#include <sys/param.h>
#ifdef SIM
#define _KERNEL
#endif
#include <sys/buf.h>
#include <sys/sysmacros.h>
#ifdef SIM
#undef _KERNEL
#endif
#include <sys/vnode.h>
#include <sys/debug.h>
#include <sys/uuid.h>
#ifndef SIM
#include <sys/sysinfo.h>
#include <sys/kmem.h>
#include <sys/conf.h>
#include <sys/user.h>
#include <sys/systm.h>
#endif
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_bio.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#ifdef SIM
#include "sim.h"
#endif
/*
* 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.
*
* Use the buffer cache routine incore_match() to find the buffer
* if it is already owned by this transaction.
*
* If we don't already own the buffer, use xfs_get_buf() to get it.
* If it doesn't yet have an associated xfs_buf_log_item structure,
* then allocate one and add the item to this transaction.
*
* If the transaction pointer is NULL, make this just a normal
* get_buf() call.
*/
buf_t *
xfs_trans_get_buf(xfs_trans_t *tp,
dev_t dev,
daddr_t blkno,
int len,
uint flags)
{
buf_t *bp;
xfs_buf_log_item_t *bip;
int s;
/*
* Default to a normal get_buf() call if the tp is NULL.
* Always specify the BUF_BUSY flag so that get_buf() does
* not try to push out dirty buffers. This keeps us from
* running out of stack space due to recursive calls into
* the buffer cache.
*/
if (tp == NULL) {
return (get_buf(dev, blkno, len, flags | BUF_BUSY));
}
/*
* If we find the buffer in the cache with this transaction
* pointer in its b_fsprivate2 field, then we know we already
* have it locked. In this case we just increment the lock
* recursion count and return the buffer to the caller.
*/
if ((bp = incore_match(dev, blkno, len, BUF_FSPRIV2, tp)) != NULL) {
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
ASSERT(bip != NULL);
bip->bli_recur++;
return (bp);
}
/*
* We always specify the BUF_BUSY flag within a transaction so
* that get_buf does not try to push out a delayed write buffer
* which might cause another transaction to take place (if the
* buffer was delayed alloc). Such recursive transactions can
* easily deadlock with our current transaction as well as cause
* us to run out of stack space.
*/
bp = xfs_get_buf(dev, blkno, len, flags | BUF_BUSY);
if (bp == NULL) {
return NULL;
}
/*
* The xfs_buf_log_item pointer is stored in b_fsprivate. If
* it doesn't have one yet, then allocate one and initialize it.
* The checks to see if one is there are in xfs_buf_item_init().
*/
xfs_buf_item_init(bp, tp->t_mountp);
/*
* Set the recursion count for the buffer within this transaction
* to 0.
*/
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
bip->bli_recur = 0;
/*
* Take a reference for this transaction on the buf item.
*/
s = splockspl(xfs_bli_reflock, splhi);
bip->bli_refcount++;
spunlockspl(xfs_bli_reflock, s);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t*)bip);
/*
* Initialize b_fsprivate2 so we can find it with incore_match()
* above.
*/
bp->b_fsprivate2 = tp;
return (bp);
}
/*
* Get and lock the superblock buffer of this file system for the
* given transaction.
*
* We don't need to use incore_match() here, because the superblock
* buffer is a private buffer which we keep a pointer to in the
* mount structure.
*/
buf_t *
xfs_trans_getsb(xfs_trans_t *tp)
{
buf_t *bp;
xfs_buf_log_item_t *bip;
int s;
/*
* Default to just trying to lock the superblock buffer
* if tp is NULL.
*/
if (tp == NULL) {
return (xfs_getsb(tp->t_mountp));
}
/*
* If the superblock buffer already has this transaction
* pointer in its b_fsprivate2 field, then we know we already
* have it locked. In this case we just increment the lock
* recursion count and return the buffer to the caller.
*/
bp = tp->t_mountp->m_sb_bp;
if (bp->b_fsprivate2 == tp) {
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
ASSERT(bip != NULL);
bip->bli_recur++;
return (bp);
}
bp = xfs_getsb(tp->t_mountp);
/*
* The xfs_buf_log_item pointer is stored in b_fsprivate. If
* it doesn't have one yet, then allocate one and initialize it.
