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* sysfs: add copyrightsTejun Heo2007-10-121-1/+9
| | | | | | | | | Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: move sysfs file poll implementation to sysfs_open_direntTejun Heo2007-10-121-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | Sysfs file poll implementation is scattered over sysfs and kobject. Event numbering is done in sysfs_dirent but wait itself is done on kobject. This not only unecessarily bloats both kobject and sysfs_dirent but is also buggy - if a sysfs_dirent is removed while there still are pollers, the associaton betwen the kobject and sysfs_dirent breaks and kobject may be freed with the pollers still sleeping on it. This patch moves whole poll implementation into sysfs_open_dirent. Each time a sysfs_open_dirent is created, event number restarts from 1 and pollers sleep on sysfs_open_dirent. As event sequence number is meaningless without any open file and pollers should have open file and thus sysfs_open_dirent, this ephemeral event counting works and is a saner implementation. This patch fixes the dnagling sleepers bug and reduces the sizes of kobject and sysfs_dirent by one pointer. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: implement sysfs_open_direntTejun Heo2007-10-121-1/+108
| | | | | | | | | | | | | | | Implement sysfs_open_dirent which represents an open file (attribute) sysfs_dirent. A file sysfs_dirent with one or more open files have one sysfs_dirent and all sysfs_buffers (one for each open instance) are linked to it. sysfs_open_dirent doesn't actually do anything yet but will be used to off-load things which are specific for open file sysfs_dirent from it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make s_elem an anonymous unionTejun Heo2007-10-121-7/+7
| | | | | | | | | | Make s_elem an anonymous union. Prefixing with s_elem makes things needlessly longer without any advantage. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill unnecessary NULL pointer check in sysfs_release()Tejun Heo2007-10-121-5/+4
| | | | | | | | | | | In sysfs_release(), sysfs_buffer pointed to by filp->private_data is guaranteed to exist. Kill the unnecessary NULL check. This also makes the code more consistent with the counterpart in fs/sysfs/bin.c. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill unnecessary sysfs_get() in open pathsTejun Heo2007-10-121-5/+1
| | | | | | | | | | | | | There's no reason to get an extra reference to sysfs_dirent for an open file. Open file has a reference to the dentry which in turn has a reference to sysfs_dirent. This is fairly obvious as otherwise open itself won't be able to access the sysfs_dirent. Kill the extra sysfs_get() and matching sysfs_put(). Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill sysfs_update_file()Tejun Heo2007-10-121-40/+0
| | | | | | | | | | | | | | sysfs_update_file() depends on inode->i_mtime but sysfs iondes are now reclaimable making the reported modification time unreliable. There's only one user (pci hotplug) of this notification mechanism and it reportedly isn't utilized from userland. Kill sysfs_update_file(). Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix sysfs_chmod_file() such that it updates sd->s_mode tooTejun Heo2007-10-121-0/+9
| | | | | | | | | | | | sysfs_chmod_file() looked and updated only inode of the target file. Dentry and inode are reclaimable and the update mode data will go away when the inode is reclaimed. This patch makes sysfs_chmod_file() update sd->s_mode too such that the change is permanent. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Introduce sysfs_rename_mutexEric W. Biederman2007-10-121-0/+4
| | | | | | | | | | | | | | | | | | | | | Looking carefully at the rename code we have a subtle dependency that the structure of sysfs not change while we are performing a rename. If the parent directory of the object we are renaming changes while the rename is being performed nasty things could happen when we go to release our locks. So introduce a sysfs_rename_mutex to prevent this highly unlikely theoretical issue. In addition hold sysfs_rename_mutex over all calls to sysfs_get_dentry. Allowing sysfs_get_dentry to be simplified in the future. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Fix typos in fs/sysfs/file.cRolf Eike Beer2007-10-121-1/+1
| | | | | | | Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_add_one() automatically check for duplicate entryTejun Heo2007-10-121-7/+5
| | | | | | | | | | | | Make sysfs_add_one() check for duplicate entry and return -EEXIST if such entry exists. This simplifies node addition code a bit. This patch doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_add/remove_one() call link/unlink_sibling() implictlyTejun Heo2007-10-121-3/+1
| | | | | | | | | | | | | | | | | When adding or removing a sysfs_dirent, the user used to be required to call link/unlink separately. It was for two reasons - code looked like that before sysfs_addrm_cxt conversion and to avoid looping through parent_sd->children list twice during removal. Performance optimization during removal just isn't worth it. Make sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly. This makes code simpler albeit slightly less efficient. This change doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs/file.c - use mutex instead of semaphoreDave Young2007-10-121-7/+7
