// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs_platform.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); } 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; } } 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. */ static void xfs_buf_item_relse( struct xfs_buf_log_item *bip) { struct xfs_buf *bp = bip->bli_buf; trace_xfs_buf_item_relse(bp, _RET_IP_); ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags)); ASSERT(atomic_read(&bip->bli_refcount) == 0); bp->b_log_item = NULL; xfs_buf_rele(bp); xfs_buf_item_free(bip); } /* Is this log iovec plausibly large enough to contain the buffer log format? */ bool xfs_buf_log_check_iovec( struct kvec *iovec) { struct xfs_buf_log_format *blfp = iovec->iov_base; char *bmp_end; char *item_end; if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->iov_len) return false; item_end = (char *)iovec->iov_base + iovec->iov_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])); } /* * 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) { int first_bit; int nbits; 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); (*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; } /* * Compute the worst case log item overhead for an invalidated buffer with the * given map count and block size. */ unsigned int xfs_buf_inval_log_space( unsigned int map_count, unsigned int blocksize) { unsigned int chunks = DIV_ROUND_UP(blocksize, XFS_BLF_CHUNK); unsigned int bitmap_size = DIV_ROUND_UP(chunks, NBWORD); unsigned int ret = offsetof(struct xfs_buf_log_format, blf_data_map) + (bitmap_size * sizeof_field(struct xfs_buf_log_format, blf_data_map[0])); return ret * map_count; } /* * 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 xlog_format_buf *lfb, struct xfs_buf *bp, uint offset, int first_bit, uint nbits) { offset += first_bit * XFS_BLF_CHUNK; xlog_format_copy(lfb, 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 xlog_format_buf *lfb, uint offset, struct xfs_buf_log_format *blfp) { struct xfs_buf *bp = bip->bli_buf; uint base_size; int first_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_format_copy(lfb, 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); xfs_buf_item_copy_iovec(lfb, 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; } /* * 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 xlog_format_buf *lfb) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); struct xfs_buf *bp = bip->bli_buf; 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, lfb, 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); } /* * For a stale BLI, process all the necessary completions that must be * performed when the final BLI reference goes away. The buffer will be * referenced and locked here - we return to the caller with the buffer still * referenced and locked for them to finalise processing of the buffer. */ static void xfs_buf_item_finish_stale( struct xfs_buf_log_item *bip) { struct xfs_buf *bp = bip->bli_buf; struct xfs_log_item *lip = &bip->bli_item; 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); 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)); return; } /* * We may or may not be on the AIL here, xfs_trans_ail_delete() will do * the right thing regardless of the situation in which we are called. */ xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR); xfs_buf_item_relse(bip); ASSERT(bp->b_log_item == NULL); } /* * 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) { 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); xfs_buf_item_finish_stale(bip); 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. */ void xfs_buf_item_put( struct xfs_buf_log_item *bip) { ASSERT(xfs_buf_islocked(bip->bli_buf)); /* drop the bli ref and return if it wasn't the last one */ if (!atomic_dec_and_test(&bip->bli_refcount)) return; /* If the BLI is in the AIL, then it is still dirty and in use */ if (test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags)) { ASSERT(bip->bli_flags & XFS_BLI_DIRTY); return; } /* * In shutdown conditions, we can be asked to free a dirty BLI that * isn't in the AIL. This can occur due to a checkpoint aborting a BLI * instead of inserting it into the AIL at checkpoint IO completion. If * there's another bli reference (e.g. a btree cursor holds a clean * reference) and it is released via xfs_trans_brelse(), we can get here * with that aborted, dirty BLI. In this case, it is safe to free the * dirty BLI immediately, as it is not in the AIL and there are no * other references to it. * * We should never get here with a stale BLI via that path as * xfs_trans_brelse() specifically holds onto stale buffers rather than * releasing them. */ ASSERT(!(bip->bli_flags & XFS_BLI_DIRTY) || test_bit(XFS_LI_ABORTED, &bip->bli_item.li_flags)); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); xfs_buf_item_relse(bip); } /* * 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. * * If the XFS_BLI_STALE flag is set, the last reference to the BLI *must* * perform a completion abort of any objects attached to the buffer for IO * tracking purposes. This generally only happens in shutdown situations, * normally xfs_buf_item_unpin() will drop the last BLI reference and perform * completion processing. However, because transaction completion can race with * checkpoint completion during a shutdown, this release context may end up * being the last active reference to the BLI and so needs to perform this * cleanup. */ 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 hold = bip->bli_flags & XFS_BLI_HOLD; bool stale = bip->bli_flags & XFS_BLI_STALE; bool aborted = test_bit(XFS_LI_ABORTED, &lip->li_flags); bool dirty = bip->bli_flags & XFS_BLI_DIRTY; #if defined(DEBUG) || defined(XFS_WARN) bool ordered = bip->bli_flags & XFS_BLI_ORDERED; #endif trace_xfs_buf_item_release(bip); ASSERT(xfs_buf_islocked(bp)); /* * 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); /* If there are other references, then we have nothing to do. */ if (!atomic_dec_and_test(&bip->bli_refcount)) goto out_release; /* * Stale buffer completion frees the BLI, unlocks and releases the * buffer. Neither the BLI or buffer are safe to reference after this * call, so there's nothing more we need to do here. * * If we get here with a stale buffer and references to the BLI remain, * we must not unlock the buffer as the last BLI reference owns lock * context, not us. */ if (stale) { xfs_buf_item_finish_stale(bip); xfs_buf_relse(bp); ASSERT(!hold); return; } /* * Dirty or clean, aborted items are done and need to be removed from * the AIL and released. This frees the BLI, but leaves the buffer * locked and referenced. */ if (aborted || xlog_is_shutdown(lip->li_log)) { ASSERT(list_empty(&bip->bli_buf->b_li_list)); xfs_buf_item_done(bp); goto out_release; } /* * Clean, unreferenced BLIs can be immediately freed, leaving the buffer * locked and referenced. * * Dirty, unreferenced BLIs *must* be in the AIL awaiting writeback. */ if (!dirty) xfs_buf_item_relse(bip); else ASSERT(test_bit(XFS_LI_IN_AIL, &lip->li_flags)); /* Not safe to reference the BLI from here */ out_release: /* * If we get here with a stale buffer, we must not unlock the * buffer as the last BLI reference owns lock context, not us. */ if (stale || hold) return; 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, }; /* * 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) { xfs_buf_item_free_format(bip); 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; } 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->b_log_item); }