* The checks to see if one is there are in xfs_buf_item_init().
*/
xfs_buf_item_init(bp, tp->t_mountp);
/*
* Set the recursion count for the buffer within this transaction
* to 0.
*/
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
bip->bli_recur = 0;
/*
* Take a reference for this transaction on the buf item.
*/
s = splockspl(xfs_bli_reflock, splhi);
bip->bli_refcount++;
spunlockspl(xfs_bli_reflock, s);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t*)bip);
/*
* Initialize b_fsprivate2 so we can find it with incore_match()
* above.
*/
bp->b_fsprivate2 = tp;
return (bp);
}
/*
* 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.
*
* Use the buffer cache routine incore_match() to find the buffer
* if it is already owned by this transaction.
*
* If we don't already own the buffer, use xfs_read_buf() to get it.
* If it doesn't yet have an associated xfs_buf_log_item structure,
* then allocate one and add the item to this transaction.
*
* If the transaction pointer is NULL, make this just a normal
* read_buf() call.
*/
buf_t *
xfs_trans_read_buf(xfs_trans_t *tp,
dev_t dev,
daddr_t blkno,
int len,
uint flags)
{
buf_t *bp;
xfs_buf_log_item_t *bip;
int s;
/*
* Default to a normal get_buf() call if the tp is NULL.
* Always specify the BUF_BUSY flag so that get_buf() does
* not try to push out dirty buffers. This keeps us from
* running out of stack space due to recursive calls into
* the buffer cache.
*/
if (tp == NULL) {
return (read_buf(dev, blkno, len, flags | BUF_BUSY));
}
/*
* If we find the buffer in the cache with this transaction
* pointer in its b_fsprivate2 field, then we know we already
* have it locked. If it is already read in we just increment
* the lock recursion count and return the buffer to the caller.
* If the buffer is not yet read in, then we read it in, increment
* the lock recursion count, and return it to the caller.
*/
if ((bp = incore_match(dev, blkno, len, BUF_FSPRIV2, tp)) != NULL) {
ASSERT(bp->b_fsprivate != NULL);
if (!(bp->b_flags & B_DONE)) {
#ifndef SIM
SYSINFO.lread += len;
#endif
ASSERT(!(bp->b_flags & B_ASYNC));
bp->b_flags |= B_READ;
bdstrat(bmajor(dev), bp);
#ifndef SIM
u.u_ior++;
SYSINFO.bread += len;
#endif
iowait(bp);
}
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
bip->bli_recur++;
return (bp);
}
/*
* We always specify the BUF_BUSY flag within a transaction so
* that get_buf does not try to push out a delayed write buffer
* which might cause another transaction to take place (if the
* buffer was delayed alloc). Such recursive transactions can
* easily deadlock with our current transaction as well as cause
* us to run out of stack space.
*/
bp = xfs_read_buf(dev, blkno, len, flags | BUF_BUSY);
if (bp == NULL) {
return NULL;
}
/*
* The xfs_buf_log_item pointer is stored in b_fsprivate. If
* it doesn't have one yet, then allocate one and initialize it.
* The checks to see if one is there are in xfs_buf_item_init().
*/
xfs_buf_item_init(bp, tp->t_mountp);
/*
* Set the recursion count for the buffer within this transaction
* to 0.
*/
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
bip->bli_recur = 0;
/*
* Take a reference for this transaction on the buf item.
*/
s = splockspl(xfs_bli_reflock, splhi);
bip->bli_refcount++;
spunlockspl(xfs_bli_reflock, s);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t*)bip);
/*
* Initialize b_fsprivate2 so we can find it with incore_match()
* above.
*/
bp->b_fsprivate2 = tp;
return (bp);
}
/*
* Release the buffer bp which was previously acquired with one of the
* xfs_trans_... buffer allocation routines if the buffer has not
* been modified within this transaction. If the buffer is modified
* within this transaction, do 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 modified before
* this transaction began, then free the buf_log_item associated with it.
*
* If the transaction pointer is NULL, make this just a normal
* brelse() call.
