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path: root/fs/kernfs/kernfs-internal.h
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2014-02-14kernfs: fix kernfs_node_from_dentry()Li Zefan
Currently kernfs_node_from_dentry() returns NULL for root dentry, because root_dentry->d_op == NULL. Due to this bug cgroupstats_build() returns -EINVAL for root cgroup. # mount -t cgroup -o cpuacct /cgroup # Documentation/accounting/getdelays -C /cgroup fatal reply error, errno -22 With this fix: # Documentation/accounting/getdelays -C /cgroup sleeping 305, blocked 0, running 1, stopped 0, uninterruptible 1 Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07kernfs: remove KERNFS_REMOVEDTejun Heo
KERNFS_REMOVED is used to mark half-initialized and dying nodes so that they don't show up in lookups and deny adding new nodes under or renaming it; however, its role overlaps that of deactivation. It's necessary to deny addition of new children while removal is in progress; however, this role considerably intersects with deactivation - KERNFS_REMOVED prevents new children while deactivation prevents new file operations. There's no reason to have them separate making things more complex than necessary. This patch removes KERNFS_REMOVED. * Instead of KERNFS_REMOVED, each node now starts its life deactivated. This means that we now use both atomic_add() and atomic_sub() on KN_DEACTIVATED_BIAS, which is INT_MIN. The compiler generates an overflow warnings when negating INT_MIN as the negation can't be represented as a positive number. Nothing is actually broken but let's bump BIAS by one to avoid the warnings for archs which negates the subtrahend.. * A new helper kernfs_active() which tests whether kn->active >= 0 is added for convenience and lockdep annotation. All KERNFS_REMOVED tests are replaced with negated kernfs_active() tests. * __kernfs_remove() is updated to deactivate, but not drain, all nodes in the subtree instead of setting KERNFS_REMOVED. This removes deactivation from kernfs_deactivate(), which is now renamed to kernfs_drain(). * Sanity check on KERNFS_REMOVED in kernfs_put() is replaced with checks on the active ref. * Some comment style updates in the affected area. v2: Reordered before removal path restructuring. kernfs_active() dropped and kernfs_get/put_active() used instead. RB_EMPTY_NODE() used in the lookup paths. v3: Reverted most of v2 except for creating a new node with KN_DEACTIVATED_BIAS. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07kernfs: remove kernfs_addrm_cxtTejun Heo
kernfs_addrm_cxt and the accompanying kernfs_addrm_start/finish() were added because there were operations which should be performed outside kernfs_mutex after adding and removing kernfs_nodes. The necessary operations were recorded in kernfs_addrm_cxt and performed by kernfs_addrm_finish(); however, after the recent changes which relocated deactivation and unmapping so that they're performed directly during removal, the only operation kernfs_addrm_finish() performs is kernfs_put(), which can be moved inside the removal path too. This patch moves the kernfs_put() of the base ref to __kernfs_remove() and remove kernfs_addrm_cxt and kernfs_addrm_start/finish(). * kernfs_add_one() is updated to grab and release kernfs_mutex itself. sysfs_addrm_start/finish() invocations around it are removed from all users. * __kernfs_remove() puts an unlinked node directly instead of chaining it to kernfs_addrm_cxt. Its callers are updated to grab and release kernfs_mutex instead of calling kernfs_addrm_start/finish() around it. v2: Rebased on top of "kernfs: associate a new kernfs_node with its parent on creation" which dropped @parent from kernfs_add_one(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-17kernfs: associate a new kernfs_node with its parent on creationTejun Heo
