// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 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_bit.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_quota.h"
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_error.h"
struct kmem_cache *xfs_buf_item_cache;
static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
{
return container_of(lip, struct xfs_buf_log_item, bli_item);
}
/* Is this log iovec plausibly large enough to contain the buffer log format? */
bool
xfs_buf_log_check_iovec(
struct xfs_log_iovec *iovec)
{
struct xfs_buf_log_format *blfp = iovec->i_addr;
char *bmp_end;
char *item_end;
if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->i_len)
return false;
item_end = (char *)iovec->i_addr + iovec->i_len;
bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size];
return bmp_end <= item_end;
}
static inline int
xfs_buf_log_format_size(
struct xfs_buf_log_format *blfp)
{
return offsetof(struct xfs_buf_log_format, blf_data_map) +
(blfp->blf_map_size * sizeof(blfp->blf_data_map[0]));
}
static inline bool
xfs_buf_item_straddle(
struct xfs_buf *bp,
uint offset,
int first_bit,
int nbits)
{
void *first, *last;
first = xfs_buf_offset(bp, offset + (first_bit << XFS_BLF_SHIFT));
last = xfs_buf_offset(bp,
offset + ((first_bit + nbits) << XFS_BLF_SHIFT));
if (last - first != nbits * XFS_BLF_CHUNK)
return true;
return false;
}
/*
* Return the number of log iovecs and space needed to log the given buf log
* item segment.
*
* 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.
*/
STATIC void
xfs_buf_item_size_segment(
struct xfs_buf_log_item *bip,
struct xfs_buf_log_format *blfp,
uint offset,
int *nvecs,
int *nbytes)
{
struct xfs_buf *bp = bip->bli_buf;
int first_bit;
int nbits;
int next_bit;
int last_bit;
first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
if (first_bit == -1)
return;
(*nvecs)++;
*nbytes += xfs_buf_log_format_size(blfp);
do {
nbits = xfs_contig_bits(blfp->blf_data_map,
blfp->blf_map_size, first_bit);
ASSERT(nbits > 0);
/*
* Straddling a page is rare because we don't log contiguous
* chunks of unmapped buffers anywhere.
*/
if (nbits > 1 &&
xfs_buf_item_straddle(bp, offset, first_bit, nbits))
goto slow_scan;
(*nvecs)++;
*nbytes += nbits * XFS_BLF_CHUNK;
/*
* 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.
*/
first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
(uint)first_bit + nbits + 1);
} while (first_bit != -1);
return;
slow_scan:
/* Count the first bit we jumped out of the above loop from */
(*nvecs)++;
*nbytes += XFS_BLF_CHUNK;
last_bit = first_bit;
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(blfp->blf_data_map, blfp->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) {
break;
} else if (next_bit != last_bit + 1 ||
xfs_buf_item_straddle(bp, offset, first_bit, nbits)) {
last_bit = next_bit;
first_bit = next_bit;
(*nvecs)++;
nbits = 1;
} else {
last_bit++;
nbits++;
}
*nbytes += XFS_BLF_CHUNK;
}
}
/*
* Return the number of log iovecs and space needed to log the given buf log
* item.
*
* Discontiguous buffers need a format structure per region that is being
* logged. This makes the changes in the buffer appear to log recovery as though
* they came from separate buffers, just like would occur if multiple buffers
* were used instead of a single discontiguous buffer. This enables
* discontiguous buffers to be in-memory constructs, completely transparent to
* what ends up on disk.
*
* If the XFS_BLI_STALE flag has been set, then log nothing but the buf log
* format structures. If the item has previously been logged and has dirty
* regions, we do not relog them in stale buffers. This has the effect of
* reducing the size of the relogged item by the amount of dirty data tracked
* by the log item. This can result in the committing transaction reducing the
* amount of space being consumed by the CIL.
*/
STATIC void
xfs_buf_item_size(
struct xfs_log_item *lip,
int *nvecs,
int *nbytes)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
int i;
int bytes;
uint offset = 0;
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 as we are never
* going to replay the changes tracked in the log item.
