1 <?xml version='1.0' encoding='UTF-8'?>
2 <!-- This document was created with Syntext Serna Free. --><chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US" xml:id="settinglustreproperties">
3 <title xml:id="settinglustreproperties.title">Setting Lustre Properties in a C Program (<literal>llapi</literal>)</title>
4 <para>This chapter describes the <literal>llapi</literal> library of commands used for setting Lustre file properties within a C program running in a cluster environment, such as a data processing or MPI application. The commands described in this chapter are:</para>
7 <para><xref linkend="dbdoclet.50438215_30970"/></para>
10 <para><xref linkend="dbdoclet.50438215_50149"/></para>
13 <para><xref linkend="dbdoclet.50438215_86607"/></para>
16 <para><xref linkend="dbdoclet.50438215_12433"/></para>
19 <para><xref linkend="dbdoclet.50438215_15718"/></para>
23 <para>Lustre programming interface man pages are found in the <literal>lustre/doc</literal> folder.</para>
25 <section xml:id="dbdoclet.50438215_30970">
27 <literal>llapi_file_create</literal>
29 <para>Use <literal>llapi_file_create</literal> to set Lustre properties for a new file.</para>
31 <title>Synopsis</title>
32 <screen>#include <lustre/lustreapi.h>
34 int llapi_file_create(char *name, long stripe_size, int stripe_offset, int stripe_count, int stripe_pattern);
38 <title>Description</title>
39 <para>The <literal>llapi_file_create()</literal> function sets a file descriptor's Lustre striping information. The file descriptor is then accessed with <literal>open()</literal>.</para>
40 <informaltable frame="all">
42 <colspec colname="c1" colwidth="50*"/>
43 <colspec colname="c2" colwidth="50*"/>
47 <para><emphasis role="bold">Option</emphasis></para>
50 <para><emphasis role="bold">Description</emphasis></para>
57 <para> <literal>llapi_file_create()</literal></para>
60 <para>If the file already exists, this parameter returns to '<literal>EEXIST</literal>'. If the stripe parameters are invalid, this parameter returns to '<literal>EINVAL</literal>'.</para>
65 <para> <literal>stripe_size</literal></para>
68 <para>This value must be an even multiple of system page size, as shown by <literal>getpagesize()</literal>. The default Lustre stripe size is 4MB.</para>
73 <para> <literal>stripe_offset</literal></para>
76 <para>Indicates the starting OST for this file.</para>
81 <para> <literal>stripe_count</literal></para>
84 <para>Indicates the number of OSTs that this file will be striped across.</para>
89 <para> <literal>stripe_pattern</literal></para>
92 <para>Indicates the RAID pattern.</para>
99 <para>Currently, only RAID 0 is supported. To use the system defaults, set these values: <literal>stripe_size</literal> = 0, <literal>stripe_offset</literal> = -1, <literal>stripe_count</literal> = 0, <literal>stripe_pattern</literal> = 0</para>
103 <title>Examples</title>
104 <para>System default size is 4 MB.</para>
105 <screen>char *tfile = TESTFILE;
106 int stripe_size = 65536</screen>
107 <para>To start at default, run:</para>
108 <screen>int stripe_offset = -1</screen>
109 <para>To start at the default, run:</para>
110 <screen>int stripe_count = 1</screen>
111 <para>To set a single stripe for this example, run:</para>
112 <screen>int stripe_pattern = 0</screen>
113 <para>Currently, only RAID 0 is supported.</para>
114 <screen>int stripe_pattern = 0;
116 rc = llapi_file_create(tfile, stripe_size,stripe_offset, stripe_count,stripe_pattern);</screen>
117 <para>Result code is inverted, you may return with '<literal>EINVAL</literal>' or an ioctl error.</para>
119 fprintf(stderr,"llapi_file_create failed: %d (%s) 0, rc, strerror(-rc));return -1; }</screen>
120 <para><literal>llapi_file_create</literal> closes the file descriptor. You must re-open the descriptor. To do this, run:</para>
