From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
The EXT4_IOC_TRANSFER_BLOCK_RANGE ioctl transfers the data blocks lying
between [start, "start + length") form source file and append them
to destination file (represented by dest_fd).
This operation leaves a hole in the source file from where data blocks
are transfrered.
If there is any fallocated area beyond isize of destination it will
be truncated.
Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx>
---
fs/ext4/ext4.h | 10 +-
fs/ext4/extents.c | 471 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/ioctl.c | 47 ++++++
3 files changed, 527 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 246a03a..8f01855 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -591,6 +591,7 @@ enum {
#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
#define EXT4_IOC_SWAP_BOOT _IO('f', 17)
#define EXT4_IOC_TRUNCATE_BLOCK_RANGE _IOW('f', 18, struct truncate_range)
+#define EXT4_IOC_TRANSFER_BLOCK_RANGE _IOW('f', 19, struct transfer_range)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
@@ -688,6 +689,12 @@ struct truncate_range {
__u32 length;
};
+struct transfer_range {
+ __u32 dest_fd;
+ __u32 start_block;
+ __u32 length;
+};
+
#define EXT4_EPOCH_BITS 2
#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
#define EXT4_NSEC_MASK (~0UL << EXT4_EPOCH_BITS)
@@ -2700,7 +2707,8 @@ extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len);
extern int ext4_ext_truncate_range(struct inode *inode, ext4_lblk_t start,
ext4_lblk_t end, ext4_lblk_t last_block);
-
+extern int ext4_ext_transfer_range(struct inode *sinode, struct inode *dinode,
+ __u32 start_block, __u32 end_block);
/* move_extent.c */
extern void ext4_double_down_write_data_sem(struct inode *first,
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index ed85e34..f95d43f 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5002,3 +5002,474 @@ out:
return ret;
}
+/**
+ * ext4_ext_prepare_extent_transfer
+ *
+ * If start lies between extent, extent is split such that start
+ * is the first block of new extent.
+ * If start lies in a hole, start is adjusted to point to the starting
+ * block of next extent.
+ * If end lies between extent, extent is split such that end is the
+ * last block of old extent.
+ *
+ * @inode: The inode of the file from which extents are to be removed
+ * @start: The starting block for removing extent
+ * @orig_end : The end block for removing extent
+ * @handle: journal handle
+ *
+ * Returns 0 on success, 1 if no transfer is needed, error otherwise
+ */
+int ext4_ext_prepare_extent_transfer(struct inode *inode, ext4_lblk_t *start,
+ ext4_lblk_t orig_end, handle_t *handle)
+{
+ int err, depth;
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ex;
+ ext4_lblk_t orig_start = *start;
+
+ err = get_ext_path(inode, orig_start, &path);
+ if (err)
+ return err;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+
+ /* if start lies between extent, split the extent */
+ if (orig_start > le32_to_cpu(ex->ee_block) && orig_start <=
+ le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex) - 1) {
+ int split_flag = 0;
+ if (ext4_ext_is_uninitialized(ex))
+ split_flag = EXT4_EXT_MARK_UNINIT1 |
+ EXT4_EXT_MARK_UNINIT2;
+ err = ext4_split_extent_at(handle, inode, path, orig_start,
+ split_flag, EXT4_GET_BLOCKS_METADATA_NOFAIL |
+ EXT4_GET_BLOCKS_PRE_IO);
+ if (err < 0)
+ goto out;
+ } else if (le32_to_cpu(ex->ee_block) +
+ ext4_ext_get_actual_len(ex) - 1 < orig_start) {
+ /*
+ * start lies in a hole, adjust start to point to
+ * the start of next extent
+ */
+ err = mext_next_extent(inode, path, &ex);
+ if (err < 0 || err == 1)
+ goto out;
+ *start = le32_to_cpu(ex->ee_block);
+ } else
+ /* start lies in a hole which is at the begining of block */
+ *start = le32_to_cpu(ex->ee_block);
+
+ /* Both start and end lies in same hole */
+ if (orig_end < *start) {
+ err = 1;
+ goto out;
+ }
+
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ path = NULL;
+
+ err = get_ext_path(inode, orig_end, &path);
+ if (err)
+ return err;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (orig_end >= le32_to_cpu(ex->ee_block) && orig_end <
+ le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex) - 1) {
+ int split_flag = 0;
+
+ if (ext4_ext_is_uninitialized(ex))
+ split_flag = EXT4_EXT_MARK_UNINIT1 |
+ EXT4_EXT_MARK_UNINIT2;
+ /*
+ * Split the extent in two so that 'end' is the last
+ * block in the first new extent
+ */
+ err = ext4_split_extent_at(handle, inode, path,
+ orig_end + 1, split_flag,
+ EXT4_GET_BLOCKS_PRE_IO |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL);
+ if (err < 0)
+ goto out;
+ }
+
+out:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ return err;
+}
+
+/*
+ * ext4_ext_transfer_extents
+ *
+ * Function to transfer extents from source inode to destination inode
+ * which lies between start and end. Unlike truncate, which start
+ * removing extents from end, we transfer from start.