*/
trace_xfs_buf_item_size_stale(bip);
ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
*nvecs += bip->bli_format_count;
for (i = 0; i < bip->bli_format_count; i++) {
*nbytes += xfs_buf_log_format_size(&bip->bli_formats[i]);
}
return;
}
ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
if (bip->bli_flags & XFS_BLI_ORDERED) {
/*
* The buffer has been logged just to order it. It is not being
* included in the transaction commit, so no vectors are used at
* all.
*/
trace_xfs_buf_item_size_ordered(bip);
*nvecs = XFS_LOG_VEC_ORDERED;
return;
}
/*
* The vector count is based on the number of buffer vectors we have
* dirty bits in. This will only be greater than one when we have a
* compound buffer with more than one segment dirty. Hence for compound
* buffers we need to track which segment the dirty bits correspond to,
* and when we move from one segment to the next increment the vector
* count for the extra buf log format structure that will need to be
* written.
*/
bytes = 0;
for (i = 0; i < bip->bli_format_count; i++) {
xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset,
nvecs, &bytes);
offset += BBTOB(bp->b_maps[i].bm_len);
}
/*
* Round up the buffer size required to minimise the number of memory
* allocations that need to be done as this item grows when relogged by
* repeated modifications.
*/
*nbytes = round_up(bytes, 512);
trace_xfs_buf_item_size(bip);
}
static inline void
xfs_buf_item_copy_iovec(
struct xfs_log_vec *lv,
struct xfs_log_iovec **vecp,
struct xfs_buf *bp,
uint offset,
int first_bit,
uint nbits)
{
offset += first_bit * XFS_BLF_CHUNK;
xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BCHUNK,
xfs_buf_offset(bp, offset),
nbits * XFS_BLF_CHUNK);
}
static void
xfs_buf_item_format_segment(
struct xfs_buf_log_item *bip,
struct xfs_log_vec *lv,
struct xfs_log_iovec **vecp,
uint offset,
struct xfs_buf_log_format *blfp)
{
struct xfs_buf *bp = bip->bli_buf;
uint base_size;
int first_bit;
int last_bit;
int next_bit;
uint nbits;
/* copy the flags across from the base format item */
blfp->blf_flags = bip->__bli_format.blf_flags;
/*
* Base size is the actual size of the ondisk structure - it reflects
* the actual size of the dirty bitmap rather than the size of the in
* memory structure.
*/
base_size = xfs_buf_log_format_size(blfp);
first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
if (!(bip->bli_flags & XFS_BLI_STALE) && first_bit == -1) {
/*
* If the map is not be dirty in the transaction, mark
* the size as zero and do not advance the vector pointer.
*/
return;
}
blfp = xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BFORMAT, blfp, base_size);
blfp->blf_size = 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(blfp->blf_flags & XFS_BLF_CANCEL);
return;
}
/*
* Fill in an iovec for each set of contiguous chunks.
*/
do {
ASSERT(first_bit >= 0);
nbits = xfs_contig_bits(blfp->blf_data_map,
blfp->blf_map_size, first_bit);
ASSERT(nbits > 0);
/*
* Straddling a page is rare because we don't log contiguous
* chunks of unmapped buffers anywhere.
*/
if (nbits > 1 &&
xfs_buf_item_straddle(bp, offset, first_bit, nbits))
goto slow_scan;
xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
first_bit, nbits);
blfp->blf_size++;
/*
* 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.
*/
first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
(uint)first_bit + nbits + 1);
} while (first_bit != -1);
return;
slow_scan:
ASSERT(bp->b_addr == NULL);
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(blfp->blf_data_map, blfp->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) {
xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
first_bit, nbits);
blfp->blf_size++;
break;
} else if (next_bit != last_bit + 1 ||
xfs_buf_item_straddle(bp, offset, first_bit, nbits)) {
xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
first_bit, nbits);
blfp->blf_size++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
} else {
last_bit++;
nbits++;
}
}
}
/*
* 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(
struct xfs_log_item *lip,
struct xfs_log_vec *lv)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
struct xfs_log_iovec *vecp = NULL;
uint offset = 0;
int i;
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
(xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
&& xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED) ||
(bip->bli_flags & XFS_BLI_STALE));
/*
* If it is an inode buffer, transfer the in-memory state to the
* format flags and clear the in-memory state.
