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authorIngo Molnar <mingo@elte.hu>2009-10-25 17:30:53 +0100
committerIngo Molnar <mingo@elte.hu>2009-10-25 17:30:53 +0100
commit0b9e31e9264f1bad89856afb96da1688292f13b4 (patch)
tree7a9e9b6456dce993efeed8734de0a15a1f16ae94 /Documentation/filesystems
parentcf82ff7ea7695b0e82ba07bc5e9f1bd03a74e1aa (diff)
parent964fe080d94db82a3268443e9b9ece4c60246414 (diff)
Merge branch 'linus' into sched/core
Conflicts: fs/proc/array.c Merge reason: resolve conflict and queue up dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/9p.txt40
-rw-r--r--Documentation/filesystems/ext3.txt16
-rw-r--r--Documentation/filesystems/ext4.txt37
-rw-r--r--Documentation/filesystems/ncpfs.txt6
-rw-r--r--Documentation/filesystems/nfs41-server.txt54
-rw-r--r--Documentation/filesystems/nfsroot.txt2
-rw-r--r--Documentation/filesystems/proc.txt28
-rw-r--r--Documentation/filesystems/sharedsubtree.txt220
-rw-r--r--Documentation/filesystems/vfat.txt2
-rw-r--r--Documentation/filesystems/vfs.txt7
10 files changed, 191 insertions, 221 deletions
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 6208f55c44c..57e0b80a527 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -18,11 +18,11 @@ the 9p client is available in the form of a USENIX paper:
Other applications are described in the following papers:
* XCPU & Clustering
- http://www.xcpu.org/xcpu-talk.pdf
+ http://xcpu.org/papers/xcpu-talk.pdf
* KVMFS: control file system for KVM
- http://www.xcpu.org/kvmfs.pdf
- * CellFS: A New ProgrammingModel for the Cell BE
- http://www.xcpu.org/cellfs-talk.pdf
+ http://xcpu.org/papers/kvmfs.pdf
+ * CellFS: A New Programming Model for the Cell BE
+ http://xcpu.org/papers/cellfs-talk.pdf
* PROSE I/O: Using 9p to enable Application Partitions
http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
@@ -48,6 +48,7 @@ OPTIONS
(see rfdno and wfdno)
virtio - connect to the next virtio channel available
(from lguest or KVM with trans_virtio module)
+ rdma - connect to a specified RDMA channel
uname=name user name to attempt mount as on the remote server. The
server may override or ignore this value. Certain user
@@ -59,16 +60,22 @@ OPTIONS
cache=mode specifies a caching policy. By default, no caches are used.
loose = no attempts are made at consistency,
intended for exclusive, read-only mounts
+ fscache = use FS-Cache for a persistent, read-only
+ cache backend.
debug=n specifies debug level. The debug level is a bitmask.
- 0x01 = display verbose error messages
- 0x02 = developer debug (DEBUG_CURRENT)
- 0x04 = display 9p trace
- 0x08 = display VFS trace
- 0x10 = display Marshalling debug
- 0x20 = display RPC debug
- 0x40 = display transport debug
- 0x80 = display allocation debug
+ 0x01 = display verbose error messages
+ 0x02 = developer debug (DEBUG_CURRENT)
+ 0x04 = display 9p trace
+ 0x08 = display VFS trace
+ 0x10 = display Marshalling debug
+ 0x20 = display RPC debug
+ 0x40 = display transport debug
+ 0x80 = display allocation debug
+ 0x100 = display protocol message debug
+ 0x200 = display Fid debug
+ 0x400 = display packet debug
+ 0x800 = display fscache tracing debug
rfdno=n the file descriptor for reading with trans=fd
@@ -100,6 +107,10 @@ OPTIONS
any = v9fs does single attach and performs all
operations as one user
+ cachetag cache tag to use the specified persistent cache.
+ cache tags for existing cache sessions can be listed at
+ /sys/fs/9p/caches. (applies only to cache=fscache)
+
RESOURCES
=========
@@ -118,7 +129,7 @@ and export.
A Linux version of the 9p server is now maintained under the npfs project
on sourceforge (http://sourceforge.net/projects/npfs). The currently
maintained version is the single-threaded version of the server (named spfs)
-available from the same CVS repository.
