diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/configfs/configfs.txt | 11 | ||||
| -rw-r--r-- | Documentation/filesystems/devpts.txt | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/efivarfs.txt | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs/fault_injection.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs/nfs-rdma.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs/nfsroot.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs/pnfs.txt | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs/rpc-server-gss.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 38 | ||||
| -rw-r--r-- | Documentation/filesystems/sharedsubtree.txt | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/tmpfs.txt | 8 | ||||
| -rw-r--r-- | Documentation/filesystems/vfat.txt | 10 |
14 files changed, 85 insertions, 40 deletions
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt index e5fe521eea1d..8ec9136aae56 100644 --- a/Documentation/filesystems/configfs/configfs.txt +++ b/Documentation/filesystems/configfs/configfs.txt @@ -250,7 +250,8 @@ child item. struct config_item cg_item; struct list_head cg_children; struct configfs_subsystem *cg_subsys; - struct config_group **default_groups; + struct list_head default_groups; + struct list_head group_entry; }; void config_group_init(struct config_group *group); @@ -420,15 +421,15 @@ These automatic subgroups, or default groups, do not preclude other children of the parent group. If ct_group_ops->make_group() exists, other child groups can be created on the parent group directly. -A configfs subsystem specifies default groups by filling in the -NULL-terminated array default_groups on the config_group structure. -Each group in that array is populated in the configfs tree at the same +A configfs subsystem specifies default groups by adding them using the +configfs_add_default_group() function to the parent config_group +structure. Each added group is populated in the configfs tree at the same time as the parent group. Similarly, they are removed at the same time as the parent. No extra notification is provided. When a ->drop_item() method call notifies the subsystem the parent group is going away, it also means every default group child associated with that parent group. -As a consequence of this, default_groups cannot be removed directly via +As a consequence of this, default groups cannot be removed directly via rmdir(2). They also are not considered when rmdir(2) on the parent group is checking for children. diff --git a/Documentation/filesystems/devpts.txt b/Documentation/filesystems/devpts.txt index 68dffd87f9b7..30d2fcb32f72 100644 --- a/Documentation/filesystems/devpts.txt +++ b/Documentation/filesystems/devpts.txt @@ -51,6 +51,15 @@ where 'ns_exec -cm /bin/bash' calls clone() with CLONE_NEWNS flag and execs /bin/bash in the child process. A pty created by the sshd is not visible in the original mount of /dev/pts. +Total count of pty pairs in all instances is limited by sysctls: +kernel.pty.max = 4096 - global limit +kernel.pty.reserve = 1024 - reserve for initial instance +kernel.pty.nr - current count of ptys + +Per-instance limit could be set by adding mount option "max=<count>". +This feature was added in kernel 3.4 together with sysctl kernel.pty.reserve. +In kernels older than 3.4 sysctl kernel.pty.max works as per-instance limit. + User-space changes ------------------ diff --git a/Documentation/filesystems/efivarfs.txt b/Documentation/filesystems/efivarfs.txt index c477af086e65..686a64bba775 100644 --- a/Documentation/filesystems/efivarfs.txt +++ b/Documentation/filesystems/efivarfs.txt @@ -14,3 +14,10 @@ filesystem. efivarfs is typically mounted like this, mount -t efivarfs none /sys/firmware/efi/efivars + +Due to the presence of numerous firmware bugs where removing non-standard +UEFI variables causes the system firmware to fail to POST, efivarfs +files that are not well-known standardized variables are created +as immutable files. This doesn't prevent removal - "chattr -i" will work - +but it does prevent this kind of failure from being accomplished +accidentally. diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index b102b436563e..e1c9f0849da6 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -102,7 +102,7 @@ background_gc=%s Turn on/off cleaning operations, namely garbage collection, triggered in background when I/O subsystem is idle. If background_gc=on, it will turn on the garbage collection and if background_gc=off, garbage collection - will be truned off. If background_gc=sync, it will turn + will be turned off. If background_gc=sync, it will turn on synchronous garbage collection running in background. Default value for this option is on. So garbage collection is on by default. @@ -145,10 +145,12 @@ extent_cache Enable an extent cache based on rb-tree, it can cache as many as extent which map between contiguous logical address and physical