*
* For buffer based inode allocation, we do not transfer
* this state if the inode buffer allocation has not yet been committed
* to the log as setting the XFS_BLI_INODE_BUF flag will prevent
* correct replay of the inode allocation.
*
* For icreate item based inode allocation, the buffers aren't written
* to the journal during allocation, and hence we should always tag the
* buffer as an inode buffer so that the correct unlinked list replay
* occurs during recovery.
*/
if (bip->bli_flags & XFS_BLI_INODE_BUF) {
if (xfs_has_v3inodes(lip->li_log->l_mp) ||
!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
xfs_log_item_in_current_chkpt(lip)))
bip->__bli_format.blf_flags |= XFS_BLF_INODE_BUF;
bip->bli_flags &= ~XFS_BLI_INODE_BUF;
}
for (i = 0; i < bip->bli_format_count; i++) {
xfs_buf_item_format_segment(bip, lv, &vecp, offset,
&bip->bli_formats[i]);
offset += BBTOB(bp->b_maps[i].bm_len);
}
/*
* Check to make sure everything is consistent.
*/
trace_xfs_buf_item_format(bip);
}
/*
* This is called to pin the buffer associated with the buf log item in memory
* so it cannot be written out.
*
* We take a reference to the buffer log item here so that the BLI life cycle
* extends at least until the buffer is unpinned via xfs_buf_item_unpin() and
* inserted into the AIL.
*
* We also need to take a reference to the buffer itself as the BLI unpin
* processing requires accessing the buffer after the BLI has dropped the final
* BLI reference. See xfs_buf_item_unpin() for an explanation.
* If unpins race to drop the final BLI reference and only the
* BLI owns a reference to the buffer, then the loser of the race can have the
* buffer fgreed from under it (e.g. on shutdown). Taking a buffer reference per
* pin count ensures the life cycle of the buffer extends for as
* long as we hold the buffer pin reference in xfs_buf_item_unpin().
*/
STATIC void
xfs_buf_item_pin(
struct xfs_log_item *lip)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_ORDERED) ||
(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_pin(bip);
xfs_buf_hold(bip->bli_buf);
atomic_inc(&bip->bli_refcount);
atomic_inc(&bip->bli_buf->b_pin_count);
}
/*
* 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(). We enter this function
* with a buffer pin count, a buffer reference and a BLI reference.
*
* We must drop the BLI reference before we unpin the buffer because the AIL
* doesn't acquire a BLI reference whenever it accesses it. Therefore if the
* refcount drops to zero, the bli could still be AIL resident and the buffer
* submitted for I/O at any point before we return. This can result in IO
* completion freeing the buffer while we are still trying to access it here.
* This race condition can also occur in shutdown situations where we abort and
* unpin buffers from contexts other that journal IO completion.
*
* Hence we have to hold a buffer reference per pin count to ensure that the
* buffer cannot be freed until we have finished processing the unpin operation.
* The reference is taken in xfs_buf_item_pin(), and we must hold it until we
* are done processing the buffer state. In the case of an abort (remove =
* true) then we re-use the current pin reference as the IO reference we hand
* off to IO failure handling.
*/
STATIC void
xfs_buf_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
int stale = bip->bli_flags & XFS_BLI_STALE;
int freed;
ASSERT(bp->b_log_item == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_buf_item_unpin(bip);
freed = atomic_dec_and_test(&bip->bli_refcount);
if (atomic_dec_and_test(&bp->b_pin_count))
wake_up_all(&bp->b_waiters);
/*
* Nothing to do but drop the buffer pin reference if the BLI is
* still active.
*/
if (!freed) {
xfs_buf_rele(bp);
return;
}
if (stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(xfs_buf_islocked(bp));
ASSERT(bp->b_flags & XBF_STALE);
ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
ASSERT(list_empty(&lip->li_trans));
ASSERT(!bp->b_transp);
trace_xfs_buf_item_unpin_stale(bip);
/*
* The buffer has been locked and referenced since it was marked
* stale so we own both lock and reference exclusively here. We
* do not need the pin reference any more, so drop it now so
* that we only have one reference to drop once item completion
* processing is complete.
