diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/9p.txt | 40 | ||||
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 13 | ||||
| -rw-r--r-- | Documentation/filesystems/ncpfs.txt | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs41-server.txt | 54 | ||||
| -rw-r--r-- | Documentation/filesystems/nfsroot.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 28 | ||||
| -rw-r--r-- | Documentation/filesystems/sharedsubtree.txt | 220 | ||||
| -rw-r--r-- | Documentation/filesystems/vfat.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 7 |
9 files changed, 166 insertions, 206 deletions
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index 6208f55c44c3..57e0b80a5274 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/ext4.txt b/Documentation/filesystems/ext4.txt index 18b5ec8cea45..bf4f4b7e11b3 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -282,9 +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 f12c30c93f2f..5af164f4b37b 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 05d81cbcb2e1..5920fe26e6ff 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 68baddf3c3e0..3ba0b945aaf8 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 ffead13f9443..2c48f945546b 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 736540045dc7..23a181074f94 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 b58b84b50fa2..eed520fd0c8e 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 f49eecf2e573..623f094c9d8d 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 =============== |