| // 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_buf_item.h" |
| #include "xfs_trans_priv.h" |
| #include "xfs_trace.h" |
| #include "xfs_log.h" |
| |
| |
| kmem_zone_t *xfs_buf_item_zone; |
| |
| 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_do_callbacks(struct xfs_buf *bp); |
| |
| 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])); |
| } |
| |
| /* |
| * 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 void |
| xfs_buf_item_size_segment( |
| struct xfs_buf_log_item *bip, |
| struct xfs_buf_log_format *blfp, |
| int *nvecs, |
| int *nbytes) |
| { |
| struct xfs_buf *bp = bip->bli_buf; |
| int next_bit; |
| int last_bit; |
| |
| last_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0); |
| if (last_bit == -1) |
| return; |
| |
| /* |
| * initial count for a dirty buffer is 2 vectors - the format structure |
| * and the first dirty region. |
| */ |
| *nvecs += 2; |
| *nbytes += xfs_buf_log_format_size(blfp) + XFS_BLF_CHUNK; |
| |
| 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) { |
| last_bit = next_bit; |
| (*nvecs)++; |
| } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) != |
| (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + |
| XFS_BLF_CHUNK)) { |
| last_bit = next_bit; |
| (*nvecs)++; |
| } else { |
| last_bit++; |
| } |
| *nbytes += XFS_BLF_CHUNK; |
| } |
| } |
| |
| /* |
| * 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. |
| * |
| * Discontiguous buffers need a format structure per region that 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. |
| */ |
| STATIC void |
| xfs_buf_item_size( |
| struct xfs_log_item *lip, |
| int *nvecs, |
| int *nbytes) |
| { |
| struct xfs_buf_log_item *bip = BUF_ITEM(lip); |
| int i; |
| |
| 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_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. |
| */ |
| for (i = 0; i < bip->bli_format_count; i++) { |
| xfs_buf_item_size_segment(bip, &bip->bli_formats[i], |
| nvecs, nbytes); |
| } |
| 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 inline bool |
| xfs_buf_item_straddle( |
| struct xfs_buf *bp, |
| uint offset, |
| int next_bit, |
| int last_bit) |
| { |
| return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != |
| (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + |
| 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. |
| */ |
| 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, next_bit, last_bit)) { |
| 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_sb_version_hascrc(&lip->li_mountp->m_sb) || |
| !((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 also always take a reference to the buffer log item here so that the bli |
| * is held while the item is pinned in memory. This means that we can |
| * unconditionally drop the reference count a transaction holds when the |
| * transaction is completed. |
| */ |
| 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); |
| |
| 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(). |
| * |
| * 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. |
| * |
| * If the remove flag is set we are called from uncommit in the |
| * forced-shutdown path. If that is true and the reference count on |
| * the log item is going to drop to zero we need to free the item's |
| * descriptor in the transaction. |
| */ |
| STATIC void |
| xfs_buf_item_unpin( |
| struct xfs_log_item *lip, |
| int remove) |
| { |
| struct xfs_buf_log_item *bip = BUF_ITEM(lip); |
| xfs_buf_t *bp = bip->bli_buf; |
| struct xfs_ail *ailp = lip->li_ailp; |
| 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); |
| |
| if (freed && 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); |
| |
| trace_xfs_buf_item_unpin_stale(bip); |
| |
| if (remove) { |
| /* |
| * If we are in a transaction context, we have to |
| * remove the log item from the transaction as we are |
| * about to release our reference to the buffer. If we |
| * don't, the unlock that occurs later in |
| * xfs_trans_uncommit() will try to reference the |
| * buffer which we no longer have a hold on. |
| */ |
| if (!list_empty(&lip->li_trans)) |
| xfs_trans_del_item(lip); |
| |
| /* |
| * Since the transaction no longer refers to the buffer, |
| * the buffer should no longer refer to the transaction. |
| */ |
| bp->b_transp = NULL; |
