kernel-ark/fs/xfs/xfs_buf_item.c
Christoph Hellwig 0b1b213fcf xfs: event tracing support
Convert the old xfs tracing support that could only be used with the
out of tree kdb and xfsidbg patches to use the generic event tracer.

To use it make sure CONFIG_EVENT_TRACING is enabled and then enable
all xfs trace channels by:

   echo 1 > /sys/kernel/debug/tracing/events/xfs/enable

or alternatively enable single events by just doing the same in one
event subdirectory, e.g.

   echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable

or set more complex filters, etc. In Documentation/trace/events.txt
all this is desctribed in more detail.  To reads the events do a

   cat /sys/kernel/debug/tracing/trace

Compared to the last posting this patch converts the tracing mostly to
the one tracepoint per callsite model that other users of the new
tracing facility also employ.  This allows a very fine-grained control
of the tracing, a cleaner output of the traces and also enables the
perf tool to use each tracepoint as a virtual performance counter,
     allowing us to e.g. count how often certain workloads git various
     spots in XFS.  Take a look at

    http://lwn.net/Articles/346470/

for some examples.

Also the btree tracing isn't included at all yet, as it will require
additional core tracing features not in mainline yet, I plan to
deliver it later.

And the really nice thing about this patch is that it actually removes
many lines of code while adding this nice functionality:

 fs/xfs/Makefile                |    8
 fs/xfs/linux-2.6/xfs_acl.c     |    1
 fs/xfs/linux-2.6/xfs_aops.c    |   52 -
 fs/xfs/linux-2.6/xfs_aops.h    |    2
 fs/xfs/linux-2.6/xfs_buf.c     |  117 +--
 fs/xfs/linux-2.6/xfs_buf.h     |   33
 fs/xfs/linux-2.6/xfs_fs_subr.c |    3
 fs/xfs/linux-2.6/xfs_ioctl.c   |    1
 fs/xfs/linux-2.6/xfs_ioctl32.c |    1
 fs/xfs/linux-2.6/xfs_iops.c    |    1
 fs/xfs/linux-2.6/xfs_linux.h   |    1
 fs/xfs/linux-2.6/xfs_lrw.c     |   87 --
 fs/xfs/linux-2.6/xfs_lrw.h     |   45 -
 fs/xfs/linux-2.6/xfs_super.c   |  104 ---
 fs/xfs/linux-2.6/xfs_super.h   |    7
 fs/xfs/linux-2.6/xfs_sync.c    |    1
 fs/xfs/linux-2.6/xfs_trace.c   |   75 ++
 fs/xfs/linux-2.6/xfs_trace.h   | 1369 +++++++++++++++++++++++++++++++++++++++++
 fs/xfs/linux-2.6/xfs_vnode.h   |    4
 fs/xfs/quota/xfs_dquot.c       |  110 ---
 fs/xfs/quota/xfs_dquot.h       |   21
 fs/xfs/quota/xfs_qm.c          |   40 -
 fs/xfs/quota/xfs_qm_syscalls.c |    4
 fs/xfs/support/ktrace.c        |  323 ---------
 fs/xfs/support/ktrace.h        |   85 --
 fs/xfs/xfs.h                   |   16
 fs/xfs/xfs_ag.h                |   14
 fs/xfs/xfs_alloc.c             |  230 +-----
 fs/xfs/xfs_alloc.h             |   27
 fs/xfs/xfs_alloc_btree.c       |    1
 fs/xfs/xfs_attr.c              |  107 ---
 fs/xfs/xfs_attr.h              |   10
 fs/xfs/xfs_attr_leaf.c         |   14
 fs/xfs/xfs_attr_sf.h           |   40 -
 fs/xfs/xfs_bmap.c              |  507 +++------------
 fs/xfs/xfs_bmap.h              |   49 -
 fs/xfs/xfs_bmap_btree.c        |    6
 fs/xfs/xfs_btree.c             |    5
 fs/xfs/xfs_btree_trace.h       |   17
 fs/xfs/xfs_buf_item.c          |   87 --
 fs/xfs/xfs_buf_item.h          |   20
 fs/xfs/xfs_da_btree.c          |    3
 fs/xfs/xfs_da_btree.h          |    7
 fs/xfs/xfs_dfrag.c             |    2
 fs/xfs/xfs_dir2.c              |    8
 fs/xfs/xfs_dir2_block.c        |   20
 fs/xfs/xfs_dir2_leaf.c         |   21
 fs/xfs/xfs_dir2_node.c         |   27
 fs/xfs/xfs_dir2_sf.c           |   26
 fs/xfs/xfs_dir2_trace.c        |  216 ------
 fs/xfs/xfs_dir2_trace.h        |   72 --
 fs/xfs/xfs_filestream.c        |    8
 fs/xfs/xfs_fsops.c             |    2
