diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/9p.txt | 3 | ||||
| -rw-r--r-- | Documentation/filesystems/afs.txt | 26 | ||||
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 24 | ||||
| -rw-r--r-- | Documentation/filesystems/gfs2-uevents.txt | 100 | ||||
| -rw-r--r-- | Documentation/filesystems/nfsroot.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 37 | ||||
| -rw-r--r-- | Documentation/filesystems/seq_file.txt | 2 |
7 files changed, 153 insertions, 41 deletions
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index bf8080640eb..6208f55c44c 100644 --- a/Documentation/filesystems/9p.txt +++ b/Documentation/filesystems/9p.txt @@ -123,6 +123,9 @@ available from the same CVS repository. There are user and developer mailing lists available through the v9fs project on sourceforge (http://sourceforge.net/projects/v9fs). +A stand-alone version of the module (which should build for any 2.6 kernel) +is available via (http://github.com/ericvh/9p-sac/tree/master) + News and other information is maintained on SWiK (http://swik.net/v9fs). Bug reports may be issued through the kernel.org bugzilla diff --git a/Documentation/filesystems/afs.txt b/Documentation/filesystems/afs.txt index 12ad6c7f4e5..ffef91c4e0d 100644 --- a/Documentation/filesystems/afs.txt +++ b/Documentation/filesystems/afs.txt @@ -23,15 +23,13 @@ it does support include: (*) Security (currently only AFS kaserver and KerberosIV tickets). - (*) File reading. + (*) File reading and writing. (*) Automounting. -It does not yet support the following AFS features: - - (*) Write support. + (*) Local caching (via fscache). - (*) Local caching. +It does not yet support the following AFS features: (*) pioctl() system call. @@ -56,7 +54,7 @@ They permit the debugging messages to be turned on dynamically by manipulating the masks in the following files: /sys/module/af_rxrpc/parameters/debug - /sys/module/afs/parameters/debug + /sys/module/kafs/parameters/debug ===== @@ -66,9 +64,9 @@ USAGE When inserting the driver modules the root cell must be specified along with a list of volume location server IP addresses: - insmod af_rxrpc.o - insmod rxkad.o - insmod kafs.o rootcell=cambridge.redhat.com:172.16.18.73:172.16.18.91 + modprobe af_rxrpc + modprobe rxkad + modprobe kafs rootcell=cambridge.redhat.com:172.16.18.73:172.16.18.91 The first module is the AF_RXRPC network protocol driver. This provides the RxRPC remote operation protocol and may also be accessed from userspace. See: @@ -81,7 +79,7 @@ is the actual filesystem driver for the AFS filesystem. Once the module has been loaded, more modules can be added by the following procedure: - echo add grand.central.org 18.7.14.88:128.2.191.224 >/proc/fs/afs/cells + echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87 >/proc/fs/afs/cells Where the parameters to the "add" command are the name of a cell and a list of volume location servers within that cell, with the latter separated by colons. @@ -101,7 +99,7 @@ The name of the volume can be suffixes with ".backup" or ".readonly" to specify connection to only volumes of those types. The name of the cell is optional, and if not given during a mount, then the -named volume will be looked up in the cell specified during insmod. +named volume will be looked up in the cell specified during modprobe. Additional cells can be added through /proc (see later section). @@ -163,14 +161,14 @@ THE CELL DATABASE The filesystem maintains an internal database of all the cells it knows and the IP addresses of the volume location servers for those cells. The cell to which -the system belongs is added to the database when insmod is performed by the +the system belongs is added to the database when modprobe is performed by the "rootcell=" argument or, if compiled in, using a "kafs.rootcell=" argument on the kernel command line. Further cells can be added by commands similar to the following: echo add CELLNAME VLADDR[:VLADDR][:VLADDR]... >/proc/fs/afs/cells - echo add grand.central.org 18.7.14.88:128.2.191.224 >/proc/fs/afs/cells + echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87 >/proc/fs/afs/cells No other cell database operations are available at this time. @@ -233,7 +231,7 @@ insmod /tmp/kafs.o rootcell=cambridge.redhat.com:172.16.18.91 mount -t afs \%root.afs. /afs mount -t afs \%cambridge.redhat.com:root.cell. /afs/cambridge.redhat.com/ -echo add grand.central.org 18.7.14.88:128.2.191.224 > /proc/fs/afs/cells +echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87 > /proc/fs/afs/cells mount -t afs "#grand.central.org:root.cell." /afs/grand.central.org/ mount -t afs "#grand.central.org:root.archive." /afs/grand.central.org/archive mount -t afs "#grand.central.org:root.contrib." /afs/grand.central.org/contrib diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 7be02ac5fa3..18b5ec8cea4 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -134,15 +134,9 @@ ro Mount filesystem read only. Note that ext4 will mount options "ro,noload" can be used to prevent writes to the filesystem. -journal_checksum Enable checksumming of the journal transactions. - This will allow the recovery code in e2fsck and