linux/fs/xfs/xfs_trans_buf.c
Dave Chinner ccf7c23fc1 xfs: Ensure inode allocation buffers are fully replayed
With delayed logging, we can get inode allocation buffers in the
same transaction inode unlink buffers. We don't currently mark inode
allocation buffers in the log, so inode unlink buffers take
precedence over allocation buffers.

The result is that when they are combined into the same checkpoint,
only the unlinked inode chain fields are replayed, resulting in
uninitialised inode buffers being detected when the next inode
modification is replayed.

To fix this, we need to ensure that we do not set the inode buffer
flag in the buffer log item format flags if the inode allocation has
not already hit the log. To avoid requiring a change to log
recovery, we really need to make this a modification that relies
only on in-memory sate.

We can do this by checking during buffer log formatting (while the
CIL cannot be flushed) if we are still in the same sequence when we
commit the unlink transaction as the inode allocation transaction.
If we are, then we do not add the inode buffer flag to the buffer
log format item flags. This means the entire buffer will be
replayed, not just the unlinked fields. We do this while
CIL flusheѕ are locked out to ensure that we don't race with the
sequence numbers changing and hence fail to put the inode buffer
flag in the buffer format flags when we really need to.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:41:22 -05:00

920 lines
26 KiB
C

/*
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_error.h"
#include "xfs_rw.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,
xfs_daddr_t blkno,
int len)
{
xfs_log_item_chunk_t *licp;
xfs_log_item_desc_t *lidp;
xfs_buf_log_item_t *blip;
int i;
len = BBTOB(len);
for (licp = &tp->t_items; licp != NULL; licp = licp->lic_next) {
if (xfs_lic_are_all_free(licp)) {
ASSERT(licp == &tp->t_items);
ASSERT(licp->lic_next == NULL);
return NULL;
}
for (i = 0; i < licp->lic_unused; i++) {
/*
* Skip unoccupied slots.
*/
if (xfs_lic_isfree(licp, i))
continue;
lidp = xfs_lic_slot(licp, i);
blip = (xfs_buf_log_item_t *)lidp->lid_item;
if (blip->bli_item.li_type != XFS_LI_BUF)
continue;
if (XFS_BUF_TARGET(blip->bli_buf) == target &&
XFS_BUF_ADDR(blip->bli_buf) == blkno &&
XFS_BUF_COUNT(blip->bli_buf) == len)
return blip->bli_buf;
}
}
return NULL;
}
/*
* 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)
{
struct xfs_buf_log_item *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, void *) == 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 = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
if (reset_recur)
bip->bli_recur = 0;
/*
* Take a reference for this transaction on the buf item.
*/
atomic_inc(&bip->bli_refcount);
/*
* 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.
*/
XFS_BUF_SET_FSPRIVATE2(bp, tp);
}
void
xfs_trans_bjoin(
struct xfs_trans *tp,
struct xfs_buf *bp)
{
_xfs_trans_bjoin(tp, bp, 0);
trace_xfs_trans_bjoin(bp->b_fspriv);
}
/*
* 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.
*/
xfs_buf_t *
xfs_trans_get_buf(xfs_trans_t *tp,
xfs_buftarg_t *target_dev,
xfs_daddr_t blkno,
int len,
uint flags)
{
xfs_buf_t *bp;
xfs_buf_log_item_t *bip;
if (flags == 0)
flags = XBF_LOCK | XBF_MAPPED;
/*
* Default to a normal get_buf() call if the tp is NULL.
*/
if (tp == NULL)
return xfs_buf_get(target_dev, blkno, len,
flags | XBF_DONT_BLOCK);
/*
* 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.
*/
bp = xfs_trans_buf_item_match(tp, target_dev, blkno, len);
if (bp != NULL) {
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
if (XFS_FORCED_SHUTDOWN(tp->t_mountp))
XFS_BUF_SUPER_STALE(bp);
/*
* If the buffer is stale then it was binval'ed
* since last read. This doesn't matter since the
* caller isn't allowed to use the data anyway.