 fs/xfs/xfs_iget.c              |  111 ---
 fs/xfs/xfs_inode.c             |   67 --
 fs/xfs/xfs_inode.h             |   76 --
 fs/xfs/xfs_inode_item.c        |    5
 fs/xfs/xfs_iomap.c             |   85 --
 fs/xfs/xfs_iomap.h             |    8
 fs/xfs/xfs_log.c               |  181 +----
 fs/xfs/xfs_log_priv.h          |   20
 fs/xfs/xfs_log_recover.c       |    1
 fs/xfs/xfs_mount.c             |    2
 fs/xfs/xfs_quota.h             |    8
 fs/xfs/xfs_rename.c            |    1
 fs/xfs/xfs_rtalloc.c           |    1
 fs/xfs/xfs_rw.c                |    3
 fs/xfs/xfs_trans.h             |   47 +
 fs/xfs/xfs_trans_buf.c         |   62 -
 fs/xfs/xfs_vnodeops.c          |    8
 70 files changed, 2151 insertions(+), 2592 deletions(-)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-14 23:08:16 -06:00

1125 lines
30 KiB
C

/*
* Copyright (c) 2000-2005 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_dmapi.h"
#include "xfs_mount.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_error.h"
#include "xfs_trace.h"
kmem_zone_t *xfs_buf_item_zone;
#ifdef XFS_TRANS_DEBUG
/*
* This function uses an alternate strategy for tracking the bytes
* that the user requests to be logged. This can then be used
* in conjunction with the bli_orig array in the buf log item to
* catch bugs in our callers' code.
*
* We also double check the bits set in xfs_buf_item_log using a
* simple algorithm to check that every byte is accounted for.
*/
STATIC void
xfs_buf_item_log_debug(
xfs_buf_log_item_t *bip,
uint first,
uint last)
{
uint x;
uint byte;
uint nbytes;
uint chunk_num;
uint word_num;
uint bit_num;
uint bit_set;
uint *wordp;
ASSERT(bip->bli_logged != NULL);
byte = first;
nbytes = last - first + 1;
bfset(bip->bli_logged, first, nbytes);
for (x = 0; x < nbytes; x++) {
chunk_num = byte >> XFS_BLI_SHIFT;
word_num = chunk_num >> BIT_TO_WORD_SHIFT;
bit_num = chunk_num & (NBWORD - 1);
wordp = &(bip->bli_format.blf_data_map[word_num]);
bit_set = *wordp & (1 << bit_num);
ASSERT(bit_set);
byte++;
}
}
/*
* This function is called when we flush something into a buffer without
* logging it. This happens for things like inodes which are logged
* separately from the buffer.
*/
void
xfs_buf_item_flush_log_debug(
xfs_buf_t *bp,
uint first,
uint last)
{
xfs_buf_log_item_t *bip;
uint nbytes;
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*);
if ((bip == NULL) || (bip->bli_item.li_type != XFS_LI_BUF)) {
return;
}
ASSERT(bip->bli_logged != NULL);
nbytes = last - first + 1;
bfset(bip->bli_logged, first, nbytes);
}
/*
* This function is called to verify that our callers have logged
* all the bytes that they changed.
*
* It does this by comparing the original copy of the buffer stored in
* the buf log item's bli_orig array to the current copy of the buffer
* and ensuring that all bytes which mismatch are set in the bli_logged
* array of the buf log item.
*/
STATIC void
xfs_buf_item_log_check(
xfs_buf_log_item_t *bip)
{
char *orig;
char *buffer;
int x;
xfs_buf_t *bp;
ASSERT(bip->bli_orig != NULL);
ASSERT(bip->bli_logged != NULL);
bp = bip->bli_buf;
ASSERT(XFS_BUF_COUNT(bp) > 0);
ASSERT(XFS_BUF_PTR(bp) != NULL);
orig = bip->bli_orig;
buffer = XFS_BUF_PTR(bp);
for (x = 0; x < XFS_BUF_COUNT(bp); x++) {
if (orig[x] != buffer[x] && !btst(bip->bli_logged, x))
cmn_err(CE_PANIC,
"xfs_buf_item_log_check bip %x buffer %x orig %x index %d",
bip, bp, orig, x);
}
}
#else
#define xfs_buf_item_log_debug(x,y,z)
#define xfs_buf_item_log_check(x)
#endif
STATIC void xfs_buf_error_relse(xfs_buf_t *bp);
STATIC void xfs_buf_do_callbacks(xfs_buf_t *bp, xfs_log_item_t *lip);
/*
* This returns the number of log iovecs needed to log the
* given buf log item.