121 <screen>fd = open(tfile, O_CREAT | O_RDWR | O_LOV_DELAY_CREATE, 0644); if (fd < 0) \ {
122 fprintf(stderr, "Can't open %s file: %s0, tfile,
129 <section xml:id="dbdoclet.50438215_50149">
130 <title>llapi_file_get_stripe</title>
131 <para>Use <literal>llapi_file_get_stripe</literal> to get striping information for a file or directory on a Lustre file system.</para>
133 <title>Synopsis</title>
135 #include <lustre/lustreapi.h>
137 int llapi_file_get_stripe(const char *<emphasis>path</emphasis>, void *<emphasis>lum</emphasis>);</screen>
140 <title>Description</title>
141 <para>The <literal>llapi_file_get_stripe()</literal> function returns striping information for a file or directory <emphasis>path</emphasis> in <emphasis>lum</emphasis> (which should point to a large enough memory region) in one of the following formats:</para>
142 <screen>struct lov_user_md_v1 {
146 __u64 lmm_object_seq;
147 __u32 lmm_stripe_size;
148 __u16 lmm_stripe_count;
149 __u16 lmm_stripe_offset;
150 struct lov_user_ost_data_v1 lmm_objects[0];
151 } __attribute__((packed));
152 struct lov_user_md_v3 {
156 __u64 lmm_object_seq;
157 __u32 lmm_stripe_size;
158 __u16 lmm_stripe_count;
159 __u16 lmm_stripe_offset;
160 char lmm_pool_name[LOV_MAXPOOLNAME];
161 struct lov_user_ost_data_v1 lmm_objects[0];
162 } __attribute__((packed));</screen>
163 <informaltable frame="all">
165 <colspec colname="c1" colwidth="50*"/>
166 <colspec colname="c2" colwidth="50*"/>
170 <para><emphasis role="bold">Option</emphasis></para>
173 <para><emphasis role="bold">Description</emphasis></para>
180 <para> <literal>lmm_magic</literal></para>
183 <para>Specifies the format of the returned striping information. <literal>LOV_MAGIC_V1</literal> is used for lov_user_md_v1. LOV_MAGIC_V3 is used for <literal>lov_user_md_v3</literal>.</para>
188 <para> <literal>lmm_pattern</literal></para>
191 <para>Holds the striping pattern. Only <literal>LOV_PATTERN_RAID0</literal> is possible in this Lustre version.</para>
196 <para> <literal>lmm_object_id</literal></para>
199 <para>Holds the MDS object ID.</para>
204 <para> <literal>lmm_object_gr</literal></para>
207 <para>Holds the MDS object group.</para>
212 <para> <literal>lmm_stripe_size</literal></para>
215 <para>Holds the stripe size in bytes.</para>
220 <para> <literal>lmm_stripe_count</literal></para>
223 <para>Holds the number of OSTs over which the file is striped.</para>
228 <para> <literal>lmm_stripe_offset</literal></para>
231 <para>Holds the OST index from which the file starts.</para>
236 <para> <literal>lmm_pool_name</literal></para>
239 <para>Holds the OST pool name to which the file belongs.</para>
244 <para> <literal>lmm_objects</literal></para>
247 <para>An array of <literal>lmm_stripe_count</literal> members containing per OST file information in</para>
248 <para>the following format:</para>
249 <screen>struct lov_user_ost_data_v1 {
254 } __attribute__((packed));</screen>
259 <para> <literal>l_object_id</literal></para>
262 <para>Holds the OST's object ID.</para>
267 <para> <literal>l_object_seq</literal></para>
270 <para>Holds the OST's object group.</para>
275 <para> <literal>l_ost_gen</literal></para>
278 <para>Holds the OST's index generation.</para>
283 <para> <literal>l_ost_idx</literal></para>
286 <para>Holds the OST's index in LOV.</para>
294 <title>Return Values</title>
295 <para><literal>llapi_file_get_stripe()</literal> returns:</para>
296 <para><literal>0</literal> On success</para>
297 <para><literal>!= 0</literal> On failure, <literal>errno</literal> is set appropriately</para>
300 <title>Errors</title>
301 <informaltable frame="all">
303 <colspec colname="c1" colwidth="50*"/>
304 <colspec colname="c2" colwidth="50*"/>
