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path: root/fs/sysfs/dir.c
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* sysfs: Fix a copy-n-paste typo in commentJean Delvare2008-01-24
| | | | | | Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix bugs in sysfs_rename/move_dir()Tejun Heo2008-01-16
| | | | | | | | | | | | sysfs_rename/move_dir() have the following bugs. - On dentry lookup failure, kfree() is called on ERR_PTR() value. - sysfs_move_dir() has an extra dput() on success path. Fix them. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: make sysfs_lookup() return ERR_PTR(-ENOENT) on failed lookupTejun Heo2008-01-16
| | | | | | | | | | | | | | sysfs tries to keep dcache a strict subset of sysfs_dirent tree by shooting down dentries when a node is removed, that is, no negative dentry for sysfs. However, the lookup function returned NULL and thus created negative dentries when the target node didn't exist. Make sysfs_lookup() return ERR_PTR(-ENOENT) on lookup failure. This fixes the NULL dereference bug in sysfs_get_dentry() discovered by bluetooth rfcomm device moving around. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: make sysfs_{get,put}_active() staticAdrian Bunk2007-10-31
| | | | | | | | sysfs_{get,put}_active() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spin_lock_unlocked cleanupsRoel Kluin2007-10-17
| | | | | | | | | Replace some SPIN_LOCK_UNLOCKED with DEFINE_SPINLOCK Signed-off-by: Roel Kluin <12o3l@tiscali.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* partially fix up the lookup_one_noperm messChristoph Hellwig2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | Try to fix the mess created by sysfs braindamage. - refactor code internal to fs/namei.c a little to avoid too much duplication: o __lookup_hash_kern is renamed back to __lookup_hash o the old __lookup_hash goes away, permission checks moves to the two callers o useless inline qualifiers on above functions go away - lookup_one_len_kern loses it's last argument and is renamed to lookup_one_noperm to make it's useage a little more clear - added kerneldoc comments to describe lookup_one_len aswell as lookup_one_noperm and make it very clear that no one should use the latter ever. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: add copyrightsTejun Heo2007-10-12
| | | | | | | | | 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 Heo2007-10-12
| | | | | | | | | | | | | | | | | | | | | | | | | 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: move sysfs_dirent->s_children into sysfs_dirent->s_dirTejun Heo2007-10-12
| | | | | | | | | | | Children list head is only meaninful for directory nodes. Move it into s_dir. This doesn't save any space currently but it will with further changes. 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: open code sysfs_attach_dentry()Tejun Heo2007-10-12
| | | | | | | | | | sysfs_attach_dentry() now has only one caller and isn't doing much other than obfuscating the code. Open code and kill 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 Heo2007-10-12
| | | | | | | | | | 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: fix comments of sysfs_add/remove_one()Tejun Heo2007-10-12
| | | | | | | | | | sysfs_add/remove_one() now link and unlink the target dirent into and from the children list. Update comments accordingly. 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: spit a warning to users when they try to create a duplicate sysfs fileGreg Kroah-Hartman2007-10-12
| | | | | | | | | We want to let people know when we create a duplicate sysfs file, as they need to fix up their code. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Rewrite sysfs_move_dir in terms of sysfs direntsEric W. Biederman2007-10-12
| | | | | | | | | | | | | | This patch rewrites sysfs_move_dir to perform it's checks as much as possible on the underlying sysfs_dirents instead of the contents of the dcache, making sysfs_move_dir more like the rest of the sysfs directory modification code. 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: Rewrite rename in terms of sysfs direntsEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | This patch rewrites sysfs_rename_dir to perform it's checks as much as possible on the underlying sysfs_dirents instead of the contents of the dcache. It turns out that this version is a little simpler, and a little more like the rest of the sysfs directory modification code. tj: fixed double locking of sysfs_mutex 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: Remove s_dentryEric W. Biederman2007-10-12
| | | | | | | | | | | | | The only uses of s_dentry left are the code that maintains s_dentry and trivial users that don't actually need it. So this patch removes the s_dentry maintenance code and restructures the trivial uses to use something else. 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: simply sysfs_get_dentryTejun Heo2007-10-12
| | | | | | | | | | | | | Now that we know the sysfs tree structure cannot change under us and sysfs shadow support is dropped, sysfs_get_dentry() can be simplified greatly. It can just look up from the root and there's no need to retry on failure. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Introduce sysfs_rename_mutexEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | | | | | | 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: Rewrite sysfs_drop_dentry.Eric W. Biederman2007-10-12