*
* It calculates this as 1 iovec for the buf log format structure
* and 1 for each stretch of non-contiguous chunks to be logged.
* Contiguous chunks are logged in a single iovec.
*
* If the XFS_BLI_STALE flag has been set, then log nothing.
*/
STATIC uint
xfs_buf_item_size(
xfs_buf_log_item_t *bip)
{
uint nvecs;
int next_bit;
int last_bit;
xfs_buf_t *bp;
ASSERT(atomic_read(&bip->bli_refcount) > 0);
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* The buffer is stale, so all we need to log
* is the buf log format structure with the
* cancel flag in it.
*/
trace_xfs_buf_item_size_stale(bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
return 1;
}
bp = bip->bli_buf;
ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
nvecs = 1;
last_bit = xfs_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size, 0);
ASSERT(last_bit != -1);
nvecs++;
while (last_bit != -1) {
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*/
next_bit = xfs_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size,
last_bit + 1);
/*
* If we run out of bits, leave the loop,
* else if we find a new set of bits bump the number of vecs,
* else keep scanning the current set of bits.
*/
if (next_bit == -1) {
last_bit = -1;
} else if (next_bit != last_bit + 1) {
last_bit = next_bit;
nvecs++;
} else if (xfs_buf_offset(bp, next_bit * XFS_BLI_CHUNK) !=
(xfs_buf_offset(bp, last_bit * XFS_BLI_CHUNK) +
XFS_BLI_CHUNK)) {
last_bit = next_bit;
nvecs++;
} else {
last_bit++;
}
}
trace_xfs_buf_item_size(bip);
return nvecs;
}
/*
* This is called to fill in the vector of log iovecs for the
* given log buf item. It fills the first entry with a buf log
* format structure, and the rest point to contiguous chunks
* within the buffer.
*/
STATIC void
xfs_buf_item_format(
xfs_buf_log_item_t *bip,
xfs_log_iovec_t *log_vector)
{
uint base_size;
uint nvecs;
xfs_log_iovec_t *vecp;
xfs_buf_t *bp;
int first_bit;
int last_bit;
int next_bit;
uint nbits;
uint buffer_offset;
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
bp = bip->bli_buf;
vecp = log_vector;
/*
* The size of the base structure is the size of the
* declared structure plus the space for the extra words
* of the bitmap. We subtract one from the map size, because
* the first element of the bitmap is accounted for in the
* size of the base structure.
*/
base_size =
(uint)(sizeof(xfs_buf_log_format_t) +
((bip->bli_format.blf_map_size - 1) * sizeof(uint)));
vecp->i_addr = (xfs_caddr_t)&bip->bli_format;
vecp->i_len = base_size;
XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_BFORMAT);
vecp++;
nvecs = 1;
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* The buffer is stale, so all we need to log
* is the buf log format structure with the
* cancel flag in it.
*/
trace_xfs_buf_item_format_stale(bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
bip->bli_format.blf_size = nvecs;
return;
}
/*
* Fill in an iovec for each set of contiguous chunks.
*/
first_bit = xfs_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size, 0);
ASSERT(first_bit != -1);
last_bit = first_bit;
nbits = 1;
for (;;) {
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*/
next_bit = xfs_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size,
(uint)last_bit + 1);
/*
* If we run out of bits fill in the last iovec and get
* out of the loop.
* Else if we start a new set of bits then fill in the
* iovec for the series we were looking at and start
* counting the bits in the new one.
* Else we're still in the same set of bits so just
* keep counting and scanning.
*/
if (next_bit == -1) {
buffer_offset = first_bit * XFS_BLI_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
vecp->i_len = nbits * XFS_BLI_CHUNK;
XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_BCHUNK);
nvecs++;
break;
} else if (next_bit != last_bit + 1) {
buffer_offset = first_bit * XFS_BLI_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
vecp->i_len = nbits * XFS_BLI_CHUNK;
XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_BCHUNK);
nvecs++;
vecp++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
} else if (xfs_buf_offset(bp, next_bit << XFS_BLI_SHIFT) !=
(xfs_buf_offset(bp, last_bit << XFS_BLI_SHIFT) +
XFS_BLI_CHUNK)) {
buffer_offset = first_bit * XFS_BLI_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
vecp->i_len = nbits * XFS_BLI_CHUNK;
XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_BCHUNK);
/* You would think we need to bump the nvecs here too, but we do not
* this number is used by recovery, and it gets confused by the boundary
* split here
* nvecs++;
*/
vecp++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
} else {
last_bit++;
nbits++;
}
}
bip->bli_format.blf_size = nvecs;
/*
* Check to make sure everything is consistent.