Once created, a kernfs_node is always destroyed by kernfs_put(). Since ba7443bc656e ("sysfs, kernfs: implement kernfs_create/destroy_root()"), kernfs_put() depends on kernfs_root() to locate the ino_ida. kernfs_root() in turn depends on kernfs_node->parent being set for !dir nodes. This means that kernfs_put() of a !dir node requires its ->parent to be initialized. This leads to oops when a newly created !dir node is destroyed without going through kernfs_add_one() or after failing kernfs_add_one() before ->parent is set. kernfs_root() invoked from kernfs_put() will try to dereference NULL parent. Fix it by moving parent association to kernfs_new_node() from kernfs_add_one(). kernfs_new_node() now takes @parent instead of @root and determines the root from the parent and also sets the new node's parent properly. @parent parameter is removed from kernfs_add_one(). As there's no parent when creating the root node, __kernfs_new_node() which takes @root as before and doesn't set the parent is used in that case. This ensures that a kernfs_node in any stage in its life has its parent associated and thus can be put. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13Revert "kernfs: remove KERNFS_REMOVED"Greg Kroah-Hartman
This reverts commit ae34372eb8408b3d07e870f1939f99007a730d28. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"Greg Kroah-Hartman
This reverts commit f601f9a2bf7dc1f7ee18feece4c4e2fc6845d6c4. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13Revert "kernfs: remove kernfs_addrm_cxt"Greg Kroah-Hartman
This reverts commit 99177a34110889a8f2c36420c34e3bcc9bfd8a70. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10kernfs: remove kernfs_addrm_cxtTejun Heo
kernfs_addrm_cxt and the accompanying kernfs_addrm_start/finish() were added because there were operations which should be performed outside kernfs_mutex after adding and removing kernfs_nodes. The necessary operations were recorded in kernfs_addrm_cxt and performed by kernfs_addrm_finish(); however, after the recent changes which relocated deactivation and unmapping so that they're performed directly during removal, the only operation kernfs_addrm_finish() performs is kernfs_put(), which can be moved inside the removal path too. This patch moves the kernfs_put() of the base ref to __kernfs_remove() and remove kernfs_addrm_cxt and kernfs_addrm_start/finish(). * kernfs_add_one() is updated to grab and release the parent's active ref and kernfs_mutex itself. kernfs_get/put_active() and kernfs_addrm_start/finish() invocations around it are removed from all users. * __kernfs_remove() puts an unlinked node directly instead of chaining it to kernfs_addrm_cxt. Its callers are updated to grab and release kernfs_mutex instead of calling kernfs_addrm_start/finish() around it. v2: Updated to fit the v2 restructuring of removal path. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()Tejun Heo
kernfs_unmap_bin_file() is supposed to unmap all memory mappings of the target file before kernfs_remove() finishes; however, it currently is being called from kernfs_addrm_finish() and has the same race problem as the original implementation of deactivation when there are multiple removers - only the remover which snatches the node to its addrm_cxt->removed list is guaranteed to wait for its completion before returning. It can be fixed by moving kernfs_unmap_bin_file() invocation from kernfs_addrm_finish() to __kernfs_remove(). The function may be called multiple times but that shouldn't do any harm. We end up dropping kernfs_mutex in the removal loop and the node may be removed inbetween by someone else. kernfs_unlink_sibling() is updated to test whether the node has already been removed and return accordingly. __kernfs_remove() in turn performs post-unlinking cleanup only if it actually unlinked the node. KERNFS_HAS_MMAP test is moved out of the unmap function into __kernfs_remove() so that we don't unlock kernfs_mutex unnecessarily. While at it, drop the now meaningless "bin" qualifier from the function name. v2: Rewritten to fit the v2 restructuring of removal path. HAS_MMAP test relocated. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10kernfs: remove KERNFS_REMOVEDTejun Heo
KERNFS_REMOVED is used to mark half-initialized and dying nodes so that they don't show up in lookups and deny adding new nodes under or renaming it; however, its role overlaps those of deactivation and removal from rbtree. It's necessary to deny addition of new children while removal is in progress; however, this role considerably intersects with deactivation - KERNFS_REMOVED prevents new children while deactivation prevents new file operations. There's no reason to have them separate making things more complex than necessary. KERNFS_REMOVED is also used to decide whether a node is still visible to vfs layer, which is rather redundant as equivalent determination can be made by testing whether the node is on its parent's children rbtree or not. This patch removes