quota: Update documentation

[karo-tx-linux.git] / Documentation / filesystems / quota.txt

diff --git a/Documentation/filesystems/quota.txt b/Documentation/filesystems/quota.txt
index a590c4093eff87470baebc430a1cb0034f8f93db..29fc015526464608e6f1f1237fceeec11b9ead19 100644 (file)
--- a/Documentation/filesystems/quota.txt
+++ b/Documentation/filesystems/quota.txt
@@ -3,14 +3,14 @@ Quota subsystem
 ===============
 
 Quota subsystem allows system administrator to set limits on used space and
-number of used inodes (inode is a filesystem structure which is associated
-with each file or directory) for users and/or groups. For both used space and
-number of used inodes there are actually two limits. The first one is called
-softlimit and the second one hardlimit.  An user can never exceed a hardlimit
-for any resource. User is allowed to exceed softlimit but only for limited
-period of time. This period is called "grace period" or "grace time". When
-grace time is over, user is not able to allocate more space/inodes until he
-frees enough of them to get below softlimit.
+number of used inodes (inode is a filesystem structure which is associated with
+each file or directory) for users and/or groups. For both used space and number
+of used inodes there are actually two limits. The first one is called softlimit
+and the second one hardlimit.  An user can never exceed a hardlimit for any
+resource (unless he has CAP_SYS_RESOURCE capability). User is allowed to exceed
+softlimit but only for limited period of time. This period is called "grace
+period" or "grace time". When grace time is over, user is not able to allocate
+more space/inodes until he frees enough of them to get below softlimit.
 
 Quota limits (and amount of grace time) are set independently for each
 filesystem.
@@ -32,7 +32,10 @@ The interface uses generic netlink framework (see
 http://lwn.net/Articles/208755/ and http://people.suug.ch/~tgr/libnl/ for more
 details about this layer). The name of the quota generic netlink interface
 is "VFS_DQUOT". Definitions of constants below are in <linux/quota.h>.
-  Currently, the interface supports only one message type QUOTA_NL_C_WARNING.
+Since the quota netlink protocol is not namespace aware, quota netlink messages
+are sent only in initial network namespace.
+
+Currently, the interface supports only one message type QUOTA_NL_C_WARNING.
 This command is used to send a notification about any of the above mentioned
 events. Each message has six attributes. These are (type of the argument is
 in parentheses):
@@ -53,6 +56,12 @@ in parentheses):
                QUOTA_NL_BSOFTLONGWARN - space (block) softlimit is exceeded
                  longer than given grace period.
                QUOTA_NL_BSOFTWARN - space (block) softlimit
+         - four warnings are also defined for the event when user stops
+           exceeding some limit:
+               QUOTA_NL_IHARDBELOW - inode hardlimit
+               QUOTA_NL_ISOFTBELOW - inode softlimit
+               QUOTA_NL_BHARDBELOW - space (block) hardlimit
+               QUOTA_NL_BSOFTBELOW - space (block) softlimit
         QUOTA_NL_A_DEV_MAJOR (u32)
          - major number of a device with the affected filesystem
         QUOTA_NL_A_DEV_MINOR (u32)