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path: root/fs/read_write.c
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Diffstat (limited to 'fs/read_write.c')
-rw-r--r--fs/read_write.c375
1 files changed, 346 insertions, 29 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index 0a2893354..dadf24e5c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -16,6 +16,8 @@
#include <linux/pagemap.h>
#include <linux/splice.h>
#include <linux/compat.h>
+#include <linux/mount.h>
+#include <linux/fs.h>
#include "internal.h"
#include <asm/uaccess.h>
@@ -171,6 +173,45 @@ loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t si
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
@@ -198,7 +239,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int whence)
struct inode *inode = file_inode(file);
loff_t retval;
- mutex_lock(&inode->i_mutex);
+ inode_lock(inode);
switch (whence) {
case SEEK_END:
offset += i_size_read(inode);
@@ -243,7 +284,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int whence)
retval = offset;
}
out:
- mutex_unlock(&inode->i_mutex);
+ inode_unlock(inode);
return retval;
}
EXPORT_SYMBOL(default_llseek);
@@ -395,9 +436,8 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
}
if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
- retval = locks_mandatory_area(
- read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
- inode, file, pos, count);
+ retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
+ read_write == READ ? F_RDLCK : F_WRLCK);
if (retval < 0)
return retval;
}
@@ -494,30 +534,6 @@ ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
}
EXPORT_SYMBOL(__vfs_write);
-vfs_readf_t vfs_readf(struct file *file)
-{
- const struct file_operations *fop = file->f_op;
-
- if (fop->read)
- return fop->read;
- if (fop->read_iter)
- return new_sync_read;
- return ERR_PTR(-ENOSYS);
-}
-EXPORT_SYMBOL_GPL(vfs_readf);
-
-vfs_writef_t vfs_writef(struct file *file)
-{
- const struct file_operations *fop = file->f_op;
-
- if (fop->write)
- return fop->write;
- if (fop->write_iter)
- return new_sync_write;
- return ERR_PTR(-ENOSYS);
-}
-EXPORT_SYMBOL_GPL(vfs_writef);
-
ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
@@ -1351,3 +1367,304 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
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;
+
+ /* copy_file_range allows full ssize_t len, ignoring MAX_RW_COUNT */
+ ret = rw_verify_area(READ, file_in, &pos_in, len);
+ if (ret >= 0)
+ ret = rw_verify_area(WRITE, file_out, &pos_out, len);
+ if (ret < 0)
+ 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;
+
+ ret = mnt_want_write_file(file_out);
+ if (ret)
+ return ret;
+
+ ret = -EOPNOTSUPP;
+ 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)
+ ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
+ len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+
+ 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);
+
+ mnt_drop_write_file(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 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);
+}
+
+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 (inode_in->i_sb != inode_out->i_sb ||
+ file_in->f_path.mnt != file_out->f_path.mnt)
+ return -EXDEV;
+
+ 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;
+
+ 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 = mnt_want_write_file(file_out);
+ if (ret)
+ return ret;
+
+ 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);
+ }
+
+ mnt_drop_write_file(file_out);
+ return ret;
+}
+EXPORT_SYMBOL(vfs_clone_file_range);
+
+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;
+
+ /* 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;
+}
+EXPORT_SYMBOL(vfs_dedupe_file_range);