| } |
| |
| /* |
| * 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); |
| bp->b_log_item = NULL; |
| list_del_init(&bp->b_li_list); |
| bp->b_iodone = NULL; |
| } else { |
| spin_lock(&ailp->ail_lock); |
| xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR); |
| xfs_buf_item_relse(bp); |
| ASSERT(bp->b_log_item == NULL); |
| } |
| xfs_buf_relse(bp); |
| } else if (freed && remove) { |
| /* |
| * There are currently two references to the buffer - the active |
| * LRU reference and the buf log item. What we are about to do |
| * here - simulate a failed IO completion - requires 3 |
| * references. |
| * |
| * The LRU reference is removed by the xfs_buf_stale() call. The |
| * buf item reference is removed by the xfs_buf_iodone() |
| * callback that is run by xfs_buf_do_callbacks() during ioend |
| * processing (via the bp->b_iodone callback), and then finally |
| * the ioend processing will drop the IO reference if the buffer |
| * is marked XBF_ASYNC. |
| * |
| * Hence we need to take an additional reference here so that IO |
| * completion processing doesn't free the buffer prematurely. |
| */ |
| xfs_buf_lock(bp); |
| xfs_buf_hold(bp); |
| bp->b_flags |= XBF_ASYNC; |
| xfs_buf_ioerror(bp, -EIO); |
| bp->b_flags &= ~XBF_DONE; |
| xfs_buf_stale(bp); |
| xfs_buf_ioend(bp); |
| } |
| } |
| |
| /* |
| * Buffer IO error rate limiting. Limit it to no more than 10 messages per 30 |
| * seconds so as to not spam logs too much on repeated detection of the same |
| * buffer being bad.. |
| */ |
| |
| static DEFINE_RATELIMIT_STATE(xfs_buf_write_fail_rl_state, 30 * HZ, 10); |
| |
| 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) && |
| ___ratelimit(&xfs_buf_write_fail_rl_state, "XFS: Failing async write")) { |
| xfs_warn(bp->b_mount, |
| "Failing async write on buffer block 0x%llx. Retrying async write.", |
| (long long)bp->b_bn); |
| } |
| |
| 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) || |
| XFS_FORCED_SHUTDOWN(lip->li_mountp); |
| 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_remove(lip, SHUTDOWN_LOG_IO_ERROR); |
| 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_lsn_t commit_lsn) |
| { |
| 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; |
| } |
| |
| static const struct xfs_item_ops xfs_buf_item_ops = { |
| .iop_size = xfs_buf_item_size, |
| .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 int |
| 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 0; |
| } |
| |
| bip->bli_formats = kmem_zalloc(count * sizeof(struct xfs_buf_log_format), |
| 0); |
| if (!bip->bli_formats) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| STATIC void |
| xfs_buf_item_free_format( |
| struct xfs_buf_log_item *bip) |
| { |
| if (bip->bli_formats != &bip->__bli_format) { |
| kmem_free(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 error; |
| 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_zone_zalloc(xfs_buf_item_zone, 0); |
| 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. |
| */ |
| error = xfs_buf_item_get_format(bip, bp->b_map_count); |
| ASSERT(error == 0); |
| if (error) { /* to stop gcc throwing set-but-unused warnings */ |
| kmem_cache_free(xfs_buf_item_zone, bip); |
| return error; |
| } |
| |
| |
| 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); |
| |
| 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; |
| |
| /* |
| * 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); |
| kmem_free(bip->bli_item.li_lv_shadow); |
| kmem_cache_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) |
| { |
| 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)); |
| |
| bp->b_log_item = NULL; |
| if (list_empty(&bp->b_li_list)) |
| bp->b_iodone = NULL; |
| |
| 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_li_list. |
| */ |
| void |
| xfs_buf_attach_iodone( |
| struct xfs_buf *bp, |
| void (*cb)(struct xfs_buf *, struct xfs_log_item *), |
| struct xfs_log_item *lip) |
| { |
| ASSERT(xfs_buf_islocked(bp)); |
| |
| lip->li_cb = cb; |
| list_add_tail(&lip->li_bio_list, &bp->b_li_list); |
| |
| ASSERT(bp->b_iodone == NULL || |
| bp->b_iodone == xfs_buf_iodone_callbacks); |
| bp->b_iodone = xfs_buf_iodone_callbacks; |
| } |
| |
| /* |
| * We can have many callbacks on a buffer. Running the callbacks individually |
