aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems
diff options
context:
space:
mode:
authorIngo Molnar <mingo@elte.hu>2009-03-26 13:49:48 -0400
committerIngo Molnar <mingo@elte.hu>2009-03-26 13:49:48 -0400
commit18ffa418aead13c56515ac74cd26105102128aca (patch)
tree2096ea8db3b2594bd25ad39a70edc691219f669b /Documentation/filesystems
parentab76f3d771590d5c89faa3219559c5d3fc0ce0c2 (diff)
parent8e0ee43bc2c3e19db56a4adaa9a9b04ce885cd84 (diff)
Merge commit 'v2.6.29' into x86/setup-lzma
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/Locking8
-rw-r--r--Documentation/filesystems/ext2.txt9
-rw-r--r--Documentation/filesystems/ext3.txt4
-rw-r--r--Documentation/filesystems/nfs-rdma.txt4
-rw-r--r--Documentation/filesystems/proc.txt323
-rw-r--r--Documentation/filesystems/squashfs.txt2
-rw-r--r--Documentation/filesystems/sysfs-pci.txt13
-rw-r--r--Documentation/filesystems/sysfs.txt50
-rw-r--r--Documentation/filesystems/ubifs.txt7
-rw-r--r--Documentation/filesystems/vfs.txt8
10 files changed, 95 insertions, 333 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index cfbfa15a46ba..ec6a9392a173 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -97,8 +97,8 @@ prototypes:
97 void (*put_super) (struct super_block *); 97 void (*put_super) (struct super_block *);
98 void (*write_super) (struct super_block *); 98 void (*write_super) (struct super_block *);
99 int (*sync_fs)(struct super_block *sb, int wait); 99 int (*sync_fs)(struct super_block *sb, int wait);
100 void (*write_super_lockfs) (struct super_block *); 100 int (*freeze_fs) (struct super_block *);
101 void (*unlockfs) (struct super_block *); 101 int (*unfreeze_fs) (struct super_block *);
102 int (*statfs) (struct dentry *, struct kstatfs *); 102 int (*statfs) (struct dentry *, struct kstatfs *);
103 int (*remount_fs) (struct super_block *, int *, char *); 103 int (*remount_fs) (struct super_block *, int *, char *);
104 void (*clear_inode) (struct inode *); 104 void (*clear_inode) (struct inode *);
@@ -119,8 +119,8 @@ delete_inode: no
119put_super: yes yes no 119put_super: yes yes no
120write_super: no yes read 120write_super: no yes read
121sync_fs: no no read 121sync_fs: no no read
122write_super_lockfs: ? 122freeze_fs: ?
123unlockfs: ? 123unfreeze_fs: ?
124statfs: no no no 124statfs: no no no
125remount_fs: yes yes maybe (see below) 125remount_fs: yes yes maybe (see below)
126clear_inode: no 126clear_inode: no
diff --git a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt
index 4333e836c495..e055acb6b2d4 100644
--- a/Documentation/filesystems/ext2.txt
+++ b/Documentation/filesystems/ext2.txt
@@ -373,10 +373,11 @@ Filesystem Resizing http://ext2resize.sourceforge.net/
373Compression (*) http://e2compr.sourceforge.net/ 373Compression (*) http://e2compr.sourceforge.net/
374 374
375Implementations for: 375Implementations for:
376Windows 95/98/NT/2000 http://uranus.it.swin.edu.au/~jn/linux/Explore2fs.htm 376Windows 95/98/NT/2000 http://www.chrysocome.net/explore2fs
377Windows 95 (*) http://www.yipton.demon.co.uk/content.html#FSDEXT2 377Windows 95 (*) http://www.yipton.net/content.html#FSDEXT2
378DOS client (*) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/ 378DOS client (*) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/
379OS/2 http://perso.wanadoo.fr/matthieu.willm/ext2-os2/ 379OS/2 (+) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/
380RISC OS client ftp://ftp.barnet.ac.uk/pub/acorn/armlinux/iscafs/ 380RISC OS client http://www.esw-heim.tu-clausthal.de/~marco/smorbrod/IscaFS/
381 381
