cregit-Linux how code gets into the kernel

Release 4.17 fs/kernfs/inode.c

Directory: fs/kernfs
/*
 * fs/kernfs/inode.c - kernfs inode implementation
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
 *
 * This file is released under the GPLv2.
 */

#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/security.h>

#include "kernfs-internal.h"


static const struct address_space_operations kernfs_aops = {
	.readpage	= simple_readpage,
	.write_begin	= simple_write_begin,
	.write_end	= simple_write_end,
};


static const struct inode_operations kernfs_iops = {
	.permission	= kernfs_iop_permission,
	.setattr	= kernfs_iop_setattr,
	.getattr	= kernfs_iop_getattr,
	.listxattr	= kernfs_iop_listxattr,
};


static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn) { static DEFINE_MUTEX(iattr_mutex); struct kernfs_iattrs *ret; struct iattr *iattrs; mutex_lock(&iattr_mutex); if (kn->iattr) goto out_unlock; kn->iattr = kzalloc(sizeof(struct kernfs_iattrs), GFP_KERNEL); if (!kn->iattr) goto out_unlock; iattrs = &kn->iattr->ia_iattr; /* assign default attributes */ iattrs->ia_mode = kn->mode; iattrs->ia_uid = GLOBAL_ROOT_UID; iattrs->ia_gid = GLOBAL_ROOT_GID; ktime_get_real_ts(&iattrs->ia_atime); iattrs->ia_mtime = iattrs->ia_atime; iattrs->ia_ctime = iattrs->ia_atime; simple_xattrs_init(&kn->iattr->xattrs); out_unlock: ret = kn->iattr; mutex_unlock(&iattr_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo13892.00%787.50%
Deepa Dinamani128.00%112.50%
Total150100.00%8100.00%


static int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr) { struct kernfs_iattrs *attrs; struct iattr *iattrs; unsigned int ia_valid = iattr->ia_valid; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; iattrs = &attrs->ia_iattr; if (ia_valid & ATTR_UID) iattrs->ia_uid = iattr->ia_uid; if (ia_valid & ATTR_GID) iattrs->ia_gid = iattr->ia_gid; if (ia_valid & ATTR_ATIME) iattrs->ia_atime = iattr->ia_atime; if (ia_valid & ATTR_MTIME) iattrs->ia_mtime = iattr->ia_mtime; if (ia_valid & ATTR_CTIME) iattrs->ia_ctime = iattr->ia_ctime; if (ia_valid & ATTR_MODE) { umode_t mode = iattr->ia_mode; iattrs->ia_mode = kn->mode = mode; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo156100.00%5100.00%
Total156100.00%5100.00%

/** * kernfs_setattr - set iattr on a node * @kn: target node * @iattr: iattr to set * * Returns 0 on success, -errno on failure. */
int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr) { int ret; mutex_lock(&kernfs_mutex); ret = __kernfs_setattr(kn, iattr); mutex_unlock(&kernfs_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo43100.00%3100.00%
Total43100.00%3100.00%


int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr) { struct inode *inode = d_inode(dentry); struct kernfs_node *kn = inode->i_private; int error; if (!kn) return -EINVAL; mutex_lock(&kernfs_mutex); error = setattr_prepare(dentry, iattr); if (error) goto out; error = __kernfs_setattr(kn, iattr); if (error) goto out; /* this ignores size changes */ setattr_copy(inode, iattr); out: mutex_unlock(&kernfs_mutex); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo9693.20%457.14%
David Howells32.91%114.29%
Jan Kara21.94%114.29%
Shaohua Li21.94%114.29%
Total103100.00%7100.00%


static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata, u32 *secdata_len) { void *old_secdata; size_t old_secdata_len; old_secdata = attrs->ia_secdata; old_secdata_len = attrs->ia_secdata_len; attrs->ia_secdata = *secdata; attrs->ia_secdata_len = *secdata_len; *secdata = old_secdata; *secdata_len = old_secdata_len; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo6496.97%375.00%
Andreas Gruenbacher23.03%125.00%
Total66100.00%4100.00%


ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size) { struct kernfs_node *kn = kernfs_dentry_node(dentry); struct kernfs_iattrs *attrs; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo5481.82%466.67%
Andreas Gruenbacher913.64%116.67%
Shaohua Li34.55%116.67%
Total66100.00%6100.00%


static inline void set_default_inode_attr(struct inode *inode, umode_t mode) { inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); }

Contributors

PersonTokensPropCommitsCommitProp
Andreas Gruenbacher2565.79%120.00%
Tejun Heo1128.95%240.00%
Deepa Dinamani12.63%120.00%
Linus Torvalds12.63%120.00%
Total38100.00%5100.00%


static inline void set_inode_attr(struct inode *inode, struct iattr *iattr) { struct super_block *sb = inode->i_sb; inode->i_uid = iattr->ia_uid; inode->i_gid = iattr->ia_gid; inode->i_atime = timespec_trunc(iattr->ia_atime, sb->s_time_gran); inode->i_mtime = timespec_trunc(iattr->ia_mtime, sb->s_time_gran); inode->i_ctime = timespec_trunc(iattr->ia_ctime, sb->s_time_gran); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo5765.52%150.00%
Deepa Dinamani3034.48%150.00%
Total87100.00%2100.00%


static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode) { struct kernfs_iattrs *attrs = kn->iattr; inode->i_mode = kn->mode; if (attrs) { /* * kernfs_node has non-default attributes get them from * persistent copy in kernfs_node. */ set_inode_attr(inode, &attrs->ia_iattr); security_inode_notifysecctx(inode, attrs->ia_secdata, attrs->ia_secdata_len); } if (kernfs_type(kn) == KERNFS_DIR) set_nlink(inode, kn->dir.subdirs + 2); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo85100.00%7100.00%
Total85100.00%7100.00%


