2727#include "receivelog.h"
2828#include "streamutil.h"
2929
30+ #include <sys/stat.h>
3031#include <sys/time.h>
3132#include <sys/types.h>
3233#include <unistd.h>
@@ -41,24 +42,128 @@ const XLogRecPtr InvalidXLogRecPtr = {0, 0};
4142 * Open a new WAL file in the specified directory. Store the name
4243 * (not including the full directory) in namebuf. Assumes there is
4344 * enough room in this buffer...
45+ *
46+ * The file will be padded to 16Mb with zeroes.
4447 */
4548static int
4649open_walfile (XLogRecPtr startpoint , uint32 timeline , char * basedir , char * namebuf )
4750{
4851 int f ;
4952 char fn [MAXPGPATH ];
53+ struct stat statbuf ;
54+ char * zerobuf ;
55+ int bytes ;
5056
5157 XLogFileName (namebuf , timeline , startpoint .xlogid ,
5258 startpoint .xrecoff / XLOG_SEG_SIZE );
5359
54- snprintf (fn , sizeof (fn ), "%s/%s" , basedir , namebuf );
55- f = open (fn , O_WRONLY | O_CREAT | O_EXCL | PG_BINARY , 0666 );
60+ snprintf (fn , sizeof (fn ), "%s/%s.partial " , basedir , namebuf );
61+ f = open (fn , O_WRONLY | O_CREAT | PG_BINARY , S_IRUSR | S_IWUSR );
5662 if (f == -1 )
63+ {
5764 fprintf (stderr , _ ("%s: Could not open WAL segment %s: %s\n" ),
58- progname , namebuf , strerror (errno ));
65+ progname , fn , strerror (errno ));
66+ return -1 ;
67+ }
68+
69+ /*
70+ * Verify that the file is either empty (just created), or a complete
71+ * XLogSegSize segment. Anything in between indicates a corrupt file.
72+ */
73+ if (fstat (f , & statbuf ) != 0 )
74+ {
75+ fprintf (stderr , _ ("%s: could not stat WAL segment %s: %s\n" ),
76+ progname , fn , strerror (errno ));
77+ close (f );
78+ return -1 ;
79+ }
80+ if (statbuf .st_size == XLogSegSize )
81+ return f ; /* File is open and ready to use */
82+ if (statbuf .st_size != 0 )
83+ {
84+ fprintf (stderr , _ ("%s: WAL segment %s is %d bytes, should be 0 or %d\n" ),
85+ progname , fn , (int ) statbuf .st_size , XLogSegSize );
86+ close (f );
87+ return -1 ;
88+ }
89+
90+ /* New, empty, file. So pad it to 16Mb with zeroes */
91+ zerobuf = xmalloc0 (XLOG_BLCKSZ );
92+ for (bytes = 0 ; bytes < XLogSegSize ; bytes += XLOG_BLCKSZ )
93+ {
94+ if (write (f , zerobuf , XLOG_BLCKSZ ) != XLOG_BLCKSZ )
95+ {
96+ fprintf (stderr , _ ("%s: could not pad WAL segment %s: %s\n" ),
97+ progname , fn , strerror (errno ));
98+ close (f );
99+ unlink (fn );
100+ return -1 ;
101+ }
102+ }
103+ free (zerobuf );
104+
105+ if (lseek (f , SEEK_SET , 0 ) != 0 )
106+ {
107+ fprintf (stderr , _ ("%s: could not seek back to beginning of WAL segment %s: %s\n" ),
108+ progname , fn , strerror (errno ));
109+ close (f );
110+ return -1 ;
111+ }
59112 return f ;
60113}
61114
115+ static bool
116+ close_walfile (int walfile , char * basedir , char * walname )
117+ {
118+ off_t currpos = lseek (walfile , 0 , SEEK_CUR );
119+
120+ if (currpos == -1 )
121+ {
122+ fprintf (stderr , _ ("%s: could not get current position in file %s: %s\n" ),
123+ progname , walname , strerror (errno ));
124+ return false;
125+ }
126+
127+ if (fsync (walfile ) != 0 )
128+ {
129+ fprintf (stderr , _ ("%s: could not fsync file %s: %s\n" ),
130+ progname , walname , strerror (errno ));
131+ return false;
132+ }
133+
134+ if (close (walfile ) != 0 )
135+ {
136+ fprintf (stderr , _ ("%s: could not close file %s: %s\n" ),
137+ progname , walname , strerror (errno ));
138+ return false;
139+ }
140+
141+ /*
142+ * Rename the .partial file only if we've completed writing the
143+ * whole segment.
144+ */
145+ if (currpos == XLOG_SEG_SIZE )
146+ {
147+ char oldfn [MAXPGPATH ];
148+ char newfn [MAXPGPATH ];
149+
150+ snprintf (oldfn , sizeof (oldfn ), "%s/%s.partial" , basedir , walname );
151+ snprintf (newfn , sizeof (newfn ), "%s/%s" , basedir , walname );
152+ if (rename (oldfn , newfn ) != 0 )
153+ {
154+ fprintf (stderr , _ ("%s: could not rename file %s: %s\n" ),
155+ progname , walname , strerror (errno ));
156+ return false;
157+ }
158+ }
159+ else
160+ fprintf (stderr , _ ("%s: not renaming %s, segment is not complete.\n" ),
161+ progname , walname );
162+
163+ return true;
164+ }
165+
166+
62167/*
63168 * Local version of GetCurrentTimestamp(), since we are not linked with
64169 * backend code.
@@ -178,10 +283,8 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
178283 if (stream_continue && stream_continue ())
179284 {
180285 if (walfile != -1 )
181- {
182- fsync (walfile );
183- close (walfile );
184- }
286+ /* Potential error message is written by close_walfile */
287+ return close_walfile (walfile , basedir , current_walfile_name );
185288 return true;
186289 }
187290
@@ -360,8 +463,10 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
360463 /* Did we reach the end of a WAL segment? */
361464 if (blockpos .xrecoff % XLOG_SEG_SIZE == 0 )
362465 {
363- fsync (walfile );
364- close (walfile );
466+ if (!close_walfile (walfile , basedir , current_walfile_name ))
467+ /* Error message written in close_walfile() */
468+ return false;
469+
365470 walfile = -1 ;
366471 xlogoff = 0 ;
367472
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