| | | | | | | | | | | | | Currently we find the dentry to drop by looking at sd->s_dentry. We can just as easily accomplish the same task by looking up the sysfs inode and finding all of the dentries from there, with the added bonus that we don't need to play with the sysfs_assoc_lock. 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: Simplify readdir.Eric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | | | | | | | | | | | At some point someone wrote sysfs_readdir to insert a cursor into the list of sysfs_dirents to ensure that sysfs_readdir would restart properly. That works but it is complex code and tends to be expensive. The same effect can be achieved by keeping the sysfs_dirents in inode order and using the inode number as the f_pos. Then when we restart we just have to find the first dirent whose inode number is equal or greater then the last sysfs_dirent we attempted to return. Removing the sysfs directory cursor also allows the remove of all of the mysterious checks for sysfs_type(sd) != 0. Which were nonbovious checks to see if a cursor was in a directory list. tj: offset marker for EOF is changed from UINT_MAX to INT_MAX to avoid overflow in case offset is 32bit. 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: In sysfs_lookup don't open code sysfs_find_direntEric W. Biederman2007-10-12
| | | | | | | | | | | This is a small cleanup patch that makes the code just a little bit cleaner. 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: Make sysfs_mount staticEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | This patch modifies the users of sysfs_mount to use sysfs_root instead (which is what they are looking for). It then makes sysfs_mount static to keep people from using it by accident. The net result is slightly faster and cleaner code. 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: Remove sysfs_instantiateEric W. Biederman2007-10-12
| | | | | | | | | | | Now that sysfs_get_inode is dropping the inode lock we no longer have a need from sysfs_instantiate. 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: Move all of inode initialization into sysfs_init_inodeEric W. Biederman2007-10-12
| | | | | | | | 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 i_mutex locking in sysfs_get_dentry()Tejun Heo2007-10-12
| | | | | | | | | | | | | lookup_one_len_kern() should be called with the parent's i_mutex locked. Fix it. Spotted by Eric W. Biederman. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_addrm_finish() return voidTejun Heo2007-10-12
| | | | | | | | | | | | | | | With the previous sysfs_add_one() update, there is only one user of the return value of sysfs_addrm_finish() and the user can switch to testing @sd easily. Make sysfs_addrm_finish() return void for cleaner semantics as suggested by Satyam Sharma. This patch doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Satyam Sharma <satyam.sharma@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_add_one() automatically check for duplicate entryTejun Heo2007-10-12
| | | | | | | | | | | | 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 Heo2007-10-12
| | | | | | | | | | | | | | | | | 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: simplify sysfs_rename_dir()Tejun Heo2007-10-12
| | | | | | | | | | | | | | | | | With the shadow directories gone, sysfs_rename_dir() can be simplified. * parent doesn't need to be grabbed separately. Just access old_dentry->d_parent. * parent sd can never change. Remove code to move under the new parent. * Massage comments a bit. 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: cosmetic changes in sysfs_lookup()Tejun Heo2007-10-12
| | | | | | | | | | | | | * remove space between * and symbol name in variable declaration. * kill unnecessary new line. * kill 'found' and test 'sd' instead. 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: Remove first pass at shadow directory supportEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | | | | While shadow directories appear to be a good idea, the current scheme of controlling their creation and destruction outside of sysfs appears to be a locking and maintenance nightmare in the face of sysfs directories dynamically coming and going. Which can now occur for directories containing network devices when CONFIG_SYSFS_DEPRECATED is not set. This patch removes everything from the initial shadow directory support that allowed the shadow directory creation to be controlled at a higher level. So except for a few bits of sysfs_rename_dir everything from commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: cleanup semaphore.hDave Young2007-10-12
| | | | | | | | | Cleanup semaphore.h Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobjects: fix up improper use of the kobject name fieldGreg Kroah-Hartman2007-10-12
| | | | | | | A number of different drivers incorrect access the kobject name field directly. This is not correct as the name might not be in the array. Use the proper accessor function instead.