*/
trace_xfs_buf_item_format(bip);
xfs_buf_item_log_check(bip);
}
/*
* This is called to pin the buffer associated with the buf log
* item in memory so it cannot be written out. Simply call bpin()
* on the buffer to do this.
*/
STATIC void
xfs_buf_item_pin(
xfs_buf_log_item_t *bip)
{
xfs_buf_t *bp;
bp = bip->bli_buf;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_pin(bip);
xfs_bpin(bp);
}
/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
* Just call bunpin() on the buffer to do this.
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*/
STATIC void
xfs_buf_item_unpin(
xfs_buf_log_item_t *bip,
int stale)
{
struct xfs_ail *ailp;
xfs_buf_t *bp;
int freed;
bp = bip->bli_buf;
ASSERT(bp != NULL);
ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_buf_item_unpin(bip);
freed = atomic_dec_and_test(&bip->bli_refcount);
ailp = bip->bli_item.li_ailp;
xfs_bunpin(bp);
if (freed && stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
trace_xfs_buf_item_unpin_stale(bip);
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_ail_delete()
* will take care of that situation.
* xfs_trans_ail_delete() drops the AIL lock.
*/
if (bip->bli_flags & XFS_BLI_STALE_INODE) {
xfs_buf_do_callbacks(bp, (xfs_log_item_t *)bip);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
} else {
spin_lock(&ailp->xa_lock);
xfs_trans_ail_delete(ailp, (xfs_log_item_t *)bip);
xfs_buf_item_relse(bp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) == NULL);
}
xfs_buf_relse(bp);
}
}
/*
* this is called from uncommit in the forced-shutdown path.
* we need to check to see if the reference count on the log item
* is going to drop to zero. If so, unpin will free the log item
* so we need to free the item's descriptor (that points to the item)
* in the transaction.
*/
STATIC void
xfs_buf_item_unpin_remove(
xfs_buf_log_item_t *bip,
xfs_trans_t *tp)
{
xfs_buf_t *bp;
xfs_log_item_desc_t *lidp;
int stale = 0;
bp = bip->bli_buf;
/*
* will xfs_buf_item_unpin() call xfs_buf_item_relse()?
*/
if ((atomic_read(&bip->bli_refcount) == 1) &&
(bip->bli_flags & XFS_BLI_STALE)) {
ASSERT(XFS_BUF_VALUSEMA(bip->bli_buf) <= 0);
trace_xfs_buf_item_unpin_stale(bip);
/*
* yes -- clear the xaction descriptor in-use flag
* and free the chunk if required. We can safely
* do some work here and then call buf_item_unpin
* to do the rest because if the if is true, then
* we are holding the buffer locked so no one else
* will be able to bump up the refcount.
*/
lidp = xfs_trans_find_item(tp, (xfs_log_item_t *) bip);
stale = lidp->lid_flags & XFS_LID_BUF_STALE;
xfs_trans_free_item(tp, lidp);
/*
* Since the transaction no longer refers to the buffer,
* the buffer should no longer refer to the transaction.
*/
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
}
xfs_buf_item_unpin(bip, stale);
return;
}
/*
* This is called to attempt to lock the buffer associated with this
* buf log item. Don't sleep on the buffer lock. If we can't get
* the lock right away, return 0. If we can get the lock, pull the
* buffer from the free list, mark it busy, and return 1.
*/
STATIC uint
xfs_buf_item_trylock(
xfs_buf_log_item_t *bip)
{
xfs_buf_t *bp;
bp = bip->bli_buf;
if (XFS_BUF_ISPINNED(bp)) {
return XFS_ITEM_PINNED;
}
if (!XFS_BUF_CPSEMA(bp)) {
return XFS_ITEM_LOCKED;
}
/*
* Remove the buffer from the free list. Only do this
* if it's on the free list. Private buffers like the
* superblock buffer are not.
*/
XFS_BUF_HOLD(bp);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_trylock(bip);
return XFS_ITEM_SUCCESS;
}
/*
* Release the buffer associated with the buf log item.
* If there is no dirty logged data associated with the
* buffer recorded in the buf log item, then free the
* buf log item and remove the reference to it in the
* buffer.
*
* This call ignores the recursion count. It is only called
* when the buffer should REALLY be unlocked, regardless
* of the recursion count.
*
* If the XFS_BLI_HOLD flag is set in the buf log item, then
* free the log item if necessary but do not unlock the buffer.
* This is for support of xfs_trans_bhold(). Make sure the
* XFS_BLI_HOLD field is cleared if we don't free the item.