| | | | | | | | Use mutex instead of semaphore in sysfs/file.c : sys_buffer. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: cosmetic clean up on node creation failure pathsTejun Heo2007-07-181-4/+5
| | | | | | | | | | | | | | | | | | | | | | Node addition failure is detected by testing return value of sysfs_addfm_finish() which returns the number of added and removed nodes. As the function is called as the last step of addition right on top of error handling block, the if blocks looked like the following. if (sysfs_addrm_finish(&acxt)) success handling, usually return; /* fall through to error handling */ This is the opposite of usual convention in sysfs and makes the code difficult to understand. This patch inverts the test and makes those blocks look more like others. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Gabriel C <nix.or.die@googlemail.com> Cc: Miles Lane <miles.lane@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make directory dentries and inodes reclaimableTejun Heo2007-07-111-75/+59
| | | | | | | | | | | | | | | | | | | | | This patch makes dentries and inodes for sysfs directories reclaimable. * sysfs_notify() is modified to walk sysfs_dirent tree instead of dentry tree. * sysfs_update_file() and sysfs_chmod_file() use sysfs_get_dentry() to grab the victim dentry. * sysfs_rename_dir() and sysfs_move_dir() grab all dentries using sysfs_get_dentry() on startup. * Dentries for all shadowed directories are pinned in memory to serve as lookup start point. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: restructure add/remove paths and fix inode updateTejun Heo2007-07-111-9/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original add/remove code had the following problems. * parent's timestamps are updated on dentry instantiation. this is incorrect with reclaimable files. * updating parent's timestamps isn't synchronized. * parent nlink update assumes the inode is accessible which won't be true once directory dentries are made reclaimable. This patch restructures add/remove paths to resolve the above problems. Add/removal are done in the following steps. 1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other resources. 2-a. sysfs_add_one() : add new sd. linking the new sd into the children list is caller's responsibility. 2-b. sysfs_remove_one() : remove a sd. unlinking the sd from the children list is caller's responsibility. 3. sysfs_addrm_finish() : release all resources and clean up. Steps 2-a and/or 2-b can be repeated multiple times. Parent's inode is looked up during sysfs_addrm_start(). If available (always at the moment), it's pinned and nlink is updated as sd's are added and removed. Timestamps are updated during finish if any sd has been added or removed. If parent's inode is not available during start, sysfs_mutex ensures that parent inode is not created till add/remove is complete. All the complexity is contained inside the helper functions. Especially, dentry/inode handling is properly hidden from the rest of sysfs which now mostly operate on sysfs_dirents. As an added bonus, codes which use these helpers to add and remove sysfs_dirents are now more structured and simpler. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: use sysfs_mutex to protect the sysfs_dirent treeTejun Heo2007-07-111-16/+15
| | | | | | | | | | | | | | As kobj sysfs dentries and inodes are gonna be made reclaimable, i_mutex can't be used to protect sysfs_dirent tree. Use sysfs_mutex globally instead. As the whole tree is protected with sysfs_mutex, there is no reason to keep sysfs_rename_sem. Drop it. While at it, add docbook comments to functions which require sysfs_mutex locking. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make kobj point to sysfs_dirent instead of dentryTejun Heo2007-07-111-23/+24
| | | | | | | | | | | | As kobj sysfs dentries and inodes are gonna be made reclaimable, dentry can't be used as naming token for sysfs file/directory, replace kobj->dentry with kobj->sd. The only external interface change is shadow directory handling. All other changes are contained in kobj and sysfs. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: implement sysfs_find_dirent() and sysfs_get_dirent()Tejun Heo2007-07-111-1/+1
| | | | | | | | | | Implement sysfs_find_dirent() and sysfs_get_dirent(). sysfs_dirent_exist() is replaced by sysfs_find_dirent(). These will be used to make directory entries reclamiable. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill unnecessary attribute->ownerTejun Heo2007-07-111-16/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill attribute file orphaningTejun Heo2007-07-111-52/+13