382(*) no longer actively developed/supported (as of Apr 2001) 382(*) no longer actively developed/supported (as of Apr 2001)
383(+) no longer actively developed/supported (as of Mar 2009)
diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt
index 9dd2a3bb2acc..e5f3833a6ef8 100644
--- a/Documentation/filesystems/ext3.txt
+++ b/Documentation/filesystems/ext3.txt
@@ -198,5 +198,5 @@ kernel source: <file:fs/ext3/>
198programs: http://e2fsprogs.sourceforge.net/ 198programs: http://e2fsprogs.sourceforge.net/
199 http://ext2resize.sourceforge.net 199 http://ext2resize.sourceforge.net
200 200
201useful links: http://www-106.ibm.com/developerworks/linux/library/l-fs7/ 201useful links: http://www.ibm.com/developerworks/library/l-fs7.html
202 http://www-106.ibm.com/developerworks/linux/library/l-fs8/ 202 http://www.ibm.com/developerworks/library/l-fs8.html
diff --git a/Documentation/filesystems/nfs-rdma.txt b/Documentation/filesystems/nfs-rdma.txt
index 44bd766f2e5d..85eaeaddd27c 100644
--- a/Documentation/filesystems/nfs-rdma.txt
+++ b/Documentation/filesystems/nfs-rdma.txt
@@ -251,7 +251,7 @@ NFS/RDMA Setup
251 251
252 Instruct the server to listen on the RDMA transport: 252 Instruct the server to listen on the RDMA transport:
253 253
254 $ echo rdma 2050 > /proc/fs/nfsd/portlist 254 $ echo rdma 20049 > /proc/fs/nfsd/portlist
255 255
256 - On the client system 256 - On the client system
257 257
@@ -263,7 +263,7 @@ NFS/RDMA Setup
263 Regardless of how the client was built (module or built-in), use this 263 Regardless of how the client was built (module or built-in), use this
264 command to mount the NFS/RDMA server: 264 command to mount the NFS/RDMA server:
265 265
266 $ mount -o rdma,port=2050 <IPoIB-server-name-or-address>:/<export> /mnt 266 $ mount -o rdma,port=20049 <IPoIB-server-name-or-address>:/<export> /mnt
267 267
268 To verify that the mount is using RDMA, run "cat /proc/mounts" and check 268 To verify that the mount is using RDMA, run "cat /proc/mounts" and check
269 the "proto" field for the given mount. 269 the "proto" field for the given mount.
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index d105eb45282a..830bad7cce0f 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1371,292 +1371,8 @@ auto_msgmni default value is 1.
13712.4 /proc/sys/vm - The virtual memory subsystem 13712.4 /proc/sys/vm - The virtual memory subsystem
1372----------------------------------------------- 1372-----------------------------------------------
1373 1373
1374The files in this directory can be used to tune the operation of the virtual 1374Please see: Documentation/sysctls/vm.txt for a description of these
1375memory (VM) subsystem of the Linux kernel. 1375entries.
1376
1377vfs_cache_pressure
1378------------------
1379
1380Controls the tendency of the kernel to reclaim the memory which is used for
1381caching of directory and inode objects.
1382
1383At the default value of vfs_cache_pressure=100 the kernel will attempt to
1384reclaim dentries and inodes at a "fair" rate with respect to pagecache and
1385swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer
1386to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100
1387causes the kernel to prefer to reclaim dentries and inodes.
1388
1389dirty_background_bytes
1390----------------------
1391
1392Contains the amount of dirty memory at which the pdflush background writeback
1393daemon will start writeback.
1394
1395If dirty_background_bytes is written, dirty_background_ratio becomes a function
1396of its value (dirty_background_bytes / the amount of dirtyable system memory).