* sysfs: fix locking in sysfs_lookup() and sysfs_rename_dir()Tejun Heo2007-08-22
| | | | | | | | | | | sd children list walking in sysfs_lookup() and sd renaming in sysfs_rename_dir() were left out during i_mutex -> sysfs_mutex conversion. Fix them. 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: cosmetic clean up on node creation failure pathsTejun Heo2007-07-18
| | | | | | | | | | | | | | | | | | | | | | 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: avoid kmem_cache_free(NULL)Akinobu Mita2007-07-18
| | | | | | | | | | kmem_cache_free() with NULL is not allowed. But it may happen if out of memory error is triggered in sysfs_new_dirent(). This patch fixes that error handling. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make directory dentries and inodes reclaimableTejun Heo2007-07-11
| | | | | | | | | | | | | | | | | | | | | 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: implement sysfs_get_dentry()Tejun Heo2007-07-11
| | | | | | | | | | | | | | | | Some sysfs operations require dentry and inode. sysfs_get_dentry() looks up and gets dentry for the specified sysfs_dirent. It finds the first ancestor with dentry attached and starts looking up dentries from there. Looking up from the nearest ancestor is necessary to support shadowed directories because we can't reliably lookup dentry for one of the shadows. Dentries for each shadow will be pinned in memory such that they can serve as the starting point for dentry lookup. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: move sysfs_drop_dentry() to dir.c and make it staticTejun Heo2007-07-11
| | | | | | | | | | After add/remove path restructuring, the only user of sysfs_drop_dentry() is sysfs_addrm_finish(). Move sysfs_drop_dentry() to dir.c and make it static. 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 Heo2007-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Heo2007-07-11
| | | | | | | | | | | | | | 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: consolidate sysfs spinlocksTejun Heo2007-07-11
| | | | | | | | | | | Replace sysfs_lock and kobj_sysfs_assoc_lock with sysfs_assoc_lock. sysfs_lock was originally to be used to protect sysfs_dirent tree but mutex seems better choice, so there is no reason to keep sysfs_lock separate. Merge the two spinlocks into one. 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 Heo2007-07-11
| | | | | | | | | | | | 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 Heo2007-07-11
| | | | | | | | | | 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: implement SYSFS_FLAG_REMOVED flagTejun Heo2007-07-11
| | | | | | | | | | Implement SYSFS_FLAG_REMOVED flag which currently is used only to improve sanity check in sysfs_deactivate(). The flag 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: rename sysfs_dirent->s_type to s_flags and make room for flagsTejun Heo2007-07-11
| | | | | | | | | | | | Rename sysfs_dirent->s_type to s_flags, pack type into lower eight bits and reserve the rest for flags. sysfs_type() can used to access the type. All existing sd->s_type accesses are converted to use sysfs_type(). While at it, type test is changed to equality test instead of bit-and test where appropriate. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: use singly-linked list for sysfs_dirent treeTejun Heo2007-07-11
| | | | | | | | | | | | | | Make sysfs_dirent use singly linked list for its tree structure. sysfs_link_sibling() and sysfs_unlink_sibling() functions are added to handle simpler cases. It adds some complexity and cpu cycle overhead but reduced memory footprint is worthwhile on big machines. This change reduces the sizeof sysfs_dirent from 104 to 88 on 64bit and from 60 to 52 on 32bit. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: slim down sysfs_dirent->s_activeTejun Heo2007-07-11
| | | | | | | | | | | | | | | | | | | | | | | | Make sysfs_dirent->s_active an atomic_t instead of rwsem. This reduces the size of sysfs_dirent from 136 to 104 on 64bit and from 76 to 60 on 32bit with lock debugging turned off. With lock debugging turned on the reduction is much larger. s_active starts at zero and each active reference increments s_active. Putting a reference decrements s_active. Deactivation subtracts SD_DEACTIVATED_BIAS which is currently INT_MIN and assumed to be small enough to make s_active negative. If s_active is negative, sysfs_get() no longer grants new references. Deactivation succeeds immediately if there is no active user; otherwise, it waits using a completion for the last put. Due to the removal of lockdep tricks, this change makes things less trickier in release_sysfs_dirent(). As all the complexity is contained in three s_active functions, I think it's more readable this way. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: move s_active functions to fs/sysfs/dir.cTejun Heo2007-07-11
| | | | | | | | | | These functions are about to receive more complexity and doesn't really need to be inlined in the first place. Move them from fs/sysfs/sysfs.h to fs/sysfs/dir.c. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: use iget_locked() instead of new_inode()Tejun Heo2007-07-11
| | | | | | | | | | | | | | | | | | After dentry is reclaimed, sysfs always used to allocate new dentry and inode if the file is accessed again. This causes problem with operations which only pin the inode. For example, if inotify watch is added to a sysfs file and the dentry for the file is reclaimed, the next update event creates new dentry and new inode making the inotify watch miss all the events from there on. This patch fixes it by using iget_locked() instead of new_inode(). sysfs_new_inode() is renamed to sysfs_get_inode() and inode is initialized iff the inode is newly allocated. sysfs_instantiate() is responsible for unlocking new inodes. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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