the - kernel to detect corruption in the kernel. It is a - compatible change and will be ignored by older kernels. - journal_async_commit Commit block can be written to disk without waiting for descriptor blocks. If enabled older kernels cannot - mount the device. This will enable 'journal_checksum' - internally. + mount the device. journal=update Update the ext4 file system's journal to the current format. @@ -263,10 +257,18 @@ resuid=n The user ID which may use the reserved blocks. sb=n Use alternate superblock at this location. -quota -noquota -grpquota -usrquota +quota These options are ignored by the filesystem. They +noquota are used only by quota tools to recognize volumes +grpquota where quota should be turned on. See documentation +usrquota in the quota-tools package for more details + (http://sourceforge.net/projects/linuxquota). + +jqfmt=<quota type> These options tell filesystem details about quota +usrjquota=<file> so that quota information can be properly updated +grpjquota=<file> during journal replay. They replace the above + quota options. See documentation in the quota-tools + package for more details + (http://sourceforge.net/projects/linuxquota). bh (*) ext4 associates buffer heads to data pages to nobh (a) cache disk block mapping information diff --git a/Documentation/filesystems/gfs2-uevents.txt b/Documentation/filesystems/gfs2-uevents.txt new file mode 100644 index 00000000000..fd966dc9979 --- /dev/null +++ b/Documentation/filesystems/gfs2-uevents.txt @@ -0,0 +1,100 @@ + uevents and GFS2 + ================== + +During the lifetime of a GFS2 mount, a number of uevents are generated. +This document explains what the events are and what they are used +for (by gfs_controld in gfs2-utils). + +A list of GFS2 uevents +----------------------- + +1. ADD + +The ADD event occurs at mount time. It will always be the first +uevent generated by the newly created filesystem. If the mount +is successful, an ONLINE uevent will follow. If it is not successful +then a REMOVE uevent will follow. + +The ADD uevent has two environment variables: SPECTATOR=[0|1] +and RDONLY=[0|1] that specify the spectator status (a read-only mount +with no journal assigned), and read-only (with journal assigned) status +of the filesystem respectively. + +2. ONLINE + +The ONLINE uevent is generated after a successful mount or remount. It +has the same environment variables as the ADD uevent. The ONLINE +uevent, along with the two environment variables for spectator and +RDONLY are a relatively recent addition (2.6.32-rc+) and will not +be generated by older kernels. + +3. CHANGE + +The CHANGE uevent is used in two places. One is when reporting the +successful mount of the filesystem by the first node (FIRSTMOUNT=Done). +This is used as a signal by gfs_controld that it is then ok for other +nodes in the cluster to mount the filesystem. + +The other CHANGE uevent is used to inform of the completion +of journal recovery for one of the filesystems journals. It has +two environment variables, JID= which specifies the journal id which +has just been recovered, and RECOVERY=[Done|Failed] to indicate the +success (or otherwise) of the operation. These uevents are generated +for every journal recovered, whether it is during the initial mount +process or as the result of gfs_controld requesting a specific journal +recovery via the /sys/fs/gfs2/<fsname>/lock_module/recovery file. + +Because the CHANGE uevent was used (in early versions of gfs_controld) +without checking the environment variables to discover the state, we +cannot add any more functions to it without running the risk of +someone using an older version of the user tools and breaking their +cluster. For this reason the ONLINE uevent was used when adding a new +uevent for a successful mount or remount. + +4. OFFLINE + +The OFFLINE uevent is only generated due to filesystem errors and is used +as part of the "withdraw" mechanism. Currently this doesn't give any +information about what the error is, which is something that needs to +be fixed. + +5. REMOVE + +The REMOVE uevent is generated at the end of an unsuccessful mount +or at the end of a umount of the filesystem. All REMOVE uevents will +have been preceeded by at least an ADD uevent for the same fileystem, +and unlike the other uevents is generated automatically by the kernel's +kobject subsystem. + + +Information common to all GFS2 uevents (uevent environment variables) +---------------------------------------------------------------------- + +1. LOCKTABLE= + +The LOCKTABLE is a string, as supplied on the mount command +line (locktable=) or via fstab. It is used as a filesystem label +as well as providing the information for a lock_dlm mount to be +able to join the cluster. + +2. LOCKPROTO= + +The LOCKPROTO is a string, and its value depends on what is set +on the mount command line, or via fstab. It will be either +lock_nolock or lock_dlm. In the future other lock managers +may be supported. + +3. JOURNALID= + +If a journal is in use by the filesystem (journals are not +assigned for spectator mounts) then this will give the +numeric journal id in all GFS2 