1 files changed, 78 insertions, 44 deletions

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index 5d18ad10c27f..8f714406528d 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -1,31 +1,16 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
  * io.c
  *
  * Buffer cache handling
  *
  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
  */
 
 #include <linux/fs.h>
 #include <linux/types.h>
 #include <linux/highmem.h>
+#include <linux/bio.h>
 
 #include <cluster/masklog.h>
 
@@ -79,7 +64,7 @@ int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
 
 	get_bh(bh); /* for end_buffer_write_sync() */
 	bh->b_end_io = end_buffer_write_sync;
-	submit_bh(WRITE, bh);
+	submit_bh(REQ_OP_WRITE, bh);
 
 	wait_on_buffer(bh);
 
@@ -90,7 +75,6 @@ int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
 		 * information for this bh as it's not marked locally
 		 * uptodate. */
 		ret = -EIO;
-		put_bh(bh);
 		mlog_errno(ret);
 	}
 
@@ -99,25 +83,34 @@ out:
 	return ret;
 }
 
+/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
+ * will be easier to handle read failure.
+ */
 int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
 			   unsigned int nr, struct buffer_head *bhs[])
 {
 	int status = 0;
 	unsigned int i;
 	struct buffer_head *bh;
+	int new_bh = 0;
 
 	trace_ocfs2_read_blocks_sync((unsigned long long)block, nr);
 
 	if (!nr)
 		goto bail;
 
+	/* Don't put buffer head and re-assign it to NULL if it is allocated
+	 * outside since the caller can't be aware of this alternation!
+	 */
+	new_bh = (bhs[0] == NULL);
+
 	for (i = 0 ; i < nr ; i++) {
 		if (bhs[i] == NULL) {
 			bhs[i] = sb_getblk(osb->sb, block++);
 			if (bhs[i] == NULL) {
-				status = -EIO;
+				status = -ENOMEM;
 				mlog_errno(status);
-				goto bail;
+				break;
 			}
 		}
 		bh = bhs[i];
@@ -140,22 +133,43 @@ int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
 
 		lock_buffer(bh);
 		if (buffer_jbd(bh)) {
+#ifdef CATCH_BH_JBD_RACES
 			mlog(ML_ERROR,
 			     "block %llu had the JBD bit set "
 			     "while I was in lock_buffer!",
 			     (unsigned long long)bh->b_blocknr);
 			BUG();
+#else
+			unlock_buffer(bh);
+			continue;
+#endif
 		}
 
-		clear_buffer_uptodate(bh);
 		get_bh(bh); /* for end_buffer_read_sync() */
 		bh->b_end_io = end_buffer_read_sync;
-		submit_bh(READ, bh);
+		submit_bh(REQ_OP_READ, bh);
 	}
 
+read_failure:
 	for (i = nr; i > 0; i--) {
 		bh = bhs[i - 1];
 
+		if (unlikely(status)) {
+			if (new_bh && bh) {
+				/* If middle bh fails, let previous bh
+				 * finish its read and then put it to
+				 * avoid bh leak
+				 */
+				if (!buffer_jbd(bh))
+					wait_on_buffer(bh);
+				put_bh(bh);
+				bhs[i - 1] = NULL;
+			} else if (bh && buffer_uptodate(bh)) {
+				clear_buffer_uptodate(bh);
+			}
+			continue;
+		}
+
 		/* No need to wait on the buffer if it's managed by JBD. */
 		if (!buffer_jbd(bh))
 			wait_on_buffer(bh);
@@ -165,8 +179,7 @@ int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
 			 * so we can safely record this and loop back
 			 * to cleanup the other buffers. */
 			status = -EIO;
-			put_bh(bh);
-			bhs[i - 1] = NULL;
+			goto read_failure;
 		}
 	}
 