KERNFS_REMOVED. * Instead of KERNFS_REMOVED, each node now starts its life deactivated. This means that we now use both atomic_add() and atomic_sub() on KN_DEACTIVATED_BIAS, which is INT_MIN. The compiler generates an overflow warnings when negating INT_MIN as the negation can't be represented as a positive number. Nothing is actually broken but let's bump BIAS by one to avoid the warnings for archs which negates the subtrahend.. * KERNFS_REMOVED tests in add and rename paths are replaced with kernfs_get/put_active() of the target nodes. Due to the way the add path is structured now, active ref handling is done in the callers of kernfs_add_one(). This will be consolidated up later. * kernfs_remove_one() is updated to deactivate instead of setting KERNFS_REMOVED. This removes deactivation from kernfs_deactivate(), which is now renamed to kernfs_drain(). * kernfs_dop_revalidate() now tests RB_EMPTY_NODE(&kn->rb) instead of KERNFS_REMOVED and KERNFS_REMOVED test in kernfs_dir_pos() is dropped. A node which is removed from the children rbtree is not included in the iteration in the first place. This means that a node may be visible through vfs a bit longer - it's now also visible after deactivation until the actual removal. This slightly enlarged window difference doesn't make any difference to the userland. * Sanity check on KERNFS_REMOVED in kernfs_put() is replaced with checks on the active ref. * Some comment style updates in the affected area. v2: Reordered before removal path restructuring. kernfs_active() dropped and kernfs_get/put_active() used instead. RB_EMPTY_NODE() used in the lookup paths. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17kernfs: mark static names with KERNFS_STATIC_NAMETejun Heo
Because sysfs used struct attribute which are supposed to stay constant, sysfs didn't copy names when creating regular files. The specified string for name was supposed to stay constant. Such distinction isn't inherent for kernfs. kernfs_create_file[_ns]() should be able to take the same @name as kernfs_create_dir[_ns]() As there can be huge number of sysfs attributes, we still want to be able to use static names for sysfs attributes. This patch renames kernfs_create_file_ns_key() to __kernfs_create_file() and adds @name_is_static parameter so that the caller can explicitly indicate that @name can be used without copying. kernfs is updated to use KERNFS_STATIC_NAME to distinguish static and copied names. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs/kernfs/ in internal functions and whatever is leftTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_*()/kernfs_*()/ in all internal functions * s/sysfs/kernfs/ in internal strings, comments and whatever is remaining * Uniformly rename various vfs operations so that they're consistently named and distinguishable. This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs/kernfs/ in global variablesTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_mutex/kernfs_mutex/ * s/sysfs_dentry_ops/kernfs_dops/ * s/sysfs_dir_operations/kernfs_dir_fops/ * s/sysfs_dir_inode_operations/kernfs_dir_iops/ * s/kernfs_file_operations/kernfs_file_fops/ - renamed for consistency * s/sysfs_symlink_inode_operations/kernfs_symlink_iops/ * s/sysfs_aops/kernfs_aops/ * s/sysfs_backing_dev_info/kernfs_bdi/ * s/sysfs_inode_operations/kernfs_iops/ * s/sysfs_dir_cachep/kernfs_node_cache/ * s/sysfs_ops/kernfs_sops/ This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs/kernfs/ in constantsTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/SYSFS_DIR/KERNFS_DIR/ * s/SYSFS_KOBJ_ATTR/KERNFS_FILE/ * s/SYSFS_KOBJ_LINK/KERNFS_LINK/ * s/SYSFS_{TYPE_FLAGS}/KERNFS_{TYPE_FLAGS}/ * s/SYSFS_FLAG_{FLAG}/KERNFS_{FLAG}/ * s/sysfs_type()/kernfs_type()/ * s/SD_DEACTIVATED_BIAS/KN_DEACTIVATED_BIAS/ This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs/kernfs/ in various data structuresTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_open_dirent/kernfs_open_node/ * s/sysfs_open_file/kernfs_open_file/ * s/sysfs_inode_attrs/kernfs_iattrs/ * s/sysfs_addrm_cxt/kernfs_addrm_cxt/ * s/sysfs_super_info/kernfs_super_info/ * s/sysfs_info()/kernfs_info()/ * s/sysfs_open_dirent_lock/kernfs_open_node_lock/ * s/sysfs_open_file_mutex/kernfs_open_file_mutex/ * s/sysfs_of()/kernfs_of()/ This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: drop s_ prefix from kernfs_node membersTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. s_ prefix for kernfs members is used inconsistently and a misnomer now. It's not like kernfs_node is used widely across the kernel making the ability to grep for the members particularly useful. Let's just drop the prefix. This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordinglyTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-04kernfs: implement "trusted.*" xattr supportTejun Heo
