Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/fs/remap_range.c b/fs/remap_range.c
new file mode 100644
index 0000000..e6099be
--- /dev/null
+++ b/fs/remap_range.c
@@ -0,0 +1,571 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#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>
+
+/*
+ * Performs necessary checks before doing a clone.
+ *
+ * Can adjust amount of bytes to clone via @req_count argument.
+ * Returns appropriate error code that caller should return or
+ * zero in case the clone should be allowed.
+ */
+static int generic_remap_checks(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t *req_count, unsigned int remap_flags)
+{
+ struct inode *inode_in = file_in->f_mapping->host;
+ struct inode *inode_out = file_out->f_mapping->host;
+ uint64_t count = *req_count;
+ uint64_t bcount;
+ loff_t size_in, size_out;
+ loff_t bs = inode_out->i_sb->s_blocksize;
+ int ret;
+
+ /* The start of both ranges must be aligned to an fs block. */
+ if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_out, bs))
+ return -EINVAL;
+
+ /* Ensure offsets don't wrap. */
+ if (pos_in + count < pos_in || pos_out + count < pos_out)
+ return -EINVAL;
+
+ size_in = i_size_read(inode_in);
+ size_out = i_size_read(inode_out);
+
+ /* Dedupe requires both ranges to be within EOF. */
+ if ((remap_flags & REMAP_FILE_DEDUP) &&
+ (pos_in >= size_in || pos_in + count > size_in ||
+ pos_out >= size_out || pos_out + count > size_out))
+ return -EINVAL;
+
+ /* Ensure the infile range is within the infile. */
+ if (pos_in >= size_in)
+ return -EINVAL;
+ count = min(count, size_in - (uint64_t)pos_in);
+
+ ret = generic_write_check_limits(file_out, pos_out, &count);
+ if (ret)
+ return ret;
+
+ /*
+ * If the user wanted us to link to the infile's EOF, round up to the
+ * next block boundary for this check.
+ *
+ * Otherwise, make sure the count is also block-aligned, having
+ * already confirmed the starting offsets' block alignment.
+ */
+ if (pos_in + count == size_in) {
+ bcount = ALIGN(size_in, bs) - pos_in;
+ } else {
+ if (!IS_ALIGNED(count, bs))
+ count = ALIGN_DOWN(count, bs);
+ bcount = count;
+ }
+
+ /* Don't allow overlapped cloning within the same file. */
+ if (inode_in == inode_out &&
+ pos_out + bcount > pos_in &&
+ pos_out < pos_in + bcount)
+ return -EINVAL;
+
+ /*
+ * We shortened the request but the caller can't deal with that, so
+ * bounce the request back to userspace.
+ */
+ if (*req_count != count && !(remap_flags & REMAP_FILE_CAN_SHORTEN))
+ return -EINVAL;
+
+ *req_count = count;
+ return 0;
+}
+
+static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
+ bool write)
+{
+ struct inode *inode = file_inode(file);
+
+ if (unlikely(pos < 0 || len < 0))
+ return -EINVAL;
+
+ if (unlikely((loff_t) (pos + len) < 0))
+ return -EINVAL;
+
+ if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
+ loff_t end = len ? pos + len - 1 : OFFSET_MAX;
+ int retval;
+
+ retval = locks_mandatory_area(inode, file, pos, end,
+ write ? F_WRLCK : F_RDLCK);
+ if (retval < 0)
+ return retval;
+ }
+
+ return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
+}
+
+/*
+ * Ensure that we don't remap a partial EOF block in the middle of something
+ * else. Assume that the offsets have already been checked for block
+ * alignment.
+ *
+ * For clone we only link a partial EOF block above or at the destination file's
+ * EOF. For deduplication we accept a partial EOF block only if it ends at the
+ * destination file's EOF (can not link it into the middle of a file).
+ *
+ * Shorten the request if possible.
