From: Darrick J. Wong <djwong@xxxxxxxxxx>
Update this utility to use fallocate to preallocate/reserve space to a
file so that we're not so dependent on legacy XFS ioctls.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
src/alloc.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 55 insertions(+), 11 deletions(-)
diff --git a/src/alloc.c b/src/alloc.c
index 57a91f81..4a446ca8 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -118,6 +118,50 @@ bozo!
}
}
+#ifdef HAVE_FALLOCATE
+# define USE_LINUX_PREALLOCATE
+enum linux_opno {
+ FREESP = 0,
+ ALLOCSP,
+ UNRESVSP,
+ RESVSP,
+};
+
+/* emulate the irix preallocation functions with linux vfs calls */
+static int
+linux_preallocate(
+ int fd,
+ enum linux_opno opno,
+ const struct flock64 *f)
+{
+ struct stat sbuf;
+ int ret;
+
+ assert(f->l_whence == SEEK_SET);
+
+ switch (opno) {
+ case FREESP:
+ return ftruncate(fd, f->l_start);
+ case ALLOCSP:
+ ret = fstat(fd, &sbuf);
+ if (ret)
+ return ret;
+
+ return fallocate(fd, 0, sbuf.st_size,
+ f->l_start - sbuf.st_size);
+ case UNRESVSP:
+ return fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ f->l_start, f->l_len);
+ case RESVSP:
+ return fallocate(fd, FALLOC_FL_KEEP_SIZE, f->l_start, f->l_len);
+ }
+
+ /* should never get here */
+ errno = EINVAL;
+ return -1;
+}
+#endif
+
int
main(int argc, char **argv)
{
@@ -136,23 +180,23 @@ main(int argc, char **argv)
"resvsp" };
int opno;
- /* Assume that if we have FREESP64 then we have the rest */
-#ifdef XFS_IOC_FREESP64
+#if defined(HAVE_FALLOCATE)
+ /* see static function above */
+#elif defined(XFS_IOC_FREESP64)
#define USE_XFSCTL
+ /* Assume that if we have FREESP64 then we have the rest */
static int optab[] = { XFS_IOC_FREESP64,
XFS_IOC_ALLOCSP64,
XFS_IOC_UNRESVSP64,
XFS_IOC_RESVSP64 };
-#else
-#ifdef F_FREESP64
+#elif defined(F_FREESP64)
#define USE_FCNTL
static int optab[] = { F_FREESP64,
F_ALLOCSP64,
F_UNRESVSP64,
F_RESVSP64 };
#else
-bozo!
-#endif
+# error Dont know how to preallocate space!
#endif
int rflag = 0;
struct statvfs64 svfs;
@@ -311,14 +355,14 @@ bozo!
opnames[opno], (long long)off, (long long)len);
f.l_len = len;
-#ifdef USE_XFSCTL
+#if defined(USE_LINUX_PREALLOCATE)
+ c = linux_preallocate(fd, opno, &f);
+#elif defined(USE_XFSCTL)
c = xfsctl(filename, fd, optab[opno], &f);
-#else
-#ifdef USE_FCNTL
+#elif defined(USE_FCNTL)
c = fcntl(fd, optab[opno], &f);
#else
-bozo!
-#endif
+# error Dont know how to preallocate space!
#endif
if (c < 0) {
perror(opnames[opno]);