*/
else if (XFS_BUF_ISSTALE(bp))
ASSERT(!XFS_BUF_ISDELAYWRITE(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(bip != NULL);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_recur++;
trace_xfs_trans_get_buf_recur(bip);
return (bp);
}
/*
* We always specify the XBF_DONT_BLOCK 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_buf_get(target_dev, blkno, len, flags | XBF_DONT_BLOCK);
if (bp == NULL) {
return NULL;
}
ASSERT(!XFS_BUF_GETERROR(bp));
_xfs_trans_bjoin(tp, bp, 1);
trace_xfs_trans_get_buf(bp->b_fspriv);
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.
*/
xfs_buf_t *
xfs_trans_getsb(xfs_trans_t *tp,
struct xfs_mount *mp,
int flags)
{
xfs_buf_t *bp;
xfs_buf_log_item_t *bip;
/*
* Default to just trying to lock the superblock buffer
* if tp is NULL.
*/
if (tp == NULL) {
return (xfs_getsb(mp, flags));
}
/*
* 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 = mp->m_sb_bp;
if (XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp) {
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*);
ASSERT(bip != NULL);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_recur++;
trace_xfs_trans_getsb_recur(bip);
return (bp);
}
bp = xfs_getsb(mp, flags);
if (bp == NULL)
return NULL;
_xfs_trans_bjoin(tp, bp, 1);
trace_xfs_trans_getsb(bp->b_fspriv);
return (bp);
}
#ifdef DEBUG
xfs_buftarg_t *xfs_error_target;
int xfs_do_error;
int xfs_req_num;
int xfs_error_mod = 33;
#endif
/*
* 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(
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_buftarg_t *target,
xfs_daddr_t blkno,
int len,
uint flags,
xfs_buf_t **bpp)
{
xfs_buf_t *bp;
xfs_buf_log_item_t *bip;
int error;
if (flags == 0)
flags = XBF_LOCK | XBF_MAPPED;
/*
* Default to a normal get_buf() call if the tp is NULL.
*/
if (tp == NULL) {
bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK);
if (!bp)
return (flags & XBF_TRYLOCK) ?
EAGAIN : XFS_ERROR(ENOMEM);
if (XFS_BUF_GETERROR(bp) != 0) {
xfs_ioerror_alert("xfs_trans_read_buf", mp,
bp, blkno);
error = XFS_BUF_GETERROR(bp);
xfs_buf_relse(bp);
return error;
}
#ifdef DEBUG
if (xfs_do_error) {
if (xfs_error_target == target) {
if (((xfs_req_num++) % xfs_error_mod) == 0) {
xfs_buf_relse(bp);
cmn_err(CE_DEBUG, "Returning error!\n");
return XFS_ERROR(EIO);
}
}
}
#endif
if (XFS_FORCED_SHUTDOWN(mp))
goto shutdown_abort;
*bpp = bp;
return 0;
}
/*
* 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.
*/
bp = xfs_trans_buf_item_match(tp, target, blkno, len);
if (bp != NULL) {
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
ASSERT((XFS_BUF_ISERROR(bp)) == 0);
if (!(XFS_BUF_ISDONE(bp))) {
trace_xfs_trans_read_buf_io(bp, _RET_IP_);
ASSERT(!XFS_BUF_ISASYNC(bp));
XFS_BUF_READ(bp);
xfsbdstrat(tp->t_mountp, bp);
error = xfs_iowait(bp);
if (error) {
xfs_ioerror_alert("xfs_trans_read_buf", mp,
bp, blkno);
xfs_buf_relse(bp);
/*
* We can gracefully recover from most read
* errors. Ones we can't are those that happen
* after the transaction's already dirty.
*/
if (tp->t_flags & XFS_TRANS_DIRTY)
xfs_force_shutdown(tp->t_mountp,
SHUTDOWN_META_IO_ERROR);
return error;
}
}
/*
* We never locked this buf ourselves, so we shouldn't
* brelse it either. Just get out.