+available from the same SVN repository.
There are user and developer mailing lists available through the v9fs project
on sourceforge (http://sourceforge.net/projects/v9fs).
@@ -126,7 +137,8 @@ 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).
+News and other information is maintained on SWiK (http://swik.net/v9fs)
+and the Wiki (http://sf.net/apps/mediawiki/v9fs/index.php).
Bug reports may be issued through the kernel.org bugzilla
(http://bugzilla.kernel.org)
diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt
index 570f9bd9be2..05d5cf1d743 100644
--- a/Documentation/filesystems/ext3.txt
+++ b/Documentation/filesystems/ext3.txt
@@ -123,10 +123,18 @@ 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 (*) ext3 associates buffer heads to data pages to
nobh (a) cache disk block mapping information
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 7be02ac5fa3..bf4f4b7e11b 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
@@ -280,9 +282,16 @@ stripe=n Number of filesystem blocks that mballoc will try
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data
disks * RAID chunk size in file system blocks.
-delalloc (*) Deferring block allocation until write-out time.
-nodelalloc Disable delayed allocation. Blocks are allocation
- when data is copied from user to page cache.
+
+delalloc (*) Defer block allocation until just before ext4
+ writes out the block(s) in question. This
+ allows ext4 to better allocation decisions
+ more efficiently.
+nodelalloc Disable delayed allocation. Blocks are allocated
+ when the data is copied from userspace to the
+ page cache, either via the write(2) system call
+ or when an mmap'ed page which was previously
+ unallocated is written for the first time.
max_batch_time=usec Maximum amount of time ext4 should wait for
additional filesystem operations to be batch
diff --git a/Documentation/filesystems/ncpfs.txt b/Documentation/filesystems/ncpfs.txt
index f12c30c93f2..5af164f4b37 100644
--- a/Documentation/filesystems/ncpfs.txt
+++ b/Documentation/filesystems/ncpfs.txt
@@ -7,6 +7,6 @@ ftp.gwdg.de/pub/linux/misc/ncpfs, but sunsite and its many mirrors
will have it as well.
Related products are linware and mars_nwe, which will give Linux partial
-NetWare server functionality. Linware's home site is
-klokan.sh.cvut.cz/pub/linux/linware; mars_nwe can be found on
-ftp.gwdg.de/pub/linux/misc/ncpfs.
+NetWare server functionality.
+
+mars_nwe can be found on ftp.gwdg.de/pub/linux/misc/ncpfs.
diff --git a/Documentation/filesystems/nfs41-server.txt b/Documentation/filesystems/nfs41-server.txt
index 05d81cbcb2e..5920fe26e6f 100644
--- a/Documentation/filesystems/nfs41-server.txt
+++ b/Documentation/filesystems/nfs41-server.txt
@@ -11,6 +11,11 @@ the /proc/fs/nfsd/versions control file. Note that to write this
control file, the nfsd service must be taken down. Use your user-mode
nfs-utils to set this up; see rpc.nfsd(8)
+(Warning: older servers will interpret "+4.1" and "-4.1" as "+4" and
+"-4", respectively. Therefore, code meant to work on both new and old
+kernels must turn 4.1 on or off *before* turning support for version 4
+on or off; rpc.nfsd does this correctly.)
+
The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based
on the latest NFSv4.1 Internet Draft:
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29
@@ -25,6 +30,49 @@ are still under development out of tree.
See http://wiki.linux-nfs.org/wiki/index.php/PNFS_prototype_design
for more information.
+The current implementation is intended for developers only: while it
+does support ordinary file operations on clients we have tested against
+(including the linux client), it is incomplete in ways which may limit
+features unexpectedly, cause known bugs in rare cases, or cause
+interoperability problems with future clients. Known issues:
+
+ - gss support is questionable: currently mounts with kerberos
+ from a linux client are possible, but we aren't really
+ conformant with the spec (for example, we don't use kerberos
+ on the backchannel correctly).
+ - no trunking support: no clients currently take advantage of
+ trunking, but this is a mandatory failure, and its use is
+ recommended to clients in a number of places. (E.g. to ensure
+ timely renewal in case an existing connection's retry timeouts
+ have gotten too long; see section 8.3 of the draft.)
