btrfs_get_block, file read/write
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
David Woodhouse
parent
4730a4bc5b
commit
dee26a9f7a
@ -8,6 +8,7 @@
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* Add block mapping tree (simple dm layer)
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* Add simple tree locking (semaphore per tree)
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* Make allocator smarter
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* Make directory hashing work on 32 bit
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* Do actual block accounting
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* Check compat and incompat flags on the inode
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* Add virtual filesystems, mountable snapshots
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@ -198,7 +198,7 @@ struct btrfs_file_extent_item {
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__le64 disk_blocknr;
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__le64 disk_num_blocks;
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/*
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* the logical offset in file bytes (no csums)
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* the logical offset in file blocks (no csums)
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* this extent record is for. This allows a file extent to point
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* into the middle of an existing extent on disk, sharing it
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* between two snapshots (useful if some bytes in the middle of the
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@ -812,12 +812,19 @@ static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
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((type *)(btrfs_leaf_data(leaf) + \
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btrfs_item_offset((leaf)->items + (slot))))
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/* extent-item.c */
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struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, u64 num_blocks, u64 search_start, u64
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search_end, u64 owner, struct btrfs_key *ins);
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int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct buffer_head *buf);
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int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, u64 blocknr, u64 num_blocks, int pin);
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int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
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btrfs_root *root);
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/* ctree.c */
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int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_key *key, struct btrfs_path *p, int
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ins_len, int cow);
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@ -834,8 +841,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
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int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf);
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int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct buffer_head *snap);
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int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
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btrfs_root *root);
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/* root-item.c */
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int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct btrfs_key *key);
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int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
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@ -846,6 +852,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
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*item);
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int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
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btrfs_root_item *item, struct btrfs_key *key);
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/* dir-item.c */
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int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, const char *name, int name_len, u64 dir, u64
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objectid, u8 type);
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@ -854,6 +861,7 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
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const char *name, int name_len, int mod);
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int btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path,
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const char *name, int name_len);
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/* inode-map.c */
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int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
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struct btrfs_root *fs_root,
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u64 dirid, u64 *objectid);
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@ -863,9 +871,21 @@ int btrfs_insert_inode_map(struct btrfs_trans_handle *trans,
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int btrfs_lookup_inode_map(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct btrfs_path *path,
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u64 objectid, int mod);
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/* inode-item.c */
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int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, u64 objectid, struct btrfs_inode_item
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*inode_item);
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int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_path *path, u64 objectid, int mod);
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/* file-item.c */
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int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 offset,
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u64 num_blocks, u64 hint_block,
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u64 *result);
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int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path, u64 objectid,
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u64 blocknr, u64 num_blocks, int mod);
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#endif
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@ -403,7 +403,7 @@ error:
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*
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* returns 0 if everything worked, non-zero otherwise.
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*/
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static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
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int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, u64 num_blocks, u64 search_start, u64
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search_end, u64 owner, struct btrfs_key *ins)
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{
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@ -458,7 +458,7 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
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int ret;
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struct buffer_head *buf;
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ret = alloc_extent(trans, root, 1, 0, (unsigned long)-1,
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ret = btrfs_alloc_extent(trans, root, 1, 0, (unsigned long)-1,
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btrfs_header_parentid(btrfs_buffer_header(root->node)), &ins);
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if (ret) {
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BUG();
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@ -1,9 +1,57 @@
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#include <linux/module.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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int btrfs_create_file(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, u64 dirid, u64 *objectid)
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int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 offset,
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u64 num_blocks, u64 hint_block,
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u64 *result)
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{
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struct btrfs_key ins;
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int ret = 0;
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struct btrfs_file_extent_item *item;
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struct btrfs_key file_key;
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struct btrfs_path path;
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btrfs_init_path(&path);
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ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
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(u64)-1, objectid, &ins);
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BUG_ON(ret);
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file_key.objectid = objectid;
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file_key.offset = offset;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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ret = btrfs_insert_empty_item(trans, root, &path, &file_key,
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sizeof(*item));
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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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btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
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btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
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btrfs_set_file_extent_offset(item, 0);
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btrfs_set_file_extent_num_blocks(item, ins.offset);
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mark_buffer_dirty(path.nodes[0]);
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*result = ins.objectid;
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btrfs_release_path(root, &path);
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return 0;
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}
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int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path, u64 objectid,
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u64 blocknr, u64 num_blocks, int mod)
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{
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int ret;
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struct btrfs_key file_key;
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int ins_len = mod < 0 ? -1 : 0;
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int cow = mod != 0;
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file_key.objectid = objectid;
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file_key.offset = blocknr;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
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return ret;
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}
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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,
|
||||
};
|
||||
|
||||
static struct address_space_operations btrfs_aops = {
|
||||
.readpage = btrfs_readpage,
|
||||
.readpages = btrfs_readpages,
|
||||
.writepage = btrfs_writepage,
|
||||
.sync_page = block_sync_page,
|
||||
.prepare_write = btrfs_prepare_write,
|
||||
.commit_write = generic_commit_write,
|
||||
};
|
||||
|
||||
static struct inode_operations btrfs_file_inode_operations = {
|
||||
.truncate = NULL,
|
||||
};
|
||||
|
||||
static struct file_operations btrfs_file_operations = {
|
||||
.llseek = generic_file_llseek,
|
||||
.read = do_sync_read,
|
||||
.write = do_sync_write,
|
||||
.aio_read = generic_file_aio_read,
|
||||
.aio_write = generic_file_aio_write,
|
||||
.mmap = generic_file_mmap,
|
||||
.open = generic_file_open,
|
||||
.sendfile = generic_file_sendfile,
|
||||
.splice_read = generic_file_splice_read,
|
||||
.splice_write = generic_file_splice_write,
|
||||
};
|
||||
|
||||
static int __init init_btrfs_fs(void)
|
||||
{
|
||||
|
||||
Loading…
Reference in New Issue
Block a user