cregit-Linux how code gets into the kernel

Release 4.10 fs/notify/fsnotify.c

Directory: fs/notify
 *  Copyright (C) 2008 Red Hat, Inc., Eric Paris <>
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  GNU General Public License for more details.
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

#include <linux/dcache.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/srcu.h>

#include <linux/fsnotify_backend.h>
#include "fsnotify.h"

 * Clear all of the marks on an inode when it is being evicted from core

void __fsnotify_inode_delete(struct inode *inode) { fsnotify_clear_marks_by_inode(inode); }


eric pariseric paris15100.00%1100.00%

void __fsnotify_vfsmount_delete(struct vfsmount *mnt) { fsnotify_clear_marks_by_mount(mnt); }


andreas gruenbacherandreas gruenbacher15100.00%1100.00%

/* * Given an inode, first check if we care what happens to our children. Inotify * and dnotify both tell their parents about events. If we care about any event * on a child we run all of our children and set a dentry flag saying that the * parent cares. Thus when an event happens on a child it can quickly tell if * if there is a need to find a parent and send the event to the parent. */
void __fsnotify_update_child_dentry_flags(struct inode *inode) { struct dentry *alias; int watched; if (!S_ISDIR(inode->i_mode)) return; /* determine if the children should tell inode about their events */ watched = fsnotify_inode_watches_children(inode); spin_lock(&inode->i_lock); /* run all of the dentries associated with this inode. Since this is a * directory, there damn well better only be one item on this list */ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { struct dentry *child; /* run all of the children of the original inode and fix their * d_flags to indicate parental interest (their parent is the * original inode) */ spin_lock(&alias->d_lock); list_for_each_entry(child, &alias->d_subdirs, d_child) { if (!child->d_inode) continue; spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); if (watched) child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; else child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; spin_unlock(&child->d_lock); } spin_unlock(&alias->d_lock); } spin_unlock(&inode->i_lock); }


eric pariseric paris10877.14%116.67%
nick pigginnick piggin2920.71%350.00%
al viroal viro32.14%233.33%

/* Notify this dentry's parent about a child's events. */
int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask) { struct dentry *parent; struct inode *p_inode; int ret = 0; if (!dentry) dentry = path->dentry; if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) return 0; parent = dget_parent(dentry); p_inode = parent->d_inode; if (unlikely(!fsnotify_inode_watches_children(p_inode))) __fsnotify_update_child_dentry_flags(p_inode); else if (p_inode->i_fsnotify_mask & mask) { /* we are notifying a parent so come up with the new mask which * specifies these are events which came from a child. */ mask |= FS_EVENT_ON_CHILD; if (path) ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH, dentry->, 0); else ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->, 0); } dput(parent); return ret; }


eric pariseric paris13986.34%555.56%
christoph hellwigchristoph hellwig138.07%111.11%
linus torvaldslinus torvalds63.73%111.11%
andreas gruenbacherandreas gruenbacher21.24%111.11%
al viroal viro10.62%111.11%

static int send_to_group(struct inode *to_tell, struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmount_mark, __u32 mask, const void *data, int data_is, u32 cookie, const unsigned char *file_name) { struct fsnotify_group *group = NULL; __u32 inode_test_mask = 0; __u32 vfsmount_test_mask = 0; if (unlikely(!inode_mark && !vfsmount_mark)) { BUG(); return 0; } /* clear ignored on inode modification */ if (mask & FS_MODIFY) { if (inode_mark && !(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) inode_mark->ignored_mask = 0; if (vfsmount_mark && !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) vfsmount_mark->ignored_mask = 0; } /* does the inode mark tell us to do something? */ if (inode_mark) { group = inode_mark->group; inode_test_mask = (mask & ~FS_EVENT_ON_CHILD); inode_test_mask &= inode_mark->mask; inode_test_mask &= ~inode_mark->ignored_mask; } /* does the vfsmount_mark tell us to do something? */ if (vfsmount_mark) { vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD); group = vfsmount_mark->group; vfsmount_test_mask &= vfsmount_mark->mask; vfsmount_test_mask &= ~vfsmount_mark->ignored_mask; if (inode_mark) vfsmount_test_mask &= ~inode_mark->ignored_mask; } pr_debug("%s: group=%p to_tell=%p mask=%x inode_mark=%p" " inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x" " data=%p data_is=%d cookie=%d\n", __func__, group, to_tell, mask, inode_mark, inode_test_mask, vfsmount_mark, vfsmount_test_mask, data, data_is, cookie); if (!inode_test_mask && !vfsmount_test_mask) return 0; return group->ops->handle_event(group, to_tell, inode_mark, vfsmount_mark, mask, data, data_is, file_name, cookie); }