| | | | | | | | | | | Now that sysfs_dirent can be disconnected from kobject on deletion, there is no need to orphan each attribute files. All [bin_]attribute nodes are automatically orphaned when the parent node is deleted. Kill attribute file orphaning. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: implement sysfs_dirent active reference and immediate disconnectTejun Heo2007-07-111-54/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs: implement sysfs_dirent active reference and immediate disconnect Opening a sysfs node references its associated kobject, so userland can arbitrarily prolong lifetime of a kobject which complicates lifetime rules in drivers. This patch implements active reference and makes the association between kobject and sysfs immediately breakable. Now each sysfs_dirent has two reference counts - s_count and s_active. s_count is a regular reference count which guarantees that the containing sysfs_dirent is accessible. As long as s_count reference is held, all sysfs internal fields in sysfs_dirent are accessible including s_parent and s_name. The newly added s_active is active reference count. This is acquired by invoking sysfs_get_active() and it's the caller's responsibility to ensure sysfs_dirent itself is accessible (should be holding s_count one way or the other). Dereferencing sysfs_dirent to access objects out of sysfs proper requires active reference. This includes access to the associated kobjects, attributes and ops. The active references can be drained and denied by calling sysfs_deactivate(). All active sysfs_dirents must be deactivated after deletion but before the default reference is dropped. This enables immediate disconnect of sysfs nodes. Once a sysfs_dirent is deleted, it won't access any entity external to sysfs proper. Because attr/bin_attr ops access both the node itself and its parent for kobject, they need to hold active references to both. sysfs_get/put_active_two() helpers are provided to help grabbing both references. Parent's is acquired first and released last. Unlike other operations, mmapped area lingers on after mmap() is finished and the module implement implementing it and kobj need to stay referenced till all the mapped pages are gone. This is accomplished by holding one set of active references to the bin_attr and its parent if there have been any mmap during lifetime of an openfile. The references are dropped when the openfile is released. This change makes sysfs lifetime rules independent from both kobject's and module's. It not only fixes several race conditions caused by sysfs not holding onto the proper module when referencing kobject, but also helps fixing and simplifying lifetime management in driver model and drivers by taking sysfs out of the equation. Please read the following message for more info. http://article.gmane.org/gmane.linux.kernel/510293 Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_dirent->s_element a unionTejun Heo2007-07-111-9/+10
| | | | | | | | | | | | | | | | | | | | | Make sd->s_element a union of sysfs_elem_{dir|symlink|attr|bin_attr} and rename it to s_elem. This is to achieve... * some level of type checking : changing symlink to point to sysfs_dirent instead of kobject is much safer and less painful now. * easier / standardized dereferencing * allow sysfs_elem_* to contain more than one entry Where possible, pointer is obtained by directly deferencing from sd instead of going through other entities. This reduces dependencies to dentry, inode and kobject. to_attr() and to_bin_attr() are unused now and removed. This is in preparation of object reference simplification. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: add sysfs_dirent->s_nameTejun Heo2007-07-111-1/+1
| | | | | | | | | | | | | | | | | Add s_name to sysfs_dirent. This is to further reduce dependency to the associated dentry. Name is copied for directories and symlinks but not for attributes. Where possible, name dereferences are converted to use sd->s_name. sysfs_symlink->link_name and sysfs_get_name() are unused now and removed. This change allows symlink to be implemented using sysfs_dirent tree proper, which is the last remaining dentry-dependent sysfs walk. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: consolidate sysfs_dirent creation functionsTejun Heo2007-07-111-5/+16
| | | | | | | | | | | | | | | | | | | | | Currently there are four functions to create sysfs_dirent - __sysfs_new_dirent(), sysfs_new_dirent(), __sysfs_make_dirent() and sysfs_make_dirent(). Other than sysfs_make_dirent(), no function has two users if calls to implement other functions are excluded. This patch consolidates sysfs_dirent creation functions into the following two. * sysfs_new_dirent() : allocate and initialize * sysfs_attach_dirent() : attach to sysfs_dirent hierarchy and/or associate with dentry This simplifies interface and gives callers more flexibility. This is in preparation of object reference simplification. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* use simple_read_from_buffer() in fs/Akinobu Mita2007-05-091-31/+2
| | | | | | | | | | Cleanup using simple_read_from_buffer() in binfmt_misc, configfs, and sysfs. Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Joel Becker <joel.becker@oracle.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* remove "struct subsystem" as it is no longer neededGreg Kroah-Hartman2007-05-021-6/+5
| | | | | | | | | | | We need to work on cleaning up the relationship between kobjects, ksets and ktypes. The removal of 'struct subsystem' is the first step of this, especially as it is not really needed at all. Thanks to Kay for fixing the bugs in this patch. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* device_schedule_callback() needs a module referenceAlan Stern2007-04-271-3/+11
