- 根目录:
- fs
- ext4
- ext4_jbd2.h
/*
* ext4_jbd2.h
*
* Written by Stephen C. Tweedie <sct@redhat.com>, 1999
*
* Copyright 1998--1999 Red Hat corp --- All Rights Reserved
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*
* Ext4-specific journaling extensions.
*/
#ifndef _EXT4_JBD2_H
#define _EXT4_JBD2_H
#include <linux/fs.h>
#include <linux/jbd2.h>
#include "ext4.h"
#define EXT4_JOURNAL(inode) (EXT4_SB((inode)->i_sb)->s_journal)
/* Define the number of blocks we need to account to a transaction to
* modify one block of data.
*
* We may have to touch one inode, one bitmap buffer, up to three
* indirection blocks, the group and superblock summaries, and the data
* block to complete the transaction.
*
* For extents-enabled fs we may have to allocate and modify up to
* 5 levels of tree, data block (for each of these we need bitmap + group
* summaries), root which is stored in the inode, sb
*/
#define EXT4_SINGLEDATA_TRANS_BLOCKS(sb) \
(EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS) \
? 20U : 8U)
/* Extended attribute operations touch at most two data buffers,
* two bitmap buffers, and two group summaries, in addition to the inode
* and the superblock, which are already accounted for. */
#define EXT4_XATTR_TRANS_BLOCKS 6U
/* Define the minimum size for a transaction which modifies data. This
* needs to take into account the fact that we may end up modifying two
* quota files too (one for the group, one for the user quota). The
* superblock only gets updated once, of course, so don't bother
* counting that again for the quota updates. */
#define EXT4_DATA_TRANS_BLOCKS(sb) (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
EXT4_XATTR_TRANS_BLOCKS - 2 + \
EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
/*
* Define the number of metadata blocks we need to account to modify data.
*
* This include super block, inode block, quota blocks and xattr blocks
*/
#define EXT4_META_TRANS_BLOCKS(sb) (EXT4_XATTR_TRANS_BLOCKS + \
EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
/* Define an arbitrary limit for the amount of data we will anticipate
* writing to any given transaction. For unbounded transactions such as
* write(2) and truncate(2) we can write more than this, but we always
* start off at the maximum transaction size and grow the transaction
* optimistically as we go. */
#define EXT4_MAX_TRANS_DATA 64U
/* We break up a large truncate or write transaction once the handle's
* buffer credits gets this low, we need either to extend the
* transaction or to start a new one. Reserve enough space here for
* inode, bitmap, superblock, group and indirection updates for at least
* one block, plus two quota updates. Quota allocations are not
* needed. */
#define EXT4_RESERVE_TRANS_BLOCKS 12U
#define EXT4_INDEX_EXTRA_TRANS_BLOCKS 8
#ifdef CONFIG_QUOTA
/* Amount of blocks needed for quota update - we know that the structure was
* allocated so we need to update only data block */
#define EXT4_QUOTA_TRANS_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
1 : 0)
/* Amount of blocks needed for quota insert/delete - we do some block writes
* but inode, sb and group updates are done only once */
#define EXT4_QUOTA_INIT_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
(DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
+3+DQUOT_INIT_REWRITE) : 0)
#define EXT4_QUOTA_DEL_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
(DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
+3+DQUOT_DEL_REWRITE) : 0)
#else
#define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
#define EXT4_QUOTA_INIT_BLOCKS(sb) 0
#define EXT4_QUOTA_DEL_BLOCKS(sb) 0
#endif
#define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
#define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
#define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
static inline int ext4_jbd2_credits_xattr(struct inode *inode)
{
int credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
/*
* In case of inline data, we may push out the data to a block,
* so we need to reserve credits for this eventuality
*/
if (ext4_has_inline_data(inode))
credits += ext4_writepage_trans_blocks(inode) + 1;
return credits;
}
/*
* Ext4 handle operation types -- for logging purposes
*/
#define EXT4_HT_MISC 0
#define EXT4_HT_INODE 1
#define EXT4_HT_WRITE_PAGE 2
#define EXT4_HT_MAP_BLOCKS 3
#define EXT4_HT_DIR 4
#define EXT4_HT_TRUNCATE 5
#define EXT4_HT_QUOTA 6
#define EXT4_HT_RESIZE 7
#define EXT4_HT_MIGRATE 8
#define EXT4_HT_MOVE_EXTENTS 9
#define EXT4_HT_XATTR 10
#define EXT4_HT_EXT_CONVERT 11
#define EXT4_HT_MAX 12
/**
* struct ext4_journal_cb_entry - Base structure for callback information.
