Attachment 6495 Details for Bug 8175 – git-am fix for 3.6.0

[patch] git-am fix for 3.6.0

0001-Fix-bug-8175-smbd-deadlock.patch (text/plain), 9.89 KB, created by Jeremy Allison on 2011-05-27 19:34:44 UTC

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Creator: Jeremy Allison

Created: 2011-05-27 19:34:44 UTC

Size: 9.89 KB

patch

obsolete

>From d16fbf3d8ab05fb5a0336bf5fc7c911fbbe89713 Mon Sep 17 00:00:00 2001
>From: Jeremy Allison <jra@samba.org>
>Date: Fri, 27 May 2011 12:22:04 -0700
>Subject: [PATCH] Fix bug #8175 - smbd deadlock.
>
>Force the open operation (which is the expensive one anyway) to
>acquire and release locks in a way compatible with the more common
>do_lock check.
>
>This should fix the issue in the mundane, non-clusered case. Volker and
>Christian, you'll have to decide if this works well enough for you
>in the clustered case.
>
>Jeremy.
>---
> source3/smbd/open.c |  134 +++++++++++++++++++++++++++++++-------------------
> 1 files changed, 83 insertions(+), 51 deletions(-)
>
>diff --git a/source3/smbd/open.c b/source3/smbd/open.c
>index bb7e6c2..26ea209 100644
>--- a/source3/smbd/open.c
>+++ b/source3/smbd/open.c
>@@ -1055,18 +1055,8 @@ static bool delay_for_exclusive_oplocks(files_struct *fsp,
> 	return false;
> }
> 
>-static bool file_has_brlocks(files_struct *fsp)
>-{
>-	struct byte_range_lock *br_lck;
>-
>-	br_lck = brl_get_locks_readonly(fsp);
>-	if (!br_lck)
>-		return false;
>-
>-	return br_lck->num_locks > 0 ? true : false;
>-}
>-
> static void grant_fsp_oplock_type(files_struct *fsp,
>+				const struct byte_range_lock *br_lck,
> 				int oplock_request,
> 				bool got_level2_oplock,
> 				bool got_a_none_oplock)
>@@ -1084,7 +1074,7 @@ static void grant_fsp_oplock_type(files_struct *fsp,
> 		DEBUG(10,("grant_fsp_oplock_type: oplock type 0x%x on file %s\n",
> 			fsp->oplock_type, fsp_str_dbg(fsp)));
> 		return;
>-	} else if (lp_locking(fsp->conn->params) && file_has_brlocks(fsp)) {
>+	} else if (br_lck && br_lck->num_locks > 0) {
> 		DEBUG(10,("grant_fsp_oplock_type: file %s has byte range locks\n",
> 			fsp_str_dbg(fsp)));
> 		fsp->oplock_type = NO_OPLOCK;
>@@ -1563,6 +1553,50 @@ void remove_deferred_open_entry(struct file_id id, uint64_t mid,
> }
> 
> /****************************************************************************
>+ Release/Acquire locks in order to prevent deadlocks.
>+****************************************************************************/
>+
>+static void free_ordered_locks(struct share_mode_lock *lck,
>+				struct byte_range_lock *br_lck)
>+{
>+	TALLOC_FREE(lck);
>+	TALLOC_FREE(br_lck);
>+}
>+
>+static bool acquire_ordered_locks(TALLOC_CTX *mem_ctx,
>+				files_struct *fsp,
>+				const struct file_id id,
>+				const char *connectpath,
>+				const struct smb_filename *smb_fname,
>+				const struct timespec *p_old_write_time,
>+				struct share_mode_lock **p_lck,
>+				struct byte_range_lock **p_br_lck)
>+{
>+	/* Ordering - we must get the br_lck for this
>+	   file before the share mode. */
>+	if (lp_locking(fsp->conn->params)) {
>+		*p_br_lck = brl_get_locks(mem_ctx, fsp);
>+		if (*p_br_lck == NULL) {
>+			DEBUG(0, ("Could not get br_lock\n"));
>+			return false;
>+		}
>+	}
>+
>+	*p_lck = get_share_mode_lock(mem_ctx,
>+				id,
>+				connectpath,
>+				smb_fname,
>+				p_old_write_time);
>+
>+	if (*p_lck == NULL) {
>+		DEBUG(0, ("Could not get share mode lock\n"));
>+		TALLOC_FREE(*p_br_lck);
>+		return false;
>+	}
>+	return true;
>+}
>+
>+/****************************************************************************
