svn commit: samba r24164 - in branches: SAMBA_3_0_25/source/smbd SAMBA_3_2/source/smbd SAMBA_3_2_0/source/smbd

[jra at samba.org]

Author: jra
Date: 2007-08-03 16:51:43 +0000 (Fri, 03 Aug 2007)
New Revision: 24164

WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=24164

Log:
Fix for write cache corruption bug reported by Jean-Francois Panisset <panisset at A52.com>.
Awaiting confirmation from reporter.
Jeremy.

Modified:
   branches/SAMBA_3_0_25/source/smbd/fileio.c
   branches/SAMBA_3_2/source/smbd/fileio.c
   branches/SAMBA_3_2_0/source/smbd/fileio.c


Changeset:
Modified: branches/SAMBA_3_0_25/source/smbd/fileio.c
===================================================================
--- branches/SAMBA_3_0_25/source/smbd/fileio.c	2007-08-03 16:06:44 UTC (rev 24163)
+++ branches/SAMBA_3_0_25/source/smbd/fileio.c	2007-08-03 16:51:43 UTC (rev 24164)
@@ -509,29 +509,39 @@
 
 			write_path = 3;
 
-                } else if ( (pos >= wcp->file_size) && 
+                } else if ( (pos >= wcp->file_size) &&
 			    (n == 1) &&
-			    (pos < wcp->offset + 2*wcp->alloc_size) &&
-			    (wcp->file_size == wcp->offset + wcp->data_size)) {
+			    (wcp->file_size == wcp->offset + wcp->data_size) &&
+			    (pos < wcp->file_size + wcp->alloc_size)) {
 
                         /*
-                        +---------------+
-                        | Cached data   |
-                        +---------------+
 
+                End of file ---->|
+
+                 +---------------+---------------+
+                 | Cached data   | Cache buffer  |
+                 +---------------+---------------+
+
+                                 |<------- allocated size ---------------->|
+
                                                          +--------+
                                                          | 1 Byte |
                                                          +--------+
 
 			MS-Office seems to do this a lot to determine if there's enough
 			space on the filesystem to write a new file.
+
+			Change to :
+
+                End of file ---->|
+                                 +-----------------------+--------+
+                                 | Zeroed Cached data    | 1 Byte |
+                                 +-----------------------+--------+
                         */
 
-			SMB_BIG_UINT new_start = wcp->offset + wcp->data_size;
-
 			flush_write_cache(fsp, WRITE_FLUSH);
-			wcp->offset = new_start;
-			wcp->data_size = pos - new_start + 1;
+			wcp->offset = wcp->file_size;
+			wcp->data_size = pos - wcp->file_size + 1;
 			memset(wcp->data, '\0', wcp->data_size);
 			memcpy(wcp->data + wcp->data_size-1, data, 1);
 

Modified: branches/SAMBA_3_2/source/smbd/fileio.c
===================================================================
--- branches/SAMBA_3_2/source/smbd/fileio.c	2007-08-03 16:06:44 UTC (rev 24163)
+++ branches/SAMBA_3_2/source/smbd/fileio.c	2007-08-03 16:51:43 UTC (rev 24164)
@@ -508,29 +508,39 @@
 
 			write_path = 3;
 
-                } else if ( (pos >= wcp->file_size) && 
+                } else if ( (pos >= wcp->file_size) &&
 			    (n == 1) &&
-			    (pos < wcp->offset + 2*wcp->alloc_size) &&
-			    (wcp->file_size == wcp->offset + wcp->data_size)) {
+			    (wcp->file_size == wcp->offset + wcp->data_size) &&
+			    (pos < wcp->file_size + wcp->alloc_size)) {
 
                         /*
-                        +---------------+
-                        | Cached data   |
-                        +---------------+
 
+                End of file ---->|
+
+                 +---------------+---------------+
+                 | Cached data   | Cache buffer  |
+                 +---------------+---------------+
+
+                                 |<------- allocated size ---------------->|
+
                                                          +--------+
                                                          | 1 Byte |
                                                          +--------+
 
 			MS-Office seems to do this a lot to determine if there's enough
 			space on the filesystem to write a new file.
+
+			Change to :
+
+                End of file ---->|
+                                 +-----------------------+--------+
+                                 | Zeroed Cached data    | 1 Byte |
+                                 +-----------------------+--------+
                         */
 
-			SMB_BIG_UINT new_start = wcp->offset + wcp->data_size;
-
 			flush_write_cache(fsp, WRITE_FLUSH);
-			wcp->offset = new_start;
-			wcp->data_size = pos - new_start + 1;
+			wcp->offset = wcp->file_size;
+			wcp->data_size = pos - wcp->file_size + 1;
 			memset(wcp->data, '\0', wcp->data_size);
 			memcpy(wcp->data + wcp->data_size-1, data, 1);
 

Modified: branches/SAMBA_3_2_0/source/smbd/fileio.c
===================================================================
--- branches/SAMBA_3_2_0/source/smbd/fileio.c	2007-08-03 16:06:44 UTC (rev 24163)
+++ branches/SAMBA_3_2_0/source/smbd/fileio.c	2007-08-03 16:51:43 UTC (rev 24164)
@@ -508,29 +508,39 @@
 
 			write_path = 3;
 
-                } else if ( (pos >= wcp->file_size) && 
+                } else if ( (pos >= wcp->file_size) &&
 			    (n == 1) &&
-			    (pos < wcp->offset + 2*wcp->alloc_size) &&
-			    (wcp->file_size == wcp->offset + wcp->data_size)) {
+			    (wcp->file_size == wcp->offset + wcp->data_size) &&
+			    (pos < wcp->file_size + wcp->alloc_size)) {
 
                         /*
-                        +---------------+
-                        | Cached data   |
-                        +---------------+
 
+                End of file ---->|
+
+                 +---------------+---------------+
+                 | Cached data   | Cache buffer  |
+                 +---------------+---------------+
+
+                                 |<------- allocated size ---------------->|
+
                                                          +--------+
                                                          | 1 Byte |
                                                          +--------+
 
 			MS-Office seems to do this a lot to determine if there's enough
 			space on the filesystem to write a new file.
+
+			Change to :
+
+                End of file ---->|
+                                 +-----------------------+--------+
+                                 | Zeroed Cached data    | 1 Byte |
+                                 +-----------------------+--------+
                         */
 
-			SMB_BIG_UINT new_start = wcp->offset + wcp->data_size;
-
 			flush_write_cache(fsp, WRITE_FLUSH);
-			wcp->offset = new_start;
-			wcp->data_size = pos - new_start + 1;
+			wcp->offset = wcp->file_size;
+			wcp->data_size = pos - wcp->file_size + 1;
 			memset(wcp->data, '\0', wcp->data_size);
 			memcpy(wcp->data + wcp->data_size-1, data, 1);