| * can cause a lot of contention on the AIL lock, so we allow for a single |
| * callback to be able to scan the remaining items in bp->b_li_list for other |
| * items of the same type and callback to be processed in the first call. |
| * |
| * As a result, the loop walking the callback list below will also modify the |
| * list. it removes the first item from the list and then runs the callback. |
| * The loop then restarts from the new first item int the list. This allows the |
| * callback to scan and modify the list attached to the buffer and we don't |
| * have to care about maintaining a next item pointer. |
| */ |
| STATIC void |
| xfs_buf_do_callbacks( |
| struct xfs_buf *bp) |
| { |
| struct xfs_buf_log_item *blip = bp->b_log_item; |
| struct xfs_log_item *lip; |
| |
| /* If there is a buf_log_item attached, run its callback */ |
| if (blip) { |
| lip = &blip->bli_item; |
| lip->li_cb(bp, lip); |
| } |
| |
| while (!list_empty(&bp->b_li_list)) { |
| lip = list_first_entry(&bp->b_li_list, struct xfs_log_item, |
| li_bio_list); |
| |
| /* |
| * Remove the item from the list, 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. |
| */ |
| list_del_init(&lip->li_bio_list); |
| lip->li_cb(bp, lip); |
| } |
| } |
| |
| /* |
| * Invoke the error state callback for each log item affected by the failed I/O. |
| * |
| * If a metadata buffer write fails with a non-permanent error, the buffer is |
| * eventually resubmitted and so the completion callbacks are not run. The error |
| * state may need to be propagated to the log items attached to the buffer, |
| * however, so the next AIL push of the item knows hot to handle it correctly. |
| */ |
| STATIC void |
| xfs_buf_do_callbacks_fail( |
| struct xfs_buf *bp) |
| { |
| struct xfs_log_item *lip; |
| struct xfs_ail *ailp; |
| |
| /* |
| * Buffer log item errors are handled directly by xfs_buf_item_push() |
| * and xfs_buf_iodone_callback_error, and they have no IO error |
| * callbacks. Check only for items in b_li_list. |
| */ |
| if (list_empty(&bp->b_li_list)) |
| return; |
| |
| lip = list_first_entry(&bp->b_li_list, struct xfs_log_item, |
| li_bio_list); |
| ailp = lip->li_ailp; |
| spin_lock(&ailp->ail_lock); |
| list_for_each_entry(lip, &bp->b_li_list, li_bio_list) { |
| if (lip->li_ops->iop_error) |
| lip->li_ops->iop_error(lip, bp); |
| } |
| spin_unlock(&ailp->ail_lock); |
| } |
| |
| static bool |
| xfs_buf_iodone_callback_error( |
| struct xfs_buf *bp) |
| { |
| struct xfs_buf_log_item *bip = bp->b_log_item; |
| struct xfs_log_item *lip; |
| struct xfs_mount *mp; |
| static ulong lasttime; |
| static xfs_buftarg_t *lasttarg; |
| struct xfs_error_cfg *cfg; |
| |
| /* |
| * The failed buffer might not have a buf_log_item attached or the |
| * log_item list might be empty. Get the mp from the available |
| * xfs_log_item |
| */ |
| lip = list_first_entry_or_null(&bp->b_li_list, struct xfs_log_item, |
| li_bio_list); |
| mp = lip ? lip->li_mountp : bip->bli_item.li_mountp; |
| |
| /* |
| * If we've already decided to shutdown the filesystem because of |
| * I/O errors, there's no point in giving this a retry. |
| */ |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| goto out_stale; |
| |
| if (bp->b_target != lasttarg || |
| time_after(jiffies, (lasttime + 5*HZ))) { |
| lasttime = jiffies; |
| xfs_buf_ioerror_alert(bp, __func__); |
| } |
| lasttarg = bp->b_target; |
| |
| /* synchronous writes will have callers process the error */ |
| if (!(bp->b_flags & XBF_ASYNC)) |
| goto out_stale; |
| |
| trace_xfs_buf_item_iodone_async(bp, _RET_IP_); |
| ASSERT(bp->b_iodone != NULL); |
| |
| cfg = xfs_error_get_cfg(mp, XFS_ERR_METADATA, bp->b_error); |
| |
| /* |
| * If the write was asynchronous then no one will be looking for the |
| * error. If this is the first failure of this type, clear the error |
| * state and write the buffer out again. This means we always retry an |
| * async write failure at least once, but we also need to set the buffer |
| * up to behave correctly now for repeated failures. |
| */ |
| if (!(bp->b_flags & (XBF_STALE | XBF_WRITE_FAIL)) || |
| bp->b_last_error != bp->b_error) { |
| bp->b_flags |= (XBF_WRITE | XBF_DONE | XBF_WRITE_FAIL); |
| bp->b_last_error = bp->b_error; |
| if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && |
| !bp->b_first_retry_time) |
| bp->b_first_retry_time = jiffies; |
| |
| xfs_buf_ioerror(bp, 0); |
| xfs_buf_submit(bp); |
| return true; |
| } |
| |
| /* |
| * Repeated failure on an async write. Take action according to the |
| * error configuration we have been set up to use. |
| */ |
| |
| if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && |
| ++bp->b_retries > cfg->max_retries) |
| goto permanent_error; |
| if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && |
| time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) |
| goto permanent_error; |
| |
| /* At unmount we may treat errors differently */ |
| if ((mp->m_flags & XFS_MOUNT_UNMOUNTING) && mp->m_fail_unmount) |
| goto permanent_error; |
| |
| /* |
| * Still a transient error, run IO completion failure callbacks and let |
| * the higher layers retry the buffer. |
| */ |
| xfs_buf_do_callbacks_fail(bp); |
| xfs_buf_ioerror(bp, 0); |
| xfs_buf_relse(bp); |
| return true; |
| |
| /* |
| * Permanent error - we need to trigger a shutdown if we haven't already |
| * to indicate that inconsistency will result from this action. |
| */ |
| permanent_error: |
| xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); |
| out_stale: |
| xfs_buf_stale(bp); |
| bp->b_flags |= XBF_DONE; |
| trace_xfs_buf_error_relse(bp, _RET_IP_); |
| return false; |
| } |
| |
| /* |
| * This is the iodone() function for buffers which have had callbacks attached |
| * to them by xfs_buf_attach_iodone(). We need to iterate the items on the |
| * callback list, mark the buffer as having no more callbacks and then push the |
| * buffer through IO completion processing. |
| */ |
| void |
| xfs_buf_iodone_callbacks( |
| struct xfs_buf *bp) |
| { |
| /* |
| * If there is an error, process it. Some errors require us |
| * to run callbacks after failure processing is done so we |
| * detect that and take appropriate action. |
| */ |
| if (bp->b_error && xfs_buf_iodone_callback_error(bp)) |
| return; |
| |
| /* |
| * Successful IO or permanent error. Either way, we can clear the |
| * retry state here in preparation for the next error that may occur. |
| */ |
| bp->b_last_error = 0; |
| bp->b_retries = 0; |
| bp->b_first_retry_time = 0; |
| |
| xfs_buf_do_callbacks(bp); |
| bp->b_log_item = NULL; |
| list_del_init(&bp->b_li_list); |
| bp->b_iodone = NULL; |
| xfs_buf_ioend(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. |
| */ |
| void |
| xfs_buf_iodone( |
| struct xfs_buf *bp, |
| struct xfs_log_item *lip) |
| { |
| struct xfs_ail *ailp = lip->li_ailp; |
| |
| ASSERT(BUF_ITEM(lip)->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->ail_lock); |
| xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); |
| xfs_buf_item_free(BUF_ITEM(lip)); |
| } |
| |
| /* |
| * Requeue a failed buffer for writeback. |
| * |
| * We clear the log item failed state here as well, but we have to be careful |
| * about reference counts because the only active reference counts on the buffer |
| * may be the failed log items. Hence if we clear the log item failed state |
| * before queuing the buffer for IO we can release all active references to |
| * the buffer and free it, leading to use after free problems in |
| * xfs_buf_delwri_queue. It makes no difference to the buffer or log items which |
| * order we process them in - the buffer is locked, and we own the buffer list |
| * so nothing on them is going to change while we are performing this action. |
| * |
| * Hence we can safely queue the buffer for IO before we clear the failed log |
| * item state, therefore always having an active reference to the buffer and |
| * avoiding the transient zero-reference state that leads to use-after-free. |
| * |
| * Return true if the buffer was added to the buffer list, false if it was |
| * already on the buffer list. |
| */ |
| bool |
| xfs_buf_resubmit_failed_buffers( |
| struct xfs_buf *bp, |
| struct list_head *buffer_list) |
| { |
| struct xfs_log_item *lip; |
| bool ret; |
| |
| ret = xfs_buf_delwri_queue(bp, buffer_list); |
| |
| /* |
| * XFS_LI_FAILED set/clear is protected by ail_lock, caller of this |
| * function already have it acquired |
| */ |
| list_for_each_entry(lip, &bp->b_li_list, li_bio_list) |
| xfs_clear_li_failed(lip); |
| |
| return ret; |
| } |