xfs_trans_buf.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_trace.h"

/*
 * Check to see if a buffer matching the given parameters is already
 * a part of the given transaction.
 */
STATIC struct xfs_buf *
xfs_trans_buf_item_match(
	struct xfs_trans	*tp,
	struct xfs_buftarg	*target,
	struct xfs_buf_map	*map,
	int			nmaps)
{ … }

/*
 * Add the locked buffer to the transaction.
 *
 * The buffer must be locked, and it cannot be associated with any
 * transaction.
 *
 * If the buffer does not yet have a buf log item associated with it,
 * then allocate one for it.  Then add the buf item to the transaction.
 */
STATIC void
_xfs_trans_bjoin(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp,
	int			reset_recur)
{ … }

void
xfs_trans_bjoin(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Get and lock the buffer for the caller if it is not already
 * locked within the given transaction.  If it is already locked
 * within the transaction, just increment its lock recursion count
 * and return a pointer to it.
 *
 * If the transaction pointer is NULL, make this just a normal
 * get_buf() call.
 */
int
xfs_trans_get_buf_map(
	struct xfs_trans	*tp,
	struct xfs_buftarg	*target,
	struct xfs_buf_map	*map,
	int			nmaps,
	xfs_buf_flags_t		flags,
	struct xfs_buf		**bpp)
{ … }

/*
 * Get and lock the superblock buffer for the given transaction.
 */
struct xfs_buf *
xfs_trans_getsb(
	struct xfs_trans	*tp)
{ … }

/*
 * Get and lock the buffer for the caller if it is not already
 * locked within the given transaction.  If it has not yet been
 * read in, read it from disk. If it is already locked
 * within the transaction and already read in, just increment its
 * lock recursion count and return a pointer to it.
 *
 * If the transaction pointer is NULL, make this just a normal
 * read_buf() call.
 */
int
xfs_trans_read_buf_map(
	struct xfs_mount	*mp,
	struct xfs_trans	*tp,
	struct xfs_buftarg	*target,
	struct xfs_buf_map	*map,
	int			nmaps,
	xfs_buf_flags_t		flags,
	struct xfs_buf		**bpp,
	const struct xfs_buf_ops *ops)
{ … }

/* Has this buffer been dirtied by anyone? */
bool
xfs_trans_buf_is_dirty(
	struct xfs_buf		*bp)
{ … }

/*
 * Release a buffer previously joined to the transaction. If the buffer is
 * modified within this transaction, decrement the recursion count but do not
 * release the buffer even if the count goes to 0. If the buffer is not modified
 * within the transaction, decrement the recursion count and release the buffer
 * if the recursion count goes to 0.
 *
 * If the buffer is to be released and it was not already dirty before this
 * transaction began, then also free the buf_log_item associated with it.
 *
 * If the transaction pointer is NULL, this is a normal xfs_buf_relse() call.
 */
void
xfs_trans_brelse(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Forcibly detach a buffer previously joined to the transaction.  The caller
 * will retain its locked reference to the buffer after this function returns.
 * The buffer must be completely clean and must not be held to the transaction.
 */
void
xfs_trans_bdetach(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Mark the buffer as not needing to be unlocked when the buf item's
 * iop_committing() routine is called.  The buffer must already be locked
 * and associated with the given transaction.
 */
/* ARGSUSED */
void
xfs_trans_bhold(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Cancel the previous buffer hold request made on this buffer
 * for this transaction.
 */
void
xfs_trans_bhold_release(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Mark a buffer dirty in the transaction.
 */
void
xfs_trans_dirty_buf(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * This is called to mark bytes first through last inclusive of the given
 * buffer as needing to be logged when the transaction is committed.
 * The buffer must already be associated with the given transaction.
 *
 * First and last are numbers relative to the beginning of this buffer,
 * so the first byte in the buffer is numbered 0 regardless of the
 * value of b_blkno.
 */
void
xfs_trans_log_buf(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp,
	uint			first,
	uint			last)
{ … }