+ *
+ * @sinode: The source inode for extent transfer
+ * @dinode: The destination inode for extent transfer
+ * @start: The starting block number for extent transfer. start should be
+ * be the first block in an extent.
+ * @end: The ending block number for extent transfer. end could lie inside
+ * hole or it sholud be the last block in an extent.
+ *
+ * Returns number of blocks successfully transfered or error
+ */
+loff_t ext4_ext_transfer_extents(struct inode *sinode, struct inode *dinode,
+ ext4_lblk_t start, ext4_lblk_t end,
+ handle_t *handle)
+{
+ int i, depth = ext_depth(sinode), err, erase_index = 0;
+ struct ext4_extent *ex, *last_ex;
+ struct ext4_ext_path *path = NULL, *d_path = NULL;
+ ext4_lblk_t move_index;
+ loff_t blocks_moved = 0;
+ struct ext4_extent_header *hdr = ext_inode_hdr(sinode);
+
+ move_index = dinode->i_size >> dinode->i_blkbits;
+ err = get_ext_path(sinode, start, &path);
+ if (err)
+ return err;
+ i = depth;
+ ex = path[i].p_ext;
+
+ while (i >= 0 && err == 0) {
+ if (i == depth) {
+ int extent_count = 0;
+ hdr = path[i].p_hdr;
+ if (!ex)
+ ex = EXT_FIRST_EXTENT(hdr);
+ last_ex = EXT_LAST_EXTENT(hdr);
+ err = ext4_trange_dirty_path(handle, sinode, path + i,
+ 1, dinode);
+ if (err)
+ goto out;
+
+ while (ex != NULL &&
+ (le32_to_cpu(ex->ee_block) <= end)) {
+ int ext_length = ext4_ext_get_actual_len(ex);
+
+ d_path = ext4_ext_find_extent(dinode,
+ move_index,
+ NULL);
+ if (IS_ERR(d_path)) {
+ err = PTR_ERR(d_path);
+ goto out;
+ }
+ ex->ee_block = cpu_to_le32(move_index);
+ err = ext4_ext_insert_extent(handle, dinode,
+ d_path, ex, 0);
+ if (err)
+ goto out;
+
+ extent_count++;
+ blocks_moved += ext_length;
+ move_index += ext_length;
+ memset(ex, 0, sizeof(struct ext4_extent));
+ le16_add_cpu(&(hdr->eh_entries), -1);
+ ext4_ext_drop_refs(d_path);
+ kfree(d_path);
+ d_path = NULL;
+
+ /* Check if all the extents in this block have
+ * transfered
+ */
+ if (++ex > last_ex)
+ ex = NULL;
+ }
+
+ ext4_ext_dirty(handle, sinode, path + i);
+
+ if (!ex) {
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ /*move level down */
+ i--;
+ if (!le16_to_cpu(hdr->eh_entries))
+ erase_index = 1;
+ else
+ erase_index = 0;
+ continue;
+ } else {
+ /* All the required extents are transfered */
+ last_ex++;
+ if (extent_count) {
+ memmove(ex - extent_count, ex,
+ (last_ex - ex) *
+ sizeof(struct ext4_extent));
+ memset(last_ex - extent_count, 0,
+ extent_count *
+ sizeof(struct ext4_extent));
+ ext4_ext_dirty(handle, sinode,
+ path + i);
+ path[i].p_ext = EXT_FIRST_EXTENT(hdr);
+ err = ext4_ext_correct_indexes(handle,
+ sinode, path);
+ }
+ break;
+ }
+ }
+
+ /* Now we are at leaf node */
+ if (erase_index) {
+ struct ext4_extent_idx *idx = path[i].p_idx;
+ struct ext4_extent_idx *last_idx =
+ EXT_LAST_INDEX(path[i].p_hdr);
+ int k = i - 1;
+ ext4_fsblk_t leaf;
+
+ leaf = ext4_idx_pblock(path[i].p_idx);
+ err = ext4_trange_dirty_path(handle, sinode, path + i,
+ 1, dinode);
+ if (err)
+ goto out;
+
+ if (idx != last_idx)
+ memmove(idx, idx + 1, (last_idx - idx) *
+ sizeof(struct ext4_extent_idx));
+
+ memset(last_idx, 0, sizeof(struct ext4_extent_idx));
+ le16_add_cpu(&(path[i].p_hdr->eh_entries), -1);
+ ext4_ext_dirty(handle, sinode, path + i);
+
+ ext4_free_blocks(handle, sinode, NULL, leaf, 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
+ erase_index = 0;
+ /* Adjust all the indexes to the top */
+ if (path[i].p_hdr->eh_entries &&
+ idx == EXT_FIRST_INDEX(path[i].p_hdr))
+ while (k >= 0) {
+ if (path[k].p_idx !=
+ EXT_FIRST_INDEX(path[k].p_hdr))
+ break;
+ err = ext4_ext_get_access(handle,
