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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /fs/read_write.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'fs/read_write.c')
-rw-r--r-- | fs/read_write.c | 948 |
1 files changed, 948 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c new file mode 100644 index 00000000..5520f8ad --- /dev/null +++ b/fs/read_write.c @@ -0,0 +1,948 @@ +/* + * linux/fs/read_write.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/fcntl.h> +#include <linux/file.h> +#include <linux/uio.h> +#include <linux/fsnotify.h> +#include <linux/security.h> +#include <linux/module.h> +#include <linux/syscalls.h> +#include <linux/pagemap.h> +#include <linux/splice.h> +#include "read_write.h" + +#include <asm/uaccess.h> +#include <asm/unistd.h> + +const struct file_operations generic_ro_fops = { + .llseek = generic_file_llseek, + .read = do_sync_read, + .aio_read = generic_file_aio_read, + .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; +} + +/** + * generic_file_llseek_unlocked - lockless generic llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @origin: type of seek + * + * Updates the file offset to the value specified by @offset and @origin. + * Locking must be provided by the caller. + */ +loff_t +generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) +{ + struct inode *inode = file->f_mapping->host; + + switch (origin) { + case SEEK_END: + offset += inode->i_size; + 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; + offset += file->f_pos; + break; + } + + if (offset < 0 && !unsigned_offsets(file)) + return -EINVAL; + if (offset > inode->i_sb->s_maxbytes) + return -EINVAL; + + /* Special lock needed here? */ + if (offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + + return offset; +} +EXPORT_SYMBOL(generic_file_llseek_unlocked); + +/** + * generic_file_llseek - generic llseek implementation for regular files + * @file: file structure to seek on + * @offset: file offset to seek to + * @origin: 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 @origin under i_mutex. + */ +loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) +{ + loff_t rval; + + mutex_lock(&file->f_dentry->d_inode->i_mutex); + rval = generic_file_llseek_unlocked(file, offset, origin); + mutex_unlock(&file->f_dentry->d_inode->i_mutex); + + return rval; +} +EXPORT_SYMBOL(generic_file_llseek); + +/** + * noop_llseek - No Operation Performed llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @origin: 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 origin) +{ + return file->f_pos; +} +EXPORT_SYMBOL(noop_llseek); + +loff_t no_llseek(struct file *file, loff_t offset, int origin) +{ + return -ESPIPE; +} +EXPORT_SYMBOL(no_llseek); + +loff_t default_llseek(struct file *file, loff_t offset, int origin) +{ + loff_t retval; + + mutex_lock(&file->f_dentry->d_inode->i_mutex); + switch (origin) { + case SEEK_END: + offset += i_size_read(file->f_path.dentry->d_inode); + break; + case SEEK_CUR: + if (offset == 0) { + retval = file->f_pos; + goto out; + } + offset += file->f_pos; + } + retval = -EINVAL; + if (offset >= 0 || unsigned_offsets(file)) { + if (offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + retval = offset; + } +out: + mutex_unlock(&file->f_dentry->d_inode->i_mutex); + return retval; +} +EXPORT_SYMBOL(default_llseek); + +loff_t vfs_llseek(struct file *file, loff_t offset, int origin) +{ + loff_t (*fn)(struct file *, loff_t, int); + + fn = no_llseek; + if (file->f_mode & FMODE_LSEEK) { + if (file->f_op && file->f_op->llseek) + fn = file->f_op->llseek; + } + return fn(file, offset, origin); +} +EXPORT_SYMBOL(vfs_llseek); + +SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin) +{ + off_t retval; + struct file * file; + int fput_needed; + + retval = -EBADF; + file = fget_light(fd, &fput_needed); + if (!file) + goto bad; + + retval = -EINVAL; + if (origin <= SEEK_MAX) { + loff_t res = vfs_llseek(file, offset, origin); + retval = res; + if (res != (loff_t)retval) + retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ + } + fput_light(file, fput_needed); +bad: + return retval; +} + +#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, origin) +{ + int retval; + struct file * file; + loff_t offset; + int fput_needed; + + retval = -EBADF; + file = fget_light(fd, &fput_needed); + if (!file) + goto bad; + + retval = -EINVAL; + if (origin > SEEK_MAX) + goto out_putf; + + offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, + origin); + + retval = (int)offset; + if (offset >= 0) { + retval = -EFAULT; + if (!copy_to_user(result, &offset, sizeof(offset))) + retval = 0; + } +out_putf: + fput_light(file, fput_needed); +bad: + return retval; +} +#endif + + +/* + * rw_verify_area doesn't like huge counts. We limit + * them to something that fits in "int" so that others + * won't have to do range checks all the time. + */ +int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) +{ + struct inode *inode; + loff_t pos; + int retval = -EINVAL; + + inode = file->f_path.dentry->d_inode; + 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_flock && mandatory_lock(inode))) { + retval = locks_mandatory_area( + read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, + inode, file, pos, count); + if (retval < 0) + return retval; + } + retval = security_file_permission(file, + read_write == READ ? MAY_READ : MAY_WRITE); + if (retval) + return retval; + return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; +} + +static void wait_on_retry_sync_kiocb(struct kiocb *iocb) +{ + set_current_state(TASK_UNINTERRUPTIBLE); + if (!kiocbIsKicked(iocb)) + schedule(); + else + kiocbClearKicked(iocb); + __set_current_state(TASK_RUNNING); +} + +ssize_t do_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; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_left = len; + kiocb.ki_nbytes = len; + + for (;;) { + ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); + if (ret != -EIOCBRETRY) + break; + wait_on_retry_sync_kiocb(&kiocb); + } + + if (-EIOCBQUEUED == ret) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; +} + +EXPORT_SYMBOL(do_sync_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_op || (!file->f_op->read && !file->f_op->aio_read)) + return -EINVAL; + if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) + return -EFAULT; + + ret = rw_verify_area(READ, file, pos, count); + if (ret >= 0) { + count = ret; + if (file->f_op->read) + ret = file->f_op->read(file, buf, count, pos); + else + ret = do_sync_read(file, buf, count, pos); + if (ret > 0) { + fsnotify_access(file); + add_rchar(current, ret); + } + inc_syscr(current); + } + + return ret; +} + +EXPORT_SYMBOL(vfs_read); + +ssize_t do_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; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_left = len; + kiocb.ki_nbytes = len; + + for (;;) { + ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); + if (ret != -EIOCBRETRY) + break; + wait_on_retry_sync_kiocb(&kiocb); + } + + if (-EIOCBQUEUED == ret) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; +} + +EXPORT_SYMBOL(do_sync_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_op || (!file->f_op->write && !file->f_op->aio_write)) + return -EINVAL; + if (unlikely(!access_ok(VERIFY_READ, buf, count))) + return -EFAULT; + + ret = rw_verify_area(WRITE, file, pos, count); + if (ret >= 0) { + count = ret; + if (file->f_op->write) + ret = file->f_op->write(file, buf, count, pos); + else + ret = do_sync_write(file, buf, count, pos); + if (ret > 0) { + fsnotify_modify(file); + add_wchar(current, ret); + } + inc_syscw(current); + } + + return ret; +} + +EXPORT_SYMBOL(vfs_write); + +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; +} + +SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + file = fget_light(fd, &fput_needed); + if (file) { + loff_t pos = file_pos_read(file); + ret = vfs_read(file, buf, count, &pos); + file_pos_write(file, pos); + fput_light(file, fput_needed); + } + + return ret; +} + +SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, + size_t, count) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + file = fget_light(fd, &fput_needed); + if (file) { + loff_t pos = file_pos_read(file); + ret = vfs_write(file, buf, count, &pos); + file_pos_write(file, pos); + fput_light(file, fput_needed); + } + + return ret; +} + +SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf, + size_t count, loff_t pos) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + if (pos < 0) + return -EINVAL; + + file = fget_light(fd, &fput_needed); + if (file) { + ret = -ESPIPE; + if (file->f_mode & FMODE_PREAD) + ret = vfs_read(file, buf, count, &pos); + fput_light(file, fput_needed); + } + + return ret; +} +#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS +asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos) +{ + return SYSC_pread64((unsigned int) fd, (char __user *) buf, + (size_t) count, pos); +} +SYSCALL_ALIAS(sys_pread64, SyS_pread64); +#endif + +SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf, + size_t count, loff_t pos) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + if (pos < 0) + return -EINVAL; + + file = fget_light(fd, &fput_needed); + if (file) { + ret = -ESPIPE; + if (file->f_mode & FMODE_PWRITE) + ret = vfs_write(file, buf, count, &pos); + fput_light(file, fput_needed); + } + + return ret; +} +#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS +asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos) +{ + return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf, + (size_t) count, pos); +} +SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64); +#endif + +/* + * 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; +} +EXPORT_SYMBOL(iov_shorten); + +ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, + unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) +{ + struct kiocb kiocb; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_left = len; + kiocb.ki_nbytes = len; + + for (;;) { + ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); + if (ret != -EIOCBRETRY) + break; + wait_on_retry_sync_kiocb(&kiocb); + } + + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; +} + +/* Do it by hand, with file-ops */ +ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, + unsigned long nr_segs, loff_t *ppos, io_fn_t fn) +{ + struct iovec *vector = iov; + ssize_t ret = 0; + + while (nr_segs > 0) { + void __user *base; + size_t len; + ssize_t nr; + + base = vector->iov_base; + len = vector->iov_len; + vector++; + nr_segs--; + + nr = fn(filp, base, len, ppos); + + if (nr < 0) { + if (!ret) + ret = nr; + break; + } + ret += nr; + if (nr != len) + break; + } + + return ret; +} + +/* A write operation does a read from user space and vice versa */ +#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) + +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 (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; +} + +static ssize_t do_readv_writev(int type, struct file *file, + const struct iovec __user * uvector, + unsigned long nr_segs, loff_t *pos) +{ + size_t tot_len; + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + ssize_t ret; + io_fn_t fn; + iov_fn_t fnv; + + if (!file->f_op) { + ret = -EINVAL; + goto out; + } + + ret = rw_copy_check_uvector(type, uvector, nr_segs, + ARRAY_SIZE(iovstack), iovstack, &iov); + if (ret <= 0) + goto out; + + tot_len = ret; + ret = rw_verify_area(type, file, pos, tot_len); + if (ret < 0) + goto out; + + fnv = NULL; + if (type == READ) { + fn = file->f_op->read; + fnv = file->f_op->aio_read; + } else { + fn = (io_fn_t)file->f_op->write; + fnv = file->f_op->aio_write; + } + + if (fnv) + ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, + pos, fnv); + else + ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); + +out: + if (iov != iovstack) + kfree(iov); + if ((ret + (type == READ)) > 0) { + if (type == READ) + fsnotify_access(file); + else + fsnotify_modify(file); + } + return ret; +} + +ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, + unsigned long vlen, loff_t *pos) +{ + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) + return -EINVAL; + + return do_readv_writev(READ, file, vec, vlen, pos); +} + +EXPORT_SYMBOL(vfs_readv); + +ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, + unsigned long vlen, loff_t *pos) +{ + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) + return -EINVAL; + + return do_readv_writev(WRITE, file, vec, vlen, pos); +} + +EXPORT_SYMBOL(vfs_writev); + +SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + file = fget_light(fd, &fput_needed); + if (file) { + loff_t pos = file_pos_read(file); + ret = vfs_readv(file, vec, vlen, &pos); + file_pos_write(file, pos); + fput_light(file, fput_needed); + } + + if (ret > 0) + add_rchar(current, ret); + inc_syscr(current); + return ret; +} + +SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen) +{ + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + file = fget_light(fd, &fput_needed); + if (file) { + loff_t pos = file_pos_read(file); + ret = vfs_writev(file, vec, vlen, &pos); + file_pos_write(file, pos); + fput_light(file, fput_needed); + } + + 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; +} + +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); + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + if (pos < 0) + return -EINVAL; + + file = fget_light(fd, &fput_needed); + if (file) { + ret = -ESPIPE; + if (file->f_mode & FMODE_PREAD) + ret = vfs_readv(file, vec, vlen, &pos); + fput_light(file, fput_needed); + } + + if (ret > 0) + add_rchar(current, ret); + inc_syscr(current); + return ret; +} + +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); + struct file *file; + ssize_t ret = -EBADF; + int fput_needed; + + if (pos < 0) + return -EINVAL; + + file = fget_light(fd, &fput_needed); + if (file) { + ret = -ESPIPE; + if (file->f_mode & FMODE_PWRITE) + ret = vfs_writev(file, vec, vlen, &pos); + fput_light(file, fput_needed); + } + + if (ret > 0) + add_wchar(current, ret); + inc_syscw(current); + return ret; +} + +static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, + size_t count, loff_t max) +{ + struct file * in_file, * out_file; + struct inode * in_inode, * out_inode; + loff_t pos; + ssize_t retval; + int fput_needed_in, fput_needed_out, fl; + + /* + * Get input file, and verify that it is ok.. + */ + retval = -EBADF; + in_file = fget_light(in_fd, &fput_needed_in); + if (!in_file) + goto out; + if (!(in_file->f_mode & FMODE_READ)) + goto fput_in; + retval = -ESPIPE; + if (!ppos) + ppos = &in_file->f_pos; + else + if (!(in_file->f_mode & FMODE_PREAD)) + goto fput_in; + retval = rw_verify_area(READ, in_file, ppos, count); + if (retval < 0) + goto fput_in; + count = retval; + + /* + * Get output file, and verify that it is ok.. + */ + retval = -EBADF; + out_file = fget_light(out_fd, &fput_needed_out); + if (!out_file) + goto fput_in; + if (!(out_file->f_mode & FMODE_WRITE)) + goto fput_out; + retval = -EINVAL; + in_inode = in_file->f_path.dentry->d_inode; + out_inode = out_file->f_path.dentry->d_inode; + retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); + if (retval < 0) + goto fput_out; + count = retval; + + if (!max) + max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); + + pos = *ppos; + 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 + retval = do_splice_direct(in_file, ppos, out_file, count, fl); + + if (retval > 0) { + add_rchar(current, retval); + add_wchar(current, retval); + } + + inc_syscr(current); + inc_syscw(current); + if (*ppos > max) + retval = -EOVERFLOW; + +fput_out: + fput_light(out_file, fput_needed_out); +fput_in: + fput_light(in_file, fput_needed_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); +} |