| | | | | | | | | | | | | | | This patch (as896b) fixes an oversight in the design of device_schedule_callback(). It is necessary to acquire a reference to the module owning the callback routine, to prevent the module from being unloaded before the callback can run. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Satyam Sharma <satyam.sharma@gmail.com> Cc: Neil Brown <neilb@suse.de> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] sysfs: reinstate exclusion between method calls and attribute ↵Alan Stern2007-03-151-5/+5
| | | | | | | | | | | | | | | | | | | unregistration This patch (as869) reinstates the mutual exclusion between sysfs attribute method calls and attribute unregistration. The previously-reported deadlocks have been fixed, and this exclusion is by far the simplest way to avoid races during driver unbinding. The check for orphaned read-buffers has been moved down slightly, so that the remainder of a partially-read buffer will still be available to userspace even after the attribute has been unregistered. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Hugh Dickins <hugh@veritas.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Oliver Neukum <oneukum@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysfs and driver core: add callback helper, used by SCSI and S390Alan Stern2007-03-151-0/+54
| | | | | | | | | | | | | | | | | | This patch (as868) adds a helper routine for device drivers that need to set up a callback to perform some action in a different process's context. This is intended for use by attribute methods that want to unregister themselves or their parent device. Attribute method calls are mutually exclusive with unregistration, so such actions cannot be taken directly. Two attribute methods are converted to use the new helper routine: one for SCSI device deletion and one for System/390 ccwgroup devices. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Hugh Dickins <hugh@veritas.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Oliver Neukum <oneukum@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: allow attributes to be added to groupsAlan Stern2007-02-231-0/+44
| | | | | | | | | | | This patch (as860) adds two new sysfs routines: sysfs_add_file_to_group() and sysfs_remove_file_from_group(). A later patch adds code that uses the new routines. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* PCI/sysfs/kobject kernel-doc fixesRandy Dunlap2007-02-161-1/+1
| | | | | | | | Fix kernel-doc warnings in PCI, sysfs, and kobject files. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: error handling in sysfs, fill_read_buffer()Oliver Neukum2007-02-071-4/+6
| | | | | | | | | | | if a driver returns an error in fill_read_buffer(), the buffer will be marked as filled. Subsequent reads will return eof. But there is no data because of an error, not because it has been read. Not marking the buffer filled is the obvious fix. Signed-off-by: Oliver Neukum <oliver@neukum.name> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kobject_put cleanupMariusz Kozlowski2007-02-071-3/+2
| | | | | | | | | This patch removes redundant argument checks for kobject_put(). Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: fix race in sysfs between sysfs_remove_file() and read()/write()Oliver Neukum2007-02-071-17/+50
| | | | | | | | | | | | | | This patch prevents a race between IO and removing a file from sysfs. It introduces a list of sysfs_buffers associated with a file at the inode. Upon removal of a file the list is walked and the buffers marked orphaned. IO to orphaned buffers fails with -ENODEV. The driver can safely free associated data structures or be unloaded. Signed-off-by: Oliver Neukum <oliver@neukum.name> Acked-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] sysfs: change uses of f_{dentry, vfsmnt} to use f_pathJosef "Jeff" Sipek2006-12-081-8/+8
| | | | | | | | | Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the sysfs filesystem code. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* sysfs: sysfs_write_file() writes zero terminated dataThomas Maier2006-12-011-0/+3
| | | | | | | | | | | | | | | | | | | | | since most of the files in sysfs are text files, it would be nice, if the "store" function called during sysfs_write_file() gets a zero terminated string / data. The current implementation seems not to ensure this. (But only if it is the first time the zeroed buffer page is allocated.) So the buffer can be scanned by sscanf() easily, for example. This patch simply sets a \0 char behind the data in buffer->page. Signed-off-by: Thomas Maier <balagi@justmail.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: update obsolete comment in sysfs_update_fileHidetoshi Seto2006-10-181-1/+1