1397
1398dirty_background_ratio
1399----------------------
1400
1401Contains, as a percentage of the dirtyable system memory (free pages + mapped
1402pages + file cache, not including locked pages and HugePages), the number of
1403pages at which the pdflush background writeback daemon will start writing out
1404dirty data.
1405
1406If dirty_background_ratio is written, dirty_background_bytes becomes a function
1407of its value (dirty_background_ratio * the amount of dirtyable system memory).
1408
1409dirty_bytes
1410-----------
1411
1412Contains the amount of dirty memory at which a process generating disk writes
1413will itself start writeback.
1414
1415If dirty_bytes is written, dirty_ratio becomes a function of its value
1416(dirty_bytes / the amount of dirtyable system memory).
1417
1418dirty_ratio
1419-----------
1420
1421Contains, as a percentage of the dirtyable system memory (free pages + mapped
1422pages + file cache, not including locked pages and HugePages), the number of
1423pages at which a process which is generating disk writes will itself start
1424writing out dirty data.
1425
1426If dirty_ratio is written, dirty_bytes becomes a function of its value
1427(dirty_ratio * the amount of dirtyable system memory).
1428
1429dirty_writeback_centisecs
1430-------------------------
1431
1432The pdflush writeback daemons will periodically wake up and write `old' data
1433out to disk. This tunable expresses the interval between those wakeups, in
1434100'ths of a second.
1435
1436Setting this to zero disables periodic writeback altogether.
1437
1438dirty_expire_centisecs
1439----------------------
1440
1441This tunable is used to define when dirty data is old enough to be eligible
1442for writeout by the pdflush daemons. It is expressed in 100'ths of a second.
1443Data which has been dirty in-memory for longer than this interval will be
1444written out next time a pdflush daemon wakes up.
1445
1446highmem_is_dirtyable
1447--------------------
1448
1449Only present if CONFIG_HIGHMEM is set.
1450
1451This defaults to 0 (false), meaning that the ratios set above are calculated
1452as a percentage of lowmem only. This protects against excessive scanning
1453in page reclaim, swapping and general VM distress.
1454
1455Setting this to 1 can be useful on 32 bit machines where you want to make
1456random changes within an MMAPed file that is larger than your available
1457lowmem without causing large quantities of random IO. Is is safe if the
1458behavior of all programs running on the machine is known and memory will
1459not be otherwise stressed.
1460
1461legacy_va_layout
1462----------------
1463
1464If non-zero, this sysctl disables the new 32-bit mmap mmap layout - the kernel
1465will use the legacy (2.4) layout for all processes.
1466
1467lowmem_reserve_ratio
1468---------------------
1469
1470For some specialised workloads on highmem machines it is dangerous for
1471the kernel to allow process memory to be allocated from the "lowmem"
1472zone. This is because that memory could then be pinned via the mlock()
1473system call, or by unavailability of swapspace.
1474
1475And on large highmem machines this lack of reclaimable lowmem memory
1476can be fatal.
1477
1478So the Linux page allocator has a mechanism which prevents allocations
1479which _could_ use highmem from using too much lowmem. This means that
1480a certain amount of lowmem is defended from the possibility of being
1481captured into pinned user memory.
1482
1483(The same argument applies to the old 16 megabyte ISA DMA region. This
1484mechanism will also defend that region from allocations which could use
1485highmem or lowmem).
1486
1487The `lowmem_reserve_ratio' tunable determines how aggressive the kernel is
1488in defending these lower zones.
1489
1490If you have a machine which uses highmem or ISA DMA and your
1491applications are using mlock(), or if you are running with no swap then
1492you probably should change the lowmem_reserve_ratio setting.
1493
1494The lowmem_reserve_ratio is an array. You can see them by reading this file.
1495-
1496% cat /proc/sys/vm/lowmem_reserve_ratio
1497256 256 32
1498-
1499Note: # of this elements is one fewer than number of zones. Because the highest
1500 zone's value is not necessary for following calculation.