*/
STATIC void
xfs_buf_item_unlock(
xfs_buf_log_item_t *bip)
{
int aborted;
xfs_buf_t *bp;
uint hold;
bp = bip->bli_buf;
/*
* Clear the buffer's association with this transaction.
*/
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
/*
* If this is a transaction abort, don't return early.
* Instead, allow the brelse to happen.
* Normally it would be done for stale (cancelled) buffers
* at unpin time, but we'll never go through the pin/unpin
* cycle if we abort inside commit.
*/
aborted = (bip->bli_item.li_flags & XFS_LI_ABORTED) != 0;
/*
* If the buf item is marked stale, then don't do anything.
* We'll unlock the buffer and free the buf item when the
* buffer is unpinned for the last time.
*/
if (bip->bli_flags & XFS_BLI_STALE) {
bip->bli_flags &= ~XFS_BLI_LOGGED;
trace_xfs_buf_item_unlock_stale(bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
if (!aborted)
return;
}
/*
* Drop the transaction's reference to the log item if
* it was not logged as part of the transaction. Otherwise
* we'll drop the reference in xfs_buf_item_unpin() when
* the transaction is really through with the buffer.
*/
if (!(bip->bli_flags & XFS_BLI_LOGGED)) {
atomic_dec(&bip->bli_refcount);
} else {
/*
* Clear the logged flag since this is per
* transaction state.
*/
bip->bli_flags &= ~XFS_BLI_LOGGED;
}
/*
* Before possibly freeing the buf item, determine if we should
* release the buffer at the end of this routine.
*/
hold = bip->bli_flags & XFS_BLI_HOLD;
trace_xfs_buf_item_unlock(bip);
/*
* If the buf item isn't tracking any data, free it.
* Otherwise, if XFS_BLI_HOLD is set clear it.
*/
if (xfs_bitmap_empty(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size)) {
xfs_buf_item_relse(bp);
} else if (hold) {
bip->bli_flags &= ~XFS_BLI_HOLD;
}
/*
* Release the buffer if XFS_BLI_HOLD was not set.
*/
if (!hold) {
xfs_buf_relse(bp);
}
}
/*
* This is called to find out where the oldest active copy of the
* buf log item in the on disk log resides now that the last log
* write of it completed at the given lsn.
* We always re-log all the dirty data in a buffer, so usually the
* latest copy in the on disk log is the only one that matters. For
* those cases we simply return the given lsn.
*
* The one exception to this is for buffers full of newly allocated
* inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
* flag set, indicating that only the di_next_unlinked fields from the
* inodes in the buffers will be replayed during recovery. If the
* original newly allocated inode images have not yet been flushed
* when the buffer is so relogged, then we need to make sure that we
* keep the old images in the 'active' portion of the log. We do this
* by returning the original lsn of that transaction here rather than
* the current one.
*/
STATIC xfs_lsn_t
xfs_buf_item_committed(
xfs_buf_log_item_t *bip,
xfs_lsn_t lsn)
{
trace_xfs_buf_item_committed(bip);
if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
(bip->bli_item.li_lsn != 0)) {
return bip->bli_item.li_lsn;
}
return (lsn);
}
/*
* This is called to asynchronously write the buffer associated with this
* buf log item out to disk. The buffer will already have been locked by
* a successful call to xfs_buf_item_trylock(). If the buffer still has
* B_DELWRI set, then get it going out to disk with a call to bawrite().
* If not, then just release the buffer.
*/
STATIC void
xfs_buf_item_push(
xfs_buf_log_item_t *bip)
{
xfs_buf_t *bp;
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_push(bip);
bp = bip->bli_buf;
if (XFS_BUF_ISDELAYWRITE(bp)) {
int error;
error = xfs_bawrite(bip->bli_item.li_mountp, bp);
if (error)
xfs_fs_cmn_err(CE_WARN, bip->bli_item.li_mountp,
"xfs_buf_item_push: pushbuf error %d on bip %p, bp %p",
error, bip, bp);
} else {
xfs_buf_relse(bp);
}
}
/* ARGSUSED */
STATIC void
xfs_buf_item_committing(xfs_buf_log_item_t *bip, xfs_lsn_t commit_lsn)
{
}
/*
* This is the ops vector shared by all buf log items.
