diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 15 | ||||
| -rw-r--r-- | Documentation/filesystems/configfs/Makefile | 3 | ||||
| -rw-r--r-- | Documentation/filesystems/configfs/configfs.txt | 17 | ||||
| -rw-r--r-- | Documentation/filesystems/configfs/configfs_example_explicit.c (renamed from Documentation/filesystems/configfs/configfs_example.c) | 18 | ||||
| -rw-r--r-- | Documentation/filesystems/configfs/configfs_example_macros.c | 448 | ||||
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/ntfs.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 21 | ||||
| -rw-r--r-- | Documentation/filesystems/quota.txt | 22 | ||||
| -rw-r--r-- | Documentation/filesystems/ubifs.txt | 2 |
10 files changed, 522 insertions, 34 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 680fb566b92..8362860e21a 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -144,8 +144,8 @@ prototypes: void (*kill_sb) (struct super_block *); locking rules: may block BKL -get_sb yes yes -kill_sb yes yes +get_sb yes no +kill_sb yes no ->get_sb() returns error or 0 with locked superblock attached to the vfsmount (exclusive on ->s_umount). @@ -409,12 +409,12 @@ ioctl: yes (see below) unlocked_ioctl: no (see below) compat_ioctl: no mmap: no -open: maybe (see below) +open: no flush: no release: no fsync: no (see below) aio_fsync: no -fasync: yes (see below) +fasync: no lock: yes readv: no writev: no @@ -431,13 +431,6 @@ For many filesystems, it is probably safe to acquire the inode semaphore. Note some filesystems (i.e. remote ones) provide no protection for i_size so you will need to use the BKL. -->open() locking is in-transit: big lock partially moved into the methods. -The only exception is ->open() in the instances of file_operations that never -end up in ->i_fop/->proc_fops, i.e. ones that belong to character devices -(chrdev_open() takes lock before replacing ->f_op and calling the secondary -method. As soon as we fix the handling of module reference counters all -instances of ->open() will be called without the BKL. - Note: ext2_release() was *the* source of contention on fs-intensive loads and dropping BKL on ->release() helps to get rid of that (we still grab BKL for cases when we close a file that had been opened r/w, but that diff --git a/Documentation/filesystems/configfs/Makefile b/Documentation/filesystems/configfs/Makefile new file mode 100644 index 00000000000..be7ec5e67db --- /dev/null +++ b/Documentation/filesystems/configfs/Makefile @@ -0,0 +1,3 @@ +ifneq ($(CONFIG_CONFIGFS_FS),) +obj-m += configfs_example_explicit.o configfs_example_macros.o +endif diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt index 44c97e6accb..fabcb0e00f2 100644 --- a/Documentation/filesystems/configfs/configfs.txt +++ b/Documentation/filesystems/configfs/configfs.txt @@ -311,9 +311,20 @@ the subsystem must be ready for it. [An Example] The best example of these basic concepts is the simple_children -subsystem/group and the simple_child item in configfs_example.c It -shows a trivial object displaying and storing an attribute, and a simple -group creating and destroying these children. +subsystem/group and the simple_child item in configfs_example_explicit.c +and configfs_example_macros.c. It shows a trivial object displaying and +storing an attribute, and a simple group creating and destroying these +children. + +The only difference between configfs_example_explicit.c and +configfs_example_macros.c is how the attributes of the childless item +are defined. The childless item has extended attributes, each with +their own show()/store() operation. This follows a convention commonly +used in sysfs. configfs_example_explicit.c creates these attributes +by explicitly defining the structures involved. Conversely +configfs_example_macros.c uses some convenience macros from configfs.h +to define the attributes. These macros are similar to their sysfs +counterparts. [Hierarchy Navigation and the Subsystem Mutex] diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example_explicit.c index 03964879170..d428cc9f07f 100644 --- a/Documentation/filesystems/configfs/configfs_example.c +++ b/Documentation/filesystems/configfs/configfs_example_explicit.c @@ -1,8 +1,10 @@ /* * vim: noexpandtab ts=8 sts=0 sw=8: * - * configfs_example.c - This file is a demonstration module containing - * a number of configfs subsystems. + * configfs_example_explicit.c - This file is a demonstration module + * containing a number of configfs subsystems. It explicitly defines + * each structure without using the helper macros defined in + * configfs.h. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public @@ -281,7 +283,6 @@ static struct config_item *simple_children_make_item(struct config_group *group, if (!simple_child) return ERR_PTR(-ENOMEM); - config_item_init_type_name(&simple_child->item, name, &simple_child_type); @@ -302,8 +303,8 @@ static struct configfs_attribute *simple_children_attrs[] = { }; static ssize_t simple_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) + struct configfs_attribute *attr, + char *page) { return sprintf(page, "[02-simple-children]\n" @@ -318,7 +319,7 @@ static void simple_children_release(struct config_item *item) } static struct configfs_item_operations simple_children_item_ops = { - .release = simple_children_release, + .release = simple_children_release, .show_attribute = simple_children_attr_show, }; @@ -368,7 +369,6 @@ static struct config_group *group_children_make_group(struct config_group *group if (!simple_children) return ERR_PTR(-ENOMEM); - config_group_init_type_name(&simple_children->group, name, &simple_children_type); @@ -387,8 +387,8 @@ static struct configfs_attribute *group_children_attrs[] = { }; static ssize_t group_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) + struct configfs_attribute *attr, + char *page) { return sprintf(page, "[03-group-children]\n" diff --git a/Documentation/filesystems/configfs/configfs_example_macros.c b/Documentation/filesystems/configfs/configfs_example_macros.c new file mode 100644 index 00000000000..d8e30a0378a --- /dev/null +++ b/Documentation/filesystems/configfs/configfs_example_macros.c @@ -0,0 +1,448 @@ +/* + * vim: noexpandtab ts=8 sts=0 sw=8: + * + * configfs_example_macros.c - This file is a demonstration module + * containing a number of configfs subsystems. It uses the helper + * macros defined by configfs.h + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include <linux/configfs.h> + + + +/* + * 01-childless + * + * This first example is a childless subsystem. It cannot create + * any config_items. It just has attributes. + * + * Note that we are enclosing the configfs_subsystem inside a container. + * This is not necessary if a subsystem has no attributes directly + * on the subsystem. See the next example, 02-simple-children, for + * such a subsystem. + */ + +struct childless { + struct configfs_subsystem subsys; + int showme; + int storeme; +}; + +static inline struct childless *to_childless(struct config_item *item) +{ + return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL; +} + +CONFIGFS_ATTR_STRUCT(childless); +#define CHILDLESS_ATTR(_name, _mode, _show, _store) \ +struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store) +#define CHILDLESS_ATTR_RO(_name, _show) \ +struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show); + +static ssize_t childless_showme_read(struct childless *childless, + char *page) +{ + ssize_t pos; + + pos = sprintf(page, "%d\n", childless->showme); + childless->showme++; + + return pos; +} + +static ssize_t childless_storeme_read(struct childless *childless, + char *page) +{ + return sprintf(page, "%d\n", childless->storeme); +} + +static ssize_t childless_storeme_write(struct childless *childless, + const char *page, + size_t count) +{ + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + childless->storeme = tmp; + + return count; +} + +static ssize_t childless_description_read(struct childless *childless, + char *page) +{ + return sprintf(page, +"[01-childless]\n" +"\n" +"The childless subsystem is the simplest possible subsystem in\n" +"configfs. It does not support the creation of child config_items.\n" +"It only has a few attributes. In fact, it isn't much different\n" +"than a directory in /proc.