Roland McGrath <rol...@hack.frob.com> wrote:
> The substance of the change seems fine. It needs a proper ChangeLog entry.
> See the glibc wiki for full instructions on posting patches.
>
> > + struct stat64 st;
> > + int r = fd >= 0 ? fstat64(fd, &st) : stat64(name, &st);
>
> Put space before paren in those calls.
> It's shorter and more common to invert the sense and use < 0.
>
> > + if (r == -1)
> > return 0;
>
> There is no need for a variable here.
> Also, it's more usual to test for failure with < 0:
>
> if ((fd < 0 ? stat64 (name, &st) : fstat64 (fd, &st)) < 0)
> return 0;
Thanks for the comments, here is an updated patch with your suggestions
and ChangeLog entry:
------------------------------- 8< ----------------------------
>From ed01f553461357e6c9ef40efd2910d897d72ddea Mon Sep 17 00:00:00 2001
From: Eric Wong <normalper...@yhbt.net>
Date: Fri, 1 Feb 2013 01:55:27 +0000
Subject: [PATCH] avoid stat/fstat in statvfs/fstatvfs
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.
2013-02-07 Eric Wong <normalper...@yhbt.net>
* 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,
update all callers.
diff --git a/sysdeps/unix/sysv/linux/fstatvfs.c
b/sysdeps/unix/sysv/linux/fstatvfs.c
index 8f08d14..6a03a87 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 2dcef94..3b49ab2 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 4cd4f04..1e1ad5f 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;
@@ -153,7 +155,7 @@ __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. */
@@ -216,14 +218,13 @@ __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;
@@ -266,7 +267,7 @@ 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 5d91d85..09b53f7 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 42c1089..cd9a7ca 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;
}
--
Eric Wong