*/
static struct xfs_item_ops xfs_buf_item_ops = {
.iop_size = (uint(*)(xfs_log_item_t*))xfs_buf_item_size,
.iop_format = (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
xfs_buf_item_format,
.iop_pin = (void(*)(xfs_log_item_t*))xfs_buf_item_pin,
.iop_unpin = (void(*)(xfs_log_item_t*, int))xfs_buf_item_unpin,
.iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t *))
xfs_buf_item_unpin_remove,
.iop_trylock = (uint(*)(xfs_log_item_t*))xfs_buf_item_trylock,
.iop_unlock = (void(*)(xfs_log_item_t*))xfs_buf_item_unlock,
.iop_committed = (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
xfs_buf_item_committed,
.iop_push = (void(*)(xfs_log_item_t*))xfs_buf_item_push,
.iop_pushbuf = NULL,
.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
xfs_buf_item_committing
};
/*
* Allocate a new buf log item to go with the given buffer.
* Set the buffer's b_fsprivate field to point to the new
* buf log item. If there are other item's attached to the
* buffer (see xfs_buf_attach_iodone() below), then put the
* buf log item at the front.
*/
void
xfs_buf_item_init(
xfs_buf_t *bp,
xfs_mount_t *mp)
{
xfs_log_item_t *lip;
xfs_buf_log_item_t *bip;
int chunks;
int map_size;
/*
* Check to see if there is already a buf log item for
* this buffer. If there is, it is guaranteed to be
* the first. If we do already have one, there is
* nothing to do here so return.
*/
if (bp->b_mount != mp)
bp->b_mount = mp;
XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb);
if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) {
lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
if (lip->li_type == XFS_LI_BUF) {
return;
}
}
/*
* chunks is the number of XFS_BLI_CHUNK size pieces
* the buffer can be divided into. Make sure not to
* truncate any pieces. map_size is the size of the
* bitmap needed to describe the chunks of the buffer.
*/
chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLI_CHUNK - 1)) >> XFS_BLI_SHIFT);
map_size = (int)((chunks + NBWORD) >> BIT_TO_WORD_SHIFT);
bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone,
KM_SLEEP);
bip->bli_item.li_type = XFS_LI_BUF;
bip->bli_item.li_ops = &xfs_buf_item_ops;
bip->bli_item.li_mountp = mp;
bip->bli_item.li_ailp = mp->m_ail;
bip->bli_buf = bp;
xfs_buf_hold(bp);
bip->bli_format.blf_type = XFS_LI_BUF;
bip->bli_format.blf_blkno = (__int64_t)XFS_BUF_ADDR(bp);
bip->bli_format.blf_len = (ushort)BTOBB(XFS_BUF_COUNT(bp));
bip->bli_format.blf_map_size = map_size;
#ifdef XFS_TRANS_DEBUG
/*
* Allocate the arrays for tracking what needs to be logged
* and what our callers request to be logged. bli_orig
* holds a copy of the original, clean buffer for comparison
* against, and bli_logged keeps a 1 bit flag per byte in
* the buffer to indicate which bytes the callers have asked
* to have logged.
*/
bip->bli_orig = (char *)kmem_alloc(XFS_BUF_COUNT(bp), KM_SLEEP);
memcpy(bip->bli_orig, XFS_BUF_PTR(bp), XFS_BUF_COUNT(bp));
bip->bli_logged = (char *)kmem_zalloc(XFS_BUF_COUNT(bp) / NBBY, KM_SLEEP);
#endif
/*
* Put the buf item into the list of items attached to the
* buffer at the front.
*/
if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) {
bip->bli_item.li_bio_list =
XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
}
XFS_BUF_SET_FSPRIVATE(bp, bip);
}
/*
* Mark bytes first through last inclusive as dirty in the buf
* item's bitmap.
*/
void
xfs_buf_item_log(
xfs_buf_log_item_t *bip,
uint first,
uint last)
{
uint first_bit;
uint last_bit;
uint bits_to_set;
uint bits_set;
uint word_num;
uint *wordp;
uint bit;
uint end_bit;
uint mask;
/*
* Mark the item as having some dirty data for
* quick reference in xfs_buf_item_dirty.
*/
bip->bli_flags |= XFS_BLI_DIRTY;
/*
* Convert byte offsets to bit numbers.
*/
first_bit = first >> XFS_BLI_SHIFT;
last_bit = last >> XFS_BLI_SHIFT;
/*
* Calculate the total number of bits to be set.
*/
bits_to_set = last_bit - first_bit + 1;
/*
* Get a pointer to the first word in the bitmap
* to set a bit in.
*/
word_num = first_bit >> BIT_TO_WORD_SHIFT;
wordp = &(bip->bli_format.blf_data_map[word_num]);
/*
* Calculate the starting bit in the first word.
*/
bit = first_bit & (uint)(NBWORD - 1);
/*
* First set any bits in the first word of our range.
* If it starts at bit 0 of the word, it will be
* set below rather than here. That is what the variable
* bit tells us. The variable bits_set tracks the number
* of bits that have been set so far. End_bit is the number
* of the last bit to be set in this word plus one.