+ */
+static int generic_remap_check_len(struct inode *inode_in,
+ struct inode *inode_out,
+ loff_t pos_out,
+ loff_t *len,
+ unsigned int remap_flags)
+{
+ u64 blkmask = i_blocksize(inode_in) - 1;
+ loff_t new_len = *len;
+
+ if ((*len & blkmask) == 0)
+ return 0;
+
+ if (pos_out + *len < i_size_read(inode_out))
+ new_len &= ~blkmask;
+
+ if (new_len == *len)
+ return 0;
+
+ if (remap_flags & REMAP_FILE_CAN_SHORTEN) {
+ *len = new_len;
+ return 0;
+ }
+
+ return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL;
+}
+
+/* Read a page's worth of file data into the page cache. */
+static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
+{
+ struct page *page;
+
+ page = read_mapping_page(inode->i_mapping, offset >> PAGE_SHIFT, NULL);
+ if (IS_ERR(page))
+ return page;
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-EIO);
+ }
+ return page;
+}
+
+/*
+ * Lock two pages, ensuring that we lock in offset order if the pages are from
+ * the same file.
+ */
+static void vfs_lock_two_pages(struct page *page1, struct page *page2)
+{
+ /* Always lock in order of increasing index. */
+ if (page1->index > page2->index)
+ swap(page1, page2);
+
+ lock_page(page1);
+ if (page1 != page2)
+ lock_page(page2);
+}
+
+/* Unlock two pages, being careful not to unlock the same page twice. */
+static void vfs_unlock_two_pages(struct page *page1, struct page *page2)
+{
+ unlock_page(page1);
+ if (page1 != page2)
+ unlock_page(page2);
+}
+
+/*
+ * Compare extents of two files to see if they are the same.
+ * Caller must have locked both inodes to prevent write races.
+ */
+static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
+ struct inode *dest, loff_t destoff,
+ loff_t len, bool *is_same)
+{
+ loff_t src_poff;
+ loff_t dest_poff;
+ void *src_addr;
+ void *dest_addr;
+ struct page *src_page;
+ struct page *dest_page;
+ loff_t cmp_len;
+ bool same;
+ int error;
+
+ error = -EINVAL;
+ same = true;
+ while (len) {
+ src_poff = srcoff & (PAGE_SIZE - 1);
+ dest_poff = destoff & (PAGE_SIZE - 1);
+ cmp_len = min(PAGE_SIZE - src_poff,
+ PAGE_SIZE - dest_poff);
+ cmp_len = min(cmp_len, len);
+ if (cmp_len <= 0)
+ goto out_error;
+
+ src_page = vfs_dedupe_get_page(src, srcoff);
+ if (IS_ERR(src_page)) {
+ error = PTR_ERR(src_page);
+ goto out_error;
+ }
+ dest_page = vfs_dedupe_get_page(dest, destoff);
+ if (IS_ERR(dest_page)) {
+ error = PTR_ERR(dest_page);
+ put_page(src_page);
+ goto out_error;
+ }
+
+ vfs_lock_two_pages(src_page, dest_page);
+
+ /*
+ * Now that we've locked both pages, make sure they're still
+ * mapped to the file data we're interested in. If not,
+ * someone is invalidating pages on us and we lose.
+ */
+ if (!PageUptodate(src_page) || !PageUptodate(dest_page) ||
+ src_page->mapping != src->i_mapping ||
+ dest_page->mapping != dest->i_mapping) {
+ same = false;
+ goto unlock;
+ }
+
+ 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:
+ vfs_unlock_two_pages(src_page, dest_page);
+ put_page(dest_page);
+ put_page(src_page);
+
+ if (!same)
+ break;
+
+ srcoff += cmp_len;
+ destoff += cmp_len;
+ len -= cmp_len;
+ }
+
+ *is_same = same;
+ return 0;
+
+out_error:
+ return error;
+}
+
+/*
+ * Check that the two inodes are eligible for cloning, the ranges make
+ * sense, and then flush all dirty data. Caller must ensure that the
+ * inodes have been locked against any other modifications.
