#include <linux/fs.h>
#include "internal.h"
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <asm/unistd.h>
typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
if (len == 0)
return 0;
- ret = mnt_want_write_file(file_out);
- if (ret)
- return ret;
+ sb_start_write(inode_out->i_sb);
- ret = -EOPNOTSUPP;
- if (file_out->f_op->copy_file_range)
+ /*
+ * 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)
- ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
- len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+ 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);
- mnt_drop_write_file(file_out);
+ sb_end_write(inode_out->i_sb);
return ret;
}
return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
}
+/*
+ * 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;
+}
+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_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;
+ /*
+ * 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))
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_modify(file_out);
}
- mnt_drop_write_file(file_out);
return ret;
}
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;
+}
+
+/*
+ * 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;
+}
+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;
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;
git.samba.org / sfrench / cifs-2.6.git / blobdiff