*/
void
xfs_trans_brelse(xfs_trans_t *tp,
buf_t *bp)
{
xfs_buf_log_item_t *bip;
xfs_log_item_desc_t *lidp;
int s;
/*
* Default to a normal brelse() call if the tp is NULL.
*/
if (tp == NULL) {
/*
* If there's a buf log item attached to the buffer,
* then let the AIL know that the buffer is being
* unlocked.
*/
if (bp->b_fsprivate != NULL) {
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
xfs_trans_unlocked_item(bip->bli_item.li_mountp,
(xfs_log_item_t*)bip);
}
brelse(bp);
return;
}
ASSERT(bp->b_fsprivate2 == tp);
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
/*
* Find the item descriptor pointing to this buffer's
* log item. It must be there.
*/
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
ASSERT(lidp != NULL);
/*
* If the release is just for a recursive lock,
* then decrement the count and return.
*/
if (bip->bli_recur > 0) {
bip->bli_recur--;
return;
}
/*
* If the buffer is dirty within this transaction, we can't
* release it until we commit.
*/
if (lidp->lid_flags & XFS_LID_DIRTY) {
return;
}
/*
* Free up the log item descriptor tracking the released item.
*/
xfs_trans_free_item(tp, lidp);
/*
* Clear the hold flag in the buf log item if it is set.
* We wouldn't want the next user of the buffer to
* get confused.
*/
if (bip->bli_flags & XFS_BLI_HOLD) {
bip->bli_flags &= ~XFS_BLI_HOLD;
}
/*
* If the buf item is not tracking data in the log, then
* we must free it before releasing the buffer back to the
* free pool. Before releasing the buffer to the free pool,
* clear the transaction pointer in b_fsprivate2 to disolve
* its relation to this transaction.
*/
if (!xfs_buf_item_dirty(bip)) {
xfs_buf_item_relse(bp);
}
bp->b_fsprivate2 = NULL;
/*
* Drop our reference to the buf log item.
*/
s = splockspl(xfs_bli_reflock, splhi);
bip->bli_refcount--;
spunlockspl(xfs_bli_reflock, s);
/*
* If we've still got a buf log item on the buffer, then
* tell the AIL that the buffer is being unlocked.
*/
if (bp->b_fsprivate != NULL) {
xfs_trans_unlocked_item(bip->bli_item.li_mountp,
(xfs_log_item_t*)bip);
}
brelse(bp);
return;
}
/*
* 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.
*/
void
xfs_trans_bjoin(xfs_trans_t *tp,
buf_t *bp)
{
int s;
xfs_buf_log_item_t *bip;
ASSERT(bp->b_flags & B_BUSY);
ASSERT(bp->b_fsprivate2 == NULL);
/*
* The xfs_buf_log_item pointer is stored in b_fsprivate. If
* it doesn't have one yet, then allocate one and initialize it.
* The checks to see if one is there are in xfs_buf_item_init().
*/
xfs_buf_item_init(bp, tp->t_mountp);
bip = bp->b_fsprivate;
/*
* Take a reference for this transaction on the buf item.
*/
s = splockspl(xfs_bli_reflock, splhi);
bip->bli_refcount++;
spunlockspl(xfs_bli_reflock, s);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t *)bip);
/*
* Initialize b_fsprivate2 so we can find it with incore_match()
* in xfs_trans_get_buf() and friends above.
*/
bp->b_fsprivate2 = tp;
}
/*
* Mark the buffer as not needing to be unlocked when the buf item's
* IOP_UNLOCK() routine is called. The buffer must already be locked
* and associated with the given transaction.
*/
void
xfs_trans_bhold(xfs_trans_t *tp,
buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(bp->b_flags & B_BUSY);
ASSERT((xfs_trans_t*)(bp->b_fsprivate2) == tp);
ASSERT(bp->b_fsprivate != NULL);
bip = (xfs_buf_log_item_t*)(bp->b_fsprivate);
bip->bli_flags |= XFS_BLI_HOLD;
}
/*
* This function is used to indicate that the buffer should not be
* unlocked until the transaction is committed to disk.
*
* It uses the log item descriptor flag XFS_LID_SYNC_UNLOCK to
* delay the buf items's unlock call until the transaction is
* committed to disk or aborted.