kernfs inherited "security.*" xattr support from sysfs. This patch extends xattr support to "trusted.*" using simple_xattr_*(). As trusted xattrs are restricted to CAP_SYS_ADMIN, simple_xattr_*() which uses kernel memory for storage shouldn't be problematic. Note that the existing "security.*" support doesn't implement get/remove/list and the this patch only implements those ops for "trusted.*". We probably want to extend those ops to include support for "security.*". This patch will allow using kernfs from cgroup which requires "trusted.*" xattr support. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David P. Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-04kernfs: update sysfs_init_inode_attrs()Tejun Heo
sysfs_init_inode_attrs() is a bit clumsy to use requiring the caller to check whether @sd->s_iattr is already set or not. Rename it to sysfs_inode_attrs(), update it to check whether @sd->s_iattr is already initialized before trying to initialize it and return @sd->s_iattr. This simplifies the callers. While at it, * Rename struct sysfs_inode_attrs pointer variables to "attrs". As kernfs no longer deals with "struct attribute", this isn't confusing and makes it easier to distinguish from struct iattr pointers. * A new field will be added to sysfs_inode_attrs. Reindent in preparation. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: remove cross inclusions of internal headersTejun Heo
fs/kernfs/kernfs-internal.h needed to include fs/sysfs/sysfs.h because part of kernfs core implementation was living in sysfs. fs/sysfs/sysfs.h needed to include fs/kernfs/kernfs-internal.h because include/linux/kernfs.h didn't expose enough interface. The separation is complete and neither is true anymore. Remove the cross inclusion and make sysfs a proper user of kernfs. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: make sysfs_dirent definition publicTejun Heo
sysfs_dirent includes some information which should be available to kernfs users - the type, flags, name and parent pointer. This patch moves sysfs_dirent definition from kernfs/kernfs-internal.h to include/linux/kernfs.h so that kernfs users can access them. The type part of flags is exported as enum kernfs_node_type, the flags kernfs_node_flag, sysfs_type() and kernfs_enable_ns() are moved to include/linux/kernfs.h and the former is updated to return the enum type. sysfs_dirent->s_parent and ->s_name are marked explicitly as public. This patch doesn't introduce any functional changes. v2: Flags exported too and kernfs_enable_ns() definition moved. v3: While moving kernfs_enable_ns() to include/linux/kernfs.h, v1 and v2 put the definition outside CONFIG_SYSFS replacing the dummy implementation with the actual implementation too. Unfortunately, this can lead to oops when !CONFIG_SYSFS because kernfs_enable_ns() may be called on a NULL @sd and now tries to dereference @sd instead of not doing anything. This issue was reported by Yuanhan Liu. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move mount core code to fs/kernfs/mount.cTejun Heo
Move core mount code to fs/kernfs/mount.c. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: prepare mount path for kernfsTejun Heo
We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges mount path so that the kernfs and sysfs parts are separate. * As sysfs_super_info won't be visible outside kernfs proper, kernfs_super_ns() is added to allow kernfs users to access a super_block's namespace tag. * Generic mount operation is separated out into kernfs_mount_ns(). sysfs_mount() now just performs sysfs-specific permission check, acquires namespace tag, and invokes kernfs_mount_ns(). * Generic superblock release is separated out into kernfs_kill_sb() which can be used directly as file_system_type->kill_sb(). As sysfs needs to put the namespace tag, sysfs_kill_sb() wraps kernfs_kill_sb() with ns tag put. * sysfs_dir_cachep init and sysfs_inode_init() are separated out into kernfs_init(). kernfs_init() uses only small amount of memory and trying to handle and propagate kernfs_init() failure doesn't make much sense. Use SLAB_PANIC for sysfs_dir_cachep and make sysfs_inode_init() panic on failure. After this change, kernfs_init() should be called before sysfs_init(), fs/namespace.c::mnt_init() modified accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: linux-fsdevel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: make inode number ida per kernfs_rootTejun Heo
