btrfs_get_block, file read/write
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
committed by
David Woodhouse
David Woodhouse
parent
4730a4bc5b
commit
dee26a9f7a
188
fs/btrfs/super.c
188
fs/btrfs/super.c
@@ -8,6 +8,7 @@
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/backing-dev.h>
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#include <linux/mpage.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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@@ -17,6 +18,9 @@
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static struct inode_operations btrfs_dir_inode_operations;
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static struct super_operations btrfs_super_ops;
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static struct file_operations btrfs_dir_file_operations;
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static struct inode_operations btrfs_file_inode_operations;
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static struct address_space_operations btrfs_aops;
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static struct file_operations btrfs_file_operations;
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static void btrfs_read_locked_inode(struct inode *inode)
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{
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@@ -57,6 +61,9 @@ static void btrfs_read_locked_inode(struct inode *inode)
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break;
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#endif
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case S_IFREG:
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inode->i_mapping->a_ops = &btrfs_aops;
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inode->i_fop = &btrfs_file_operations;
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inode->i_op = &btrfs_file_inode_operations;
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break;
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case S_IFDIR:
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inode->i_op = &btrfs_dir_inode_operations;
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@@ -214,35 +221,6 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
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return d_splice_alias(inode, dentry);
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}
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static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path)
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{
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struct buffer_head *bh;
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struct btrfs_node *node;
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int i;
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int nritems;
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u64 objectid;
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u64 item_objectid;
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u64 blocknr;
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int slot;
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if (!path->nodes[1])
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return;
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node = btrfs_buffer_node(path->nodes[1]);
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slot = path->slots[1];
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objectid = btrfs_disk_key_objectid(&node->ptrs[slot].key);
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nritems = btrfs_header_nritems(&node->header);
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for (i = slot; i < nritems; i++) {
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item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
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if (item_objectid != objectid)
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break;
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blocknr = btrfs_node_blockptr(node, i);
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bh = sb_getblk(root->fs_info->sb, blocknr);
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ll_rw_block(READ, 1, &bh);
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brelse(bh);
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}
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}
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static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
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{
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struct inode *inode = filp->f_path.dentry->d_inode;
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@@ -269,21 +247,18 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
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goto err;
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}
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advance = 0;
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reada_leaves(root, &path);
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while(1) {
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leaf = btrfs_buffer_leaf(path.nodes[0]);
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nritems = btrfs_header_nritems(&leaf->header);
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slot = path.slots[0];
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if (advance) {
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if (slot == nritems -1) {
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if (advance || slot >= nritems) {
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if (slot >= nritems -1) {
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ret = btrfs_next_leaf(root, &path);
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if (ret)
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break;
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leaf = btrfs_buffer_leaf(path.nodes[0]);
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nritems = btrfs_header_nritems(&leaf->header);
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slot = path.slots[0];
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if (path.nodes[1] && path.slots[1] == 0)
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reada_leaves(root, &path);
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} else {
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slot++;
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path.slots[0]++;
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@@ -297,6 +272,8 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
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continue;
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if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
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continue;
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advance = 1;
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di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
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over = filldir(dirent, (const char *)(di + 1),
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btrfs_dir_name_len(di),
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@@ -524,6 +501,11 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
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err = btrfs_add_nondir(trans, dentry, inode);
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if (err)
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drop_inode = 1;
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else {
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inode->i_mapping->a_ops = &btrfs_aops;
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inode->i_fop = &btrfs_file_operations;
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inode->i_op = &btrfs_file_inode_operations;
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}
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dir->i_sb->s_dirt = 1;
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btrfs_end_transaction(trans, root);
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out_unlock:
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@@ -623,11 +605,124 @@ printk("btrfs sync_fs\n");
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return 0;
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}
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static int btrfs_get_block(struct inode *inode, sector_t iblock,
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struct buffer_head *result, int create)
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{
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int ret;
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int err = 0;
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u64 blocknr;
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u64 extent_start = 0;
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u64 extent_end = 0;
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u64 objectid = inode->i_ino;
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struct btrfs_path path;
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struct btrfs_root *root = btrfs_sb(inode->i_sb);
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struct btrfs_trans_handle *trans = NULL;
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struct btrfs_file_extent_item *item;
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struct btrfs_leaf *leaf;