address per inode, resulting in increasing the cache hit ratio. Set by default. -noextent_cache Diable an extent cache based on rb-tree explicitly, see +noextent_cache Disable an extent cache based on rb-tree explicitly, see the above extent_cache mount option. noinline_data Disable the inline data feature, inline data feature is enabled by default. +data_flush Enable data flushing before checkpoint in order to + persist data of regular and symlink. ================================================================================ DEBUGFS ENTRIES @@ -192,7 +194,7 @@ Files in /sys/fs/f2fs/<devname> policy for garbage collection. Setting gc_idle = 0 (default) will disable this option. Setting gc_idle = 1 will select the Cost Benefit approach - & setting gc_idle = 2 will select the greedy aproach. + & setting gc_idle = 2 will select the greedy approach. reclaim_segments This parameter controls the number of prefree segments to be reclaimed. If the number of prefree @@ -298,7 +300,7 @@ The dump.f2fs shows the information of specific inode and dumps SSA and SIT to file. Each file is dump_ssa and dump_sit. The dump.f2fs is used to debug on-disk data structures of the f2fs filesystem. -It shows on-disk inode information reconized by a given inode number, and is +It shows on-disk inode information recognized by a given inode number, and is able to dump all the SSA and SIT entries into predefined files, ./dump_ssa and ./dump_sit respectively. diff --git a/Documentation/filesystems/nfs/fault_injection.txt b/Documentation/filesystems/nfs/fault_injection.txt index 426d166089a3..f3a5b0a8ac05 100644 --- a/Documentation/filesystems/nfs/fault_injection.txt +++ b/Documentation/filesystems/nfs/fault_injection.txt @@ -49,13 +49,13 @@ forget_locks: forget_delegations: A delegation is used to assure the client that a file, or part of a file, has not changed since the delegation was awarded. Clearing this list will - force the client to reaquire its delegation before accessing the file + force the client to reacquire its delegation before accessing the file again. recall_delegations: Delegations can be recalled by the server when another client attempts to access a file. This test will notify the client that its delegation has - been revoked, forcing the client to reaquire the delegation before using + been revoked, forcing the client to reacquire the delegation before using the file again. diff --git a/Documentation/filesystems/nfs/nfs-rdma.txt b/Documentation/filesystems/nfs/nfs-rdma.txt index 906b6c233f62..1e6564545edf 100644 --- a/Documentation/filesystems/nfs/nfs-rdma.txt +++ b/Documentation/filesystems/nfs/nfs-rdma.txt @@ -218,7 +218,7 @@ NFS/RDMA Setup /vol0 192.168.0.0/255.255.255.0(fsid=0,rw,async,insecure,no_root_squash) The IP address(es) is(are) the client's IPoIB address for an InfiniBand - HCA or the cleint's iWARP address(es) for an RNIC. + HCA or the client's iWARP address(es) for an RNIC. NOTE: The "insecure" option must be used because the NFS/RDMA client does not use a reserved port. diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt index bb5ab6de5924..0b2883b17d4c 100644 --- a/Documentation/filesystems/nfs/nfsroot.txt +++ b/Documentation/filesystems/nfs/nfsroot.txt @@ -166,7 +166,7 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>: Value gets exported by /proc/net/pnp which is often linked on embedded systems by /etc/resolv.conf. - <dns1-ip> IP address of secound nameserver. + <dns1-ip> IP address of second nameserver. Same as above. diff --git a/Documentation/filesystems/nfs/pnfs.txt b/Documentation/filesystems/nfs/pnfs.txt index 44a9f2493a88..8de578a98222 100644 --- a/Documentation/filesystems/nfs/pnfs.txt +++ b/Documentation/filesystems/nfs/pnfs.txt @@ -64,8 +64,8 @@ table which are called by the nfs-client pnfs-core to implement the different layout types. Files-layout-driver code is in: fs/nfs/filelayout/.. directory -Objects-layout-deriver code is in: fs/nfs/objlayout/.. directory -Blocks-layout-deriver code is in: fs/nfs/blocklayout/.. directory +Objects-layout-driver code is in: fs/nfs/objlayout/.. directory +Blocks-layout-driver code is in: fs/nfs/blocklayout/.. directory Flexfiles-layout-driver code is in: fs/nfs/flexfilelayout/.. directory objects-layout setup @@ -91,7 +91,7 @@ The API to the login script is as follows: Usage: $0 -u <URI> -o <OSDNAME> -s <SYSTEMID> Options: -u target uri e.g. iscsi://<ip>:<port> - (allways exists) + (always exists) (More protocols can be defined in the future. The client does not interpret this string it is passed unchanged as received from the Server) diff --git a/Documentation/filesystems/nfs/rpc-server-gss.txt b/Documentation/filesystems/nfs/rpc-server-gss.txt index 716f4be8e8b3..310bbbaf9080 100644 --- a/Documentation/filesystems/nfs/rpc-server-gss.txt +++ b/Documentation/filesystems/nfs/rpc-server-gss.txt @@ -57,7 +57,7 @@ the Kerberos tickets, that needs to be sent through