+ Therefore, lack of this feature may cause future clients to
+ fail.
+ - Incomplete backchannel support: incomplete backchannel gss
+ support and no support for BACKCHANNEL_CTL mean that
+ callbacks (hence delegations and layouts) may not be
+ available and clients confused by the incomplete
+ implementation may fail.
+ - Server reboot recovery is unsupported; if the server reboots,
+ clients may fail.
+ - We do not support SSV, which provides security for shared
+ client-server state (thus preventing unauthorized tampering
+ with locks and opens, for example). It is mandatory for
+ servers to support this, though no clients use it yet.
+ - Mandatory operations which we do not support, such as
+ DESTROY_CLIENTID, FREE_STATEID, SECINFO_NO_NAME, and
+ TEST_STATEID, are not currently used by clients, but will be
+ (and the spec recommends their uses in common cases), and
+ clients should not be expected to know how to recover from the
+ case where they are not supported. This will eventually cause
+ interoperability failures.
+
+In addition, some limitations are inherited from the current NFSv4
+implementation:
+
+ - Incomplete delegation enforcement: if a file is renamed or
+ unlinked, a client holding a delegation may continue to
+ indefinitely allow opens of the file under the old name.
+
The table below, taken from the NFSv4.1 document, lists
the operations that are mandatory to implement (REQ), optional
(OPT), and NFSv4.0 operations that are required not to implement (MNI)
@@ -142,6 +190,12 @@ NS*| CB_WANTS_CANCELLED | OPT | FDELG, | Section 20.10 |
Implementation notes:
+DELEGPURGE:
+* mandatory only for servers that support CLAIM_DELEGATE_PREV and/or
+ CLAIM_DELEG_PREV_FH (which allows clients to keep delegations that
+ persist across client reboots). Thus we need not implement this for
+ now.
+
EXCHANGE_ID:
* only SP4_NONE state protection supported
* implementation ids are ignored
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 ffead13f944..2c48f945546 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -176,6 +176,7 @@ read the file /proc/PID/status:
CapBnd: ffffffffffffffff
voluntary_ctxt_switches: 0
nonvoluntary_ctxt_switches: 1
+ Stack usage: 12 kB
This shows you nearly the same information you would get if you viewed it with
the ps command. In fact, ps uses the proc file system to obtain its
@@ -229,6 +230,7 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7)
Mems_allowed_list Same as previous, but in "list format"
voluntary_ctxt_switches number of voluntary context switches
nonvoluntary_ctxt_switches number of non voluntary context switches
+ Stack usage: stack usage high water mark (round up to page size)
..............................................................................
Table 1-3: Contents of the statm files (as of 2.6.8-rc3)
@@ -307,7 +309,7 @@ address perms offset dev inode pathname
08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
a7cb1000-a7cb2000 ---p 00000000 00:00 0
-a7cb2000-a7eb2000 rw-p 00000000 00:00 0
+a7cb2000-a7eb2000 rw-p 00000000 00:00 0 [threadstack:001ff4b4]
a7eb2000-a7eb3000 ---p 00000000 00:00 0
a7eb3000-a7ed5000 rw-p 00000000 00:00 0
a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
@@ -343,6 +345,7 @@ is not associated with a file:
[stack] = the stack of the main process
[vdso] = the "virtual dynamic shared object",
the kernel system call handler
+ [threadstack:xxxxxxxx] = the stack of the thread, xxxxxxxx is the stack size
or if empty, the mapping is anonymous.
@@ -375,6 +378,19 @@ 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 +1048,9 @@ 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 +1072,7 @@ 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
@@ -1096,7 +1113,6 @@ Table 1-12: Files in /proc/fs/ext4/<devname>
..............................................................................
File Content
mb_groups details of multiblock allocator buddy cache of free blocks
- mb_history multiblock allocation history
..............................................................................
