[PATCH] xfs_io: implement 'inode' command V5
Brian Foster
bfoster at redhat.com
Mon Nov 30 07:22:19 CST 2015
On Thu, Nov 26, 2015 at 04:46:35PM +0100, Carlos Maiolino wrote:
> Implements a new xfs_io command, named 'inode', which is supposed to be
> used to query information about inode's existence and its physical size
> in the filesystem.
>
> Supported options:
>
> Default: -- Return true(1) or false(0) if any inode greater than
> 32bits has been found in the filesystem
> -v -- verbose mode
> Display the number and the physical size (in bits)
> of the largest inode in the filesystem
> [num] -- Return true(1) or false(0) if the inode [num] is in use
> -n [num] -- Return the next valid inode after [num]
>
> No manpage sent because there were changes in the supported options and its
> descriptions.
> I'll send the manpage after the options and descriptions are reviewed.
>
> - Changelog
>
> V3:
> - Merge all 3 patches from the V2 together in a single patch
> - Rework of '-n [num]' and 'num' only arguments algorithm
> - Argument -n now relies on bulkreq.count to check for next inodes, not
> on bstat.bs_ino anymore.
> - for loop in ret_lsize or ret_largest case, now relies on count being 0
> to break the loop
>
> V4:
> - Refactor inode_f function to reduce its size and easier logic
> - Implement error handlers for invalid command combination (hopefully
> all invalid combinations).
> - use a single xfs_inogrp array for keep track of inodes
> - Fix missing newline in inode_help()
> - Rewrite help message in inode_help()
> - Fix indentation
>
> V5:
> - Reduce the amount of options
> - remove igrp_rec variable, and use igroup[lastgrp] directly to get
> information from the last inode groups returned by ioctl
>
> Signed-off-by: Carlos Maiolino <cmaiolino at redhat.com>
> ---
> io/open.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 143 insertions(+)
>
> diff --git a/io/open.c b/io/open.c
> index ac5a5e0..1e38ea8 100644
> --- a/io/open.c
> +++ b/io/open.c
> @@ -20,6 +20,7 @@
> #include "input.h"
> #include "init.h"
> #include "io.h"
> +#include "libxfs.h"
>
> #ifndef __O_TMPFILE
> #if defined __alpha__
> @@ -44,6 +45,7 @@ static cmdinfo_t statfs_cmd;
> static cmdinfo_t chproj_cmd;
> static cmdinfo_t lsproj_cmd;
> static cmdinfo_t extsize_cmd;
> +static cmdinfo_t inode_cmd;
> static prid_t prid;
> static long extsize;
>
> @@ -750,6 +752,136 @@ statfs_f(
> return 0;
> }
>
> +static void
> +inode_help(void)
> +{
> + printf(_(
> +"\n"
> +"Query physical information about the inode"
> +"\n"
> +" Default: -- Return true(1) or false(0) if any inode greater than\n"
> +" 32bits has been found in the filesystem\n"
> +" -v -- verbose mode\n"
> +" Display the number and the physical size (in bits)\n"
> +" of the largest inode in the filesystem\n"
> +"[num] -- Return true(1) or false(0) if the inode [num] is in use\n"
> +" -n [num] -- Return the next valid inode after [num]\n"
> +"\n"));
> +}
> +
> +static int
> +inode_f(
> + int argc,
> + char **argv)
> +{
> + __s32 count = 0;
> + __s32 lastgrp = 0;
> + __u64 last = 0;
> + __u64 lastino = 0;
> + __u64 userino = 0;
> + char *p;
> + int c;
> + int verbose = 0;
> + int ret_next = 0;
> + int cmd = 0;
> + struct xfs_inogrp igroup[1024];
> + struct xfs_fsop_bulkreq bulkreq;
> + struct xfs_bstat bstat;
> +
> + while ((c = getopt(argc, argv, "nv")) != EOF) {
I think we want "n:v" here since -n expects an argument, even if we
don't process the arg here.
> + switch (c) {
> + case 'v':
> + verbose = 1;
> + break;
> + case 'n':
> + ret_next = 1;
> + break;
> + default:
> + return command_usage(&inode_cmd);
> + }
> + }
> +
> + if (ret_next && verbose)
> + return command_usage(&inode_cmd);
> +
Why is this not supported? Hmm, I see that -n returns an inode number
and otherwise we print 0/1 or <inode>:<size> with -v. Perhaps this would
be easier if the command semantics/output were more consistent. E.g.,
"inode": print 0/1 based on largest inode size
"inode -v": print <ino>:<size> of largest inode
"inode <ino>": print <ino> if inode exists
"inode -v <ino>": print <ino>:<size> if inode exists
"inode -n <ino>": print <next ino> if next inode exists
"inode -nv <ino>": print <next ino>:<size> if next inode exists
In other words, the default behavior is to identify the 32-bit/64-bit
state of the fs. If an inode is provided, we print the inode number if
the inode exists. The -n flags alters this behavior to find the next
inode. The -v flag alters the previous two situations to also print the
inode size.
> + if (optind < argc) {
A comment above this check to explain what it means (i.e., user passed
an inode number) would be nice.
> + if (verbose)
> + return command_usage(&inode_cmd);
Also, why is this not supported (see above)?
> +
> + if (ret_next) {
> + cmd = XFS_IOC_FSBULKSTAT;
> + } else {
> + if (argc > 2)
> + return command_usage(&inode_cmd);
> + else
> + cmd = XFS_IOC_FSBULKSTAT_SINGLE;
> + }
> +
> + userino = strtoull(argv[optind], &p, 10);
> + if ((*p != '\0')) {
> + printf(_("[num] must be a numeric value\n"));
> + exitcode = 1;
> + return 0;
> + }
> +
> + bulkreq.lastip = &userino;
> + bulkreq.icount = 1;
> + bulkreq.ubuffer = &bstat;
> + bulkreq.ocount = &count;
> +
> + if (xfsctl(file->name, file->fd, cmd, &bulkreq)) {
> + if (errno == EINVAL) {
> + if (!ret_next)
> + printf("0\n");
> + } else {
> + perror("xfsctl");
> + }
> + exitcode = 1;
> + return 0;
> + }
> +
> + if (ret_next) {
> + printf("%llu\n", bstat.bs_ino);
> + return 0;
> + } else {
> + /* Inode number used*/
> + printf("1\n");
> + return 0;
> + }
The return 0 can go after the if/else.
> + }
> +
/*
* The user has not provided an inode number. Therefore, find
* the largest inode in the fs.
*/
Brian
> + bulkreq.lastip = &last;
> + bulkreq.icount = 1024; /* User-defined maybe!? */
> + bulkreq.ubuffer = &igroup;
> + bulkreq.ocount = &count;
> +
> + for (;;) {
> + if (xfsctl(file->name, file->fd, XFS_IOC_FSINUMBERS,
> + &bulkreq)) {
> + perror("XFS_IOC_FSINUMBERS");
> + exitcode = 1;
> + return 0;
> + }
> +
> + if (count == 0)
> + break;
> +
> + lastgrp = count;
> + }
> +
> + lastgrp--;
> + lastino = igroup[lastgrp].xi_startino +
> + xfs_highbit64(igroup[lastgrp].xi_allocmask);
> +
> + if (verbose)
> + printf("%llu:%d\n", lastino,
> + lastino > XFS_MAXINUMBER_32 ? 64 : 32);
> + else
> + printf("%d\n", lastino > XFS_MAXINUMBER_32 ? 1 : 0);
> +
> + return 0;
> +}
> +
> void
> open_init(void)
> {
> @@ -815,6 +947,16 @@ open_init(void)
> _("get/set preferred extent size (in bytes) for the open file");
> extsize_cmd.help = extsize_help;
>
> + inode_cmd.name = "inode";
> + inode_cmd.cfunc = inode_f;
> + inode_cmd.args = _("[-n | -v] [num]");
> + inode_cmd.argmin = 0;
> + inode_cmd.argmax = 2;
> + inode_cmd.flags = CMD_NOMAP_OK;
> + inode_cmd.oneline =
> + _("Query inode number usage in the filesystem");
> + inode_cmd.help = inode_help;
> +
> add_command(&open_cmd);
> add_command(&stat_cmd);
> add_command(&close_cmd);
> @@ -822,4 +964,5 @@ open_init(void)
> add_command(&chproj_cmd);
> add_command(&lsproj_cmd);
> add_command(&extsize_cmd);
> + add_command(&inode_cmd);
> }
> --
> 2.4.3
>
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