1501
1502But, these values are not used directly. The kernel calculates # of protection
1503pages for each zones from them. These are shown as array of protection pages
1504in /proc/zoneinfo like followings. (This is an example of x86-64 box).
1505Each zone has an array of protection pages like this.
1506
1507-
1508Node 0, zone DMA
1509 pages free 1355
1510 min 3
1511 low 3
1512 high 4
1513 :
1514 :
1515 numa_other 0
1516 protection: (0, 2004, 2004, 2004)
1517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1518 pagesets
1519 cpu: 0 pcp: 0
1520 :
1521-
1522These protections are added to score to judge whether this zone should be used
1523for page allocation or should be reclaimed.
1524
1525In this example, if normal pages (index=2) are required to this DMA zone and
1526pages_high is used for watermark, the kernel judges this zone should not be
1527used because pages_free(1355) is smaller than watermark + protection[2]
1528(4 + 2004 = 2008). If this protection value is 0, this zone would be used for
1529normal page requirement. If requirement is DMA zone(index=0), protection[0]
1530(=0) is used.
1531
1532zone[i]'s protection[j] is calculated by following expression.
1533
1534(i < j):
1535 zone[i]->protection[j]
1536 = (total sums of present_pages from zone[i+1] to zone[j] on the node)
1537 / lowmem_reserve_ratio[i];
1538(i = j):
1539 (should not be protected. = 0;
1540(i > j):
1541 (not necessary, but looks 0)
1542
1543The default values of lowmem_reserve_ratio[i] are
1544 256 (if zone[i] means DMA or DMA32 zone)
1545 32 (others).
1546As above expression, they are reciprocal number of ratio.
1547256 means 1/256. # of protection pages becomes about "0.39%" of total present
1548pages of higher zones on the node.
1549
1550If you would like to protect more pages, smaller values are effective.
1551The minimum value is 1 (1/1 -> 100%).
1552
1553page-cluster
1554------------
1555
1556page-cluster controls the number of pages which are written to swap in
1557a single attempt. The swap I/O size.
1558
1559It is a logarithmic value - setting it to zero means "1 page", setting
1560it to 1 means "2 pages", setting it to 2 means "4 pages", etc.
1561
1562The default value is three (eight pages at a time). There may be some
1563small benefits in tuning this to a different value if your workload is
1564swap-intensive.
1565
1566overcommit_memory
1567-----------------
1568
1569Controls overcommit of system memory, possibly allowing processes
1570to allocate (but not use) more memory than is actually available.
1571
1572
15730 - Heuristic overcommit handling. Obvious overcommits of
1574 address space are refused. Used for a typical system. It
1575 ensures a seriously wild allocation fails while allowing
1576 overcommit to reduce swap usage. root is allowed to
1577 allocate slightly more memory in this mode. This is the
1578 default.
1579
15801 - Always overcommit. Appropriate for some scientific
1581 applications.
1582
15832 - Don't overcommit. The total address space commit
1584 for the system is not permitted to exceed swap plus a
1585 configurable percentage (default is 50) of physical RAM.
1586 Depending on the percentage you use, in most situations
1587 this means a process will not be killed while attempting
1588 to use already-allocated memory but will receive errors
1589 on memory allocation as appropriate.
1590
1591overcommit_ratio
1592----------------
1593
1594Percentage of physical memory size to include in overcommit calculations
1595(see above.)
1596
1597Memory allocation limit = swapspace + physmem * (overcommit_ratio / 100)
1598
1599 swapspace = total size of all swap areas
1600 physmem = size of physical memory in system
1601
1602nr_hugepages and hugetlb_shm_group
1603----------------------------------
1604
1605nr_hugepages configures number of hugetlb page reserved for the system.
1606
1607hugetlb_shm_group contains group id that is allowed to create SysV shared
1608memory segment using hugetlb page.