*/
if (bit) {
end_bit = MIN(bit + bits_to_set, (uint)NBWORD);
mask = ((1 << (end_bit - bit)) - 1) << bit;
*wordp |= mask;
wordp++;
bits_set = end_bit - bit;
} else {
bits_set = 0;
}
/*
* Now set bits a whole word at a time that are between
* first_bit and last_bit.
*/
while ((bits_to_set - bits_set) >= NBWORD) {
*wordp |= 0xffffffff;
bits_set += NBWORD;
wordp++;
}
/*
* Finally, set any bits left to be set in one last partial word.
*/
end_bit = bits_to_set - bits_set;
if (end_bit) {
mask = (1 << end_bit) - 1;
*wordp |= mask;
}
xfs_buf_item_log_debug(bip, first, last);
}
/*
* Return 1 if the buffer has some data that has been logged (at any
* point, not just the current transaction) and 0 if not.
*/
uint
xfs_buf_item_dirty(
xfs_buf_log_item_t *bip)
{
return (bip->bli_flags & XFS_BLI_DIRTY);
}
STATIC void
xfs_buf_item_free(
xfs_buf_log_item_t *bip)
{
#ifdef XFS_TRANS_DEBUG
kmem_free(bip->bli_orig);
kmem_free(bip->bli_logged);
#endif /* XFS_TRANS_DEBUG */
kmem_zone_free(xfs_buf_item_zone, bip);
}
/*
* This is called when the buf log item is no longer needed. It should
* free the buf log item associated with the given buffer and clear
* the buffer's pointer to the buf log item. If there are no more
* items in the list, clear the b_iodone field of the buffer (see
* xfs_buf_attach_iodone() below).
*/
void
xfs_buf_item_relse(
xfs_buf_t *bp)
{
xfs_buf_log_item_t *bip;
trace_xfs_buf_item_relse(bp, _RET_IP_);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*);
XFS_BUF_SET_FSPRIVATE(bp, bip->bli_item.li_bio_list);
if ((XFS_BUF_FSPRIVATE(bp, void *) == NULL) &&
(XFS_BUF_IODONE_FUNC(bp) != NULL)) {
XFS_BUF_CLR_IODONE_FUNC(bp);
}
xfs_buf_rele(bp);
xfs_buf_item_free(bip);
}
/*
* Add the given log item with its callback to the list of callbacks
* to be called when the buffer's I/O completes. If it is not set
* already, set the buffer's b_iodone() routine to be
* xfs_buf_iodone_callbacks() and link the log item into the list of
* items rooted at b_fsprivate. Items are always added as the second
* entry in the list if there is a first, because the buf item code
* assumes that the buf log item is first.
*/
void
xfs_buf_attach_iodone(
xfs_buf_t *bp,
void (*cb)(xfs_buf_t *, xfs_log_item_t *),
xfs_log_item_t *lip)
{
xfs_log_item_t *head_lip;
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
lip->li_cb = cb;
if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) {
head_lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
lip->li_bio_list = head_lip->li_bio_list;
head_lip->li_bio_list = lip;
} else {
XFS_BUF_SET_FSPRIVATE(bp, lip);
}
ASSERT((XFS_BUF_IODONE_FUNC(bp) == xfs_buf_iodone_callbacks) ||
(XFS_BUF_IODONE_FUNC(bp) == NULL));
XFS_BUF_SET_IODONE_FUNC(bp, xfs_buf_iodone_callbacks);
}
STATIC void
xfs_buf_do_callbacks(
xfs_buf_t *bp,
xfs_log_item_t *lip)
{
xfs_log_item_t *nlip;
while (lip != NULL) {
nlip = lip->li_bio_list;
ASSERT(lip->li_cb != NULL);
/*
* Clear the next pointer so we don't have any
* confusion if the item is added to another buf.
* Don't touch the log item after calling its
* callback, because it could have freed itself.
*/
lip->li_bio_list = NULL;
lip->li_cb(bp, lip);
lip = nlip;
}
}
/*
* This is the iodone() function for buffers which have had callbacks
* attached to them by xfs_buf_attach_iodone(). It should remove each
* log item from the buffer's list and call the callback of each in turn.
* When done, the buffer's fsprivate field is set to NULL and the buffer
* is unlocked with a call to iodone().
*/
void
xfs_buf_iodone_callbacks(
xfs_buf_t *bp)
{
xfs_log_item_t *lip;
static ulong lasttime;
static xfs_buftarg_t *lasttarg;
xfs_mount_t *mp;
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
if (XFS_BUF_GETERROR(bp) != 0) {
/*
* If we've already decided to shutdown the filesystem
* because of IO errors, there's no point in giving this
* a retry.