the GSS layer in order to perform context establishment. B) It does not properly handle creds where the user is member of more -than a few housand groups (the current hard limit in the kernel is 65K +than a few thousand groups (the current hard limit in the kernel is 65K groups) due to limitation on the size of the buffer that can be send back to the kernel (4KiB). diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 0f88e6020487..f1b87d8aa2da 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -508,7 +508,11 @@ in your dentry operations instead. [mandatory] any symlink that might use page_follow_link_light/page_put_link() must have inode_nohighmem(inode) called before anything might start playing with - its pagecache. + its pagecache. No highmem pages should end up in the pagecache of such + symlinks. That includes any preseeding that might be done during symlink + creation. __page_symlink() will honour the mapping gfp flags, so once + you've done inode_nohighmem() it's safe to use, but if you allocate and + insert the page manually, make sure to use the right gfp flags. -- [mandatory] ->follow_link() is replaced with ->get_link(); same API, except that diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 402ab99e409f..843b045b4069 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -169,6 +169,9 @@ read the file /proc/PID/status: VmLck: 0 kB VmHWM: 476 kB VmRSS: 476 kB + RssAnon: 352 kB + RssFile: 120 kB + RssShmem: 4 kB VmData: 156 kB VmStk: 88 kB VmExe: 68 kB @@ -231,14 +234,20 @@ Table 1-2: Contents of the status files (as of 4.1) VmSize total program size VmLck locked memory size VmHWM peak resident set size ("high water mark") - VmRSS size of memory portions - VmData size of data, stack, and text segments - VmStk size of data, stack, and text segments + VmRSS size of memory portions. It contains the three + following parts (VmRSS = RssAnon + RssFile + RssShmem) + RssAnon size of resident anonymous memory + RssFile size of resident file mappings + RssShmem size of resident shmem memory (includes SysV shm, + mapping of tmpfs and shared anonymous mappings) + VmData size of private data segments + VmStk size of stack segments VmExe size of text segment VmLib size of shared library code VmPTE size of page table entries VmPMD size of second level page tables - VmSwap size of swap usage (the number of referred swapents) + VmSwap amount of swap used by anonymous private data + (shmem swap usage is not included) HugetlbPages size of hugetlb memory portions Threads number of threads SigQ number of signals queued/max. number for queue @@ -265,7 +274,8 @@ Table 1-3: Contents of the statm files (as of 2.6.8-rc3) Field Content size total program size (pages) (same as VmSize in status) resident size of memory portions (pages) (same as VmRSS in status) - shared number of pages that are shared (i.e. backed by a file) + shared number of pages that are shared (i.e. backed by a file, same + as RssFile+RssShmem in status) trs number of pages that are 'code' (not including libs; broken, includes data segment) lrs number of pages of library (always 0 on 2.6) @@ -346,7 +356,7 @@ address perms offset dev inode pathname a7cb1000-a7cb2000 ---p 00000000 00:00 0 a7cb2000-a7eb2000 rw-p 00000000 00:00 0 a7eb2000-a7eb3000 ---p 00000000 00:00 0 -a7eb3000-a7ed5000 rw-p 00000000 00:00 0 [stack:1001] +a7eb3000-a7ed5000 rw-p 00000000 00:00 0 a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6 a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6 a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6 @@ -378,7 +388,6 @@ is not associated with a file: [heap] = the heap of the program [stack] = the stack of the main process - [stack:1001] = the stack of the thread with tid 1001 [vdso] = the "virtual dynamic shared object", the kernel system call handler @@ -386,10 +395,8 @@ is not associated with a file: The /proc/PID/task/TID/maps is a view of the virtual memory from the viewpoint of the individual tasks of a process. In this file you will see a mapping marked -as [stack] if that task sees it as a stack. This is a key difference from the -content of /proc/PID/maps, where you will see all mappings that are being used -as stack by all of those tasks. Hence, for the example above, the task-level -map, i.e. /proc/PID/task/TID/maps for thread 1001 will look like this: +as [stack] if that task sees it as a stack. Hence, for the example above, the +task-level map, i.e. /proc/PID/task/TID/maps for thread 1001 will look like this: 08048000-08049000 r-xp 00000000 03:00 8312 /opt/test 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test @@ -459,7 +466,10 @@ and a page is modified, the file page is replaced by a private anonymous copy. hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field. "Swap" shows how much would-be-anonymous memory is also used, but out on swap. -"SwapPss" shows proportional swap share of this mapping. +For shmem