1609
1610hugepages_treat_as_movable
1611--------------------------
1612
1613This parameter is only useful when kernelcore= is specified at boot time to
1614create ZONE_MOVABLE for pages that may be reclaimed or migrated. Huge pages
1615are not movable so are not normally allocated from ZONE_MOVABLE. A non-zero
1616value written to hugepages_treat_as_movable allows huge pages to be allocated
1617from ZONE_MOVABLE.
1618
1619Once enabled, the ZONE_MOVABLE is treated as an area of memory the huge
1620pages pool can easily grow or shrink within. Assuming that applications are
1621not running that mlock() a lot of memory, it is likely the huge pages pool
1622can grow to the size of ZONE_MOVABLE by repeatedly entering the desired value
1623into nr_hugepages and triggering page reclaim.
1624
1625laptop_mode
1626-----------
1627
1628laptop_mode is a knob that controls "laptop mode". All the things that are
1629controlled by this knob are discussed in Documentation/laptops/laptop-mode.txt.
1630
1631block_dump
1632----------
1633
1634block_dump enables block I/O debugging when set to a nonzero value. More
1635information on block I/O debugging is in Documentation/laptops/laptop-mode.txt.
1636
1637swap_token_timeout
1638------------------
1639
1640This file contains valid hold time of swap out protection token. The Linux
1641VM has token based thrashing control mechanism and uses the token to prevent
1642unnecessary page faults in thrashing situation. The unit of the value is
1643second. The value would be useful to tune thrashing behavior.
1644
1645drop_caches
1646-----------
1647
1648Writing to this will cause the kernel to drop clean caches, dentries and
1649inodes from memory, causing that memory to become free.
1650
1651To free pagecache:
1652 echo 1 > /proc/sys/vm/drop_caches
1653To free dentries and inodes:
1654 echo 2 > /proc/sys/vm/drop_caches
1655To free pagecache, dentries and inodes:
1656 echo 3 > /proc/sys/vm/drop_caches
1657
1658As this is a non-destructive operation and dirty objects are not freeable, the
1659user should run `sync' first.
1660 1376
1661 1377
16622.5 /proc/sys/dev - Device specific parameters 13782.5 /proc/sys/dev - Device specific parameters
@@ -1762,6 +1478,13 @@ of problems on the network like duplicate address or bad checksums. Normally,
1762this should be enabled, but if the problem persists the messages can be 1478this should be enabled, but if the problem persists the messages can be
1763disabled. 1479disabled.
1764 1480
1481netdev_budget
1482-------------
1483
1484Maximum number of packets taken from all interfaces in one polling cycle (NAPI
1485poll). In one polling cycle interfaces which are registered to polling are
1486probed in a round-robin manner. The limit of packets in one such probe can be
1487set per-device via sysfs class/net/<device>/weight .
1765 1488
1766netdev_max_backlog 1489netdev_max_backlog
1767------------------ 1490------------------
@@ -2311,6 +2034,34 @@ increase the likelihood of this process being killed by the oom-killer. Valid
2311values are in the range -16 to +15, plus the special value -17, which disables 2034values are in the range -16 to +15, plus the special value -17, which disables
2312oom-killing altogether for this process. 2035oom-killing altogether for this process.
2313 2036
2037The process to be killed in an out-of-memory situation is selected among all others
2038based on its badness score. This value equals the original memory size of the process
2039and is then updated according to its CPU time (utime + stime) and the
2040run time (uptime - start time). The longer it runs the smaller is the score.
2041Badness score is divided by the square root of the CPU time and then by
2042the double square root of the run time.
2043
2044Swapped out tasks are killed first. Half of each child's memory size is added to
2045the parent's score if they do not share the same memory. Thus forking servers
2046are the prime candidates to be killed. Having only one 'hungry' child will make
2047parent less preferable than the child.
2048
2049/proc/<pid>/oom_score shows process' current badness score.
2050
2051The following heuristics are then applied:
2052 * if the task was reniced, its score doubles
2053 * superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE
2054 or CAP_SYS_RAWIO) have their score divided by 4
2055 * if oom condition happened in one cpuset and checked task does not belong
2056 to it, its score is divided by 8
2057 * the resulting score is multiplied by two to the power of oom_adj, i.e.