*/
mp = lip->li_mountp;
if (XFS_FORCED_SHUTDOWN(mp)) {
ASSERT(XFS_BUF_TARGET(bp) == mp->m_ddev_targp);
XFS_BUF_SUPER_STALE(bp);
trace_xfs_buf_item_iodone(bp, _RET_IP_);
xfs_buf_do_callbacks(bp, lip);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
xfs_biodone(bp);
return;
}
if ((XFS_BUF_TARGET(bp) != lasttarg) ||
(time_after(jiffies, (lasttime + 5*HZ)))) {
lasttime = jiffies;
cmn_err(CE_ALERT, "Device %s, XFS metadata write error"
" block 0x%llx in %s",
XFS_BUFTARG_NAME(XFS_BUF_TARGET(bp)),
(__uint64_t)XFS_BUF_ADDR(bp), mp->m_fsname);
}
lasttarg = XFS_BUF_TARGET(bp);
if (XFS_BUF_ISASYNC(bp)) {
/*
* If the write was asynchronous then noone will be
* looking for the error. Clear the error state
* and write the buffer out again delayed write.
*
* XXXsup This is OK, so long as we catch these
* before we start the umount; we don't want these
* DELWRI metadata bufs to be hanging around.
*/
XFS_BUF_ERROR(bp,0); /* errno of 0 unsets the flag */
if (!(XFS_BUF_ISSTALE(bp))) {
XFS_BUF_DELAYWRITE(bp);
XFS_BUF_DONE(bp);
XFS_BUF_SET_START(bp);
}
ASSERT(XFS_BUF_IODONE_FUNC(bp));
trace_xfs_buf_item_iodone_async(bp, _RET_IP_);
xfs_buf_relse(bp);
} else {
/*
* If the write of the buffer was not asynchronous,
* then we want to make sure to return the error
* to the caller of bwrite(). Because of this we
* cannot clear the B_ERROR state at this point.
* Instead we install a callback function that
* will be called when the buffer is released, and
* that routine will clear the error state and
* set the buffer to be written out again after
* some delay.
*/
/* We actually overwrite the existing b-relse
function at times, but we're gonna be shutting down
anyway. */
XFS_BUF_SET_BRELSE_FUNC(bp,xfs_buf_error_relse);
XFS_BUF_DONE(bp);
XFS_BUF_FINISH_IOWAIT(bp);
}
return;
}
xfs_buf_do_callbacks(bp, lip);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
xfs_biodone(bp);
}
/*
* This is a callback routine attached to a buffer which gets an error
* when being written out synchronously.
*/
STATIC void
xfs_buf_error_relse(
xfs_buf_t *bp)
{
xfs_log_item_t *lip;
xfs_mount_t *mp;
lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
mp = (xfs_mount_t *)lip->li_mountp;
ASSERT(XFS_BUF_TARGET(bp) == mp->m_ddev_targp);
XFS_BUF_STALE(bp);
XFS_BUF_DONE(bp);
XFS_BUF_UNDELAYWRITE(bp);
XFS_BUF_ERROR(bp,0);
trace_xfs_buf_error_relse(bp, _RET_IP_);
if (! XFS_FORCED_SHUTDOWN(mp))
xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
/*
* We have to unpin the pinned buffers so do the
* callbacks.
*/
xfs_buf_do_callbacks(bp, lip);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
XFS_BUF_SET_BRELSE_FUNC(bp,NULL);
xfs_buf_relse(bp);
}
/*
* This is the iodone() function for buffers which have been
* logged. It is called when they are eventually flushed out.
* It should remove the buf item from the AIL, and free the buf item.
* It is called by xfs_buf_iodone_callbacks() above which will take
* care of cleaning up the buffer itself.
*/
/* ARGSUSED */
void
xfs_buf_iodone(
xfs_buf_t *bp,
xfs_buf_log_item_t *bip)
{
struct xfs_ail *ailp = bip->bli_item.li_ailp;
ASSERT(bip->bli_buf == bp);
xfs_buf_rele(bp);
/*
* If we are forcibly shutting down, this may well be
* off the AIL already. That's because we simulate the
* log-committed callbacks to unpin these buffers. Or we may never
* have put this item on AIL because of the transaction was
* aborted forcibly. xfs_trans_ail_delete() takes care of these.
*
* Either way, AIL is useless if we're forcing a shutdown.
*/
spin_lock(&ailp->xa_lock);
xfs_trans_ail_delete(ailp, (xfs_log_item_t *)bip);
xfs_buf_item_free(bip);
}