>  Open a file with a share mode. Passed in an already created files_struct *.
> ****************************************************************************/
> 
>@@ -1595,6 +1629,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 	uint32 existing_dos_attributes = 0;
> 	struct timeval request_time = timeval_zero();
> 	struct share_mode_lock *lck = NULL;
>+	struct byte_range_lock *br_lck = NULL;
> 	uint32 open_access_mask = access_mask;
> 	NTSTATUS status;
> 	char *parent_dir;
>@@ -1914,12 +1949,14 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		struct timespec old_write_time = smb_fname->st.st_ex_mtime;
> 		id = vfs_file_id_from_sbuf(conn, &smb_fname->st);
> 
>-		lck = get_share_mode_lock(talloc_tos(), id,
>-					  conn->connectpath,
>-					  smb_fname, &old_write_time);
>-
>-		if (lck == NULL) {
>-			DEBUG(0, ("Could not get share mode lock\n"));
>+		if (!acquire_ordered_locks(talloc_tos(),
>+					fsp,
>+					id,
>+					conn->connectpath,
>+					smb_fname,
>+					&old_write_time,
>+					&lck,
>+					&br_lck)) {
> 			return NT_STATUS_SHARING_VIOLATION;
> 		}
> 
>@@ -1939,7 +1976,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 					oplock_request,
> 					batch_entry)) {
> 			schedule_defer_open(lck, request_time, req);
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			return NT_STATUS_SHARING_VIOLATION;
> 		}
> 
>@@ -1961,18 +1998,19 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 						oplock_request,
> 						exclusive_entry)) {
> 				schedule_defer_open(lck, request_time, req);
>-				TALLOC_FREE(lck);
>+				free_ordered_locks(lck, br_lck);
> 				return NT_STATUS_SHARING_VIOLATION;
> 			}
> 		}
> 
> 		if (NT_STATUS_EQUAL(status, NT_STATUS_DELETE_PENDING)) {
> 			/* DELETE_PENDING is not deferred for a second */
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			return status;
> 		}
> 
> 		grant_fsp_oplock_type(fsp,
>+				br_lck,
>                                 oplock_request,
>                                 got_level2_oplock,
>                                 got_a_none_oplock);
>@@ -1991,7 +2029,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 				if (req == NULL) {
> 					DEBUG(0, ("DOS open without an SMB "
> 						  "request!\n"));
>-					TALLOC_FREE(lck);
>+					free_ordered_locks(lck, br_lck);
> 					return NT_STATUS_INTERNAL_ERROR;
> 				}
> 
>@@ -2009,7 +2047,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 							create_options);
> 
> 				if (NT_STATUS_IS_OK(status)) {
>-					TALLOC_FREE(lck);
>+					free_ordered_locks(lck, br_lck);
> 					if (pinfo) {
> 						*pinfo = FILE_WAS_OPENED;
> 					}
>@@ -2085,7 +2123,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 				}
> 			}
> 
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			if (can_access) {
> 				/*
> 				 * We have detected a sharing violation here
>@@ -2099,12 +2137,11 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		}
> 
> 		/*
>-		 * We exit this block with the share entry *locked*.....
>+		 * We exit this block with the share entry and byte range
>+		 * entry *locked*.....
> 		 */
> 	}
> 
>-	SMB_ASSERT(!file_existed || (lck != NULL));
>-
> 	/*
> 	 * Ensure we pay attention to default ACLs on directories if required.
> 	 */
>@@ -2129,9 +2166,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 			     open_access_mask);
> 
> 	if (!NT_STATUS_IS_OK(fsp_open)) {
>-		if (lck != NULL) {
>-			TALLOC_FREE(lck);
>-		}
>+		free_ordered_locks(lck, br_lck);
> 		return fsp_open;
> 	}
> 
>@@ -2158,15 +2193,14 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 