*/
void
xfs_trans_bhold_until_committed(xfs_trans_t *tp,
buf_t *bp)
{
xfs_log_item_desc_t *lidp;
xfs_buf_log_item_t *bip;
ASSERT(bp->b_flags & B_BUSY);
ASSERT((xfs_trans_t*)(bp->b_fsprivate2) == tp);
ASSERT(bp->b_fsprivate != NULL);
bip = (xfs_buf_log_item_t *)(bp->b_fsprivate);
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
ASSERT(lidp != NULL);
lidp->lid_flags |= XFS_LID_SYNC_UNLOCK;
}
/*
* 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(xfs_trans_t *tp,
buf_t *bp,
uint first,
uint last)
{
xfs_buf_log_item_t *bip;
xfs_log_item_desc_t *lidp;
ASSERT(bp->b_flags & B_BUSY);
ASSERT((xfs_trans_t*)bp->b_fsprivate2 == tp);
ASSERT(bp->b_fsprivate != NULL);
ASSERT((first <= last) && (last <= bp->b_bcount));
ASSERT((bp->b_iodone == NULL) ||
(bp->b_iodone == xfs_buf_iodone_callbacks));
/*
* Mark the buffer as needing to be written out eventually,
* and set its iodone function to remove the buffer's buf log
* item from the AIL and free it when the buffer is flushed
* to disk. See xfs_buf_attach_iodone() for more details
* on li_cb and xfs_buf_iodone_callbacks().
*/
bp->b_flags |= B_DELWRI | B_DONE;
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
if (bp->b_iodone == NULL) {
bp->b_iodone = xfs_buf_iodone_callbacks;
}
bip->bli_item.li_cb = (void(*)(buf_t*,xfs_log_item_t*))xfs_buf_iodone;
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
ASSERT(lidp != NULL);
tp->t_flags |= XFS_TRANS_DIRTY;
lidp->lid_flags |= XFS_LID_DIRTY;
xfs_buf_item_log(bip, first, last);
}
/*
* This called to 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 clearing the
* B_DELWRI flag. We can't always
* get rid of the buf log item at this point, though, because
* the buffer may still be pinned by other 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().
*/
void
xfs_trans_binval(
xfs_trans_t *tp,
buf_t *bp)
{
xfs_log_item_desc_t *lidp;
xfs_buf_log_item_t *bip;
xfs_log_item_chunk_t *licp;
ASSERT(bp->b_flags & B_BUSY);
ASSERT((xfs_trans_t*)(bp->b_fsprivate2) == tp);
ASSERT(bp->b_fsprivate != NULL);
bip = (xfs_buf_log_item_t *)(bp->b_fsprivate);
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
ASSERT(lidp != NULL);
if (!(bp->b_flags & B_DELWRI)) {
/*
* The buffer isn't dirty so the buf item isn't
* in the AIL and the buffer isn't pinned.
* In this case we can just free the buf item
* and release the buffer from the transaction.
*/
ASSERT(bp->b_pincount == 0);
ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
ASSERT(bip->bli_refcount == 1);
xfs_buf_item_relse(bp);
/*
* There had better not be any log items attached to
* this buffer waiting for it to be written out, because
* it is never going out.
*/
ASSERT(bp->b_fsprivate == NULL);
/*
* Free up the descriptor pointing at the buf log item.
*/
licp = XFS_LIC_DESC_TO_CHUNK(lidp);
XFS_LIC_RELSE(licp, XFS_LIC_DESC_TO_SLOT(lidp));
brelse(bp);
return;
}
/*
* The buffer is dirty, so we can't clean it up until this
* transaction is permanent on disk. Mark the buf item descriptor
* dirty so that we'll keep it around across the commit.
* Clear the B_DELWRI flag in the buffer so that it won't be
* written out anymore. We set the XFS_BLI_STALE flag in the
* buf log item to indicate to the xfs_buf_item_unpin() that
* it should clean up when the last reference to the buf item
* is given up.
*/
bp->b_flags &= ~B_DELWRI;
bip->bli_flags |= XFS_BLI_STALE;
lidp->lid_flags |= XFS_LID_DIRTY;
tp->t_flags |= XFS_TRANS_DIRTY;
}
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