Merge branch 'develop' into mongodb-3.4mongodb-3.3.6

1 files changed, 36 insertions, 17 deletions

diff --git a/src/block/block_write.c b/src/block/block_write.c
index 134272b52f9..4f1224f3c13 100644
--- a/src/block/block_write.c
+++ b/src/block/block_write.c
@@ -15,6 +15,24 @@
 int
 __wt_block_truncate(WT_SESSION_IMPL *session, WT_BLOCK *block, wt_off_t len)
 {
+	/*
+	 * Backups are done by copying files outside of WiredTiger, potentially
+	 * by system utilities. We cannot truncate the file during the backup
+	 * window, we might surprise an application.
+	 *
+	 * Stop block truncation. This affects files that aren't involved in the
+	 * backup (for example, doing incremental backups, which only copies log
+	 * files, or targeted backups, stops all truncation). We may want a more
+	 * targeted solution at some point.
+	 */
+	if (S2C(session)->hot_backup)
+		return (EBUSY);
+
+	/*
+	 * Additionally, the truncate might fail if there's a file mapping (if
+	 * there's an open checkpoint on the file), in which case the underlying
+	 * function returns EBUSY.
+	 */
 	WT_RET(__wt_ftruncate(session, block->fh, len));
 
 	block->size = block->extend_size = len;
@@ -30,27 +48,28 @@ int
 __wt_block_discard(WT_SESSION_IMPL *session, WT_BLOCK *block, size_t added_size)
 {
 	WT_DECL_RET;
+	WT_FILE_HANDLE *handle;
 
+	/* The file may not support this call. */
+	handle = block->fh->handle;
+	if (handle->fadvise == NULL)
+		return (0);
+
+	/* The call may not be configured. */
 	if (block->os_cache_max == 0)
 		return (0);
 
 	/*
 	 * We're racing on the addition, but I'm not willing to serialize on it
-	 * in the standard read path with more evidence it's needed.
+	 * in the standard read path without evidence it's needed.
 	 */
 	if ((block->os_cache += added_size) <= block->os_cache_max)
 		return (0);
 
 	block->os_cache = 0;
-	WT_ERR(block->fh->fh_advise(session,
-	    block->fh, (wt_off_t)0, (wt_off_t)0, POSIX_FADV_DONTNEED));
-	return (0);
-
-err:	/* Ignore ENOTSUP, but don't try again. */
-	if (ret != ENOTSUP)
-		return (ret);
-	block->os_cache_max = 0;
-	return (0);
+	ret = handle->fadvise(handle, (WT_SESSION *)session,
+	    (wt_off_t)0, (wt_off_t)0, WT_FILE_HANDLE_DONTNEED);
+	return (ret == EBUSY || ret == ENOTSUP ? 0 : ret);
 }
 
 /*
@@ -62,6 +81,7 @@ __wt_block_extend(WT_SESSION_IMPL *session, WT_BLOCK *block,
     WT_FH *fh, wt_off_t offset, size_t align_size, bool *release_lockp)
 {
 	WT_DECL_RET;
+	WT_FILE_HANDLE *handle;
 	bool locked;
 
 	/*
@@ -107,7 +127,8 @@ __wt_block_extend(WT_SESSION_IMPL *session, WT_BLOCK *block,
 	 * based on the filesystem type, fall back to ftruncate in that case,
 	 * and remember that ftruncate requires locking.
 	 */
-	if (fh->fallocate_available != WT_FALLOCATE_NOT_AVAILABLE) {
+	handle = fh->handle;
+	if (handle->fallocate != NULL || handle->fallocate_nolock != NULL) {
 		/*
 		 * Release any locally acquired lock if not needed to extend the
 		 * file, extending the file may require updating on-disk file's
@@ -115,7 +136,7 @@ __wt_block_extend(WT_SESSION_IMPL *session, WT_BLOCK *block,
 		 * configure for file extension on systems that require locking
 		 * over the extend call.)
 		 */
-		if (!fh->fallocate_requires_locking && *release_lockp) {
+		if (handle->fallocate_nolock != NULL && *release_lockp) {
 			*release_lockp = locked = false;
 			__wt_spin_unlock(session, &block->live_lock);
 		}
@@ -131,8 +152,7 @@ __wt_block_extend(WT_SESSION_IMPL *session, WT_BLOCK *block,
 		if ((ret = __wt_fallocate(
 		    session, fh, block->size, block->extend_len * 2)) == 0)
 			return (0);
-		if (ret != ENOTSUP)
-			return (ret);
+		WT_RET_ERROR_OK(ret, ENOTSUP);
 	}
 
 	/*
@@ -155,9 +175,8 @@ __wt_block_extend(WT_SESSION_IMPL *session, WT_BLOCK *block,
 	 * The truncate might fail if there's a mapped file (in other words, if
 	 * there's an open checkpoint on the file), that's OK.
 	 */
-	if ((ret = __wt_ftruncate(session, fh, block->extend_size)) == EBUSY)
-		ret = 0;
-	return (ret);
+	WT_RET_BUSY_OK(__wt_ftruncate(session, fh, block->extend_size));
+	return (0);
 }
 
 /*