2058 points <<= oom_adj when it is positive and
2059 points >>= -(oom_adj) otherwise
2060
2061The task with the highest badness score is then selected and its children
2062are killed, process itself will be killed in an OOM situation when it does
2063not have children or some of them disabled oom like described above.
2064
23142.13 /proc/<pid>/oom_score - Display current oom-killer score 20652.13 /proc/<pid>/oom_score - Display current oom-killer score
2315------------------------------------------------------------- 2066-------------------------------------------------------------
2316 2067
diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt
index 3e79e4a7a392..b324c033035a 100644
--- a/Documentation/filesystems/squashfs.txt
+++ b/Documentation/filesystems/squashfs.txt
@@ -22,7 +22,7 @@ Squashfs filesystem features versus Cramfs:
22 22
23 Squashfs Cramfs 23 Squashfs Cramfs
24 24
25Max filesystem size: 2^64 16 MiB 25Max filesystem size: 2^64 256 MiB
26Max file size: ~ 2 TiB 16 MiB 26Max file size: ~ 2 TiB 16 MiB
27Max files: unlimited unlimited 27Max files: unlimited unlimited
28Max directories: unlimited unlimited 28Max directories: unlimited unlimited
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt
index 68ef48839c04..9f8740ca3f3b 100644
--- a/Documentation/filesystems/sysfs-pci.txt
+++ b/Documentation/filesystems/sysfs-pci.txt
@@ -9,6 +9,7 @@ that support it. For example, a given bus might look like this:
9 | |-- class 9 | |-- class
10 | |-- config 10 | |-- config
11 | |-- device 11 | |-- device
12 | |-- enable
12 | |-- irq 13 | |-- irq
13 | |-- local_cpus 14 | |-- local_cpus
14 | |-- resource 15 | |-- resource
@@ -32,6 +33,7 @@ files, each with their own function.
32 class PCI class (ascii, ro) 33 class PCI class (ascii, ro)
33 config PCI config space (binary, rw) 34 config PCI config space (binary, rw)
34 device PCI device (ascii, ro) 35 device PCI device (ascii, ro)
36 enable Whether the device is enabled (ascii, rw)
35 irq IRQ number (ascii, ro) 37 irq IRQ number (ascii, ro)
36 local_cpus nearby CPU mask (cpumask, ro) 38 local_cpus nearby CPU mask (cpumask, ro)
37 resource PCI resource host addresses (ascii, ro) 39 resource PCI resource host addresses (ascii, ro)
@@ -57,10 +59,19 @@ used to do actual device programming from userspace. Note that some platforms
57don't support mmapping of certain resources, so be sure to check the return 59don't support mmapping of certain resources, so be sure to check the return
58value from any attempted mmap. 60value from any attempted mmap.
59 61
62The 'enable' file provides a counter that indicates how many times the device
63has been enabled. If the 'enable' file currently returns '4', and a '1' is
64echoed into it, it will then return '5'. Echoing a '0' into it will decrease
65the count. Even when it returns to 0, though, some of the initialisation
66may not be reversed.
67
60The 'rom' file is special in that it provides read-only access to the device's 68The 'rom' file is special in that it provides read-only access to the device's
61ROM file, if available. It's disabled by default, however, so applications 69ROM file, if available. It's disabled by default, however, so applications
62should write the string "1" to the file to enable it before attempting a read 70should write the string "1" to the file to enable it before attempting a read
63call, and disable it following the access by writing "0" to the file. 71call, and disable it following the access by writing "0" to the file. Note
72that the device must be enabled for a rom read to return data succesfully.
73In the event a driver is not bound to the device, it can be enabled using the
74'enable' file, documented above.
