; ret = -EINVAL; if (!S_ISREG(src->i_mode)) goto out; ret = clone_verify_area(file, off, len, false); if (ret < 0) goto out; ret = 0; if (off + len > i_size_read(src)) return -EINVAL; /* 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 inode *dst; struct fd dst_fd = fdget(info->dest_fd); dst_file = dst_fd.file; if (!dst_file) { info->status = -EBADF; goto next_loop; } dst = file_inode(dst_file); ret = mnt_want_write_file(dst_file); if (ret) { info->status = ret; goto next_loop; } dst_off = info->dest_offset; ret = clone_verify_area(dst_file, dst_off, len, true); if (ret < 0) { info->status = ret; goto next_file; } ret = 0; if (info->reserved) { info->status = -EINVAL; } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { info->status = -EINVAL; } else if (file->f_path.mnt != dst_file->f_path.mnt) { info->status = -EXDEV; } else if (S_ISDIR(dst->i_mode)) { info->status = -EISDIR; } else if (dst_file->f_op->dedupe_file_range == NULL) { info->status = -EINVAL; } else { deduped = dst_file->f_op->dedupe_file_range(file, off, len, dst_file, info->dest_offset); if (deduped == -EBADE) info->status = FILE_DEDUPE_RANGE_DIFFERS; else if (deduped < 0) info->status = deduped; else info->bytes_deduped += deduped; } next_file: mnt_drop_write_file(dst_file); next_loop: fdput(dst_fd); if (fatal_signal_pending(current)) goto out; } out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Darrick J. Wong544100.00%3100.00%
Total544100.00%3100.00%

EXPORT_SYMBOL(vfs_dedupe_file_range);

Overall Contributors

PersonTokensPropCommitsCommitProp
Al Viro233224.70%3016.30%
Darrick J. Wong147815.65%52.72%
Christoph Hellwig142115.05%1910.33%
Linus Torvalds (pre-git)6106.46%2915.76%
Milosz Tanski5665.99%10.54%
Linus Torvalds5365.68%2010.87%
Zach Brown5265.57%10.54%
Heiko Carstens2522.67%63.26%
Gerd Hoffmann2142.27%10.54%
Badari Pulavarty2102.22%42.17%
Miklos Szeredi1741.84%42.17%
Andi Kleen1471.56%31.63%
Andrew Morton1391.47%105.43%
H. J. Lu900.95%10.54%
Neil Brown840.89%21.09%
Dmitry Kasatkin680.72%10.54%
Jay Lan570.60%10.54%
Amir Goldstein510.54%31.63%
Josef Bacik480.51%10.54%
Alexey Dobriyan470.50%10.54%
Anna Schumaker450.48%10.54%
Kamezawa Hiroyuki380.40%10.54%
Arnaldo Carvalho de Melo340.36%10.54%
Robert Love320.34%21.09%
Jens Axboe310.33%42.17%
James Morris260.28%10.54%
Jan Blunck250.26%10.54%
Alain Knaff190.20%10.54%
Stephen D. Smalley170.18%10.54%
Eric Sandeen170.18%21.09%
Dan Carpenter160.17%10.54%
Scott Wolchok140.15%10.54%
Goldwyn Rodrigues100.11%10.54%
Jie Liu90.10%10.54%
Dave Hansen90.10%10.54%
Arnd Bergmann70.07%21.09%
Art Haas70.07%10.54%
Eric Dumazet40.04%10.54%
Alan Cox40.04%10.54%
Wouter van Kesteren40.04%10.54%
Chris Snook40.04%21.09%
Christopher Yeoh40.04%21.09%
Benjamin LaHaise40.04%21.09%
Ingo Molnar30.03%10.54%
Eric Biggers20.02%10.54%
Paul Gortmaker10.01%10.54%
David Sterba10.01%10.54%
Jeff Layton10.01%10.54%
Arjan van de Ven10.01%10.54%
Vegard Nossum10.01%10.54%
Lei Ming10.01%10.54%
Pavel Emelyanov10.01%10.54%
Total9442100.00%184100.00%
Directory: fs
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