+ sinode, path + k);
+ if (err)
+ break;
+ path[k].p_idx->ei_block = idx->ei_block;
+ err = ext4_ext_dirty(handle, sinode,
+ path + k);
+ if (err)
+ break;
+ k--;
+ }
+ } else {
+ if (!path[i].p_idx)
+ path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
+ else
+ path[i].p_idx++;
+ }
+
+ if (path[i].p_idx <= EXT_LAST_INDEX(path[i].p_hdr)) {
+ struct buffer_head *bh = NULL;
+
+ memset(path + i + 1, 0, sizeof(struct ext4_ext_path));
+ bh = sb_bread(sinode->i_sb,
+ ext4_idx_pblock(path[i].p_idx));
+ if (!bh) {
+ err = -EIO;
+ goto out;
+ }
+ if (ext4_ext_check(sinode, ext_block_hdr(bh),
+ depth - i - 1)) {
+ err = -EIO;
+ put_bh(bh);
+ goto out;
+ }
+ path[i + 1].p_bh = bh;
+ path[i + 1].p_hdr = ext_block_hdr(path[i+1].p_bh);
+ i++;
+ } else {
+ erase_index = 0;
+ if (!le16_to_cpu(path[i].p_hdr->eh_entries)) {
+ erase_index = 1;
+ path[i].p_hdr->eh_depth = 0;
+ }
+
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ }
+ }
+out:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+
+ if (d_path)
+ ext4_ext_drop_refs(d_path);
+ kfree(d_path);
+ if (err)
+ return err;
+ else
+ return blocks_moved;
+}
+
+/*
+ * ext4_ext_can_transfer_range: Check if transfer range
+ * can be performed
+ *
+ * @sinode: Source file inode
+ * @dinode: Destination file inode
+ *
+ * This function returns 0 on success, error otherwise
+ */
+static int ext4_ext_can_transfer_range(struct inode *sinode,
+ struct inode *dinode)
+{
+ /* source file could not be empty */
+ if (!i_size_read(sinode))
+ return -EINVAL;
+
+ /* source and destination inode should be from same fs */
+ if (sinode->i_sb != dinode->i_sb)
+ return -EINVAL;
+
+ /* source and destination should be different inodes */
+ if (sinode == dinode)
+ return -EINVAL;
+
+ /* Regular file check */
+ if (!S_ISREG(sinode->i_mode) || !S_ISREG(dinode->i_mode))
+ return -EINVAL;
+
+ /* cannot move blocks for immutable files */
+ if (IS_IMMUTABLE(sinode) || IS_APPEND(dinode))
+ return -EPERM;
+
+ /* Ignore swap files */
+ if (IS_SWAPFILE(sinode) || IS_SWAPFILE(dinode))
+ return -EINVAL;
+
+ /* Ext4 move block range supports only extent based file */
+ if (!(ext4_test_inode_flag(sinode, EXT4_INODE_EXTENTS)) ||
+ !(ext4_test_inode_flag(dinode, EXT4_INODE_EXTENTS)))
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+/**
+ * ext4_ext_transfer_range
+ *
+ * @sinode: source inode from which blocks are to be moved
+ * @dinode: destination inode to which blocks are added
+ * @start_block: The starting block number from which the
+ * block movement starts
+ * @end_block: The last block number which is to be moved
+ *
+ * This function returns 0 on success or error otherwise
+ */
+int ext4_ext_transfer_range(struct inode *sinode, struct inode *dinode,
+ __u32 start_block, __u32 end_block)
+{
+ ext4_lblk_t s_last_block;
+ int ret, credits, blkbits = EXT4_BLOCK_SIZE_BITS(sinode->i_sb);
+ handle_t *handle;
+ struct address_space *mapping = sinode->i_mapping;
+ loff_t daligned_size, blocks_moved;
+ loff_t first_page_offset, last_page_offset;
+
+ ret = ext4_ext_can_transfer_range(sinode, dinode);
+ if (ret)
+ return ret;
+
+ ext4_inode_double_lock(sinode, dinode);
+ ext4_inode_block_unlocked_dio(sinode);
+ ext4_inode_block_unlocked_dio(dinode);
+ inode_dio_wait(sinode);
+ inode_dio_wait(dinode);
+
+ s_last_block = ((round_up(sinode->i_size,
+ EXT4_BLOCK_SIZE(sinode->i_sb))) >> blkbits) - 1;
+
+ /* start_block cannot be greater than source end_block or last_block */
+ if (start_block > end_block || start_block > s_last_block) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* If end_block is greater than source last_block, adjust it */
