On 08/11/2014 10:30 PM, John Ferlan wrote:
> Currently virStorageFileResize() function uses build conditionals to
> choose either the posix_fallocate() or mmap() with no fallback in order
> to preallocate the space in the newly resized file.
>
> This patch will modify the logic in order to allow fallbacks in the event
> that posix_fallocate() or the sys_fallocate syscall() doesn't work properly.
> The fallback will be to use the slow safewrite of zero filled buffers to
> the file.
>
> Use the virFileFdPosixFallocate() rather than a local function.
>
> Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
> ---
> src/util/virstoragefile.c | 52 +++++++++++++++++++++++++++++++----------------
> 1 file changed, 34 insertions(+), 18 deletions(-)
>
> diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
> index 5b6b2f5..4d37de1 100644
> --- a/src/util/virstoragefile.c
> +++ b/src/util/virstoragefile.c
> @@ -1086,6 +1086,39 @@ virStorageFileChainGetBroken(virStorageSourcePtr chain,
> return 0;
> }
>
> +static int
> +resizeSysFallocate(const char *path,
> + int fd,
> + off_t offset,
> + off_t len)
> +{
> + int rc = -1;
> +#if HAVE_SYS_SYSCALL_H && defined(SYS_fallocate)
> + if ((rc = syscall(SYS_fallocate, fd, 0, offset, len)) != 0) {
> + virReportSystemError(errno,
> + _("Failed to pre-allocate space for "
> + "file '%s'"), path);
I think this should not log an error, since we have a fallback.
VIR_DEBUG maybe?
> + }
> +#endif
> + return rc;
> +}
> +
> +static int
> +doResize(const char *path,
> + int fd,
> + off_t offset,
> + off_t len)
> +{
> + if (virFileFdPosixFallocate(fd, offset, len) == 0 ||
> + resizeSysFallocate(path, fd, offset, len) == 0 ||
> + safezero(fd, offset, len) == 0)
> + return 0;
> +
> + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
> + _("preallocate is not supported on this platform"));
> + return -1;
safezero is always supported. And this function should do:
return safezero(fd, offset, len);
> +}
> +
>
> /**
> * virStorageFileResize:
> @@ -1113,25 +1146,8 @@ virStorageFileResize(const char *path,
> }
>
> if (pre_allocate) {
> -#if HAVE_POSIX_FALLOCATE
> - if ((rc = posix_fallocate(fd, offset, len)) != 0) {
> - virReportSystemError(rc,
> - _("Failed to pre-allocate space for "
> - "file '%s'"), path);
> - goto cleanup;
> - }
> -#elif HAVE_SYS_SYSCALL_H && defined(SYS_fallocate)
> - if (syscall(SYS_fallocate, fd, 0, offset, len) != 0) {
> - virReportSystemError(errno,
> - _("Failed to pre-allocate space for "
> - "file '%s'"), path);
> + if (doResize(path, fd, offset, len) < 0)
> goto cleanup;
> - }
> -#else
> - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
> - _("preallocate is not supported on this platform"));
> - goto cleanup;
> -#endif
> } else {
> if (ftruncate(fd, capacity) < 0) {
> virReportSystemError(errno,
>
Attachment:
signature.asc
Description: OpenPGP digital signature
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list