*/
if (XFS_FORCED_SHUTDOWN(mp)) {
trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
*bpp = NULL;
return XFS_ERROR(EIO);
}
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*);
bip->bli_recur++;
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_trans_read_buf_recur(bip);
*bpp = bp;
return 0;
}
/*
* We always specify the XBF_DONT_BLOCK 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_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK);
if (bp == NULL) {
*bpp = NULL;
return 0;
}
if (XFS_BUF_GETERROR(bp) != 0) {
XFS_BUF_SUPER_STALE(bp);
error = XFS_BUF_GETERROR(bp);
xfs_ioerror_alert("xfs_trans_read_buf", mp,
bp, blkno);
if (tp->t_flags & XFS_TRANS_DIRTY)
xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);
xfs_buf_relse(bp);
return error;
}
#ifdef DEBUG
if (xfs_do_error && !(tp->t_flags & XFS_TRANS_DIRTY)) {
if (xfs_error_target == target) {
if (((xfs_req_num++) % xfs_error_mod) == 0) {
xfs_force_shutdown(tp->t_mountp,
SHUTDOWN_META_IO_ERROR);
xfs_buf_relse(bp);
cmn_err(CE_DEBUG, "Returning trans error!\n");
return XFS_ERROR(EIO);
}
}
}
#endif
if (XFS_FORCED_SHUTDOWN(mp))
goto shutdown_abort;
_xfs_trans_bjoin(tp, bp, 1);
trace_xfs_trans_read_buf(bp->b_fspriv);
*bpp = bp;
return 0;
shutdown_abort:
/*
* the theory here is that buffer is good but we're
* bailing out because the filesystem is being forcibly
* shut down. So we should leave the b_flags alone since
* the buffer's not staled and just get out.
*/
#if defined(DEBUG)
if (XFS_BUF_ISSTALE(bp) && XFS_BUF_ISDELAYWRITE(bp))
cmn_err(CE_NOTE, "about to pop assert, bp == 0x%p", bp);
#endif
ASSERT((XFS_BUF_BFLAGS(bp) & (XBF_STALE|XBF_DELWRI)) !=
(XBF_STALE|XBF_DELWRI));
trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
xfs_buf_relse(bp);
*bpp = NULL;
return XFS_ERROR(EIO);
}
/*
* 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,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
xfs_log_item_t *lip;
xfs_log_item_desc_t *lidp;
/*
* Default to a normal brelse() call if the tp is NULL.
*/
if (tp == NULL) {
ASSERT(XFS_BUF_FSPRIVATE2(bp, void *) == NULL);
/*
* If there's a buf log item attached to the buffer,
* then let the AIL know that the buffer is being
* unlocked.
*/
if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) {
lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
if (lip->li_type == XFS_LI_BUF) {
bip = XFS_BUF_FSPRIVATE(bp,xfs_buf_log_item_t*);
xfs_trans_unlocked_item(bip->bli_item.li_ailp,
lip);
}
}
xfs_buf_relse(bp);
return;
}
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
/*
* 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);
trace_xfs_trans_brelse(bip);
/*
* 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;
/*
* If the buffer has been invalidated, then we can't release
* it until the transaction commits to disk unless it is re-dirtied
* as part of this transaction. This prevents us from pulling
* the item from the AIL before we should.
*/
if (bip->bli_flags & XFS_BLI_STALE)
return;
ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
/*
* 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;
}
/*
* Drop our reference to the buf log item.
*/
atomic_dec(&bip->bli_refcount);
/*
* 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 dissolve
* its relation to this transaction.
*/
if (!xfs_buf_item_dirty(bip)) {
/***
ASSERT(bp->b_pincount == 0);
***/
ASSERT(atomic_read(&bip->bli_refcount) == 0);
ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
ASSERT(!(bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF));
xfs_buf_item_relse(bp);
bip = NULL;
}
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
/*
* If we've still got a buf log item on the buffer, then
* tell the AIL that the buffer is being unlocked.
*/
if (bip != NULL) {
xfs_trans_unlocked_item(bip->bli_item.li_ailp,
(xfs_log_item_t*)bip);
}
xfs_buf_relse(bp);
return;
}
/*
* 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.