int kernfs_iop_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); struct kernfs_node *kn = inode->i_private; mutex_lock(&kernfs_mutex); kernfs_refresh_inode(kn, inode); mutex_unlock(&kernfs_mutex); generic_fillattr(inode, stat); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo4967.12%457.14%
David Howells1520.55%228.57%
Shaohua Li912.33%114.29%
Total73100.00%7100.00%


static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode) { kernfs_get(kn); inode->i_private = kn; inode->i_mapping->a_ops = &kernfs_aops; inode->i_op = &kernfs_iops; inode->i_generation = kn->id.generation; set_default_inode_attr(inode, kn->mode); kernfs_refresh_inode(kn, inode); /* initialize inode according to type */ switch (kernfs_type(kn)) { case KERNFS_DIR: inode->i_op = &kernfs_dir_iops; inode->i_fop = &kernfs_dir_fops; if (kn->flags & KERNFS_EMPTY_DIR) make_empty_dir_inode(inode); break; case KERNFS_FILE: inode->i_size = kn->attr.size; inode->i_fop = &kernfs_file_fops; break; case KERNFS_LINK: inode->i_op = &kernfs_symlink_iops; break; default: BUG(); } unlock_new_inode(inode); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo12884.77%666.67%
Eric W. Biedermann138.61%111.11%
Shaohua Li106.62%222.22%
Total151100.00%9100.00%

/** * kernfs_get_inode - get inode for kernfs_node * @sb: super block * @kn: kernfs_node to allocate inode for * * Get inode for @kn. If such inode doesn't exist, a new inode is * allocated and basics are initialized. New inode is returned * locked. * * LOCKING: * Kernel thread context (may sleep). * * RETURNS: * Pointer to allocated inode on success, NULL on failure. */
struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn) { struct inode *inode; inode = iget_locked(sb, kn->id.ino); if (inode && (inode->i_state & I_NEW)) kernfs_init_inode(kn, inode); return inode; }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo5596.49%480.00%
Shaohua Li23.51%120.00%
Total57100.00%5100.00%

/* * The kernfs_node serves as both an inode and a directory entry for * kernfs. To prevent the kernfs inode numbers from being freed * prematurely we take a reference to kernfs_node from the kernfs inode. A * super_operations.evict_inode() implementation is needed to drop that * reference upon inode destruction. */
void kernfs_evict_inode(struct inode *inode) { struct kernfs_node *kn = inode->i_private; truncate_inode_pages_final(&inode->i_data); clear_inode(inode); kernfs_put(kn); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo3697.30%375.00%
Johannes Weiner12.70%125.00%
Total37100.00%4100.00%


int kernfs_iop_permission(struct inode *inode, int mask) { struct kernfs_node *kn; if (mask & MAY_NOT_BLOCK) return -ECHILD; kn = inode->i_private; mutex_lock(&kernfs_mutex); kernfs_refresh_inode(kn, inode); mutex_unlock(&kernfs_mutex); return generic_permission(inode, mask); }

Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo61100.00%4100.00%
Total61100.00%4100.00%


static int kernfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *suffix, void *value, size_t size) { const char *name = xattr_full_name(handler, suffix); struct kernfs_node *kn = inode->i_private; struct kernfs_iattrs *attrs; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; return simple_xattr_get(&attrs->xattrs, name, value, size); }

Contributors

PersonTokensPropCommitsCommitProp
Andreas Gruenbacher91100.00%1100.00%
Total91100.00%1100.00%


static int kernfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *suffix, const void *value, size_t size, int flags) { const char *name = xattr_full_name(handler, suffix); struct kernfs_node *kn = inode->i_private; struct kernfs_iattrs *attrs; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; return simple_xattr_set(&attrs->xattrs, name, value, size, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Andreas Gruenbacher97100.00%1100.00%
Total97100.00%1100.00%

static const struct xattr_handler kernfs_trusted_xattr_handler = { .prefix = XATTR_TRUSTED_PREFIX, .get = kernfs_xattr_get, .set = kernfs_xattr_set, };
static int kernfs_security_xattr_set(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *suffix, const void *value, size_t size, int flags) { struct kernfs_node *kn = inode->i_private; struct kernfs_iattrs *attrs; void *secdata; u32 secdata_len = 0; int error; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; error = security_inode_setsecurity(inode, suffix, value, size, flags); if (error) return error; error = security_inode_getsecctx(inode, &secdata, &secdata_len); if (error) return error; mutex_lock(&kernfs_mutex); error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len); mutex_unlock(&kernfs_mutex); if (secdata) security_release_secctx(secdata, secdata_len); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Andreas Gruenbacher161100.00%1100.00%
Total161100.00%1100.00%

static const struct xattr_handler kernfs_security_xattr_handler = { .prefix = XATTR_SECURITY_PREFIX, .get = kernfs_xattr_get, .set = kernfs_security_xattr_set, }; const struct xattr_handler *kernfs_xattr_handlers[] = { &kernfs_trusted_xattr_handler, &kernfs_security_xattr_handler, NULL };

Overall Contributors

PersonTokensPropCommitsCommitProp
Tejun Heo111266.83%1147.83%
Andreas Gruenbacher44626.80%14.35%
Deepa Dinamani432.58%14.35%
Shaohua Li261.56%313.04%
David Howells181.08%28.70%
Eric W. Biedermann130.78%14.35%
Bart Van Assche20.12%14.35%
Jan Kara20.12%14.35%
Linus Torvalds10.06%14.35%
Johannes Weiner10.06%14.35%
Total1664100.00%23100.00%
Directory: fs/kernfs
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