uevents. + +4. UUID= + +With recent versions of gfs2-utils, mkfs.gfs2 writes a UUID +into the filesystem superblock. If it exists, this will +be included in every uevent relating to the filesystem. + + + diff --git a/Documentation/filesystems/nfsroot.txt b/Documentation/filesystems/nfsroot.txt index 68baddf3c3e..3ba0b945aaf 100644 --- a/Documentation/filesystems/nfsroot.txt +++ b/Documentation/filesystems/nfsroot.txt @@ -105,7 +105,7 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf> the client address and this parameter is NOT empty only replies from the specified server are accepted. - Only required for for NFS root. That is autoconfiguration + Only required for NFS root. That is autoconfiguration will not be triggered if it is missing and NFS root is not in operation. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index fad18f9456e..75988ba26a5 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -375,6 +375,19 @@ of memory currently marked as referenced or accessed. This file is only present if the CONFIG_MMU kernel configuration option is enabled. +The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG +bits on both physical and virtual pages associated with a process. +To clear the bits for all the pages associated with the process + > echo 1 > /proc/PID/clear_refs + +To clear the bits for the anonymous pages associated with the process + > echo 2 > /proc/PID/clear_refs + +To clear the bits for the file mapped pages associated with the process + > echo 3 > /proc/PID/clear_refs +Any other value written to /proc/PID/clear_refs will have no effect. + + 1.2 Kernel data --------------- @@ -1032,9 +1045,9 @@ Various pieces of information about kernel activity are available in the since the system first booted. For a quick look, simply cat the file: > cat /proc/stat - cpu 2255 34 2290 22625563 6290 127 456 0 - cpu0 1132 34 1441 11311718 3675 127 438 0 - cpu1 1123 0 849 11313845 2614 0 18 0 + cpu 2255 34 2290 22625563 6290 127 456 0 0 + cpu0 1132 34 1441 11311718 3675 127 438 0 0 + cpu1 1123 0 849 11313845 2614 0 18 0 0 intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...] ctxt 1990473 btime 1062191376 @@ -1056,6 +1069,7 @@ second). The meanings of the columns are as follows, from left to right: - irq: servicing interrupts - softirq: servicing softirqs - steal: involuntary wait +- guest: running a guest The "intr" line gives counts of interrupts serviced since boot time, for each of the possible system interrupts. The first column is the total of all @@ -1167,13 +1181,11 @@ CHAPTER 3: PER-PROCESS PARAMETERS 3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score ------------------------------------------------------ -This file can be used to adjust the score used to select which processes should -be killed in an out-of-memory situation. The oom_adj value is a characteristic -of the task's mm, so all threads that share an mm with pid will have the same -oom_adj value. A high value will increase the likelihood of this process being -killed by the oom-killer. Valid values are in the range -16 to +15 as -explained below and a special value of -17, which disables oom-killing -altogether for threads sharing pid's mm. +This file can be used to adjust the score used to select which processes +should be killed in an out-of-memory situation. Giving it a high score will +increase the likelihood of this process being killed by the oom-killer. Valid +values are in the range -16 to +15, plus the special value -17, which disables +oom-killing altogether for this process. The process to be killed in an out-of-memory situation is selected among all others based on its badness score. This value equals the original memory size of the process @@ -1187,16 +1199,13 @@ the parent's score if they do not share the same memory. Thus forking servers are the prime candidates to be killed. Having only one 'hungry' child will make parent less preferable than the child. -/proc/<pid>/oom_adj cannot be changed for kthreads since they are immune from -oom-killing already. - /proc/<pid>/oom_score shows process' current badness score. The following heuristics are then applied: * if the task was reniced, its score doubles * superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE or CAP_SYS_RAWIO) have their score divided by 4 - * if oom condition happened in one cpuset and checked task does not belong + * if oom condition happened in one cpuset and checked process does not belong to it, its score is divided by 8 * the resulting score is multiplied by two to the power of oom_adj, i.e. points <<= oom_adj when it is positive and diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt index b843743aa0b..0d15ebccf5b 100644 --- a/Documentation/filesystems/seq_file.txt +++ b/Documentation/filesystems/seq_file.txt @@ -46,7 +46,7 @@ better to do. The file is seekable, in that one can do something like the following: dd if=/proc/sequence of=out1 count=1 - dd if=/proc/sequence skip=1 out=out2 count=1 + dd if=/proc/sequence skip=1 of=out2 count=1 Then concatenate the output files out1 and out2 and get the right result. Yes, it is a thoroughly useless module, but the point is to show |