@@ -174,6 +187,9 @@ bail:
 	return status;
 }
 
+/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
+ * will be easier to handle read failure.
+ */
 int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 		      struct buffer_head *bhs[], int flags,
 		      int (*validate)(struct super_block *sb,
@@ -183,6 +199,7 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 	int i, ignore_cache = 0;
 	struct buffer_head *bh;
 	struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
+	int new_bh = 0;
 
 	trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
 
@@ -208,15 +225,20 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 		goto bail;
 	}
 
+	/* Don't put buffer head and re-assign it to NULL if it is allocated
+	 * outside since the caller can't be aware of this alternation!
+	 */
+	new_bh = (bhs[0] == NULL);
+
 	ocfs2_metadata_cache_io_lock(ci);
 	for (i = 0 ; i < nr ; i++) {
 		if (bhs[i] == NULL) {
 			bhs[i] = sb_getblk(sb, block++);
 			if (bhs[i] == NULL) {
-				ocfs2_metadata_cache_io_unlock(ci);
-				status = -EIO;
+				status = -ENOMEM;
 				mlog_errno(status);
-				goto bail;
+				/* Don't forget to put previous bh! */
+				break;
 			}
 		}
 		bh = bhs[i];
@@ -301,22 +323,38 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 				continue;
 			}
 
-			clear_buffer_uptodate(bh);
 			get_bh(bh); /* for end_buffer_read_sync() */
 			if (validate)
 				set_buffer_needs_validate(bh);
 			bh->b_end_io = end_buffer_read_sync;
-			submit_bh(READ, bh);
+			submit_bh(REQ_OP_READ, bh);
 			continue;
 		}
 	}
 
-	status = 0;
-
+read_failure:
 	for (i = (nr - 1); i >= 0; i--) {
 		bh = bhs[i];
 
 		if (!(flags & OCFS2_BH_READAHEAD)) {
+			if (unlikely(status)) {
+				/* Clear the buffers on error including those
+				 * ever succeeded in reading
+				 */
+				if (new_bh && bh) {
+					/* If middle bh fails, let previous bh
+					 * finish its read and then put it to
+					 * avoid bh leak
+					 */
+					if (!buffer_jbd(bh))
+						wait_on_buffer(bh);
+					put_bh(bh);
+					bhs[i] = NULL;
+				} else if (bh && buffer_uptodate(bh)) {
+					clear_buffer_uptodate(bh);
+				}
+				continue;
+			}
 			/* We know this can't have changed as we hold the
 			 * owner sem. Avoid doing any work on the bh if the
 			 * journal has it. */
@@ -331,9 +369,8 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 				 * for this bh as it's not marked locally
 				 * uptodate. */
 				status = -EIO;
-				put_bh(bh);
-				bhs[i] = NULL;
-				continue;
+				clear_buffer_needs_validate(bh);
+				goto read_failure;
 			}
 
 			if (buffer_needs_validate(bh)) {
@@ -343,18 +380,16 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 				BUG_ON(buffer_jbd(bh));
 				clear_buffer_needs_validate(bh);
 				status = validate(sb, bh);
-				if (status) {
-					put_bh(bh);
-					bhs[i] = NULL;
-					continue;
-				}
+				if (status)
+					goto read_failure;
 			}
 		}
 
 		/* Always set the buffer in the cache, even if it was
 		 * a forced read, or read-ahead which hasn't yet
 		 * completed. */
-		ocfs2_set_buffer_uptodate(ci, bh);
+		if (bh)
+			ocfs2_set_buffer_uptodate(ci, bh);
 	}
 	ocfs2_metadata_cache_io_unlock(ci);
 
@@ -414,13 +449,12 @@ int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
 	get_bh(bh); /* for end_buffer_write_sync() */
 	bh->b_end_io = end_buffer_write_sync;
 	ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
-	submit_bh(WRITE, bh);
+	submit_bh(REQ_OP_WRITE, bh);
 
 	wait_on_buffer(bh);
 
 	if (!buffer_uptodate(bh)) {
 		ret = -EIO;
-		put_bh(bh);
 		mlog_errno(ret);
 	}