@@ -1191,7 +1207,7 @@ 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/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt
index 736540045dc..23a181074f9 100644
--- a/Documentation/filesystems/sharedsubtree.txt
+++ b/Documentation/filesystems/sharedsubtree.txt
@@ -4,7 +4,7 @@ Shared Subtrees
Contents:
1) Overview
2) Features
- 3) smount command
+ 3) Setting mount states
4) Use-case
5) Detailed semantics
6) Quiz
@@ -41,14 +41,14 @@ replicas continue to be exactly same.
Here is an example:
- Lets say /mnt has a mount that is shared.
+ Let's say /mnt has a mount that is shared.
mount --make-shared /mnt
- note: mount command does not yet support the --make-shared flag.
- I have included a small C program which does the same by executing
- 'smount /mnt shared'
+ Note: mount(8) command now supports the --make-shared flag,
+ so the sample 'smount' program is no longer needed and has been
+ removed.
- #mount --bind /mnt /tmp
+ # mount --bind /mnt /tmp
The above command replicates the mount at /mnt to the mountpoint /tmp
and the contents of both the mounts remain identical.
@@ -58,8 +58,8 @@ replicas continue to be exactly same.
#ls /tmp
a b c
- Now lets say we mount a device at /tmp/a
- #mount /dev/sd0 /tmp/a
+ Now let's say we mount a device at /tmp/a
+ # mount /dev/sd0 /tmp/a
#ls /tmp/a
t1 t2 t2
@@ -80,21 +80,20 @@ replicas continue to be exactly same.
Here is an example:
- Lets say /mnt has a mount which is shared.
- #mount --make-shared /mnt
+ Let's say /mnt has a mount which is shared.
+ # mount --make-shared /mnt
- Lets bind mount /mnt to /tmp
- #mount --bind /mnt /tmp
+ Let's bind mount /mnt to /tmp
+ # mount --bind /mnt /tmp
the new mount at /tmp becomes a shared mount and it is a replica of
the mount at /mnt.
- Now lets make the mount at /tmp; a slave of /mnt
- #mount --make-slave /tmp
- [or smount /tmp slave]
+ Now let's make the mount at /tmp; a slave of /mnt
+ # mount --make-slave /tmp
- lets mount /dev/sd0 on /mnt/a
- #mount /dev/sd0 /mnt/a
+ let's mount /dev/sd0 on /mnt/a
+ # mount /dev/sd0 /mnt/a
#ls /mnt/a
t1 t2 t3
@@ -104,9 +103,9 @@ replicas continue to be exactly same.
Note the mount event has propagated to the mount at /tmp
- However lets see what happens if we mount something on the mount at /tmp
+ However let's see what happens if we mount something on the mount at /tmp
- #mount /dev/sd1 /tmp/b
+ # mount /dev/sd1 /tmp/b
#ls /tmp/b
s1 s2 s3
@@ -124,12 +123,11 @@ replicas continue to be exactly same.
2d) A unbindable mount is a unbindable private mount
- lets say we have a mount at /mnt and we make is unbindable
+ let's say we have a mount at /mnt and we make is unbindable
- #mount --make-unbindable /mnt
- [ smount /mnt unbindable ]
+ # mount --make-unbindable /mnt
- Lets try to bind mount this mount somewhere else.
+ Let's try to bind mount this mount somewhere else.
# mount --bind /mnt /tmp
mount: wrong fs type, bad option, bad superblock on /mnt,
or too many mounted file systems
@@ -137,149 +135,15 @@ replicas continue to be exactly same.
Binding a unbindable mount is a invalid operation.
-3) smount command
+3) Setting mount states
- Currently the mount command is not aware of shared subtree features.
- Work is in progress to add the support in mount ( util-linux package ).
- Till then use the following program.