*/
xfs_buf_rele(bp);
/*
* 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_item_done(bp);
xfs_buf_inode_iodone(bp);
ASSERT(list_empty(&bp->b_li_list));
} else {
xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
xfs_buf_item_relse(bp);
ASSERT(bp->b_log_item == NULL);
}
xfs_buf_relse(bp);
return;
}
if (remove) {
/*
* We need to simulate an async IO failures here to ensure that
* the correct error completion is run on this buffer. This
* requires a reference to the buffer and for the buffer to be
* locked. We can safely pass ownership of the pin reference to
* the IO to ensure that nothing can free the buffer while we
* wait for the lock and then run the IO failure completion.
*/
xfs_buf_lock(bp);
bp->b_flags |= XBF_ASYNC;
xfs_buf_ioend_fail(bp);
return;
}
/*
* BLI has no more active references - it will be moved to the AIL to
* manage the remaining BLI/buffer life cycle. There is nothing left for
* us to do here so drop the pin reference to the buffer.
*/
xfs_buf_rele(bp);
}
STATIC uint
xfs_buf_item_push(
struct xfs_log_item *lip,
struct list_head *buffer_list)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
uint rval = XFS_ITEM_SUCCESS;
if (xfs_buf_ispinned(bp))
return XFS_ITEM_PINNED;
if (!xfs_buf_trylock(bp)) {
/*
* If we have just raced with a buffer being pinned and it has
* been marked stale, we could end up stalling until someone else
* issues a log force to unpin the stale buffer. Check for the
* race condition here so xfsaild recognizes the buffer is pinned
* and queues a log force to move it along.
*/
if (xfs_buf_ispinned(bp))
return XFS_ITEM_PINNED;
return XFS_ITEM_LOCKED;
}
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_push(bip);
/* has a previous flush failed due to IO errors? */
if (bp->b_flags & XBF_WRITE_FAIL) {
xfs_buf_alert_ratelimited(bp, "XFS: Failing async write",
"Failing async write on buffer block 0x%llx. Retrying async write.",
(long long)xfs_buf_daddr(bp));
}
if (!xfs_buf_delwri_queue(bp, buffer_list))
rval = XFS_ITEM_FLUSHING;
xfs_buf_unlock(bp);
return rval;
}
/*
* Drop the buffer log item refcount and take appropriate action. This helper
* determines whether the bli must be freed or not, since a decrement to zero
* does not necessarily mean the bli is unused.
*
* Return true if the bli is freed, false otherwise.
*/
bool
xfs_buf_item_put(
struct xfs_buf_log_item *bip)
{
struct xfs_log_item *lip = &bip->bli_item;
bool aborted;
bool dirty;
/* drop the bli ref and return if it wasn't the last one */
if (!atomic_dec_and_test(&bip->bli_refcount))
return false;
/*
* We dropped the last ref and must free the item if clean or aborted.
* If the bli is dirty and non-aborted, the buffer was clean in the
* transaction but still awaiting writeback from previous changes. In
* that case, the bli is freed on buffer writeback completion.
*/
aborted = test_bit(XFS_LI_ABORTED, &lip->li_flags) ||
xlog_is_shutdown(lip->li_log);
dirty = bip->bli_flags & XFS_BLI_DIRTY;
if (dirty && !aborted)
return false;
/*
* The bli is aborted or clean. An aborted item may be in the AIL
* regardless of dirty state. For example, consider an aborted
* transaction that invalidated a dirty bli and cleared the dirty
* state.
*/
if (aborted)
xfs_trans_ail_delete(lip, 0);
xfs_buf_item_relse(bip->bli_buf);
return true;
}
/*
* 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.
*
* We unconditionally drop the transaction's reference to the log item. If the
* item was logged, then another reference was taken when it was pinned, so we
* can safely drop the transaction reference now. This also allows us to avoid
* potential races with the unpin code freeing the bli by not referencing the
* bli after we've dropped the reference 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_release(
struct xfs_log_item *lip)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
bool released;
bool hold = bip->bli_flags & XFS_BLI_HOLD;
bool stale = bip->bli_flags & XFS_BLI_STALE;
#if defined(DEBUG) || defined(XFS_WARN)
bool ordered = bip->bli_flags & XFS_BLI_ORDERED;
bool dirty = bip->bli_flags & XFS_BLI_DIRTY;
bool aborted = test_bit(XFS_LI_ABORTED,
&lip->li_flags);
#endif
trace_xfs_buf_item_release(bip);
/*
* The bli dirty state should match whether the blf has logged segments
* except for ordered buffers, where only the bli should be dirty.