+ *
+ * If there's an error, then the usual negative error code is returned.
+ * Otherwise returns 0 with *len set to the request length.
+ */
+int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t *len, unsigned int remap_flags)
+{
+ struct inode *inode_in = file_inode(file_in);
+ struct inode *inode_out = file_inode(file_out);
+ bool same_inode = (inode_in == inode_out);
+ int ret;
+
+ /* Don't touch certain kinds of inodes */
+ if (IS_IMMUTABLE(inode_out))
+ return -EPERM;
+
+ if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
+ return -ETXTBSY;
+
+ /* Don't reflink dirs, pipes, sockets... */
+ if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
+ return -EISDIR;
+ if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+ return -EINVAL;
+
+ /* Zero length dedupe exits immediately; reflink goes to EOF. */
+ if (*len == 0) {
+ loff_t isize = i_size_read(inode_in);
+
+ if ((remap_flags & REMAP_FILE_DEDUP) || pos_in == isize)
+ return 0;
+ if (pos_in > isize)
+ return -EINVAL;
+ *len = isize - pos_in;
+ if (*len == 0)
+ return 0;
+ }
+
+ /* Check that we don't violate system file offset limits. */
+ ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len,
+ remap_flags);
+ if (ret)
+ return ret;
+
+ /* Wait for the completion of any pending IOs on both files */
+ inode_dio_wait(inode_in);
+ if (!same_inode)
+ inode_dio_wait(inode_out);
+
+ ret = filemap_write_and_wait_range(inode_in->i_mapping,
+ pos_in, pos_in + *len - 1);
+ if (ret)
+ return ret;
+
+ ret = filemap_write_and_wait_range(inode_out->i_mapping,
+ pos_out, pos_out + *len - 1);
+ if (ret)
+ return ret;
+
+ /*
+ * Check that the extents are the same.
+ */
+ if (remap_flags & REMAP_FILE_DEDUP) {
+ bool is_same = false;
+
+ ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
+ inode_out, pos_out, *len, &is_same);
+ if (ret)
+ return ret;
+ if (!is_same)
+ return -EBADE;
+ }
+
+ ret = generic_remap_check_len(inode_in, inode_out, pos_out, len,
+ remap_flags);
+ if (ret)
+ return ret;
+
+ /* If can't alter the file contents, we're done. */
+ if (!(remap_flags & REMAP_FILE_DEDUP))
+ ret = file_modified(file_out);
+
+ return ret;
+}
+EXPORT_SYMBOL(generic_remap_file_range_prep);
+
+loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags)
+{
+ loff_t ret;
+
+ WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);
+
+ /*
+ * 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 (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
+ return -EXDEV;
+
+ ret = generic_file_rw_checks(file_in, file_out);
+ if (ret < 0)
+ return ret;
+
+ if (!file_in->f_op->remap_file_range)
+ return -EOPNOTSUPP;
+
+ ret = remap_verify_area(file_in, pos_in, len, false);
+ if (ret)
+ return ret;
+
+ ret = remap_verify_area(file_out, pos_out, len, true);
+ if (ret)
+ return ret;
+
+ ret = file_in->f_op->remap_file_range(file_in, pos_in,
+ file_out, pos_out, len, remap_flags);
+ if (ret < 0)
+ return ret;
+
+ fsnotify_access(file_in);
+ fsnotify_modify(file_out);
+ return ret;
+}
+EXPORT_SYMBOL(do_clone_file_range);
+
+loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags)
+{
+ loff_t ret;
+
+ file_start_write(file_out);
+ ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len,
+ remap_flags);
