1QUOTACTL(2) System Calls Manual QUOTACTL(2)
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6 quotactl - manipulate disk quotas
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9 #include <linux/quota.h>
10 #include <xfs/xqm.h>
11 #include <linux/dqblk_v1.h>
12 #include <linux/dqblk_v2.h>
13 long quotactl(int cmd, char ∗special, qid_t id, caddr_t addr)
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17 The quotactl() call manipulates disk quotas. cmd indicates a command
18 to be applied to UID id or GID id. To set the type of quota use the
19 QCMD(cmd, type) macro. special is a pointer to a null-terminated
20 string containing the path name of the block special device for the
21 filesystem being manipulated. addr is the address of an optional, com‐
22 mand specific, data structure which is copied in or out of the system.
23 The interpretation of addr is given with each command below.
24 Q_QUOTAON Turn on quotas for a filesystem. id is the identifica‐
26 tion number of the quota format to be used. Format num‐
27 bers are defined in the header file of appropriate for‐
28 mat. Currently there are two supported quota formats
29 whose numbers are defined by constants QFMT_VFS_OLD
30 (original quota format) and QFMT_VFS_V0 (new VFS v0
31 quota format). addr points to the path name of file
32 containing the quotas for the filesystem. The quota
33 file must exist; it is normally created with the quo‐
34 tacheck(8) program. This call is restricted to the
35 super-user.
36 Q_QUOTAOFF Turn off quotas for a filesystem. addr and id are
38 ignored. This call is restricted to the super-user.
39 Q_GETQUOTA Get disk quota limits and current usage for user or
41 group id. addr is a pointer to an if_dqblk structure
42 (defined in <linux/quota.h>). The field dqb_valid
43 defines the entries in the structure which are set cor‐
44 rectly. On Q_GETQUOTA call all entries are valid. Only
45 the super-user may get the quotas of a user other than
46 himself.
47 Q_SETQUOTA Set current quota information for user or group id.
49 addr is a pointer to an if_dqblk structure (defined in
50 <linux/quota.h>). The field dqb_valid defines which
51 entries in the quota structure are valid and should be
52 set. The constants for dqb_valid field are defined in
53 the <linux/quota.h> header file. This call obsoletes
54 calls Q_SETQLIM and Q_SETUSE in the previous quota
55 interfaces. This call is restricted to the super-user.
56 Q_GETINFO Get information (like grace times) about quotafile.
58 addr should be a pointer to an if_dqinfo structure
59 (defined in <linux/quota.h>). The dqi_valid field in
60 the structure defines entries in it which are valid. On
61 Q_GETINFO call all entries are valid. Parameter id is
62 ignored.
63 Q_SETINFO Set information about quotafile. addr should be a
65 pointer to if_dqinfo structure (defined in
66 <linux/quota.h>). The field dqi_valid defines which
67 entries in the quota info structure are valid and should
68 be set. The constants for dqi_valid field are defined in
69 the <linux/quota.h> header file. This call obsoletes
70 calls Q_SETGRACE and Q_SETFLAGS in the previous quota
71 interfaces. Parameter id is ignored. This operation is
72 restricted to super-user.
73 Q_GETFMT Get quota format used on the specified filesystem. addr
75 should be a pointer to a memory (4 bytes) where the for‐
76 mat number will be stored.
77 Q_SYNC Update the on-disk copy of quota usages for a filesys‐
79 tem. If special is null then all filesystems with
80 active quotas are sync'ed. addr and id are ignored.
81 Q_GETSTATS Get statistics and other generic information about quota
83 subsystem. addr should be a pointer to dqstats struc‐
84 ture (defined in <linux/quota.h>) in which data should
85 be stored. special and id are ignored.
86 For XFS filesystems making use of the XFS Quota Manager (XQM), the
88 above commands are bypassed and the following commands are used:
89 Q_XQUOTAON Turn on quotas for an XFS filesystem. XFS provides the
91 ability to turn on/off quota limit enforcement with
92 quota accounting. Therefore, XFS expects the addr to be
93 a pointer to an unsigned int that contains either the
94 flags XFS_QUOTA_UDQ_ACCT and/or XFS_QUOTA_UDQ_ENFD (for
95 user quota), or XFS_QUOTA_GDQ_ACCT and/or
96 XFS_QUOTA_GDQ_ENFD (for group quota), as defined in
97 <xfs/xqm.h>. This call is restricted to the superuser.
98 Q_XQUOTAOFF Turn off quotas for an XFS filesystem. As in Q_QUOTAON,
100 XFS filesystems expect a pointer to an unsigned int that
101 specifies whether quota accounting and/or limit enforce‐
102 ment need to be turned off. This call is restricted to
103 the superuser.
104 Q_XGETQUOTA Get disk quota limits and current usage for user id.
106 addr is a pointer to a fs_disk_quota structure (defined
107 in <xfs/xqm.h>). Only the superuser may get the quotas
108 of a user other than himself.
109 Q_XSETQLIM Set disk quota limits for user id. addr is a pointer to
111 a fs_disk_quota structure (defined in <xfs/xqm.h>).
112 This call is restricted to the superuser.
113 Q_XGETQSTAT Returns a fs_quota_stat structure containing XFS
115 filesystem specific quota information. This is useful
116 in finding out how much space is spent to store quota
117 information, and also to get quotaon/off status of a
118 given local XFS filesystem.
119 Q_XQUOTARM Free the disk space taken by disk quotas. Quotas must
121 have already been turned off.
122 There is no command equivalent to Q_SYNC for XFS since sync(1) writes
124 quota information to disk (in addition to the other filesystem metadata
125 it writes out).
126
128 quotactl() returns:
129 0 on success.
131 -1 on failure and sets errno to indicate the error.
133
135 EFAULT addr or special are invalid.
136 ENOSYS The kernel has not been compiled with the QUOTA option.
138 EINVAL
140 cmd or type is invalid.
142 ENOENT The file specified by special or addr does not exist.
144 ENOTBLK special is not a block device.
146 EPERM The call is privileged and the caller was not the super-
148 user.
149 ESRCH No disc quota is found for the indicated user.
151 Quotas have not been turned on for this filesystem.
153 If cmd is Q_QUOTAON, quotactl() may set errno to:
155 EACCES The quota file pointed to by addr exists but is not a
157 regular file.
158 The quota file pointed to by addr exists but is not on
160 the filesystem pointed to by special.
161 EINVAL The quota file is corrupted.
163 ESRCH Specified quota format was not found.
165 EBUSY Q_QUOTAON attempted while another Q_QUOTAON has already
167 taken place.
168
170 quota(1), getrlimit(2), quotacheck(8), quotaon(8)
171 QUOTACTL(2)