64 75
65Accessing legacy resources through sysfs 76Accessing legacy resources through sysfs
66---------------------------------------- 77----------------------------------------
diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt
index 9e9c348275a9..7e81e37c0b1e 100644
--- a/Documentation/filesystems/sysfs.txt
+++ b/Documentation/filesystems/sysfs.txt
@@ -2,8 +2,10 @@
2sysfs - _The_ filesystem for exporting kernel objects. 2sysfs - _The_ filesystem for exporting kernel objects.
3 3
4Patrick Mochel <mochel@osdl.org> 4Patrick Mochel <mochel@osdl.org>
5Mike Murphy <mamurph@cs.clemson.edu>
5 6
610 January 2003 7Revised: 22 February 2009
8Original: 10 January 2003
7 9
8 10
9What it is: 11What it is:
@@ -64,12 +66,13 @@ An attribute definition is simply:
64 66
65struct attribute { 67struct attribute {
66 char * name; 68 char * name;
69 struct module *owner;
67 mode_t mode; 70 mode_t mode;
68}; 71};
69 72
70 73
71int sysfs_create_file(struct kobject * kobj, struct attribute * attr); 74int sysfs_create_file(struct kobject * kobj, const struct attribute * attr);
72void sysfs_remove_file(struct kobject * kobj, struct attribute * attr); 75void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr);
73 76
74 77
75A bare attribute contains no means to read or write the value of the 78A bare attribute contains no means to read or write the value of the
@@ -80,9 +83,11 @@ a specific object type.
80For example, the driver model defines struct device_attribute like: 83For example, the driver model defines struct device_attribute like:
81 84
82struct device_attribute { 85struct device_attribute {
83 struct attribute attr; 86 struct attribute attr;
84 ssize_t (*show)(struct device * dev, char * buf); 87 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
85 ssize_t (*store)(struct device * dev, const char * buf); 88 char *buf);
89 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
90 const char *buf, size_t count);
86}; 91};
87 92
88int device_create_file(struct device *, struct device_attribute *); 93int device_create_file(struct device *, struct device_attribute *);
@@ -90,12 +95,8 @@ void device_remove_file(struct device *, struct device_attribute *);
90 95
91It also defines this helper for defining device attributes: 96It also defines this helper for defining device attributes:
92 97
93#define DEVICE_ATTR(_name, _mode, _show, _store) \ 98#define DEVICE_ATTR(_name, _mode, _show, _store) \
94struct device_attribute dev_attr_##_name = { \ 99struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
95 .attr = {.name = __stringify(_name) , .mode = _mode }, \
96 .show = _show, \
97 .store = _store, \
98};
99 100
100For example, declaring 101For example, declaring
101 102
@@ -107,9 +108,9 @@ static struct device_attribute dev_attr_foo = {
107 .attr = { 108 .attr = {
108 .name = "foo", 109 .name = "foo",
109 .mode = S_IWUSR | S_IRUGO, 110 .mode = S_IWUSR | S_IRUGO,
111 .show = show_foo,
112 .store = store_foo,
110 }, 113 },
111 .show = show_foo,
112 .store = store_foo,
113}; 114};
114 115
115 116
@@ -161,10 +162,12 @@ To read or write attributes, show() or store() methods must be
161specified when declaring the attribute. The method types should be as 162specified when declaring the attribute. The method types should be as
162simple as those defined for device attributes: 163simple as those defined for device attributes:
163 164
164 ssize_t (*show)(struct device * dev, char * buf); 165ssize_t (*show)(struct device * dev, struct device_attribute * attr,
165 ssize_t (*store)(struct device * dev, const char * buf); 166 char * buf);
167ssize_t (*store)(struct device * dev, struct device_attribute * attr,
168 const char * buf);
166 169
167IOW, they should take only an object and a buffer as parameters. 170IOW, they should take only an object, an attribute, and a buffer as parameters.