mappings, "Swap" includes also the size of the mapped (and not +replaced by copy-on-write) part of the underlying shmem object out on swap. +"SwapPss" shows proportional swap share of this mapping. Unlike "Swap", this +does not take into account swapped out page of underlying shmem objects. "Locked" indicates whether the mapping is locked in memory or not. "VmFlags" field deserves a separate description. This member represents the kernel @@ -807,7 +817,7 @@ by migrate-type and finishes with details on how many page blocks of each type exist. If min_free_kbytes has been tuned correctly (recommendations made by hugeadm -from libhugetlbfs http://sourceforge.net/projects/libhugetlbfs/), one can +from libhugetlbfs https://github.com/libhugetlbfs/libhugetlbfs/), one can make an estimate of the likely number of huge pages that can be allocated at a given point in time. All the "Movable" blocks should be allocatable unless memory has been mlock()'d. Some of the Reclaimable blocks should @@ -842,6 +852,7 @@ Dirty: 968 kB Writeback: 0 kB AnonPages: 861800 kB Mapped: 280372 kB +Shmem: 644 kB Slab: 284364 kB SReclaimable: 159856 kB SUnreclaim: 124508 kB @@ -898,6 +909,7 @@ MemAvailable: An estimate of how much memory is available for starting new AnonPages: Non-file backed pages mapped into userspace page tables AnonHugePages: Non-file backed huge pages mapped into userspace page tables Mapped: files which have been mmaped, such as libraries + Shmem: Total memory used by shared memory (shmem) and tmpfs Slab: in-kernel data structures cache SReclaimable: Part of Slab, that might be reclaimed, such as caches SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt index 32a173dd3158..8ccfbd55244b 100644 --- a/Documentation/filesystems/sharedsubtree.txt +++ b/Documentation/filesystems/sharedsubtree.txt @@ -123,7 +123,7 @@ replicas continue to be exactly same. 2d) A unbindable mount is a unbindable private mount - let's say we have a mount at /mnt and we make is unbindable + let's say we have a mount at /mnt and we make it unbindable # mount --make-unbindable /mnt @@ -197,13 +197,13 @@ replicas continue to be exactly same. namespaces are made first class objects with user API to associate/disassociate a namespace with userid, then each user could have his/her own namespace and tailor it to his/her - requirements. Offcourse its needs support from PAM. + requirements. This needs to be supported in PAM. D) Versioned files If the entire mount tree is visible at multiple locations, then - a underlying versioning file system can return different - version of the file depending on the path used to access that + an underlying versioning file system can return different + versions of the file depending on the path used to access that file. An example is: @@ -664,7 +664,7 @@ replicas continue to be exactly same. if one rbind mounts a tree within the same subtree 'n' times the number of mounts created is an exponential function of 'n'. Having unbindable mount can help prune the unneeded bind - mounts. Here is a example. + mounts. Here is an example. step 1: let's say the root tree has just two directories with diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt index 98ef55124158..d392e1505f17 100644 --- a/Documentation/filesystems/tmpfs.txt +++ b/Documentation/filesystems/tmpfs.txt @@ -17,10 +17,10 @@ RAM, where you have to create an ordinary filesystem on top. Ramdisks cannot swap and you do not have the possibility to resize them. Since tmpfs lives completely in the page cache and on swap, all tmpfs -pages currently in memory will show up as cached. It will not show up -as shared or something like that. Further on you can check the actual -RAM+swap use of a tmpfs instance with df(1) and du(1). - +pages will be shown as "Shmem" in /proc/meminfo and "Shared" in +free(1). Notice that these counters also include shared memory +(shmem, see ipcs(1)). The most reliable way to get the count is +using df(1) and du(1). tmpfs has the following uses: diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt index ce1126aceed8..223c32171dcc 100644 --- a/Documentation/filesystems/vfat.txt +++ b/Documentation/filesystems/vfat.txt @@ -180,6 +180,16 @@ dos1xfloppy -- If set, use a fallback default BIOS Parameter Block <bool>: 0,1,yes,no,true,false +LIMITATION +--------------------------------------------------------------------- +* The fallocated region of file is discarded at umount/evict time + when using fallocate with FALLOC_FL_KEEP_SIZE. + So, User should assume that fallocated region can be discarded at + last close if there is memory pressure resulting in eviction of + the inode from the memory. As a result, for any dependency on + the fallocated region, user should make sure to recheck fallocate + after reopening the file. + TODO ---------------------------------------------------------------------- * Need to get rid of the raw scanning stuff. Instead, always use |
