Avoid stat/fstat in statvfs/fstatvfs (BZ #15132)

Delay the use of stat/fstat until stat data is required.  When the
kernel returns ST_VALID, stat data is not used by __internal_statvfs.

7 files changed, 44 insertions, 37 deletions

diff --git a/ChangeLog b/ChangeLog
index 8ffe903d6e..a93d36717a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2014-05-29  Eric Wong  <normalperson@yhbt.net>
+
+	[BZ #15132]
+	* sysdeps/unix/sysv/linux/internal_statvfs.c (__statvfs_getflags):
+	Call fstat64 or stat64 internally, depending on arguments passed.
+	Replace stat buffer argument with file descriptor argument.
+	(INTERNAL_STATVFS): Update arguments to match __statvfs_getflags.
+	* sysdeps/unix/sysv/linux/fstatvfs.c (fstatvfs):
+	Pass fd to __internal_statvfs instead of calling fstat64.
+	* sysdeps/unix/sysv/linux/fstatvfs64.c (__fstatvfs64):
+	Pass fd to __internal_statvfs64 instead of calling fstat64.
+	* sysdeps/unix/sysv/linux/statvfs.c (statvfs):
+	Pass -1 to __internal_statvfs instead of calling stat64.
+	* sysdeps/unix/sysv/linux/statvfs64.c (__statvfs64):
+	Pass -1 to __internal_statvfs64 instead of calling stat64.
+
 2014-05-28  Roland McGrath  <roland@hack.frob.com>
 
 	* sysdeps/unix/sysv/linux/sh/clone.S: Deconditionalize the code
diff --git a/NEWS b/NEWS
index 6a0c222cbd..52d5714d44 100644
--- a/NEWS
+++ b/NEWS
@@ -9,16 +9,16 @@ Version 2.20
 
 * The following bugs are resolved with this release:
 
-  6804, 9894, 12994, 13347, 13651, 14308, 14770, 15119, 15347, 15514, 15804,
-  15894, 16002, 16064, 16198, 16284, 16348, 16349, 16357, 16362, 16447,
-  16516, 16532, 16545, 16564, 16574, 16599, 16600, 16609, 16610, 16611,
-  16613, 16619, 16623, 16629, 16632, 16634, 16639, 16642, 16648, 16649,
-  16670, 16674, 16677, 16680, 16683, 16689, 16695, 16701, 16706, 16707,
-  16712, 16713, 16714, 16724, 16731, 16739, 16740, 16743, 16754, 16758,
-  16759, 16760, 16770, 16786, 16789, 16791, 16796, 16799, 16800, 16815,
-  16823, 16824, 16831, 16838, 16849, 16854, 16876, 16877, 16878, 16885,
-  16888, 16890, 16912, 16915, 16916, 16917, 16922, 16927, 16928, 16932,
-  16943, 16958, 16966, 16967, 16965, 16977, 16978, 16984, 16990.
+  6804, 9894, 12994, 13347, 13651, 14308, 14770, 15119, 15132, 15347, 15514,
+  15804, 15894, 16002, 16064, 16198, 16284, 16348, 16349, 16357, 16362,
+  16447, 16516, 16532, 16545, 16564, 16574, 16599, 16600, 16609, 16610,
+  16611, 16613, 16619, 16623, 16629, 16632, 16634, 16639, 16642, 16648,
+  16649, 16670, 16674, 16677, 16680, 16683, 16689, 16695, 16701, 16706,
+  16707, 16712, 16713, 16714, 16724, 16731, 16739, 16740, 16743, 16754,
+  16758, 16759, 16760, 16770, 16786, 16789, 16791, 16796, 16799, 16800,
+  16815, 16823, 16824, 16831, 16838, 16849, 16854, 16876, 16877, 16878,
+  16885, 16888, 16890, 16912, 16915, 16916, 16917, 16922, 16927, 16928,
+  16932, 16943, 16958, 16966, 16967, 16965, 16977, 16978, 16984, 16990.
 
 * The minimum Linux kernel version that this version of the GNU C Library
   can be used with is 2.6.32.
diff --git a/sysdeps/unix/sysv/linux/fstatvfs.c b/sysdeps/unix/sysv/linux/fstatvfs.c
index da1f27e721..689ab7ad10 100644
--- a/sysdeps/unix/sysv/linux/fstatvfs.c
+++ b/sysdeps/unix/sysv/linux/fstatvfs.c
@@ -22,7 +22,7 @@
 #include <sys/statvfs.h>
 
 extern void __internal_statvfs (const char *name, struct statvfs *buf,
-				struct statfs *fsbuf, struct stat64 *st);
+				struct statfs *fsbuf, int fd);
 
 
 int
@@ -36,7 +36,7 @@ fstatvfs (int fd, struct statvfs *buf)
     return -1;
 
   /* Convert the result.  */
-  __internal_statvfs (NULL, buf, &fsbuf, fstat64 (fd, &st) == -1 ? NULL : &st);
+  __internal_statvfs (NULL, buf, &fsbuf, fd);
 
   /* We signal success if the statfs call succeeded.  */
   return 0;
diff --git a/sysdeps/unix/sysv/linux/fstatvfs64.c b/sysdeps/unix/sysv/linux/fstatvfs64.c
index dd10c1ffec..006b0591ba 100644
--- a/sysdeps/unix/sysv/linux/fstatvfs64.c
+++ b/sysdeps/unix/sysv/linux/fstatvfs64.c
@@ -25,7 +25,7 @@
 
 
 extern void __internal_statvfs64 (const char *name, struct statvfs64 *buf,
-				  struct statfs64 *fsbuf, struct stat64 *st);
+				  struct statfs64 *fsbuf, int fd);
 