\n"); +} + +CHILDLESS_ATTR_RO(showme, childless_showme_read); +CHILDLESS_ATTR(storeme, S_IRUGO | S_IWUSR, childless_storeme_read, + childless_storeme_write); +CHILDLESS_ATTR_RO(description, childless_description_read); + +static struct configfs_attribute *childless_attrs[] = { + &childless_attr_showme.attr, + &childless_attr_storeme.attr, + &childless_attr_description.attr, + NULL, +}; + +CONFIGFS_ATTR_OPS(childless); +static struct configfs_item_operations childless_item_ops = { + .show_attribute = childless_attr_show, + .store_attribute = childless_attr_store, +}; + +static struct config_item_type childless_type = { + .ct_item_ops = &childless_item_ops, + .ct_attrs = childless_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct childless childless_subsys = { + .subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "01-childless", + .ci_type = &childless_type, + }, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 02-simple-children + * + * This example merely has a simple one-attribute child. Note that + * there is no extra attribute structure, as the child's attribute is + * known from the get-go. Also, there is no container for the + * subsystem, as it has no attributes of its own. + */ + +struct simple_child { + struct config_item item; + int storeme; +}; + +static inline struct simple_child *to_simple_child(struct config_item *item) +{ + return item ? container_of(item, struct simple_child, item) : NULL; +} + +static struct configfs_attribute simple_child_attr_storeme = { + .ca_owner = THIS_MODULE, + .ca_name = "storeme", + .ca_mode = S_IRUGO | S_IWUSR, +}; + +static struct configfs_attribute *simple_child_attrs[] = { + &simple_child_attr_storeme, + NULL, +}; + +static ssize_t simple_child_attr_show(struct config_item *item, + struct configfs_attribute *attr, + char *page) +{ + ssize_t count; + struct simple_child *simple_child = to_simple_child(item); + + count = sprintf(page, "%d\n", simple_child->storeme); + + return count; +} + +static ssize_t simple_child_attr_store(struct config_item *item, + struct configfs_attribute *attr, + const char *page, size_t count) +{ + struct simple_child *simple_child = to_simple_child(item); + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + simple_child->storeme = tmp; + + return count; +} + +static void simple_child_release(struct config_item *item) +{ + kfree(to_simple_child(item)); +} + +static struct configfs_item_operations simple_child_item_ops = { + .release = simple_child_release, + .show_attribute = simple_child_attr_show, + .store_attribute = simple_child_attr_store, +}; + +static struct config_item_type simple_child_type = { + .ct_item_ops = &simple_child_item_ops, + .ct_attrs = simple_child_attrs, + .ct_owner = THIS_MODULE, +}; + + +struct simple_children { + struct config_group group; +}; + +static inline struct simple_children *to_simple_children(struct config_item *item) +{ + return item ? container_of(to_config_group(item), struct simple_children, group) : NULL; +} + +static struct config_item *simple_children_make_item(struct config_group *group, const char *name) +{ + struct simple_child *simple_child; + + simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); + if (!simple_child) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&simple_child->item, name, + &simple_child_type); + + simple_child->storeme = 0; + + return &simple_child->item; +} + +static struct configfs_attribute simple_children_attr_description = { + .ca_owner = THIS_MODULE, + .ca_name = "description", + .ca_mode = S_IRUGO, +}; + +static struct configfs_attribute *simple_children_attrs[] = { + &simple_children_attr_description, + NULL, +}; + +static ssize_t simple_children_attr_show(struct config_item *item, + struct configfs_attribute *attr, + char *page) +{ + return sprintf(page, +"[02-simple-children]\n" +"\n" +"This subsystem allows the creation of child config_items. These\n" +"items have only one attribute that is readable and writeable.\n"); +} + +static void simple_children_release(struct config_item *item) +{ + kfree(to_simple_children(item)); +} + +static struct configfs_item_operations simple_children_item_ops = { + .release = simple_children_release, + .show_attribute = simple_children_attr_show, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations simple_children_group_ops = { + .make_item = simple_children_make_item, +}; + +static struct config_item_type simple_children_type = { + .ct_item_ops = &simple_children_item_ops, + .ct_group_ops = &simple_children_group_ops, + .