*
* This struct is a 'seed' structure for a using with your own callback
* structs. If you are using callbacks you must allocate one of these
* or another struct of your own definition which has this struct
* as it's first element and pass it to ext4_journal_callback_add().
*/
struct ext4_journal_cb_entry {
/* list information for other callbacks attached to the same handle */
struct list_head jce_list;
/* Function to call with this callback structure */
void (*jce_func)(struct super_block *sb,
struct ext4_journal_cb_entry *jce, int error);
/* user data goes here */
};
/**
* ext4_journal_callback_add: add a function to call after transaction commit
* @handle: active journal transaction handle to register callback on
* @func: callback function to call after the transaction has committed:
* @sb: superblock of current filesystem for transaction
* @jce: returned journal callback data
* @rc: journal state at commit (0 = transaction committed properly)
* @jce: journal callback data (internal and function private data struct)
*
* The registered function will be called in the context of the journal thread
* after the transaction for which the handle was created has completed.
*
* No locks are held when the callback function is called, so it is safe to
* call blocking functions from within the callback, but the callback should
* not block or run for too long, or the filesystem will be blocked waiting for
* the next transaction to commit. No journaling functions can be used, or
* there is a risk of deadlock.
*
* There is no guaranteed calling order of multiple registered callbacks on
* the same transaction.
*/
static inline void ext4_journal_callback_add(handle_t *handle,
void (*func)(struct super_block *sb,
struct ext4_journal_cb_entry *jce,
int rc),
struct ext4_journal_cb_entry *jce)
{
struct ext4_sb_info *sbi =
EXT4_SB(handle->h_transaction->t_journal->j_private);
/* Add the jce to transaction's private list */
jce->jce_func = func;
spin_lock(&sbi->s_md_lock);
list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
spin_unlock(&sbi->s_md_lock);
}
/**
* ext4_journal_callback_del: delete a registered callback
* @handle: active journal transaction handle on which callback was registered
* @jce: registered journal callback entry to unregister
* Return true if object was successfully removed
*/
static inline bool ext4_journal_callback_try_del(handle_t *handle,
struct ext4_journal_cb_entry *jce)
{
bool deleted;
struct ext4_sb_info *sbi =
EXT4_SB(handle->h_transaction->t_journal->j_private);
spin_lock(&sbi->s_md_lock);
deleted = !list_empty(&jce->jce_list);
list_del_init(&jce->jce_list);
spin_unlock(&sbi->s_md_lock);
return deleted;
}
int
ext4_mark_iloc_dirty(handle_t *handle,
struct inode *inode,
struct ext4_iloc *iloc);
/*
* On success, We end up with an outstanding reference count against
* iloc->bh. This _must_ be cleaned up later.
*/
int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
struct ext4_iloc *iloc);
int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
/*
* Wrapper functions with which ext4 calls into JBD.