308 <para><emphasis role="bold">Errors</emphasis></para>
311 <para><emphasis role="bold">Description</emphasis></para>
318 <para> <literal>ENOMEM</literal></para>
321 <para>Failed to allocate memory</para>
326 <para> <literal>ENAMETOOLONG</literal></para>
329 <para>Path was too long</para>
334 <para> <literal>ENOENT</literal></para>
337 <para>Path does not point to a file or directory</para>
342 <para> <literal>ENOTTY</literal></para>
345 <para>Path does not point to a Lustre file system</para>
350 <para> <literal>EFAULT</literal></para>
353 <para>Memory region pointed by lum is not properly mapped</para>
361 <title>Examples</title>
363 #include <stdio.h>
364 #include <stdlib.h>
365 #include <errno.h>
366 #include <lustre/lustreapi.h>
368 static inline int maxint(int a, int b)
370 return a > b ? a : b;
372 static void *alloc_lum()
375 v1 = sizeof(struct lov_user_md_v1) +
376 LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);
377 v3 = sizeof(struct lov_user_md_v3) +
378 LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);
379 return malloc(maxint(v1, v3));
381 int main(int argc, char** argv)
383 struct lov_user_md *lum_file = NULL;
387 fprintf(stderr, "Usage: %s <filename>\n", argv[0]);
390 lum_file = alloc_lum();
391 if (lum_file == NULL) {
395 rc = llapi_file_get_stripe(argv[1], lum_file);
400 /* stripe_size stripe_count */
401 printf("%d %d\n",
402 lum_file->lmm_stripe_size,
403 lum_file->lmm_stripe_count);
405 if (lum_file != NULL)
412 <section xml:id="dbdoclet.50438215_86607">
414 <literal>llapi_file_open</literal>
416 <para>The <literal>llapi_file_open</literal> command opens (or creates) a file or device on a Lustre filesystem.</para>
418 <title>Synopsis</title>
419 <screen>#include <lustre/lustreapi.h>
420 int llapi_file_open(const char *<emphasis>name</emphasis>, int <emphasis>flags</emphasis>, int <emphasis>mode</emphasis>,
421 unsigned long long <emphasis>stripe_size</emphasis>, int <emphasis>stripe_offset</emphasis>,
422 int <emphasis>stripe_count</emphasis>, int <emphasis>stripe_pattern</emphasis>);
423 int llapi_file_create(const char *<emphasis>name</emphasis>, unsigned long long <emphasis>stripe_size</emphasis>,
424 int <emphasis>stripe_offset</emphasis>, int <emphasis>stripe_count</emphasis>,
425 int <emphasis>stripe_pattern</emphasis>);
429 <title>Description</title>
430 <para>The <literal>llapi_file_create()</literal> call is equivalent to the <literal>llapi_file_open</literal> call with <emphasis>flags</emphasis> equal to <literal>O_CREAT|O_WRONLY</literal> and <emphasis>mode</emphasis> equal to <literal>0644</literal>, followed by file close.</para>
431 <para><literal>llapi_file_open()</literal> opens a file with a given name on a Lustre filesystem.</para>
432 <informaltable frame="all">
434 <colspec colname="c1" colwidth="50*"/>
435 <colspec colname="c2" colwidth="50*"/>
439 <para><emphasis role="bold">Option</emphasis></para>
442 <para><emphasis role="bold">Description</emphasis></para>
449 <para> <literal>flags</literal></para>
452 <para>Can be a combination of <literal>O_RDONLY</literal>, <literal>O_WRONLY</literal>, <literal>O_RDWR</literal>, <literal>O_CREAT</literal>, <literal>O_EXCL</literal>, <literal>O_NOCTTY</literal>, <literal>O_TRUNC</literal>, <literal>O_APPEND</literal>, <literal>O_NONBLOCK</literal>, <literal>O_SYNC</literal>, <literal>FASYNC</literal>, <literal>O_DIRECT</literal>, <literal>O_LARGEFILE</literal>, <literal>O_DIRECTORY</literal>, <literal>O_NOFOLLOW</literal>, <literal>O_NOATIME</literal>.</para>
457 <para> <literal>mode</literal></para>
460 <para>Specifies the permission bits to be used for a new file when <literal>O_CREAT</literal> is used.</para>
465 <para> <literal>stripe_size</literal></para>
468 <para>Specifies stripe size (in bytes). Should be multiple of 64 KB, not exceeding 4 GB.</para>
473 <para> <literal>stripe_offset</literal></para>
476 <para>Specifies an OST index from which the file should start. The default value is -1.</para>
481 <para> <literal>stripe_count</literal></para>
484 <para>Specifies the number of OSTs to stripe the file across. The default value is -1.</para>
489 <para> <literal>stripe_pattern</literal></para>
492 <para>Specifies the striping pattern. In this version of Lustre, only <literal>LOV_PATTERN_RAID0</literal> is available. The default value is 0.</para>
500 <title>Return Values</title>
501 <para><literal>llapi_file_open()</literal> and <literal>llapi_file_create()</literal> return:</para>
502 <para><literal>>=0</literal> On success, for <literal>llapi_file_open</literal> the return value is a file descriptor</para>
503 <para><literal><0</literal> On failure, the absolute value is an error code</para>
506 <title>Errors</title>
507 <informaltable frame="all">
509 <colspec colname="c1" colwidth="50*"/>
510 <colspec colname="c2" colwidth="50*"/>
514 <para><emphasis role="bold">Errors</emphasis></para>
517 <para><emphasis role="bold">Description</emphasis></para>
524 <para> <literal>EINVAL</literal></para>
527 <para><literal>stripe_size</literal> or <literal>stripe_offset</literal> or <literal>stripe_count</literal> or <literal>stripe_pattern</literal> is invalid.</para>
532 <para> <literal>EEXIST</literal></para>
535 <para>Striping information has already been set and cannot be altered; <literal>name</literal> already exists.</para>
540 <para> <literal>EALREADY</literal></para>
543 <para>Striping information has already been set and cannot be altered</para>
548 <para> <literal>ENOTTY</literal></para>
551 <para> <literal>name</literal> may not point to a Lustre filesystem.</para>
559 <title>Example</title>
561 #include <stdio.h>
562 #include <lustre/lustreapi.h>
564 int main(int argc, char *argv[])
569 rc = llapi_file_create(argv[1], 1048576, 0, 2, LOV_PATTERN_RAID0);
571 fprintf(stderr, "file creation has failed, %s\n", strerror(-rc));
574 printf("%s with stripe size 1048576, striped across 2 OSTs,"
575 " has been created!\n", argv[1]);
581 <section xml:id="dbdoclet.50438215_12433">
583 <literal>llapi_quotactl</literal>
585 <para>Use <literal>llapi_quotact</literal>l to manipulate disk quotas on a Lustre file system.</para>
587 <title>Synopsis</title>
588 <screen>#include <lustre/lustreapi.h>
589 int llapi_quotactl(char" " *mnt," " struct if_quotactl" " *qctl)
596 struct obd_dqinfo qc_dqinfo;
597 struct obd_dqblk qc_dqblk;
599 struct obd_uuid obd_uuid;
602 __u64 dqb_bhardlimit;
603 __u64 dqb_bsoftlimit;
605 __u64 dqb_ihardlimit;
606 __u64 dqb_isoftlimit;
624 <title>Description</title>
625 <para>The <literal>llapi_quotactl()</literal> command manipulates disk quotas on a Lustre file system mount. qc_cmd indicates a command to be applied to UID <literal>qc_id</literal> or GID <literal>qc_id</literal>.</para>
626 <informaltable frame="all">
628 <colspec colname="c1" colwidth="50*"/>
629 <colspec colname="c2" colwidth="50*"/>
633 <para><emphasis role="bold">Option</emphasis></para>
636 <para><emphasis role="bold">Description</emphasis></para>
643 <para> <literal>LUSTRE_Q_QUOTAON</literal></para>
646 <para>Turns on quotas for a Lustre file system. Deprecated as of 2.4.0. <emphasis>qc_type</emphasis> is <literal>USRQUOTA</literal>, <literal>GRPQUOTA</literal> or <literal>UGQUOTA</literal> (both user and group quota). The quota files must exist. They are normally created with the <literal>llapi_quotacheck</literal> call. This call is restricted to the super user privilege. As of 2.4.0, quota is now enabled on a per-filesystem basis via <literal>lctl conf_param</literal> (see <xref linkend="enabling_disk_quotas"/>) on the MGS node and quotacheck isn't needed any more.</para>
651 <para> <literal>LUSTRE_Q_QUOTAOFF</literal></para>
654 <para>Turns off quotas for a Lustre file system. Deprecated as of 2.4.0. <emphasis>qc_type</emphasis> is <literal>USRQUOTA</literal>, <literal>GRPQUOTA</literal> or <literal>UGQUOTA</literal> (both user and group quota). This call is restricted to the super user privilege. As of 2.4.0, quota is disabled via <literal>lctl conf_param</literal> (see <xref linkend="enabling_disk_quotas"/>).</para>
659 <para> <literal>LUSTRE_Q_GETQUOTA</literal></para>
662 <para>Gets disk quota limits and current usage for user or group <emphasis>qc_id</emphasis>. <emphasis>qc_type</emphasis> is <literal>USRQUOTA</literal> or <literal>GRPQUOTA</literal>. <emphasis>uuid</emphasis> may be filled with <literal>OBD UUID</literal> string to query quota information from a specific node. <emphasis>dqb_valid</emphasis> may be set nonzero to query information only from MDS. If <emphasis>uuid</emphasis> is an empty string and <emphasis>dqb_valid</emphasis> is zero then cluster-wide limits and usage are returned. On return, <emphasis>obd_dqblk</emphasis> contains the requested information (block limits unit is kilobyte). Quotas must be turned on before using this command.</para>
667 <para> <literal>LUSTRE_Q_SETQUOTA</literal></para>
670 <para>Sets disk quota limits for user or group <emphasis>qc_id</emphasis>. <emphasis>qc_type</emphasis> is <literal>USRQUOTA</literal> or <literal>GRPQUOTA</literal>. <emphasis>dqb_valid</emphasis> must be set to <literal>QIF_ILIMITS</literal>, <literal>QIF_BLIMITS</literal> or <literal>QIF_LIMITS</literal> (both inode limits and block limits) dependent on updating limits. <emphasis>obd_dqblk</emphasis> must be filled with limits values (as set in <emphasis>dqb_valid</emphasis>, block limits unit is kilobyte). Quotas must be turned on before using this command.</para>
675 <para> <literal>LUSTRE_Q_GETINFO</literal></para>
678 <para>Gets information about quotas. <emphasis>qc_type</emphasis> is either <literal>USRQUOTA</literal> or <literal>GRPQUOTA</literal>. On return, <emphasis>dqi_igrace</emphasis> is inode grace time (in seconds), <emphasis>dqi_bgrace</emphasis> is block grace time (in seconds), <emphasis>dqi_flags</emphasis> is not used by the current Lustre version.</para>
683 <para> <literal>LUSTRE_Q_SETINFO</literal></para>
686 <para>Sets quota information (like grace times). <emphasis>qc_type</emphasis> is either <literal>USRQUOTA</literal> or <literal>GRPQUOTA</literal>. <emphasis>dqi_igrace</emphasis> is inode grace time (in seconds), <emphasis>dqi_bgrace</emphasis> is block grace time (in seconds), <emphasis>dqi_flags</emphasis> is not used by the current Lustre version and must be zeroed.</para>
694 <title>Return Values</title>
695 <para><literal>llapi_quotactl()</literal> returns:</para>
696 <para><literal>0</literal> On success</para>
697 <para><literal> -1 </literal> On failure and sets error number (<literal>errno</literal>) to indicate the error</para>
700 <title>Errors</title>
701 <para><literal>llapi_quotactl</literal> errors are described below.</para>
702 <informaltable frame="all">
704 <colspec colname="c1" colwidth="50*"/>
705 <colspec colname="c2" colwidth="50*"/>
709 <para><emphasis role="bold">Errors</emphasis></para>
712 <para><emphasis role="bold">Description</emphasis></para>
719 <para> <literal>EFAULT</literal></para>
722 <para><emphasis>qctl</emphasis> is invalid.</para>
727 <para> <literal>ENOSYS</literal></para>
730 <para>Kernel or Lustre modules have not been compiled with the <literal>QUOTA</literal> option.</para>
735 <para> <literal>ENOMEM</literal></para>
738 <para>Insufficient memory to complete operation.</para>
743 <para> <literal>ENOTTY</literal></para>
746 <para> <emphasis>qc_cmd</emphasis> is invalid.</para>
751 <para> <literal>EBUSY</literal></para>
754 <para>Cannot process during quotacheck.</para>
759 <para> <literal>ENOENT</literal></para>
762 <para> <emphasis>uuid</emphasis> does not correspond to OBD or <emphasis>mnt</emphasis> does not exist.</para>
767 <para> <literal>EPERM</literal></para>
770 <para>The call is privileged and the caller is not the super user.</para>
775 <para> <literal>ESRCH</literal></para>
778 <para>No disk quota is found for the indicated user. Quotas have not been turned on for this file system.</para>
786 <section xml:id="dbdoclet.50438215_15718">
788 <literal>llapi_path2fid</literal>
790 <para>Use <literal>llapi_path2fid</literal> to get the FID from the pathname.</para>
792 <title>Synopsis</title>
793 <screen>#include <lustre/lustreapi.h>
795 int llapi_path2fid(const char *path, unsigned long long *seq, unsigned long *oid, unsigned long *ver)</screen>
798 <title>Description</title>
799 <para>The <literal>llapi_path2fid</literal> function returns the FID (sequence : object ID : version) for the pathname.</para>
802 <title>Return Values</title>
803 <para><literal>llapi_path2fid</literal> returns:</para>
804 <para><literal>0</literal> On success</para>
805 <para>non-zero value On failure</para>
808 <section xml:id="dbdoclet.50438215_marker-1297700">
809 <title>Example Using the <literal>llapi</literal> Library</title>
810 <para>Use <literal>llapi_file_create</literal> to set Lustre properties for a new file. For a synopsis and description of llapi_file_create and examples of how to use it, see <xref linkend="configurationfilesmoduleparameters"/>.</para>
811 <para>You can set striping from inside programs like <literal>ioctl</literal>. To compile the sample program, you need to install the Lustre client source RPM.</para>
812 <para><emphasis role="bold">A simple C program to demonstrate striping API - libtest.c</emphasis></para>
814 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
815 * vim:expandtab:shiftwidth=8:tabstop=8:
817 * lustredemo - a simple example of lustreapi functions
819 #include <stdio.h>
820 #include <fcntl.h>
821 #include <dirent.h>
822 #include <errno.h>
823 #include <stdlib.h>
824 #include <lustre/lustreapi.h>
825 #define MAX_OSTS 1024
826 #define LOV_EA_SIZE(lum, num) (sizeof(*lum) + num * sizeof(*lum->lmm_objects))
827 #define LOV_EA_MAX(lum) LOV_EA_SIZE(lum, MAX_OSTS)
830 * This program provides crude examples of using the lustreapi API functions
832 /* Change these definitions to suit */
834 #define TESTDIR "/tmp" /* Results directory */
835 #define TESTFILE "lustre_dummy" /* Name for the file we create/destroy */
836 #define FILESIZE 262144 /* Size of the file in words */
837 #define DUMWORD "DEADBEEF" /* Dummy word used to fill files */
838 #define MY_STRIPE_WIDTH 2 /* Set this to the number of OST required */
839 #define MY_LUSTRE_DIR "/mnt/lustre/ftest"
841 int close_file(int fd)
843 if (close(fd) < 0) {
844 fprintf(stderr, "File close failed: %d (%s)\n", errno, strerror(errno));
850 int write_file(int fd)
852 char *stng = DUMWORD;
855 for( cnt = 0; cnt < FILESIZE; cnt++) {
856 write(fd, stng, sizeof(stng));
860 /* Open a file, set a specific stripe count, size and starting OST
861 * Adjust the parameters to suit */
862 int open_stripe_file()
864 char *tfile = TESTFILE;
865 int stripe_size = 65536; /* System default is 4M */
866 int stripe_offset = -1; /* Start at default */
867 int stripe_count = MY_STRIPE_WIDTH; /*Single stripe for this demo*/
868 int stripe_pattern = 0; /* only RAID 0 at this time */
871 rc = llapi_file_create(tfile,
872 stripe_size,stripe_offset,stripe_count,stripe_pattern);
873 /* result code is inverted, we may return -EINVAL or an ioctl error.
874 * We borrow an error message from sanity.c
877 fprintf(stderr,"llapi_file_create failed: %d (%s) \n", rc, strerror(-rc));
880 /* llapi_file_create closes the file descriptor, we must re-open */
881 fd = open(tfile, O_CREAT | O_RDWR | O_LOV_DELAY_CREATE, 0644);
883 fprintf(stderr, "Can't open %s file: %d (%s)\n", tfile, errno, strerror(errno));
889 /* output a list of uuids for this file */
890 int get_my_uuids(int fd)
892 struct obd_uuid uuids[1024], *uuidp; /* Output var */
896 rc = llapi_lov_get_uuids(fd, uuids, &obdcount);
898 fprintf(stderr, "get uuids failed: %d (%s)\n",errno, strerror(errno));
900 printf("This file system has %d obds\n", obdcount);
901 for (i = 0, uuidp = uuids; i < obdcount; i++, uuidp++) {
902 printf("UUID %d is %s\n",i, uuidp->uuid);
907 /* Print out some LOV attributes. List our objects */
908 int get_file_info(char *path)
911 struct lov_user_md *lump;
915 lump = malloc(LOV_EA_MAX(lump));
920 rc = llapi_file_get_stripe(path, lump);
923 fprintf(stderr, "get_stripe failed: %d (%s)\n",errno, strerror(errno));
927 printf("Lov magic %u\n", lump->lmm_magic);
928 printf("Lov pattern %u\n", lump->lmm_pattern);
929 printf("Lov object id %llu\n", lump->lmm_object_id);
930 printf("Lov stripe size %u\n", lump->lmm_stripe_size);
931 printf("Lov stripe count %hu\n", lump->lmm_stripe_count);
932 printf("Lov stripe offset %u\n", lump->lmm_stripe_offset);
933 for (i = 0; i < lump->lmm_stripe_count; i++) {
934 printf("Object index %d Objid %llu\n", lump->lmm_objects[i].l_ost_idx, lump->lmm_objects[i].l_object_id);
942 /* Ping all OSTs that belong to this filesystem */
950 sprintf(osc_dir, "/proc/fs/lustre/osc");
951 dir = opendir(osc_dir);
953 printf("Can't open dir\n");
956 while((d = readdir(dir)) != NULL) {
957 if ( d->d_type == DT_DIR ) {
958 if (! strncmp(d->d_name, "OSC", 3)) {
959 printf("Pinging OSC %s ", d->d_name);
960 rc = llapi_ping("osc", d->d_name);
962 printf(" bad\n");
964 printf(" good\n");
980 sprintf(filename, "%s/%s",MY_LUSTRE_DIR, TESTFILE);
982 printf("Open a file with striping\n");
983 file = open_stripe_file();
985 printf("Exiting\n");
988 printf("Getting uuid list\n");
989 rc = get_my_uuids(file);
990 printf("Write to the file\n");
991 rc = write_file(file);
992 rc = close_file(file);
993 printf("Listing LOV data\n");
994 rc = get_file_info(filename);
995 printf("Ping our OSTs\n");
998 /* the results should match lfs getstripe */
999 printf("Confirming our results with lfs getstripe\n");
1000 sprintf(sys_cmd, "/usr/bin/lfs getstripe %s/%s", MY_LUSTRE_DIR, TESTFILE);
1003 printf("All done\n");
1007 <para><emphasis role="bold">Makefile for sample application:</emphasis></para>
1009 gcc -g -O2 -Wall -o lustredemo libtest.c -llustreapi
1011 rm -f core lustredemo *.o
1014 rm -f /mnt/lustre/ftest/lustredemo
1015 rm -f /mnt/lustre/ftest/lustre_dummy
1016 cp lustredemo /mnt/lustre/ftest/
1018 <section remap="h5">
1019 <title>See Also</title>
1023 <xref linkend="dbdoclet.50438215_30970"/>
1028 <xref linkend="dbdoclet.50438215_50149"/>
1033 <xref linkend="dbdoclet.50438215_86607"/>
1038 <xref linkend="dbdoclet.50438215_12433"/>