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struct btrfs_disk_key *found_key;
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btrfs_init_path(&path);
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mutex_lock(&root->fs_info->fs_mutex);
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if (create)
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trans = btrfs_start_transaction(root, 1);
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ret = btrfs_lookup_file_extent(trans, root, &path,
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inode->i_ino, iblock, 1, 0);
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if (ret < 0) {
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btrfs_release_path(root, &path);
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err = ret;
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goto out;
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}
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if (ret != 0) {
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if (path.slots[0] == 0) {
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btrfs_release_path(root, &path);
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goto allocate;
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}
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path.slots[0]--;
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}
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item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
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struct btrfs_file_extent_item);
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leaf = btrfs_buffer_leaf(path.nodes[0]);
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blocknr = btrfs_file_extent_disk_blocknr(item);
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blocknr += btrfs_file_extent_offset(item);
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/* exact match found, use it */
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if (ret == 0) {
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err = 0;
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map_bh(result, inode->i_sb, blocknr);
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btrfs_release_path(root, &path);
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goto out;
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}
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/* are we inside the extent that was found? */
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found_key = &leaf->items[path.slots[0]].key;
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if (btrfs_disk_key_objectid(found_key) != objectid ||
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btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
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extent_end = 0;
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extent_start = 0;
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btrfs_release_path(root, &path);
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goto allocate;
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}
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extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key);
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extent_start += btrfs_file_extent_offset(item);
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extent_end = extent_start + btrfs_file_extent_num_blocks(item);
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btrfs_release_path(root, &path);
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if (iblock >= extent_start && iblock < extent_end) {
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err = 0;
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map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
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goto out;
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}
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allocate:
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/* ok, create a new extent */
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if (!create) {
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err = 0;
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goto out;
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}
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ret = btrfs_alloc_file_extent(trans, root, objectid, iblock,
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1, extent_end, &blocknr);
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if (ret) {
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err = ret;
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goto out;
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}
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map_bh(result, inode->i_sb, blocknr);
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out:
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if (trans)
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btrfs_end_transaction(trans, root);
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mutex_unlock(&root->fs_info->fs_mutex);
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return err;
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}
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static int btrfs_prepare_write(struct file *file, struct page *page,
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unsigned from, unsigned to)
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{
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return block_prepare_write(page, from, to, btrfs_get_block);
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}
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static void btrfs_write_super(struct super_block *sb)
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{
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btrfs_sync_fs(sb, 1);
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}
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static int btrfs_readpage(struct file *file, struct page *page)
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{
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return mpage_readpage(page, btrfs_get_block);
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}
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static int btrfs_readpages(struct file *file, struct address_space *mapping,
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struct list_head *pages, unsigned nr_pages)
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{
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return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
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}
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static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
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{
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return block_write_full_page(page, btrfs_get_block, wbc);
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}
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static int btrfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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@@ -667,6 +762,31 @@ static struct file_operations btrfs_dir_file_operations = {
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.readdir = btrfs_readdir,
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};
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static struct address_space_operations btrfs_aops = {
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.readpage = btrfs_readpage,
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.readpages = btrfs_readpages,
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.writepage = btrfs_writepage,
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.sync_page = block_sync_page,
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.prepare_write = btrfs_prepare_write,
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.commit_write = generic_commit_write,
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};
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static struct inode_operations btrfs_file_inode_operations = {
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.truncate = NULL,
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};
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static struct file_operations btrfs_file_operations = {
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.llseek = generic_file_llseek,
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.read = do_sync_read,
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.write = do_sync_write,
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.aio_read = generic_file_aio_read,
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.aio_write = generic_file_aio_write,
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.mmap = generic_file_mmap,
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.open = generic_file_open,
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.sendfile = generic_file_sendfile,
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.splice_read = generic_file_splice_read,
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.splice_write = generic_file_splice_write,
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};
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static int __init init_btrfs_fs(void)
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{
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