*/
ASSERT((!ordered && dirty == xfs_buf_item_dirty_format(bip)) ||
(ordered && dirty && !xfs_buf_item_dirty_format(bip)));
ASSERT(!stale || (bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
/*
* Clear the buffer's association with this transaction and
* per-transaction state from the bli, which has been copied above.
*/
bp->b_transp = NULL;
bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
/*
* Unref the item and unlock the buffer unless held or stale. Stale
* buffers remain locked until final unpin unless the bli is freed by
* the unref call. The latter implies shutdown because buffer
* invalidation dirties the bli and transaction.
*/
released = xfs_buf_item_put(bip);
if (hold || (stale && !released))
return;
ASSERT(!stale || aborted);
xfs_buf_relse(bp);
}
STATIC void
xfs_buf_item_committing(
struct xfs_log_item *lip,
xfs_csn_t seq)
{
return xfs_buf_item_release(lip);
}
/*
* 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(
struct xfs_log_item *lip,
xfs_lsn_t lsn)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
trace_xfs_buf_item_committed(bip);
if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && lip->li_lsn != 0)
return lip->li_lsn;
return lsn;
}
#ifdef DEBUG_EXPENSIVE
static int
xfs_buf_item_precommit(
struct xfs_trans *tp,
struct xfs_log_item *lip)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
struct xfs_mount *mp = bp->b_mount;
xfs_failaddr_t fa;
if (!bp->b_ops || !bp->b_ops->verify_struct)
return 0;
if (bip->bli_flags & XFS_BLI_STALE)
return 0;
fa = bp->b_ops->verify_struct(bp);
if (fa) {
xfs_buf_verifier_error(bp, -EFSCORRUPTED, bp->b_ops->name,
bp->b_addr, BBTOB(bp->b_length), fa);
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
ASSERT(fa == NULL);
}
return 0;
}
#else
# define xfs_buf_item_precommit NULL
#endif
static const struct xfs_item_ops xfs_buf_item_ops = {
.iop_size = xfs_buf_item_size,
.iop_precommit = xfs_buf_item_precommit,
.iop_format = xfs_buf_item_format,
.iop_pin = xfs_buf_item_pin,
.iop_unpin = xfs_buf_item_unpin,
.iop_release = xfs_buf_item_release,
.iop_committing = xfs_buf_item_committing,
.iop_committed = xfs_buf_item_committed,
.iop_push = xfs_buf_item_push,
};
STATIC void
xfs_buf_item_get_format(
struct xfs_buf_log_item *bip,
int count)
{
ASSERT(bip->bli_formats == NULL);
bip->bli_format_count = count;
if (count == 1) {
bip->bli_formats = &bip->__bli_format;
return;
}
bip->bli_formats = kzalloc(count * sizeof(struct xfs_buf_log_format),
GFP_KERNEL | __GFP_NOFAIL);
}
STATIC void
xfs_buf_item_free_format(
struct xfs_buf_log_item *bip)
{
if (bip->bli_formats != &bip->__bli_format) {
kfree(bip->bli_formats);
bip->bli_formats = NULL;
}
}
/*
* Allocate a new buf log item to go with the given buffer.
* Set the buffer's b_log_item field to point to the new
* buf log item.
*/
int
xfs_buf_item_init(
struct xfs_buf *bp,
struct xfs_mount *mp)
{
struct xfs_buf_log_item *bip = bp->b_log_item;
int chunks;
int map_size;
int i;
/*
* Check to see if there is already a buf log item for
* this buffer. If we do already have one, there is
* nothing to do here so return.
*/
ASSERT(bp->b_mount == mp);
if (bip) {
ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
ASSERT(!bp->b_transp);
ASSERT(bip->bli_buf == bp);
return 0;
}
bip = kmem_cache_zalloc(xfs_buf_item_cache, GFP_KERNEL | __GFP_NOFAIL);
xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops);
bip->bli_buf = bp;
/*
* chunks is the number of XFS_BLF_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.