*/
int __ext4_journal_get_write_access(const char *where, unsigned int line,
handle_t *handle, struct buffer_head *bh);
int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
int is_metadata, struct inode *inode,
struct buffer_head *bh, ext4_fsblk_t blocknr);
int __ext4_journal_get_create_access(const char *where, unsigned int line,
handle_t *handle, struct buffer_head *bh);
int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
handle_t *handle, struct inode *inode,
struct buffer_head *bh);
int __ext4_handle_dirty_super(const char *where, unsigned int line,
handle_t *handle, struct super_block *sb);
#define ext4_journal_get_write_access(handle, bh) \
__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
#define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
__ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
(bh), (block_nr))
#define ext4_journal_get_create_access(handle, bh) \
__ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
#define ext4_handle_dirty_metadata(handle, inode, bh) \
__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
(bh))
#define ext4_handle_dirty_super(handle, sb) \
__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
int type, int blocks, int rsv_blocks);
int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
/* Note: Do not use this for NULL handles. This is only to determine if
* a properly allocated handle is using a journal or not. */
static inline int ext4_handle_valid(handle_t *handle)
{
if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
return 0;
return 1;
}
static inline void ext4_handle_sync(handle_t *handle)
{
if (ext4_handle_valid(handle))
handle->h_sync = 1;
}
static inline int ext4_handle_is_aborted(handle_t *handle)
{
if (ext4_handle_valid(handle))
return is_handle_aborted(handle);
return 0;
}
static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
{
if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
return 0;
return 1;
}
#define ext4_journal_start_sb(sb, type, nblocks) \
__ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0)
#define ext4_journal_start(inode, type, nblocks) \
__ext4_journal_start((inode), __LINE__, (type), (nblocks), 0)
#define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks) \
__ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks))
static inline handle_t *__ext4_journal_start(struct inode *inode,
unsigned int line, int type,
int blocks, int rsv_blocks)
{
return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
rsv_blocks);
}
#define ext4_journal_stop(handle) \
__ext4_journal_stop(__func__, __LINE__, (handle))
#define ext4_journal_start_reserved(handle, type) \
__ext4_journal_start_reserved((handle), __LINE__, (type))
handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
int type);
static inline void ext4_journal_free_reserved(handle_t *handle)
{
if (ext4_handle_valid(handle))
jbd2_journal_free_reserved(handle);
}
static inline handle_t *ext4_journal_current_handle(void)
{
return journal_current_handle();
}
static inline int ext4_journal_extend(handle_t *handle, int nblocks)
{
if (ext4_handle_valid(handle))
return jbd2_journal_extend(handle, nblocks);
return 0;
}
static inline int ext4_journal_restart(handle_t *handle, int nblocks)
{
if (ext4_handle_valid(handle))
return jbd2_journal_restart(handle, nblocks);
return 0;
}
static inline int ext4_journal_blocks_per_page(struct inode *inode)
{
if (EXT4_JOURNAL(inode) != NULL)
return jbd2_journal_blocks_per_page(inode);
return 0;
}
static inline int ext4_journal_force_commit(journal_t *journal)
{
if (journal)
return jbd2_journal_force_commit(journal);
return 0;
}
static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
{
if (ext4_handle_valid(handle))
return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode);
return 0;
}
static inline void ext4_update_inode_fsync_trans(handle_t *handle,
struct inode *inode,
int datasync)
{
struct ext4_inode_info *ei = EXT4_I(inode);
if (ext4_handle_valid(handle)) {
ei->i_sync_tid = handle->h_transaction->t_tid;
if (datasync)
ei->i_datasync_tid = handle->h_transaction->t_tid;
}
}
/* super.c */
int ext4_force_commit(struct super_block *sb);
/*
* Ext4 inode journal modes
*/
#define EXT4_INODE_JOURNAL_DATA_MODE 0x01 /* journal data mode */
#define EXT4_INODE_ORDERED_DATA_MODE 0x02 /* ordered data mode */
#define EXT4_INODE_WRITEBACK_DATA_MODE 0x04 /* writeback data mode */
static inline int ext4_inode_journal_mode(struct inode *inode)
{
if (EXT4_JOURNAL(inode) == NULL)
return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */
/* We do not support data journalling with delayed allocation */
if (!S_ISREG(inode->i_mode) ||
test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */
if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
!test_opt(inode->i_sb, DELALLOC))
return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */
if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */
if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */
else
BUG();
}
static inline int ext4_should_journal_data(struct inode *inode)
{
return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
}
static inline int ext4_should_order_data(struct inode *inode)
{
return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
}
static inline int ext4_should_writeback_data(struct inode *inode)
{
return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
}
/*
* This function controls whether or not we should try to go down the
* dioread_nolock code paths, which makes it safe to avoid taking
* i_mutex for direct I/O reads. This only works for extent-based
* files, and it doesn't work if data journaling is enabled, since the
* dioread_nolock code uses b_private to pass information back to the
* I/O completion handler, and this conflicts with the jbd's use of
* b_private.
*/
static inline int ext4_should_dioread_nolock(struct inode *inode)
{
if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
return 0;
if (!S_ISREG(inode->i_mode))
return 0;
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
return 0;
if (ext4_should_journal_data(inode))
return 0;
return 1;
}
#endif /* _EXT4_JBD2_H */