*/
/* ARGSUSED */
void
xfs_trans_bhold(xfs_trans_t *tp,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_HOLD;
trace_xfs_trans_bhold(bip);
}
/*
* Cancel the previous buffer hold request made on this buffer
* for this transaction.
*/
void
xfs_trans_bhold_release(xfs_trans_t *tp,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT(bip->bli_flags & XFS_BLI_HOLD);
bip->bli_flags &= ~XFS_BLI_HOLD;
trace_xfs_trans_bhold_release(bip);
}
/*
* 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,
xfs_buf_t *bp,
uint first,
uint last)
{
xfs_buf_log_item_t *bip;
xfs_log_item_desc_t *lidp;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
ASSERT((first <= last) && (last < XFS_BUF_COUNT(bp)));
ASSERT((XFS_BUF_IODONE_FUNC(bp) == NULL) ||
(XFS_BUF_IODONE_FUNC(bp) == 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().
* If we end up aborting this transaction, we trap this buffer
* inside the b_bdstrat callback so that this won't get written to
* disk.
*/
XFS_BUF_DELAYWRITE(bp);
XFS_BUF_DONE(bp);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
XFS_BUF_SET_IODONE_FUNC(bp, xfs_buf_iodone_callbacks);
bip->bli_item.li_cb = (void(*)(xfs_buf_t*,xfs_log_item_t*))xfs_buf_iodone;
trace_xfs_trans_log_buf(bip);
/*
* If we invalidated the buffer within this transaction, then
* cancel the invalidation now that we're dirtying the buffer
* again. There are no races with the code in xfs_buf_item_unpin(),
* because we have a reference to the buffer this entire time.
*/
if (bip->bli_flags & XFS_BLI_STALE) {
bip->bli_flags &= ~XFS_BLI_STALE;
ASSERT(XFS_BUF_ISSTALE(bp));
XFS_BUF_UNSTALE(bp);
bip->bli_format.blf_flags &= ~XFS_BLF_CANCEL;
}
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;
bip->bli_flags |= XFS_BLI_LOGGED;
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 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 it is cleaned up we
* will keep the buffer locked so that the buffer and buf log item
* are not reused.
*/
void
xfs_trans_binval(
xfs_trans_t *tp,
xfs_buf_t *bp)
{
xfs_log_item_desc_t *lidp;
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
ASSERT(lidp != NULL);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_trans_binval(bip);
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* If the buffer is already invalidated, then
* just return.
*/
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY)));
ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_INODE_BUF));
ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
ASSERT(lidp->lid_flags & XFS_LID_DIRTY);
ASSERT(tp->t_flags & XFS_TRANS_DIRTY);
return;
}
/*
* Clear the dirty bit in the buffer and set the STALE flag
* in the buf log item. The STALE flag will be used in
* xfs_buf_item_unpin() to determine if it should clean up
* when the last reference to the buf item is given up.
* We 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.
*/
XFS_BUF_UNDELAYWRITE(bp);
XFS_BUF_STALE(bp);
bip->bli_flags |= XFS_BLI_STALE;
bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY);
bip->bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
bip->bli_format.blf_flags |= XFS_BLF_CANCEL;
memset((char *)(bip->bli_format.blf_data_map), 0,
(bip->bli_format.blf_map_size * sizeof(uint)));
lidp->lid_flags |= XFS_LID_DIRTY;
tp->t_flags |= XFS_TRANS_DIRTY;
}
/*
* 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,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_INODE_BUF;
}
/*
* 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,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_STALE_INODE;
bip->bli_item.li_cb = (void(*)(xfs_buf_t*,xfs_log_item_t*))
xfs_buf_iodone;
}
/*
* 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,
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
}
/*
* 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,
xfs_buf_t *bp,
uint type)
{
xfs_buf_log_item_t *bip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
ASSERT(type == XFS_BLF_UDQUOT_BUF ||
type == XFS_BLF_PDQUOT_BUF ||
type == XFS_BLF_GDQUOT_BUF);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_format.blf_flags |= type;
}