*
* Discontiguous buffer support follows the layout of the underlying
* buffer. This makes the implementation as simple as possible.
*/
xfs_buf_item_get_format(bip, bp->b_map_count);
for (i = 0; i < bip->bli_format_count; i++) {
chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len),
XFS_BLF_CHUNK);
map_size = DIV_ROUND_UP(chunks, NBWORD);
if (map_size > XFS_BLF_DATAMAP_SIZE) {
kmem_cache_free(xfs_buf_item_cache, bip);
xfs_err(mp,
"buffer item dirty bitmap (%u uints) too small to reflect %u bytes!",
map_size,
BBTOB(bp->b_maps[i].bm_len));
return -EFSCORRUPTED;
}
bip->bli_formats[i].blf_type = XFS_LI_BUF;
bip->bli_formats[i].blf_blkno = bp->b_maps[i].bm_bn;
bip->bli_formats[i].blf_len = bp->b_maps[i].bm_len;
bip->bli_formats[i].blf_map_size = map_size;
}
bp->b_log_item = bip;
xfs_buf_hold(bp);
return 0;
}
/*
* Mark bytes first through last inclusive as dirty in the buf
* item's bitmap.
*/
static void
xfs_buf_item_log_segment(
uint first,
uint last,
uint *map)
{
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;
ASSERT(first < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
ASSERT(last < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
/*
* Convert byte offsets to bit numbers.
*/
first_bit = first >> XFS_BLF_SHIFT;
last_bit = last >> XFS_BLF_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 = &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 = ((1U << (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 = (1U << end_bit) - 1;
*wordp |= mask;
}
}
/*
* Mark bytes first through last inclusive as dirty in the buf
* item's bitmap.
*/
void
xfs_buf_item_log(
struct xfs_buf_log_item *bip,
uint first,
uint last)
{
int i;
uint start;
uint end;
struct xfs_buf *bp = bip->bli_buf;
/*
* walk each buffer segment and mark them dirty appropriately.
*/
start = 0;
for (i = 0; i < bip->bli_format_count; i++) {
if (start > last)
break;
end = start + BBTOB(bp->b_maps[i].bm_len) - 1;
/* skip to the map that includes the first byte to log */
if (first > end) {
start += BBTOB(bp->b_maps[i].bm_len);
continue;
}
/*
* Trim the range to this segment and mark it in the bitmap.
* Note that we must convert buffer offsets to segment relative
* offsets (e.g., the first byte of each segment is byte 0 of
* that segment).
*/
if (first < start)
first = start;
if (end > last)
end = last;
xfs_buf_item_log_segment(first - start, end - start,
&bip->bli_formats[i].blf_data_map[0]);
start += BBTOB(bp->b_maps[i].bm_len);
}
}
/*
* Return true if the buffer has any ranges logged/dirtied by a transaction,
* false otherwise.
*/
bool
xfs_buf_item_dirty_format(
struct xfs_buf_log_item *bip)
{
int i;
for (i = 0; i < bip->bli_format_count; i++) {
if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
bip->bli_formats[i].blf_map_size))
return true;
}
return false;
}
STATIC void
xfs_buf_item_free(
struct xfs_buf_log_item *bip)
{
xfs_buf_item_free_format(bip);
kvfree(bip->bli_item.li_lv_shadow);
kmem_cache_free(xfs_buf_item_cache, bip);
}
/*
* xfs_buf_item_relse() is called when the buf log item is no longer needed.
*/
void
xfs_buf_item_relse(
struct xfs_buf *bp)
{
struct xfs_buf_log_item *bip = bp->b_log_item;
trace_xfs_buf_item_relse(bp, _RET_IP_);
ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags));
if (atomic_read(&bip->bli_refcount))
return;
bp->b_log_item = NULL;
xfs_buf_rele(bp);
xfs_buf_item_free(bip);
}
void
xfs_buf_item_done(
struct xfs_buf *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.
*
* Note that log recovery writes might have buffer items that are not on
* the AIL even when the file system is not shut down.
*/
xfs_trans_ail_delete(&bp->b_log_item->bli_item,
(bp->b_flags & _XBF_LOGRECOVERY) ? 0 :
SHUTDOWN_CORRUPT_INCORE);
xfs_buf_item_relse(bp);
}
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