On Mar 28, 2017, at 8:38 AM, David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Here are my current changes to Eric's statx interface patch. I've made it
> analoguous to the stat command and so it only does statx-of-fd.
>
> I've made the "-m" flag able to take the words "basic" and "all" in
> preference to a number and able to take an octal or hex number as an
> alternative too.
>
> I've dropped the -A and -L flags since it no longer passes a path over.
>
> Finally, I've added a -c flag that causes an fstat() to be done as well and
> the buffers compared as a consistency check.
It probably makes sense to use "-C" to avoid confusion with xfs_io's "-c"
option, and also the "stat -c" option to dump only specific fields (which
may be useful to add at some point in the future as well).
Cheers, Andreas
>
> David
> ---
> diff --git a/io/stat.c b/io/stat.c
> index a7aebcd..961b6d1 100644
> --- a/io/stat.c
> +++ b/io/stat.c
> @@ -189,12 +189,10 @@ statx_help(void)
> " Display extended file status.\n"
> "\n"
> " Options:\n"
> -" -m mask -- Specify the field mask for the statx call (default STATX_ALL)\n"
> -" -A -- Suppress terminal automount traversal\n"
> +" -c -- Compare against fstat/fstatat on the same file/fd\n"
> +" -m mask -- Specify the field mask for the statx call (can also be 'basic' or 'all'; default STATX_ALL)\n"
> " -D -- Don't sync attributes with the server\n"
> " -F -- Force the attributes to be sync'd with the server\n"
> -" -L -- Follow symlinks (statx link target)\n"
> -" -O -- Add only basic stats (STATX_BASIC_STATS) to default mask\n"
> "\n"));
> }
>
> @@ -227,6 +225,65 @@ dump_statx(struct statx *stx)
> }
>
> /*
> + * Compare the contents of a statx struct with that of a stat struct and check
> + * that they're the same.
> + */
> +static int
> +cmp_statx(const struct statx *stx, const struct stat *st)
> +{
> + const char *what = NULL;
> +
> +#define cmp(x) \
> + do { \
> + what = #x; \
> + if (stx->stx_##x != st->st_##x) \
> + goto mismatch; \
> + } while (0)
> +
> + cmp(blksize);
> + cmp(nlink);
> + cmp(uid);
> + cmp(gid);
> + cmp(mode);
> + cmp(ino);
> + cmp(size);
> + cmp(blocks);
> +
> +#define devcmp(x) \
> + do { \
> + what = #x".major"; \
> + if (stx->stx_##x##_major != major(st->st_##x)) \
> + goto mismatch; \
> + what = #x".minor"; \
> + if (stx->stx_##x##_minor != minor(st->st_##x)) \
> + goto mismatch; \
> + } while (0)
> +
> + devcmp(dev);
> + devcmp(rdev);
> +
> +#define timecmp(x) \
> + do { \
> + what = #x".tv_sec"; \
> + if (stx->stx_##x##time.tv_sec != st->st_##x##tim.tv_sec) \
> + goto mismatch; \
> + what = #x".tv_nsec"; \
> + if (stx->stx_##x##time.tv_nsec != st->st_##x##tim.tv_nsec) \
> + goto mismatch; \
> + } while (0)
> +
> + timecmp(a);
> + timecmp(c);
> + timecmp(m);
> +
> + return 0;
> +
> +mismatch:
> + fprintf(stderr, "Mismatch between stat and statx output (%s)\n", what);
> + return -1;
> +}
> +
> +/*
> * options:
> * - input flags - query type
> * - output style for flags (and all else?) (chars vs. hex?)
> @@ -239,16 +296,23 @@ statx_f(
> {
> int c;
> struct statx stx;
> - int atflag = AT_SYMLINK_NOFOLLOW;
> - unsigned int m_mask = 0; /* mask requested with -m */
> - int Oflag = 0, mflag = 0; /* -O or -m was used */
> + struct stat st;
> + int atflag = 0;
> unsigned int mask = STATX_ALL;
> + int compare = 0;
>
> - while ((c = getopt(argc, argv, "m:FDLOA")) != EOF) {
> + while ((c = getopt(argc, argv, "cm:FD")) != EOF) {
> switch (c) {
> + case 'c':
> + compare = 1;
> + break;
> case 'm':
> - m_mask = atoi(optarg);
> - mflag = 1;
> + if (strcmp(optarg, "basic") == 0)
> + mask = STATX_BASIC_STATS;
> + else if (strcmp(optarg, "all") == 0)
> + mask = STATX_ALL;
> + else
> + mask = strtoul(optarg, NULL, 0);
> break;
> case 'F':
> atflag &= ~AT_STATX_SYNC_TYPE;
> @@ -258,38 +322,28 @@ statx_f(
> atflag &= ~AT_STATX_SYNC_TYPE;
> atflag |= AT_STATX_DONT_SYNC;
> break;
> - case 'L':
> - atflag &= ~AT_SYMLINK_NOFOLLOW;
> - break;
> - case 'O':
> - mask = STATX_BASIC_STATS;
> - Oflag = 1;
> - break;
> - case 'A':
> - atflag |= AT_NO_AUTOMOUNT;
> - break;
> default:
> return command_usage(&statx_cmd);
> }
> }
>
> - if (Oflag && mflag) {
> - printf("Cannot specify both -m mask and -O\n");
> - return 0;
> - }
> -
> - /* -m overrides any other mask options */
> - if (mflag)
> - mask = m_mask;
> -
> memset(&stx, 0xbf, sizeof(stx));
> - if (statx(AT_FDCWD, file->name, atflag, mask, &stx) < 0) {
> +
> + if (statx(file->fd, NULL, atflag, mask, &stx) < 0) {
> perror("statx");
> return 0;
> }
>
> - dump_statx(&stx);
> + if (compare) {
> + if (fstat(file->fd, &st) < 0) {
> + perror("fstat");
> + return 0;
> + }
>
> + cmp_statx(&stx, &st);
> + }
> +
> + dump_statx(&stx);
> return 0;
> }
>
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 77ba760..d82f882 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -884,16 +884,23 @@ and the XFS_IOC_GETXATTR system call on the current file. If the
> option is specified, the atime (last access), mtime
> (last modify), and ctime (last change) timestamps are also displayed.
> .TP
> -.BR statx " [ " \-O " | " "\-m mask" " ][ \-" FDLA " ]"
> +.BR statx " [ " "\-m mask" " ][ \-" cFD " ]"
> Extended information from the statx syscall.
> .RS 1.0i
> .PD 0
> .TP 0.4i
> .B \-m mask
> -Specify the field mask for the statx call (default STATX_ALL)
> +Specify the field mask for the statx call as an decimal, hex or octal integer
> +or
> +.RI \" basic "\" or \"" all \"
> +to specify the basic stats that
> +.IR stat ()
> +returns or all the stats known by the header file. All is the default.
> .TP
> -.B \-O
> -Add only basic stats (STATX_BASIC_STATS) to default mask
> +.B \-c
> +Do an
> +.IR fstat ()
> +call as well and compare the buffers.
> .TP
> .B \-F
> Force the attributes to be sync'd with the server
> @@ -901,12 +908,6 @@ Force the attributes to be sync'd with the server
> .B \-D
> Don't sync attributes with the server
> .TP
> -.B \-L
> -Follow symlinks (statx link target)
> -.TP
> -.B \-A
> -Suppress terminal automount traversal
> -.TP
> .RE
> .IP
> .TP
Cheers, Andreas
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