Allow rotate log across different filesystems

* Remove the check for different filesystems
* Act as the "mv" command when rotate log
* Update the mannual
* Fix a bug in the mannual(\f should be \fR)

Upstream-Status: Pending

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
---
 config.c    |    8 --------
 logrotate.8 |    9 ++++-----
 logrotate.c |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/config.c b/config.c
--- a/config.c
+++ b/config.c
@@ -1482,14 +1482,6 @@ duperror:
 				dirName, strerror(errno));
 			goto error;
 		    }
-
-		    if (sb.st_dev != sb2.st_dev) {
-			message(MESS_ERROR,
-				"%s:%d olddir %s and log file %s "
-				"are on different devices\n", configFile,
-				lineNum, newlog->oldDir, newlog->files[i]);
-			goto error;
-		    }
 		}
 	    }
 
diff --git a/logrotate.8 b/logrotate.8
--- a/logrotate.8
+++ b/logrotate.8
@@ -354,10 +354,9 @@ Do not rotate the log if it is empty (this overrides the \fBifempty\fR option).
 .TP
 \fBolddir \fIdirectory\fR
 Logs are moved into \fIdirectory\fR for rotation. The \fIdirectory\fR
-must be on the same physical device as the log file being rotated,
-and is assumed to be relative to the directory holding the log file
-unless an absolute path name is specified. When this option is used all
-old versions of the log end up in \fIdirectory\fR.  This option may be
+is assumed to be relative to the directory holding the log file unless
+an absolute path name is specified. When this option is used all old
+versions of the log end up in \fIdirectory\fR. This option may be
 overridden by the \fBnoolddir\fR option.
 
 .TP
@@ -415,7 +414,7 @@ Log files are rotated when they grow bigger than \fIsize\fR bytes. If
 \fIsize\fR is followed by \fIk\fR, the size is assumed to be in kilobytes.
 If the \fIM\fR is used, the size is in megabytes, and if \fIG\fR is used, the
 size is in gigabytes. So \fBsize 100\fR, \fIsize 100k\fR, \fIsize 100M\fR and
-\fIsize 100G\f are all valid.
+\fIsize 100G\fR are all valid.
 
 .TP
 \fBsharedscripts\fR
diff --git a/logrotate.c b/logrotate.c
--- a/logrotate.c
+++ b/logrotate.c
@@ -625,6 +625,53 @@ int findNeedRotating(struct logInfo *log, int logNum)
     return 0;
 }
 
+/* Act as the "mv" command, if rename failed, then read the old file and
+ * write to new file. The function which invokes the mvFile will use
+ * the strerror(errorno) to handle the error message, so we don't have
+ * to print the error message here */
+
+int mvFile (char *oldName, char *newName, struct logInfo *log)
+{
+    struct stat sbprev;
+    int fd_old, fd_new, n;
+    char buf[BUFSIZ];
+
+    /* Do the rename first */
+    if (!rename(oldName, newName))
+        return 0;
+
+    /* If the errno is EXDEV, then read old file, write newfile and
+     * remove the oldfile */
+    if (errno == EXDEV) {
+        /* Open the old file to read */
+        if ((fd_old = open(oldName, O_RDONLY)) < 0)
+            return 1;
+
+        /* Create the file to write, keep the same attribute as the old file */
+        if (stat(oldName, &sbprev))
+            return 1;
+        else {
+            if ((fd_new = createOutputFile(newName,
+                O_WRONLY | O_CREAT | O_TRUNC, &sbprev)) < 0 )
+                return 1;
+        }
+
+        /* Read and write */
+        while ((n = read(fd_old, buf, BUFSIZ)) > 0)
+            if (write(fd_new, buf, n) != n)
+                return 1;
+
+        if ((close(fd_old) < 0) ||
+            removeLogFile(oldName, log) ||
+            (close(fd_new) < 0))
+            return 1;
+
+        return 0;
+    }
+
+    return 1;
+}
+
 int prerotateSingleLog(struct logInfo *log, int logNum, struct logState *state,
 		       struct logNames *rotNames)
 {
@@ -958,15 +1005,15 @@ int prerotateSingleLog(struct logInfo *log, int logNum, struct logState *state,
 		    rotNames->baseName, i, fileext, compext);
 
 	    message(MESS_DEBUG,
-		    "renaming %s to %s (rotatecount %d, logstart %d, i %d), \n",
+		    "moving %s to %s (rotatecount %d, logstart %d, i %d), \n",
 		    oldName, newName, rotateCount, logStart, i);
 
-	    if (!debug && rename(oldName, newName)) {
+	    if (!debug && mvFile(oldName, newName, log)) {
 		if (errno == ENOENT) {
 		    message(MESS_DEBUG, "old log %s does not exist\n",
 			    oldName);
 		} else {
-		    message(MESS_ERROR, "error renaming %s to %s: %s\n",
+		    message(MESS_ERROR, "error moving %s to %s: %s\n",
 			    oldName, newName, strerror(errno));
 		    hasErrors = 1;
 		}
@@ -1082,11 +1129,11 @@ int rotateSingleLog(struct logInfo *log, int logNum, struct logState *state,
 						log->files[logNum]);
 		}
 #endif
-		message(MESS_DEBUG, "renaming %s to %s\n", log->files[logNum],
+		message(MESS_DEBUG, "moving %s to %s\n", log->files[logNum],
 		    rotNames->finalName);
 	    if (!debug && !hasErrors &&
-		rename(log->files[logNum], rotNames->finalName)) {
-		message(MESS_ERROR, "failed to rename %s to %s: %s\n",
+		mvFile(log->files[logNum], rotNames->finalName, log)) {
+		message(MESS_ERROR, "failed to move %s to %s: %s\n",
 			log->files[logNum], rotNames->finalName,
 			strerror(errno));
 			hasErrors = 1;
-- 
1.7.4.1