kernfs is being updated to allow multiple sysfs_dirent hierarchies so that it can also be used by other users. Currently, inode number is allocated using a global ida, sysfs_ino_ida; however, inos for different hierarchies should be handled separately. This patch makes ino allocation per kernfs_root. sysfs_ino_ida is replaced by kernfs_root->ino_ida and sysfs_new_dirent() is updated to take @root and allocate ino from it. ida_simple_get/remove() are used instead of sysfs_ino_lock and sysfs_alloc/free_ino(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: implement kernfs_create/destroy_root()Tejun Heo
There currently is single kernfs hierarchy in the whole system which is used for sysfs. kernfs needs to support multiple hierarchies to allow other users. This patch introduces struct kernfs_root which serves as the root of each kernfs hierarchy and implements kernfs_create/destroy_root(). * Each kernfs_root is associated with a root sd (sysfs_dentry). The root is freed when the root sd is released and kernfs_destory_root() simply invokes kernfs_remove() on the root sd. sysfs_remove_one() is updated to handle release of the root sd. Note that ps_iattr update in sysfs_remove_one() is trivially updated for readability. * Root sd's are now dynamically allocated using sysfs_new_dirent(). Update sysfs_alloc_ino() so that it gives out ino from 1 so that the root sd still gets ino 1. * While kernfs currently only points to the root sd, it'll soon grow fields which are specific to each hierarchy. As determining a given sd's root will be necessary, sd->s_dir.root is added. This backlink fits better as a separate field in sd; however, sd->s_dir is inside union with space to spare, so use it to save space and provide kernfs_root() accessor to determine the root sd. * As hierarchies may be destroyed now, each mount needs to hold onto the hierarchy it's attached to. Update sysfs_fill_super() and sysfs_kill_sb() so that they get and put the kernfs_root respectively. * sysfs_root is replaced with kernfs_root which is dynamically created by invoking kernfs_create_root() from sysfs_init(). This patch doesn't introduce any visible behavior changes. v2: kernfs_create_root() forgot to set @sd->priv. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move symlink core code to fs/kernfs/symlink.cTejun Heo
Move core symlink code to fs/kernfs/symlink.c. fs/sysfs/symlink.c now only contains sysfs wrappers around kernfs interfaces. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move file core code to fs/kernfs/file.cTejun Heo
Move core file code to fs/kernfs/file.c. fs/sysfs/file.c now contains sysfs kernfs_ops callbacks, sysfs wrappers around kernfs interfaces, and sysfs_schedule_callback(). The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. v2: Refreshed on top of the v2 of "sysfs, kernfs: prepare read path for kernfs". v3: Refreshed on top of the v3 of "sysfs, kernfs: prepare read path for kernfs". Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move dir core code to fs/kernfs/dir.cTejun Heo
Move core dir code to fs/kernfs/dir.c. fs/sysfs/dir.c now only contains sysfs_warn_dup() and sysfs wrappers around kernfs interfaces. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. v2: sysfs_symlink_target_lock was mistakenly relocated to kernfs. It should remain with sysfs. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move inode code to fs/kernfs/inode.cTejun Heo
There's nothing sysfs-specific in fs/sysfs/inode.c. Move everything in it to fs/kernfs/inode.c. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.hTejun Heo
Move data structure, constant and basic accessor declarations from fs/sysfs/sysfs.h to fs/kernfs/kernfs-internal.h. The two files currently include each other. Once kernfs / sysfs separation is complete, the cross inclusions will be removed. Inclusion protectors are added to fs/sysfs/sysfs.h to allow cross-inclusion. This patch doesn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>