168 171
169 172
170sysfs allocates a buffer of size (PAGE_SIZE) and passes it to the 173sysfs allocates a buffer of size (PAGE_SIZE) and passes it to the
@@ -299,14 +302,16 @@ The following interface layers currently exist in sysfs:
299Structure: 302Structure:
300 303
301struct device_attribute { 304struct device_attribute {
302 struct attribute attr; 305 struct attribute attr;
303 ssize_t (*show)(struct device * dev, char * buf); 306 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
304 ssize_t (*store)(struct device * dev, const char * buf); 307 char *buf);
308 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
309 const char *buf, size_t count);
305}; 310};
306 311
307Declaring: 312Declaring:
308 313
309DEVICE_ATTR(_name, _str, _mode, _show, _store); 314DEVICE_ATTR(_name, _mode, _show, _store);
310 315
311Creation/Removal: 316Creation/Removal:
312 317
@@ -342,7 +347,8 @@ Structure:
342struct driver_attribute { 347struct driver_attribute {
343 struct attribute attr; 348 struct attribute attr;
344 ssize_t (*show)(struct device_driver *, char * buf); 349 ssize_t (*show)(struct device_driver *, char * buf);
345 ssize_t (*store)(struct device_driver *, const char * buf); 350 ssize_t (*store)(struct device_driver *, const char * buf,
351 size_t count);
346}; 352};
347 353
348Declaring: 354Declaring:
diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt
index 84da2a4ba25a..12fedb7834c6 100644
--- a/Documentation/filesystems/ubifs.txt
+++ b/Documentation/filesystems/ubifs.txt
@@ -79,13 +79,6 @@ Mount options
79 79
80(*) == default. 80(*) == default.
81 81
82norm_unmount (*) commit on unmount; the journal is committed
83 when the file-system is unmounted so that the
84 next mount does not have to replay the journal
85 and it becomes very fast;
86fast_unmount do not commit on unmount; this option makes
87 unmount faster, but the next mount slower
88 because of the need to replay the journal.
89bulk_read read more in one go to take advantage of flash 82bulk_read read more in one go to take advantage of flash
90 media that read faster sequentially 83 media that read faster sequentially
91no_bulk_read (*) do not bulk-read 84no_bulk_read (*) do not bulk-read
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index ef19afa186a9..deeeed0faa8f 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -210,8 +210,8 @@ struct super_operations {
210 void (*put_super) (struct super_block *); 210 void (*put_super) (struct super_block *);
211 void (*write_super) (struct super_block *); 211 void (*write_super) (struct super_block *);
212 int (*sync_fs)(struct super_block *sb, int wait); 212 int (*sync_fs)(struct super_block *sb, int wait);
213 void (*write_super_lockfs) (struct super_block *); 213 int (*freeze_fs) (struct super_block *);
214 void (*unlockfs) (struct super_block *); 214 int (*unfreeze_fs) (struct super_block *);
215 int (*statfs) (struct dentry *, struct kstatfs *); 215 int (*statfs) (struct dentry *, struct kstatfs *);
216 int (*remount_fs) (struct super_block *, int *, char *); 216 int (*remount_fs) (struct super_block *, int *, char *);
217 void (*clear_inode) (struct inode *); 217 void (*clear_inode) (struct inode *);
@@ -270,11 +270,11 @@ or bottom half).
270 a superblock. The second parameter indicates whether the method 270 a superblock. The second parameter indicates whether the method
271 should wait until the write out has been completed. Optional. 271 should wait until the write out has been completed. Optional.
272 272
273 write_super_lockfs: called when VFS is locking a filesystem and 273 freeze_fs: called when VFS is locking a filesystem and
274 forcing it into a consistent state. This method is currently 274 forcing it into a consistent state. This method is currently
275 used by the Logical Volume Manager (LVM). 275 used by the Logical Volume Manager (LVM).
276 276
277 unlockfs: called when VFS is unlocking a filesystem and making it writable 277 unfreeze_fs: called when VFS is unlocking a filesystem and making it writable
278 again. 278 again.
279 279
280 statfs: called when the VFS needs to get filesystem statistics. This 280 statfs: called when the VFS needs to get filesystem statistics. This