 
 /* Return information about the filesystem on which FD resides.  */
@@ -60,12 +60,8 @@ __fstatvfs64 (int fd, struct statvfs64 *buf)
 #endif
 
   if (res == 0)
-    {
-      /* Convert the result.  */
-      struct stat64 st;
-      __internal_statvfs64 (NULL, buf, &fsbuf,
-			    fstat64 (fd, &st) == -1 ? NULL : &st);
-    }
+    /* Convert the result.  */
+    __internal_statvfs64 (NULL, buf, &fsbuf, fd);
 
   return res;
 }
diff --git a/sysdeps/unix/sysv/linux/internal_statvfs.c b/sysdeps/unix/sysv/linux/internal_statvfs.c
index 2424c138ac..d71ed0cd72 100644
--- a/sysdeps/unix/sysv/linux/internal_statvfs.c
+++ b/sysdeps/unix/sysv/linux/internal_statvfs.c
@@ -43,9 +43,11 @@
 
 # ifndef __ASSUME_STATFS_F_FLAGS
 int
-__statvfs_getflags (const char *name, int fstype, struct stat64 *st)
+__statvfs_getflags (const char *name, int fstype, int fd)
 {
-  if (st == NULL)
+  struct stat64 st;
+
+  if ((fd < 0 ? stat64 (name, &st) : fstat64 (fd, &st)) < 0)
     return 0;
 
   const char *fsname = NULL;
@@ -159,7 +161,7 @@ __statvfs_getflags (const char *name, int fstype, struct stat64 *st)
 	  /* Find out about the device the current entry is for.  */
 	  struct stat64 fsst;
 	  if (stat64 (mntbuf.mnt_dir, &fsst) >= 0
-	      && st->st_dev == fsst.st_dev)
+	      && st.st_dev == fsst.st_dev)
 	    {
 	      /* Bingo, we found the entry for the device FD is on.
 		 Now interpret the option string.  */
@@ -222,14 +224,13 @@ __statvfs_getflags (const char *name, int fstype, struct stat64 *st)
 }
 # endif
 #else
-extern int __statvfs_getflags (const char *name, int fstype,
-			       struct stat64 *st);
+extern int __statvfs_getflags (const char *name, int fstype, int fd);
 #endif
 
 
 void
 INTERNAL_STATVFS (const char *name, struct STATVFS *buf,
-		  struct STATFS *fsbuf, struct stat64 *st)
+		  struct STATFS *fsbuf, int fd)
 {
   /* Now fill in the fields we have information for.  */
   buf->f_bsize = fsbuf->f_bsize;
@@ -272,7 +273,7 @@ INTERNAL_STATVFS (const char *name, struct STATVFS *buf,
        the /etc/mtab file and search for the entry which matches the given
        file.  The way we can test for matching filesystem is using the
        device number.  */
-    buf->f_flag = __statvfs_getflags (name, fsbuf->f_type, st);
+    buf->f_flag = __statvfs_getflags (name, fsbuf->f_type, fd);
   else
 #endif
     buf->f_flag = fsbuf->f_flags ^ ST_VALID;
diff --git a/sysdeps/unix/sysv/linux/statvfs.c b/sysdeps/unix/sysv/linux/statvfs.c
index 8a3df97c76..14279613b0 100644
--- a/sysdeps/unix/sysv/linux/statvfs.c
+++ b/sysdeps/unix/sysv/linux/statvfs.c
@@ -22,22 +22,20 @@
 #include <sys/statvfs.h>
 
 extern void __internal_statvfs (const char *name, struct statvfs *buf,
-				struct statfs *fsbuf, struct stat64 *st);
+				struct statfs *fsbuf, int fd);
 
 
 int
 statvfs (const char *file, struct statvfs *buf)
 {
   struct statfs fsbuf;
-  struct stat64 st;
 
   /* Get as much information as possible from the system.  */
   if (__statfs (file, &fsbuf) < 0)
     return -1;
 
   /* Convert the result.  */
-  __internal_statvfs (file, buf, &fsbuf,
-		      stat64 (file, &st) == -1 ? NULL : &st);
+  __internal_statvfs (file, buf, &fsbuf, -1);
 
   /* We signal success if the statfs call succeeded.  */
   return 0;
diff --git a/sysdeps/unix/sysv/linux/statvfs64.c b/sysdeps/unix/sysv/linux/statvfs64.c
index e33e923a05..0ec8524a44 100644
--- a/sysdeps/unix/sysv/linux/statvfs64.c
+++ b/sysdeps/unix/sysv/linux/statvfs64.c
@@ -26,7 +26,7 @@
 
 
 extern void __internal_statvfs64 (const char *name, struct statvfs64 *buf,
-				  struct statfs64 *fsbuf, struct stat64 *st);
+				  struct statfs64 *fsbuf, int fd);
 
 
 /* Return information about the filesystem on which FILE resides.  */
@@ -61,12 +61,8 @@ __statvfs64 (const char *file, struct statvfs64 *buf)
 #endif
 
   if (res == 0)
-    {
-      /* Convert the result.  */
-      struct stat64 st;
-      __internal_statvfs64 (file, buf, &fsbuf,
-			    stat64 (file, &st) == -1 ? NULL : &st);
-    }
+    /* Convert the result.  */
+    __internal_statvfs64 (file, buf, &fsbuf, -1);
 
   return res;
 }