kernel.git/fs/kernfs/inode.c, branch linux-3.14.y

kernfs: protect lazy kernfs_iattrs allocation with mutex

2014-04-27T00:19:04Z

commit 4afddd60a770560d370d6f85c5aef57c16bf7502 upstream. kernfs_iattrs is allocated lazily when operations which require it take place; unfortunately, the lazy allocation and returning weren't properly synchronized and when there are multiple concurrent operations, it might end up returning kernfs_iattrs which hasn't finished initialization yet or different copies to different callers. Fix it by synchronizing with a mutex. This can be smarter with memory barriers but let's go there if it actually turns out to be necessary. Signed-off-by: Tejun Heo Link: http://lkml.kernel.org/g/533ABA32.9080602@oracle.com Reported-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

kernfs: s/sysfs/kernfs/ in internal functions and whatever is left

2013-12-12T01:39:20Z

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 Signed-off-by: Greg Kroah-Hartman

kernfs: s/sysfs/kernfs/ in global variables

2013-12-12T01:39:20Z

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 Signed-off-by: Greg Kroah-Hartman

kernfs: s/sysfs/kernfs/ in constants

2013-12-12T01:39:20Z

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 Signed-off-by: Greg Kroah-Hartman

kernfs: s/sysfs/kernfs/ in various data structures

2013-12-12T01:39:20Z

kernfs: drop s_ prefix from kernfs_node members

2013-12-11T23:43:48Z

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 Signed-off-by: Greg Kroah-Hartman

kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly

2013-12-11T23:28:36Z

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 Cc: Neil Brown Cc: Linus Walleij Cc: Ashutosh Dixit Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman

kernfs: implement "trusted.*" xattr support

2013-12-04T15:34:45Z

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 Cc: David P. Quigley Signed-off-by: Greg Kroah-Hartman

kernfs: update sysfs_init_inode_attrs()

2013-12-04T15:34:45Z

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 Signed-off-by: Greg Kroah-Hartman

sysfs, kernfs: prepare mount path for kernfs

2013-11-30T02:16:08Z

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 Cc: linux-fsdevel@vger.kernel.org Cc: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman