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27 .TH QUOTACTL 2 2021-03-22 "Linux" "Linux Programmer's Manual"
29 quotactl \- manipulate disk quotas
32 .B #include <sys/quota.h>
33 .BR "#include <xfs/xqm.h>" " /* Definition of " Q_X* " and " XFS_QUOTA_* \
35 .RB " (or " <linux/dqblk_xfs.h> "; see NOTES) */"
37 .BI "int quotactl(int " cmd ", const char *" special ", int " id \
41 The quota system can be used to set per-user, per-group, and per-project limits
42 on the amount of disk space used on a filesystem.
43 For each user and/or group,
44 a soft limit and a hard limit can be set for each filesystem.
45 The hard limit can't be exceeded.
46 The soft limit can be exceeded, but warnings will ensue.
47 Moreover, the user can't exceed the soft limit for more than grace period
48 duration (one week by default) at a time;
49 after this, the soft limit counts as a hard limit.
53 call manipulates disk quotas.
56 argument indicates a command to be applied to the user or
62 .IR "QCMD(subcmd, type)"
70 for group quotas, or (since Linux 4.1)
71 .\" 847aac644e92e5624f2c153bab409bf713d5ff9a
76 value is described below.
80 argument is a pointer to a null-terminated string containing the pathname
81 of the (mounted) block special device for the filesystem being manipulated.
85 argument is the address of an optional, command-specific, data structure
86 that is copied in or out of the system.
89 is given with each operation below.
93 value is one of the following operations:
96 Turn on quotas for a filesystem.
99 argument is the identification number of the quota format to be used.
100 Currently, there are three supported quota formats:
104 The original quota format.
107 The standard VFS v0 quota format, which can handle 32-bit UIDs and GIDs
108 and quota limits up to 2^42 bytes and 2^32 inodes.
111 A quota format that can handle 32-bit UIDs and GIDs
112 and quota limits of 2^64 bytes and 2^64 inodes.
117 argument points to the pathname of a file containing the quotas for
119 The quota file must exist; it is normally created with the
123 Quota information can be also stored in hidden system inodes
124 for ext4, XFS, and other filesystems if the filesystem is configured so.
125 In this case, there are no visible quota files and there is no need to
128 Quota information is always kept consistent by the filesystem and the
130 operation serves only to enable enforcement of quota limits.
131 The presence of hidden
132 system inodes with quota information is indicated by the
136 field returned by the
140 This operation requires privilege
141 .RB ( CAP_SYS_ADMIN ).
144 Turn off quotas for a filesystem.
149 arguments are ignored.
150 This operation requires privilege
151 .RB ( CAP_SYS_ADMIN ).
154 Get disk quota limits and current usage for user or group
158 argument is a pointer to a
166 /* uint64_t is an unsigned 64\-bit integer;
167 uint32_t is an unsigned 32\-bit integer */
169 struct dqblk { /* Definition since Linux 2.4.22 */
170 uint64_t dqb_bhardlimit; /* Absolute limit on disk
171 quota blocks alloc */
172 uint64_t dqb_bsoftlimit; /* Preferred limit on
174 uint64_t dqb_curspace; /* Current occupied space
176 uint64_t dqb_ihardlimit; /* Maximum number of
178 uint64_t dqb_isoftlimit; /* Preferred inode limit */
179 uint64_t dqb_curinodes; /* Current number of
181 uint64_t dqb_btime; /* Time limit for excessive
183 uint64_t dqb_itime; /* Time limit for excessive
185 uint32_t dqb_valid; /* Bit mask of QIF_*
189 /* Flags in dqb_valid that indicate which fields in
190 dqblk structure are valid. */
192 #define QIF_BLIMITS 1
194 #define QIF_ILIMITS 4
198 #define QIF_LIMITS (QIF_BLIMITS | QIF_ILIMITS)
199 #define QIF_USAGE (QIF_SPACE | QIF_INODES)
200 #define QIF_TIMES (QIF_BTIME | QIF_ITIME)
201 #define QIF_ALL (QIF_LIMITS | QIF_USAGE | QIF_TIMES)
207 field is a bit mask that is set to indicate the entries in the
209 structure that are valid.
210 Currently, the kernel fills in all entries of the
212 structure and marks them as valid in the
215 Unprivileged users may retrieve only their own quotas;
217 .RB ( CAP_SYS_ADMIN )
218 can retrieve the quotas of any user.
220 .BR Q_GETNEXTQUOTA " (since Linux 4.6)"
221 .\" commit 926132c0257a5a8d149a6a395cc3405e55420566
222 This operation is the same as
224 but it returns quota information for the next ID greater than or equal to
226 that has a quota set.
230 argument is a pointer to a
232 structure whose fields are as for the
234 except for the addition of a
236 field that is used to return the ID for which
237 quota information is being returned:
242 uint64_t dqb_bhardlimit;
243 uint64_t dqb_bsoftlimit;
244 uint64_t dqb_curspace;
245 uint64_t dqb_ihardlimit;
246 uint64_t dqb_isoftlimit;
247 uint64_t dqb_curinodes;
257 Set quota information for user or group
259 using the information supplied in the
261 structure pointed to by
267 structure indicates which entries in the structure have been set by the caller.
268 This operation supersedes the
272 operations in the previous quota interfaces.
273 This operation requires privilege
274 .RB ( CAP_SYS_ADMIN ).
276 .BR Q_GETINFO " (since Linux 2.4.22)"
277 Get information (like grace times) about quotafile.
280 argument should be a pointer to a
283 This structure is defined in
289 /* uint64_t is an unsigned 64\-bit integer;
290 uint32_t is an unsigned 32\-bit integer */
292 struct dqinfo { /* Defined since kernel 2.4.22 */
293 uint64_t dqi_bgrace; /* Time before block soft limit
294 becomes hard limit */
295 uint64_t dqi_igrace; /* Time before inode soft limit
296 becomes hard limit */
297 uint32_t dqi_flags; /* Flags for quotafile
302 /* Bits for dqi_flags */
304 /* Quota format QFMT_VFS_OLD */
306 #define DQF_ROOT_SQUASH (1 << 0) /* Root squash enabled */
307 /* Before Linux v4.0, this had been defined
308 privately as V1_DQF_RSQUASH */
310 /* Quota format QFMT_VFS_V0 / QFMT_VFS_V1 */
312 #define DQF_SYS_FILE (1 << 16) /* Quota stored in
315 /* Flags in dqi_valid that indicate which fields in
316 dqinfo structure are valid. */
321 #define IIF_ALL (IIF_BGRACE | IIF_IGRACE | IIF_FLAGS)
329 structure indicates the entries in the structure that are valid.
330 Currently, the kernel fills in all entries of the
332 structure and marks them all as valid in the
339 .BR Q_SETINFO " (since Linux 2.4.22)"
340 Set information about quotafile.
343 argument should be a pointer to a
350 structure indicates the entries in the structure
351 that have been set by the caller.
352 This operation supersedes the
356 operations in the previous quota interfaces.
360 This operation requires privilege
361 .RB ( CAP_SYS_ADMIN ).
363 .BR Q_GETFMT " (since Linux 2.4.22)"
364 Get quota format used on the specified filesystem.
367 argument should be a pointer to a 4-byte buffer
368 where the format number will be stored.
371 Update the on-disk copy of quota usages for a filesystem.
374 is NULL, then all filesystems with active quotas are sync'ed.
379 arguments are ignored.
381 .BR Q_GETSTATS " (supported up to Linux 2.4.21)"
382 Get statistics and other generic information about the quota subsystem.
385 argument should be a pointer to a
387 structure in which data should be stored.
388 This structure is defined in
394 arguments are ignored.
396 This operation is obsolete and was removed in Linux 2.4.22.
398 .I /proc/sys/fs/quota/
399 carry the information instead.
401 For XFS filesystems making use of the XFS Quota Manager (XQM),
402 the above operations are bypassed and the following operations are used:
405 Turn on quotas for an XFS filesystem.
406 XFS provides the ability to turn on/off quota limit enforcement
407 with quota accounting.
408 Therefore, XFS expects
410 to be a pointer to an
412 that contains a bitwise combination of the following flags (defined in
417 XFS_QUOTA_UDQ_ACCT /* User quota accounting */
418 XFS_QUOTA_UDQ_ENFD /* User quota limits enforcement */
419 XFS_QUOTA_GDQ_ACCT /* Group quota accounting */
420 XFS_QUOTA_GDQ_ENFD /* Group quota limits enforcement */
421 XFS_QUOTA_PDQ_ACCT /* Project quota accounting */
422 XFS_QUOTA_PDQ_ENFD /* Project quota limits enforcement */
426 This operation requires privilege
427 .RB ( CAP_SYS_ADMIN ).
433 Turn off quotas for an XFS filesystem.
436 XFS filesystems expect a pointer to an
438 that specifies whether quota accounting and/or limit enforcement need
439 to be turned off (using the same flags as for
442 This operation requires privilege
443 .RB ( CAP_SYS_ADMIN ).
449 Get disk quota limits and current usage for user
453 argument is a pointer to an
455 structure, which is defined in
461 /* All the blk units are in BBs (Basic Blocks) of
464 #define FS_DQUOT_VERSION 1 /* fs_disk_quota.d_version */
466 #define XFS_USER_QUOTA (1<<0) /* User quota type */
467 #define XFS_PROJ_QUOTA (1<<1) /* Project quota type */
468 #define XFS_GROUP_QUOTA (1<<2) /* Group quota type */
470 struct fs_disk_quota {
471 int8_t d_version; /* Version of this structure */
472 int8_t d_flags; /* XFS_{USER,PROJ,GROUP}_QUOTA */
473 uint16_t d_fieldmask; /* Field specifier */
474 uint32_t d_id; /* User, project, or group ID */
475 uint64_t d_blk_hardlimit; /* Absolute limit on
477 uint64_t d_blk_softlimit; /* Preferred limit on
479 uint64_t d_ino_hardlimit; /* Maximum # allocated
481 uint64_t d_ino_softlimit; /* Preferred inode limit */
482 uint64_t d_bcount; /* # disk blocks owned by
484 uint64_t d_icount; /* # inodes owned by the user */
485 int32_t d_itimer; /* Zero if within inode limits */
486 /* If not, we refuse service */
487 int32_t d_btimer; /* Similar to above; for
489 uint16_t d_iwarns; /* # warnings issued with
490 respect to # of inodes */
491 uint16_t d_bwarns; /* # warnings issued with
492 respect to disk blocks */
493 int32_t d_padding2; /* Padding \- for future use */
494 uint64_t d_rtb_hardlimit; /* Absolute limit on realtime
496 uint64_t d_rtb_softlimit; /* Preferred limit on RT
498 uint64_t d_rtbcount; /* # realtime blocks owned */
499 int32_t d_rtbtimer; /* Similar to above; for RT
501 uint16_t d_rtbwarns; /* # warnings issued with
502 respect to RT disk blocks */
503 int16_t d_padding3; /* Padding \- for future use */
504 char d_padding4[8]; /* Yet more padding */
509 Unprivileged users may retrieve only their own quotas;
511 .RB ( CAP_SYS_ADMIN )
512 may retrieve the quotas of any user.
514 .BR Q_XGETNEXTQUOTA " (since Linux 4.6)"
515 .\" commit 8b37524962b9c54423374717786198f5c0820a28
516 This operation is the same as
518 but it returns (in the
522 quota information for the next ID greater than or equal to
524 that has a quota set.
529 field, no separate structure type is needed (in contrast with
536 Set disk quota limits for user
540 argument is a pointer to an
543 This operation requires privilege
544 .RB ( CAP_SYS_ADMIN ).
547 Returns XFS filesystem-specific quota information in the
551 This is useful for finding out how much space is used to store quota
552 information, and also to get the quota on/off status of a given local XFS
556 structure itself is defined as follows:
560 #define FS_QSTAT_VERSION 1 /* fs_quota_stat.qs_version */
562 struct fs_qfilestat {
563 uint64_t qfs_ino; /* Inode number */
564 uint64_t qfs_nblks; /* Number of BBs
566 uint32_t qfs_nextents; /* Number of extents */
569 struct fs_quota_stat {
570 int8_t qs_version; /* Version number for
572 uint16_t qs_flags; /* XFS_QUOTA_{U,P,G}DQ_{ACCT,ENFD} */
573 int8_t qs_pad; /* Unused */
574 struct fs_qfilestat qs_uquota; /* User quota storage
576 struct fs_qfilestat qs_gquota; /* Group quota storage
578 uint32_t qs_incoredqs; /* Number of dquots in core */
579 int32_t qs_btimelimit; /* Limit for blocks timer */
580 int32_t qs_itimelimit; /* Limit for inodes timer */
581 int32_t qs_rtbtimelimit;/* Limit for RT
583 uint16_t qs_bwarnlimit; /* Limit for # of warnings */
584 uint16_t qs_iwarnlimit; /* Limit for # of warnings */
594 Returns XFS filesystem-specific quota information in the
598 This version of the operation uses a structure with proper versioning support,
599 along with appropriate layout (all fields are naturally aligned) and
600 padding to avoiding special compat handling;
601 it also provides the ability to get statistics regarding
602 the project quota file.
605 structure itself is defined as follows:
609 #define FS_QSTATV_VERSION1 1 /* fs_quota_statv.qs_version */
611 struct fs_qfilestatv {
612 uint64_t qfs_ino; /* Inode number */
613 uint64_t qfs_nblks; /* Number of BBs
615 uint32_t qfs_nextents; /* Number of extents */
616 uint32_t qfs_pad; /* Pad for 8\-byte alignment */
619 struct fs_quota_statv {
620 int8_t qs_version; /* Version for future
622 uint8_t qs_pad1; /* Pad for 16\-bit alignment */
623 uint16_t qs_flags; /* XFS_QUOTA_.* flags */
624 uint32_t qs_incoredqs; /* Number of dquots incore */
625 struct fs_qfilestatv qs_uquota; /* User quota
627 struct fs_qfilestatv qs_gquota; /* Group quota
629 struct fs_qfilestatv qs_pquota; /* Project quota
631 int32_t qs_btimelimit; /* Limit for blocks timer */
632 int32_t qs_itimelimit; /* Limit for inodes timer */
633 int32_t qs_rtbtimelimit; /* Limit for RT blocks
635 uint16_t qs_bwarnlimit; /* Limit for # of warnings */
636 uint16_t qs_iwarnlimit; /* Limit for # of warnings */
637 uint64_t qs_pad2[8]; /* For future proofing */
644 field of the structure should be filled with the version of the structure
645 supported by the callee (for now, only
648 The kernel will fill the structure in accordance with
654 .B Q_XQUOTARM " (since Linux 3.16)"
655 .\" 9da93f9b7cdf8ab28da6b364cdc1fafc8670b4dc
656 Free the disk space taken by disk quotas.
659 argument should be a pointer to an
661 value containing flags (the same as in
666 which identify what types of quota
668 (Note that the quota type passed in the
670 argument is ignored, but should remain valid in order to pass preliminary
671 quotactl syscall handler checks.)
673 Quotas must have already been turned off.
678 .BR Q_XQUOTASYNC " (since Linux 2.6.15; no-op since Linux 3.4)"
679 .\" Added in commit ee34807a65aa0c5911dc27682863afca780a003e
680 This operation was an XFS quota equivalent to
682 but it is no-op since Linux 3.4,
683 .\" 4b217ed9e30f94b6e8e5e262020ef0ceab6113af
686 writes quota information to disk now
687 (in addition to the other filesystem metadata that it writes out).
689 .IR special ", " id " and " addr
690 arguments are ignored.
694 returns 0; on error \-1
697 is set to indicate the error.
704 and the quota file pointed to by
706 exists, but is not a regular file or
707 is not on the filesystem pointed to by
716 had already been performed.
734 but the specified quota file is corrupted.
736 .BR EINVAL " (since Linux 5.5)"
737 .\" 3dd4d40b420846dd35869ccc8f8627feef2cff32
743 does not point to valid quota types.
746 The file specified by
753 The kernel has not been compiled with the
759 is not a block device.
762 The caller lacked the required privilege
763 .RB ( CAP_SYS_ADMIN )
764 for the specified operation.
770 but the specified limits are out of the range allowed by the quota format.
773 No disk quota is found for the indicated user.
774 Quotas have not been turned on for this filesystem.
780 but the specified quota format was not found.
787 .BR Q_XGETNEXTQUOTA ,
788 but there is no ID greater than or equal to
790 that has an active quota.
795 .IR <linux/dqblk_xfs.h> ,
796 taking into account that there are several naming discrepancies:
798 Quota enabling flags (of format
799 .BR XFS_QUOTA_[UGP]DQ_{ACCT,ENFD} )
800 are defined without a leading "X", as
801 .BR FS_QUOTA_[UGP]DQ_{ACCT,ENFD} .
804 .B XFS_{USER,GROUP,PROJ}_QUOTA
805 quota type flags, which are defined as
806 .BR FS_{USER,GROUP,PROJ}_QUOTA .
810 header file defines its own
815 constants for the available quota types, but their values are the same as for
816 constants without the