| | | | | | | | And the obsolete comment should be updated (or totally removed). Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: remove duplicated dput in sysfs_update_fileHidetoshi Seto2006-10-181-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Following function can drops d_count twice against one reference by lookup_one_len. <SOURCE> /** * sysfs_update_file - update the modified timestamp on an object attribute. * @kobj: object we're acting for. * @attr: attribute descriptor. */ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) { struct dentry * dir = kobj->dentry; struct dentry * victim; int res = -ENOENT; mutex_lock(&dir->d_inode->i_mutex); victim = lookup_one_len(attr->name, dir, strlen(attr->name)); if (!IS_ERR(victim)) { /* make sure dentry is really there */ if (victim->d_inode && (victim->d_parent->d_inode == dir->d_inode)) { victim->d_inode->i_mtime = CURRENT_TIME; fsnotify_modify(victim); /** * Drop reference from initial sysfs_get_dentry(). */ dput(victim); res = 0; } else d_drop(victim); /** * Drop the reference acquired from sysfs_get_dentry() above. */ dput(victim); } mutex_unlock(&dir->d_inode->i_mutex); return res; } </SOURCE> PCI-hotplug (drivers/pci/hotplug/pci_hotplug_core.c) is only user of this function. I confirmed that dentry of /sys/bus/pci/slots/XXX/* have negative d_count value. This patch removes unnecessary dput(). Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] pr_debug: sysfs: use size_t length modifier in pr_debug format argumentsZach Brown2006-10-031-2/+2
| | | | | | | | sysfs: use size_t length modifier in pr_debug format arguments Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sysfs: Allow sysfs attribute files to be pollableNeilBrown2006-04-141-0/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | It works like this: Open the file Read all the contents. Call poll requesting POLLERR or POLLPRI (so select/exceptfds works) When poll returns, close the file and go to top of loop. or lseek to start of file and go back to the 'read'. Events are signaled by an object manager calling sysfs_notify(kobj, dir, attr); If the dir is non-NULL, it is used to find a subdirectory which contains the attribute (presumably created by sysfs_create_group). This has a cost of one int per attribute, one wait_queuehead per kobject, one int per open file. The name "sysfs_notify" may be confused with the inotify functionality. Maybe it would be nice to support inotify for sysfs attributes as well? This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action to be pollable Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] sysfs: zero terminate sysfs write buffersGreg Kroah-Hartman2006-04-021-1/+1
| | | | | | | | | | No one should be writing a PAGE_SIZE worth of data to a normal sysfs file, so properly terminate the buffer. Thanks to Al Viro for pointing out my supidity here. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Make most file operations structs in fs/ constArjan van de Ven2006-03-281-1/+1
| | | | | | | | | | | | | | This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sysfs: fix problem with duplicate sysfs directories and filesManeesh Soni2006-03-201-2/+4
| | | | | | | | The following patch checks for existing sysfs_dirent before preparing new one while creating sysfs directories and files. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] sysfs: kzalloc conversionEric Sesterhenn2006-03-201-2/+1
| | | | | | | | this converts fs/sysfs to kzalloc() usage. compile tested with make allyesconfig Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_semJes Sorensen2006-01-091-9/+8
| | | | | | | | | | | | | This patch converts the inode semaphore to a mutex. I have tested it on XFS and compiled as much as one can consider on an ia64. Anyway your luck with it might be different. Modified-by: Ingo Molnar <mingo@elte.hu> (finished the conversion) Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [PATCH] sysfs: fix sysfs_chmod_fileManeesh Soni2005-07-291-8/+10
| | | | | | | | | | o sysfs_chmod_file() must update the new iattr field in sysfs_dirent else the mode change will not be persistent in case of inode evacuation from cache. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] inotifyRobert Love2005-07-121-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inotify is intended to correct the deficiencies of dnotify, particularly its inability to scale and its terrible user interface: * dnotify requires the opening of one fd per each directory that you intend to watch. This quickly results in too many open files and pins removable media, preventing unmount. * dnotify is directory-based. You only learn about changes to directories. Sure, a change to a file in a directory affects the directory, but you are then forced to keep a cache of stat structures. * dnotify's interface to user-space is awful. Signals? inotify provides a more usable, simple, powerful solution to file change notification: * inotify's interface is a system call that returns a fd, not SIGIO. You get a single fd, which is select()-able. * inotify has an event that says "the filesystem that the item you were watching is on was unmounted." * inotify can watch directories or files. Inotify is currently used by Beagle (a desktop search infrastructure), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] DocBook: update commentsMartin Waitz2005-06-241-2/+3
| | | | | | | | This patch updates some comments to match code changes. Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove duplicate get_dentry functions in various placesChristoph Hellwig2005-06-231-2/+3
| | | | | | | | | | | | | | Various filesystem drivers have grown a get_dentry() function that's a duplicate of lookup_one_len, except that it doesn't take a maximum length argument and doesn't check for \0 or / in the passed in filename. Switch all these places to use lookup_one_len. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Greg KH <greg@kroah.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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