+ file_end_write(file_out);
+
+ return ret;
+}
+EXPORT_SYMBOL(vfs_clone_file_range);
+
+/* Check whether we are allowed to dedupe the destination file */
+static bool allow_file_dedupe(struct file *file)
+{
+ if (capable(CAP_SYS_ADMIN))
+ return true;
+ if (file->f_mode & FMODE_WRITE)
+ return true;
+ if (uid_eq(current_fsuid(), file_inode(file)->i_uid))
+ return true;
+ if (!inode_permission(file_inode(file), MAY_WRITE))
+ return true;
+ return false;
+}
+
+loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
+ struct file *dst_file, loff_t dst_pos,
+ loff_t len, unsigned int remap_flags)
+{
+ loff_t ret;
+
+ WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP |
+ REMAP_FILE_CAN_SHORTEN));
+
+ ret = mnt_want_write_file(dst_file);
+ if (ret)
+ return ret;
+
+ ret = remap_verify_area(dst_file, dst_pos, len, true);
+ if (ret < 0)
+ goto out_drop_write;
+
+ ret = -EPERM;
+ if (!allow_file_dedupe(dst_file))
+ goto out_drop_write;
+
+ ret = -EXDEV;
+ if (src_file->f_path.mnt != dst_file->f_path.mnt)
+ goto out_drop_write;
+
+ ret = -EISDIR;
+ if (S_ISDIR(file_inode(dst_file)->i_mode))
+ goto out_drop_write;
+
+ ret = -EINVAL;
+ if (!dst_file->f_op->remap_file_range)
+ goto out_drop_write;
+
+ if (len == 0) {
+ ret = 0;
+ goto out_drop_write;
+ }
+
+ ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file,
+ dst_pos, len, remap_flags | REMAP_FILE_DEDUP);
+out_drop_write:
+ mnt_drop_write_file(dst_file);
+
+ return ret;
+}
+EXPORT_SYMBOL(vfs_dedupe_file_range_one);
+
+int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
+{
+ struct file_dedupe_range_info *info;
+ struct inode *src = file_inode(file);
+ u64 off;
+ u64 len;
+ int i;
+ int ret;
+ u16 count = same->dest_count;
+ loff_t deduped;
+
+ if (!(file->f_mode & FMODE_READ))
+ return -EINVAL;
+
+ if (same->reserved1 || same->reserved2)
+ return -EINVAL;
+
+ off = same->src_offset;
+ len = same->src_length;
+
+ if (S_ISDIR(src->i_mode))
+ return -EISDIR;
+
+ if (!S_ISREG(src->i_mode))
+ return -EINVAL;
+
+ if (!file->f_op->remap_file_range)
+ return -EOPNOTSUPP;
+
+ ret = remap_verify_area(file, off, len, false);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+
+ if (off + len > i_size_read(src))
+ return -EINVAL;
+
+ /* Arbitrary 1G limit on a single dedupe request, can be raised. */
+ len = min_t(u64, len, 1 << 30);
+
+ /* pre-format output fields to sane values */
+ for (i = 0; i < count; i++) {
+ same->info[i].bytes_deduped = 0ULL;
+ same->info[i].status = FILE_DEDUPE_RANGE_SAME;
+ }
+
+ for (i = 0, info = same->info; i < count; i++, info++) {
+ struct fd dst_fd = fdget(info->dest_fd);
+ struct file *dst_file = dst_fd.file;
+
+ if (!dst_file) {
+ info->status = -EBADF;
+ goto next_loop;
+ }
+
+ if (info->reserved) {
+ info->status = -EINVAL;
+ goto next_fdput;
+ }
+
+ deduped = vfs_dedupe_file_range_one(file, off, dst_file,
+ info->dest_offset, len,
+ REMAP_FILE_CAN_SHORTEN);
+ if (deduped == -EBADE)
+ info->status = FILE_DEDUPE_RANGE_DIFFERS;
+ else if (deduped < 0)
+ info->status = deduped;
+ else
+ info->bytes_deduped = len;
+
+next_fdput:
+ fdput(dst_fd);
+next_loop:
+ if (fatal_signal_pending(current))
+ break;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vfs_dedupe_file_range);