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem simple_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "02-simple-children", + .ci_type = &simple_children_type, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 03-group-children + * + * This example reuses the simple_children group from above. However, + * the simple_children group is not the subsystem itself, it is a + * child of the subsystem. Creation of a group in the subsystem creates + * a new simple_children group. That group can then have simple_child + * children of its own. + */ + +static struct config_group *group_children_make_group(struct config_group *group, const char *name) +{ + struct simple_children *simple_children; + + simple_children = kzalloc(sizeof(struct simple_children), + GFP_KERNEL); + if (!simple_children) + return ERR_PTR(-ENOMEM); + + config_group_init_type_name(&simple_children->group, name, + &simple_children_type); + + return &simple_children->group; +} + +static struct configfs_attribute group_children_attr_description = { + .ca_owner = THIS_MODULE, + .ca_name = "description", + .ca_mode = S_IRUGO, +}; + +static struct configfs_attribute *group_children_attrs[] = { + &group_children_attr_description, + NULL, +}; + +static ssize_t group_children_attr_show(struct config_item *item, + struct configfs_attribute *attr, + char *page) +{ + return sprintf(page, +"[03-group-children]\n" +"\n" +"This subsystem allows the creation of child config_groups. These\n" +"groups are like the subsystem simple-children.\n"); +} + +static struct configfs_item_operations group_children_item_ops = { + .show_attribute = group_children_attr_show, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations group_children_group_ops = { + .make_group = group_children_make_group, +}; + +static struct config_item_type group_children_type = { + .ct_item_ops = &group_children_item_ops, + .ct_group_ops = &group_children_group_ops, + .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem group_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "03-group-children", + .ci_type = &group_children_type, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * We're now done with our subsystem definitions. + * For convenience in this module, here's a list of them all. It + * allows the init function to easily register them. Most modules + * will only have one subsystem, and will only call register_subsystem + * on it directly. + */ +static struct configfs_subsystem *example_subsys[] = { + &childless_subsys.subsys, + &simple_children_subsys, + &group_children_subsys, + NULL, +}; + +static int __init configfs_example_init(void) +{ + int ret; + int i; + struct configfs_subsystem *subsys; + + for (i = 0; example_subsys[i]; i++) { + subsys = example_subsys[i]; + + config_group_init(&subsys->su_group); + mutex_init(&subsys->su_mutex); + ret = configfs_register_subsystem(subsys); + if (ret) { + printk(KERN_ERR "Error %d while registering subsystem %s\n", + ret, + subsys->su_group.cg_item.ci_namebuf); + goto out_unregister; + } + } + + return 0; + +out_unregister: + for (; i >= 0; i--) { + configfs_unregister_subsystem(example_subsys[i]); + } + + return ret; +} + +static void __exit configfs_example_exit(void) +{ + int i; + + for (i = 0; example_subsys[i]; i++) { + configfs_unregister_subsystem(example_subsys[i]); + } +} + +module_init(configfs_example_init); +module_exit(configfs_example_exit); +MODULE_LICENSE("GPL"); diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 80e193d82e2..0d5394920a3 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -26,6 +26,12 @@ Mailing list: linux-ext4@vger.kernel.org git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git + - Note that it is highly important to install the mke2fs.conf file + that comes with the e2fsprogs 1.41.x sources in /etc/mke2fs.conf. If + you have edited the /etc/mke2fs.conf file installed on your system, + you will need to merge your changes with the version from e2fsprogs + 1.41.x. + - Create a new filesystem using the ext4dev filesystem type: # mke2fs -t ext4dev /dev/hda1 diff --git a/Documentation/filesystems/ntfs.txt b/Documentation/filesystems/ntfs.txt index e79ee2db183..ac2a261c5f7 100644 --- a/Documentation/filesystems/ntfs.txt +++ b/Documentation/filesystems/ntfs.txt @@ -40,7 +40,7 @@ Web site ======== There is plenty of additional information on the linux-ntfs web site -at http://linux-ntfs.sourceforge.net/ +at http://www.linux-ntfs.org/ The web site has a lot of additional information, such as a comprehensive FAQ, documentation on the NTFS on-disk format, information on the Linux-NTFS @@ -272,7 +272,7 @@ And you would know that /dev/hda2 has a size of 37768814 - 4209030 + 1 = For Win2k and later dynamic disks, you can for example use the ldminfo utility which is part of the Linux LDM tools (the latest version at the time of writing is linux-ldm-0.0.8.tar.bz2). You can download it from: - http://linux-ntfs.sourceforge.net/downloads.html + http://www.linux-ntfs.org/ Simply extract the downloaded archive (tar xvjf linux-ldm-0.0.8.tar.bz2), go into it (cd