+ if (end_block > s_last_block)
+ end_block = s_last_block;
+
+ /* sync dirty pages for transfer */
+ if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
+ ret = filemap_write_and_wait_range(mapping,
+ (loff_t)start_block << blkbits,
+ ((loff_t)(end_block + 1) << blkbits) - 1);
+ if (ret)
+ goto out;
+ }
+
+ first_page_offset = round_down((loff_t)start_block << blkbits,
+ PAGE_SIZE);
+ last_page_offset = round_up((loff_t)end_block << blkbits, PAGE_SIZE);
+ truncate_pagecache_range(sinode, first_page_offset,
+ last_page_offset - 1);
+
+ /* Protect extent tree against block allocations via delalloc */
+ down_write(&EXT4_I(sinode)->i_data_sem);
+
+ /* we need to update 2 inodes */
+ credits = ext4_writepage_trans_blocks(sinode) +
+ ext4_writepage_trans_blocks(dinode);
+ handle = ext4_journal_start(sinode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out2;
+ }
+
+ ret = ext4_ext_prepare_extent_transfer(sinode, &start_block,
+ end_block, handle);
+ if (ret != 0) {
+ if (ret == 1)
+ /* No need to move blocks */
+ ret = 0;
+ goto stop_journal;
+ }
+
+ daligned_size = (loff_t)(round_up(dinode->i_size,
+ EXT4_BLOCK_SIZE(dinode->i_sb)));
+ /* if dest inode isize is not block aligned, make it block aligned */
+ if (dinode->i_size != daligned_size)
+ i_size_write(dinode, daligned_size);
+
+ /* Discard any falloacted area beyond i_size for dest inode */
+ ext4_truncate(dinode);
+
+ down_write(&EXT4_I(dinode)->i_data_sem);
+ blocks_moved = ext4_ext_transfer_extents(sinode, dinode, start_block,
+ end_block, handle);
+ if (blocks_moved <= 0) {
+ ret = blocks_moved;
+ goto out3;
+ }
+
+ /* Update size and disksize here */
+ i_size_write(dinode,
+ (dinode->i_size + (blocks_moved << blkbits)));
+ EXT4_I(dinode)->i_disksize += (blocks_moved << blkbits);
+ sinode->i_blocks -= (blocks_moved << (blkbits - 9));
+ dinode->i_blocks += (blocks_moved << (blkbits - 9));
+
+ sinode->i_mtime = sinode->i_ctime = ext4_current_time(sinode);
+ ext4_mark_inode_dirty(handle, sinode);
+
+ dinode->i_mtime = dinode->i_ctime = ext4_current_time(dinode);
+ ext4_mark_inode_dirty(handle, dinode);
+out3:
+ up_write(&EXT4_I(dinode)->i_data_sem);
+stop_journal:
+ ext4_journal_stop(handle);
+out2:
+ up_write(&EXT4_I(sinode)->i_data_sem);
+out:
+ ext4_inode_resume_unlocked_dio(sinode);
+ ext4_inode_resume_unlocked_dio(dinode);
+ ext4_inode_double_unlock(sinode, dinode);
+
+ return ret;
+}
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 0530daf..f2240f6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -685,6 +685,53 @@ resizefs_out:
return error;
}
+ case EXT4_IOC_TRANSFER_BLOCK_RANGE:
+ {
+ struct transfer_range tr;
+ struct fd dest_fd;
+ int err;
+ ext4_lblk_t end_block;
+
+ if (!(filp->f_mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
+ ext4_msg(sb, KERN_ERR,
+ "Move block range not supported with bigalloc");
+ return -EOPNOTSUPP;
+ }
+
+ if (copy_from_user(&tr, (struct transfer_range __user *)arg,
+ sizeof(tr)))
+ return -EFAULT;
+
+ if (tr.length == 0)
+ return -EINVAL;
+ end_block = tr.start_block + tr.length - 1;
+
+ dest_fd = fdget(tr.dest_fd);
+ if (!dest_fd.file)
+ return -EBADF;
+
+ if (!(dest_fd.file->f_mode & FMODE_WRITE)) {
+ err = -EBADF;
+ goto fput_out;
+ }
+
+ err = mnt_want_write_file(filp);
+ if (err)
+ goto fput_out;
+
+ err = ext4_ext_transfer_range(inode, file_inode(dest_fd.file),
+ tr.start_block, end_block);
+ mnt_drop_write_file(filp);
+
+fput_out:
+ fdput(dest_fd);
+ return err;
+ }
+
default:
return -ENOTTY;
}
--
1.7.9.5
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