+ The mount command (util-linux package) can be used to set mount
+ states:
- ------------------------------------------------------------------------
- //
- //this code was developed my Miklos Szeredi <miklos@szeredi.hu>
- //and modified by Ram Pai <linuxram@us.ibm.com>
- // sample usage:
- // smount /tmp shared
- //
- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <string.h>
- #include <sys/mount.h>
- #include <sys/fsuid.h>
-
- #ifndef MS_REC
- #define MS_REC 0x4000 /* 16384: Recursive loopback */
- #endif
-
- #ifndef MS_SHARED
- #define MS_SHARED 1<<20 /* Shared */
- #endif
-
- #ifndef MS_PRIVATE
- #define MS_PRIVATE 1<<18 /* Private */
- #endif
-
- #ifndef MS_SLAVE
- #define MS_SLAVE 1<<19 /* Slave */
- #endif
-
- #ifndef MS_UNBINDABLE
- #define MS_UNBINDABLE 1<<17 /* Unbindable */
- #endif
-
- int main(int argc, char *argv[])
- {
- int type;
- if(argc != 3) {
- fprintf(stderr, "usage: %s dir "
- "<rshared|rslave|rprivate|runbindable|shared|slave"
- "|private|unbindable>\n" , argv[0]);
- return 1;
- }
-
- fprintf(stdout, "%s %s %s\n", argv[0], argv[1], argv[2]);
-
- if (strcmp(argv[2],"rshared")==0)
- type=(MS_SHARED|MS_REC);
- else if (strcmp(argv[2],"rslave")==0)
- type=(MS_SLAVE|MS_REC);
- else if (strcmp(argv[2],"rprivate")==0)
- type=(MS_PRIVATE|MS_REC);
- else if (strcmp(argv[2],"runbindable")==0)
- type=(MS_UNBINDABLE|MS_REC);
- else if (strcmp(argv[2],"shared")==0)
- type=MS_SHARED;
- else if (strcmp(argv[2],"slave")==0)
- type=MS_SLAVE;
- else if (strcmp(argv[2],"private")==0)
- type=MS_PRIVATE;
- else if (strcmp(argv[2],"unbindable")==0)
- type=MS_UNBINDABLE;
- else {
- fprintf(stderr, "invalid operation: %s\n", argv[2]);
- return 1;
- }
- setfsuid(getuid());
-
- if(mount("", argv[1], "dontcare", type, "") == -1) {
- perror("mount");
- return 1;
- }
- return 0;
- }
- -----------------------------------------------------------------------
-
- Copy the above code snippet into smount.c
- gcc -o smount smount.c
-
-
- (i) To mark all the mounts under /mnt as shared execute the following
- command:
-
- smount /mnt rshared
- the corresponding syntax planned for mount command is
- mount --make-rshared /mnt
-
- just to mark a mount /mnt as shared, execute the following
- command:
- smount /mnt shared
- the corresponding syntax planned for mount command is
- mount --make-shared /mnt
-
- (ii) To mark all the shared mounts under /mnt as slave execute the
- following
-
- command:
- smount /mnt rslave
- the corresponding syntax planned for mount command is
- mount --make-rslave /mnt
-
- just to mark a mount /mnt as slave, execute the following
- command:
- smount /mnt slave
- the corresponding syntax planned for mount command is
- mount --make-slave /mnt
-
- (iii) To mark all the mounts under /mnt as private execute the
- following command:
-
- smount /mnt rprivate
- the corresponding syntax planned for mount command is
- mount --make-rprivate /mnt
-
- just to mark a mount /mnt as private, execute the following
- command:
- smount /mnt private
- the corresponding syntax planned for mount command is
- mount --make-private /mnt
-
- NOTE: by default all the mounts are created as private. But if
- you want to change some shared/slave/unbindable mount as
- private at a later point in time, this command can help.
-
- (iv) To mark all the mounts under /mnt as unbindable execute the
- following
-
- command:
- smount /mnt runbindable
- the corresponding syntax planned for mount command is
- mount --make-runbindable /mnt
-
- just to mark a mount /mnt as unbindable, execute the following
- command:
- smount /mnt unbindable
- the corresponding syntax planned for mount command is
- mount --make-unbindable /mnt
+ mount --make-shared mountpoint
+ mount --make-slave mountpoint
+ mount --make-private mountpoint
+ mount --make-unbindable mountpoint
4) Use cases
@@ -350,7 +214,7 @@ replicas continue to be exactly same.
mount --rbind / /view/v3
mount --rbind / /view/v4
- and if /usr has a versioning filesystem mounted, than that
+ and if /usr has a versioning filesystem mounted, then that
mount appears at /view/v1/usr, /view/v2/usr, /view/v3/usr and
/view/v4/usr too
@@ -390,7 +254,7 @@ replicas continue to be exactly same.