> 		id = fsp->file_id;
> 
>-		lck = get_share_mode_lock(talloc_tos(), id,
>-					  conn->connectpath,
>-					  smb_fname, &old_write_time);
>-
>-		if (lck == NULL) {
>-			DEBUG(0, ("open_file_ntcreate: Could not get share "
>-				  "mode lock for %s\n",
>-				  smb_fname_str_dbg(smb_fname)));
>-			fd_close(fsp);
>+		if (!acquire_ordered_locks(talloc_tos(),
>+					fsp,
>+					id,
>+					conn->connectpath,
>+					smb_fname,
>+					&old_write_time,
>+					&lck,
>+					&br_lck)) {
> 			return NT_STATUS_SHARING_VIOLATION;
> 		}
> 
>@@ -2186,7 +2220,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 					oplock_request,
> 					batch_entry)) {
> 			schedule_defer_open(lck, request_time, req);
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			fd_close(fsp);
> 			return NT_STATUS_SHARING_VIOLATION;
> 		}
>@@ -2207,7 +2241,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 						oplock_request,
> 						exclusive_entry)) {
> 				schedule_defer_open(lck, request_time, req);
>-				TALLOC_FREE(lck);
>+				free_ordered_locks(lck, br_lck);
> 				fd_close(fsp);
> 				return NT_STATUS_SHARING_VIOLATION;
> 			}
>@@ -2216,8 +2250,6 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		if (!NT_STATUS_IS_OK(status)) {
> 			struct deferred_open_record state;
> 
>-			fd_close(fsp);
>-
> 			state.delayed_for_oplocks = False;
> 			state.id = id;
> 
>@@ -2232,11 +2264,13 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 				defer_open(lck, request_time, timeval_zero(),
> 					   req, &state);
> 			}
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
>+			fd_close(fsp);
> 			return status;
> 		}
> 
> 		grant_fsp_oplock_type(fsp,
>+				br_lck,
>                                 oplock_request,
>                                 got_level2_oplock,
>                                 got_a_none_oplock);
>@@ -2247,14 +2281,12 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 
> 	}
> 
>-	SMB_ASSERT(lck != NULL);
>-
> 	/* Delete streams if create_disposition requires it */
> 	if (file_existed && clear_ads &&
> 	    !is_ntfs_stream_smb_fname(smb_fname)) {
> 		status = delete_all_streams(conn, smb_fname->base_name);
> 		if (!NT_STATUS_IS_OK(status)) {
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			fd_close(fsp);
> 			return status;
> 		}
>@@ -2273,7 +2305,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		ret_flock = SMB_VFS_KERNEL_FLOCK(fsp, share_access, access_mask);
> 		if(ret_flock == -1 ){
> 
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			fd_close(fsp);
> 
> 			return NT_STATUS_SHARING_VIOLATION;
>@@ -2298,7 +2330,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		if ((SMB_VFS_FTRUNCATE(fsp, 0) == -1) ||
> 		    (SMB_VFS_FSTAT(fsp, &smb_fname->st)==-1)) {
> 			status = map_nt_error_from_unix(errno);
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			fd_close(fsp);
> 			return status;
> 		}
>@@ -2369,7 +2401,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		if (!NT_STATUS_IS_OK(status)) {
> 			/* Remember to delete the mode we just added. */
> 			del_share_mode(lck, fsp);
>-			TALLOC_FREE(lck);
>+			free_ordered_locks(lck, br_lck);
> 			fd_close(fsp);
> 			return status;
> 		}
>@@ -2452,7 +2484,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 		del_deferred_open_entry(lck, req->mid,
> 					sconn_server_id(req->sconn));
> 	}
>-	TALLOC_FREE(lck);
>+	free_ordered_locks(lck, br_lck);
> 
> 	return NT_STATUS_OK;
> }
>-- 
>1.7.3.1
>

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Attachments on bug 8175: 6495 | 6511