linux-ldm-0.0.8) and change to the test directory (cd test). You will find the precompiled (i386) ldminfo utility there. NOTE: You will not be diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 64557821ee5..f566ad9bcb7 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1339,6 +1339,25 @@ Enables/Disables the protection of the per-process proc entries "maps" and "smaps". When enabled, the contents of these files are visible only to readers that are allowed to ptrace() the given process. +msgmni +------ + +Maximum number of message queue ids on the system. +This value scales to the amount of lowmem. It is automatically recomputed +upon memory add/remove or ipc namespace creation/removal. +When a value is written into this file, msgmni's value becomes fixed, i.e. it +is not recomputed anymore when one of the above events occurs. +Use auto_msgmni to change this behavior. + +auto_msgmni +----------- + +Enables/Disables automatic recomputing of msgmni upon memory add/remove or +upon ipc namespace creation/removal (see the msgmni description above). +Echoing "1" into this file enables msgmni automatic recomputing. +Echoing "0" turns it off. +auto_msgmni default value is 1. + 2.4 /proc/sys/vm - The virtual memory subsystem ----------------------------------------------- @@ -2394,6 +2413,8 @@ The following 4 memory types are supported: - (bit 1) anonymous shared memory - (bit 2) file-backed private memory - (bit 3) file-backed shared memory + - (bit 4) ELF header pages in file-backed private memory areas (it is + effective only if the bit 2 is cleared) Note that MMIO pages such as frame buffer are never dumped and vDSO pages are always dumped regardless of the bitmask status. diff --git a/Documentation/filesystems/quota.txt b/Documentation/filesystems/quota.txt index a590c4093ef..5e8de25bf0f 100644 --- a/Documentation/filesystems/quota.txt +++ b/Documentation/filesystems/quota.txt @@ -3,14 +3,14 @@ Quota subsystem =============== Quota subsystem allows system administrator to set limits on used space and -number of used inodes (inode is a filesystem structure which is associated -with each file or directory) for users and/or groups. For both used space and -number of used inodes there are actually two limits. The first one is called -softlimit and the second one hardlimit. An user can never exceed a hardlimit -for any resource. User is allowed to exceed softlimit but only for limited -period of time. This period is called "grace period" or "grace time". When -grace time is over, user is not able to allocate more space/inodes until he -frees enough of them to get below softlimit. +number of used inodes (inode is a filesystem structure which is associated with +each file or directory) for users and/or groups. For both used space and number +of used inodes there are actually two limits. The first one is called softlimit +and the second one hardlimit. An user can never exceed a hardlimit for any +resource (unless he has CAP_SYS_RESOURCE capability). User is allowed to exceed +softlimit but only for limited period of time. This period is called "grace +period" or "grace time". When grace time is over, user is not able to allocate +more space/inodes until he frees enough of them to get below softlimit. Quota limits (and amount of grace time) are set independently for each filesystem. @@ -53,6 +53,12 @@ in parentheses): QUOTA_NL_BSOFTLONGWARN - space (block) softlimit is exceeded longer than given grace period. QUOTA_NL_BSOFTWARN - space (block) softlimit + - four warnings are also defined for the event when user stops + exceeding some limit: + QUOTA_NL_IHARDBELOW - inode hardlimit + QUOTA_NL_ISOFTBELOW - inode softlimit + QUOTA_NL_BHARDBELOW - space (block) hardlimit + QUOTA_NL_BSOFTBELOW - space (block) softlimit QUOTA_NL_A_DEV_MAJOR (u32) - major number of a device with the affected filesystem QUOTA_NL_A_DEV_MINOR (u32) diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index 540e9e7f59c..6a0d70a22f0 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -57,7 +57,7 @@ Similarly to JFFS2, UBIFS supports on-the-flight compression which makes it possible to fit quite a lot of data to the flash. Similarly to JFFS2, UBIFS is tolerant of unclean reboots and power-cuts. -It does not need stuff like ckfs.ext2. UBIFS automatically replays its +It does not need stuff like fsck.ext2. UBIFS automatically replays its journal and recovers from crashes, ensuring that the on-flash data structures are consistent. |