/*
 * Invalidate a buffer that is being used within a transaction.
 *
 * Typically this is because the blocks in the buffer are being freed, so we
 * need to prevent it from being written out when we're done.  Allowing it
 * to be written again might overwrite data in the free blocks if they are
 * reallocated to a file.
 *
 * We prevent the buffer from being written out by marking it stale.  We can't
 * get rid of the buf log item at this point because the buffer may still be
 * pinned by another transaction.  If that is the case, then we'll wait until
 * the buffer is committed to disk for the last time (we can tell by the ref
 * count) and free it in xfs_buf_item_unpin().  Until that happens we will
 * keep the buffer locked so that the buffer and buf log item are not reused.
 *
 * We also set the XFS_BLF_CANCEL flag in the buf log format structure and log
 * the buf item.  This will be used at recovery time to determine that copies
 * of the buffer in the log before this should not be replayed.
 *
 * We mark the item descriptor and the transaction dirty so that we'll hold
 * the buffer until after the commit.
 *
 * Since we're invalidating the buffer, we also clear the state about which
 * parts of the buffer have been logged.  We also clear the flag indicating
 * that this is an inode buffer since the data in the buffer will no longer
 * be valid.
 *
 * We set the stale bit in the buffer as well since we're getting rid of it.
 */
void
xfs_trans_binval(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * This call is used to indicate that the buffer contains on-disk inodes which
 * must be handled specially during recovery.  They require special handling
 * because only the di_next_unlinked from the inodes in the buffer should be
 * recovered.  The rest of the data in the buffer is logged via the inodes
 * themselves.
 *
 * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be
 * transferred to the buffer's log format structure so that we'll know what to
 * do at recovery time.
 */
void
xfs_trans_inode_buf(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * This call is used to indicate that the buffer is going to
 * be staled and was an inode buffer. This means it gets
 * special processing during unpin - where any inodes
 * associated with the buffer should be removed from ail.
 * There is also special processing during recovery,
 * any replay of the inodes in the buffer needs to be
 * prevented as the buffer may have been reused.
 */
void
xfs_trans_stale_inode_buf(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Mark the buffer as being one which contains newly allocated
 * inodes.  We need to make sure that even if this buffer is
 * relogged as an 'inode buf' we still recover all of the inode
 * images in the face of a crash.  This works in coordination with
 * xfs_buf_item_committed() to ensure that the buffer remains in the
 * AIL at its original location even after it has been relogged.
 */
/* ARGSUSED */
void
xfs_trans_inode_alloc_buf(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Mark the buffer as ordered for this transaction. This means that the contents
 * of the buffer are not recorded in the transaction but it is tracked in the
 * AIL as though it was. This allows us to record logical changes in
 * transactions rather than the physical changes we make to the buffer without
 * changing writeback ordering constraints of metadata buffers.
 */
bool
xfs_trans_ordered_buf(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp)
{ … }

/*
 * Set the type of the buffer for log recovery so that it can correctly identify
 * and hence attach the correct buffer ops to the buffer after replay.
 */
void
xfs_trans_buf_set_type(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp,
	enum xfs_blft		type)
{ … }

void
xfs_trans_buf_copy_type(
	struct xfs_buf		*dst_bp,
	struct xfs_buf		*src_bp)
{ … }

/*
 * Similar to xfs_trans_inode_buf(), this marks the buffer as a cluster of
 * dquots. However, unlike in inode buffer recovery, dquot buffers get
 * recovered in their entirety. (Hence, no XFS_BLI_DQUOT_ALLOC_BUF flag).
 * The only thing that makes dquot buffers different from regular
 * buffers is that we must not replay dquot bufs when recovering
 * if a _corresponding_ quotaoff has happened. We also have to distinguish
 * between usr dquot bufs and grp dquot bufs, because usr and grp quotas
 * can be turned off independently.
 */
/* ARGSUSED */
void
xfs_trans_dquot_buf(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp,
	uint			type)
{ … }
linux/fs/xfs/xfs_trans_buf.c