For example:
mount --make-shared /mnt
- mount --bin /mnt /tmp
+ mount --bind /mnt /tmp
The mount at /mnt and that at /tmp are both shared and belong
to the same peer group. Anything mounted or unmounted under
@@ -558,7 +422,7 @@ replicas continue to be exactly same.
then the subtree under the unbindable mount is pruned in the new
location.
- eg: lets say we have the following mount tree.
+ eg: let's say we have the following mount tree.
A
/ \
@@ -566,7 +430,7 @@ replicas continue to be exactly same.
/ \ / \
D E F G
- Lets say all the mount except the mount C in the tree are
+ Let's say all the mount except the mount C in the tree are
of a type other than unbindable.
If this tree is rbound to say Z
@@ -683,13 +547,13 @@ replicas continue to be exactly same.
'b' on mounts that receive propagation from mount 'B' and does not have
sub-mounts within them are unmounted.
- Example: Lets say 'B1', 'B2', 'B3' are shared mounts that propagate to
+ Example: Let's say 'B1', 'B2', 'B3' are shared mounts that propagate to
each other.
- lets say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
+ let's say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
'B1', 'B2' and 'B3' respectively.
- lets say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
+ let's say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
mount 'B1', 'B2' and 'B3' respectively.
if 'C1' is unmounted, all the mounts that are most-recently-mounted on
@@ -710,7 +574,7 @@ replicas continue to be exactly same.
A cloned namespace contains all the mounts as that of the parent
namespace.
- Lets say 'A' and 'B' are the corresponding mounts in the parent and the
+ Let's say 'A' and 'B' are the corresponding mounts in the parent and the
child namespace.
If 'A' is shared, then 'B' is also shared and 'A' and 'B' propagate to
@@ -759,11 +623,11 @@ replicas continue to be exactly same.
mount --make-slave /mnt
At this point we have the first mount at /tmp and
- its root dentry is 1. Lets call this mount 'A'
+ its root dentry is 1. Let's call this mount 'A'
And then we have a second mount at /tmp1 with root
- dentry 2. Lets call this mount 'B'
+ dentry 2. Let's call this mount 'B'
Next we have a third mount at /mnt with root dentry
- mnt. Lets call this mount 'C'
+ mnt. Let's call this mount 'C'
'B' is the slave of 'A' and 'C' is a slave of 'B'
A -> B -> C
@@ -794,7 +658,7 @@ replicas continue to be exactly same.
Q3 Why is unbindable mount needed?
- Lets say we want to replicate the mount tree at multiple
+ Let's say we want to replicate the mount tree at multiple
locations within the same subtree.
if one rbind mounts a tree within the same subtree 'n' times
@@ -803,7 +667,7 @@ replicas continue to be exactly same.
mounts. Here is a example.
step 1:
- lets say the root tree has just two directories with
+ let's say the root tree has just two directories with
one vfsmount.
root
/ \
@@ -875,7 +739,7 @@ replicas continue to be exactly same.
Unclonable mounts come in handy here.
step 1:
- lets say the root tree has just two directories with
+ let's say the root tree has just two directories with
one vfsmount.
root
/ \
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index b58b84b50fa..eed520fd0c8 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -102,7 +102,7 @@ shortname=lower|win95|winnt|mixed
winnt: emulate the Windows NT rule for display/create.
mixed: emulate the Windows NT rule for display,
emulate the Windows 95 rule for create.
- Default setting is `lower'.
+ Default setting is `mixed'.
tz=UTC -- Interpret timestamps as UTC rather than local time.
This option disables the conversion of timestamps
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index f49eecf2e57..623f094c9d8 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -536,6 +536,7 @@ struct address_space_operations {
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
+ int (*error_remove_page) (struct mapping *mapping, struct page *page);
};
writepage: called by the VM to write a dirty page to backing store.
@@ -694,6 +695,12 @@ struct address_space_operations {
prevent redirtying the page, it is kept locked during the whole
operation.
+ error_remove_page: normally set to generic_error_remove_page if truncation
+ is ok for this address space. Used for memory failure handling.
+ Setting this implies you deal with pages going away under you,
+ unless you have them locked or reference counts increased.
+
+
The File Object
===============