eric pariseric paris25794.83%1071.43%
jan karajan kara124.43%214.29%
dan carpenterdan carpenter10.37%17.14%
al viroal viro10.37%17.14%

/* * This is the main call to fsnotify. The VFS calls into hook specific functions * in linux/fsnotify.h. Those functions then in turn call here. Here will call * out to all of the registered fsnotify_group. Those groups can then use the * notification event in whatever means they feel necessary. */
int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, const unsigned char *file_name, u32 cookie) { struct hlist_node *inode_node = NULL, *vfsmount_node = NULL; struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL; struct fsnotify_group *inode_group, *vfsmount_group; struct mount *mnt; int idx, ret = 0; /* global tests shouldn't care about events on child only the specific event */ __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD); if (data_is == FSNOTIFY_EVENT_PATH) mnt = real_mount(((const struct path *)data)->mnt); else mnt = NULL; /* * Optimization: srcu_read_lock() has a memory barrier which can * be expensive. It protects walking the *_fsnotify_marks lists. * However, if we do not walk the lists, we do not have to do * SRCU because we have no references to any objects and do not * need SRCU to keep them "alive". */ if (hlist_empty(&to_tell->i_fsnotify_marks) && (!mnt || hlist_empty(&mnt->mnt_fsnotify_marks))) return 0; /* * if this is a modify event we may need to clear the ignored masks * otherwise return if neither the inode nor the vfsmount care about * this type of event. */ if (!(mask & FS_MODIFY) && !(test_mask & to_tell->i_fsnotify_mask) && !(mnt && test_mask & mnt->mnt_fsnotify_mask)) return 0; idx = srcu_read_lock(&fsnotify_mark_srcu); if ((mask & FS_MODIFY) || (test_mask & to_tell->i_fsnotify_mask)) inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first, &fsnotify_mark_srcu); if (mnt && ((mask & FS_MODIFY) || (test_mask & mnt->mnt_fsnotify_mask))) { vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first, &fsnotify_mark_srcu); inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first, &fsnotify_mark_srcu); } /* * We need to merge inode & vfsmount mark lists so that inode mark * ignore masks are properly reflected for mount mark notifications. * That's why this traversal is so complicated... */ while (inode_node || vfsmount_node) { inode_group = NULL; inode_mark = NULL; vfsmount_group = NULL; vfsmount_mark = NULL; if (inode_node) { inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu), struct fsnotify_mark, obj_list); inode_group = inode_mark->group; } if (vfsmount_node) { vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu), struct fsnotify_mark, obj_list); vfsmount_group = vfsmount_mark->group; } if (inode_group && vfsmount_group) { int cmp = fsnotify_compare_groups(inode_group, vfsmount_group); if (cmp > 0) { inode_group = NULL; inode_mark = NULL; } else if (cmp < 0) { vfsmount_group = NULL; vfsmount_mark = NULL; } } ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask, data, data_is, cookie, file_name); if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) goto out; if (inode_group) inode_node = srcu_dereference(inode_node->next, &fsnotify_mark_srcu); if (vfsmount_group) vfsmount_node = srcu_dereference(vfsmount_node->next, &fsnotify_mark_srcu); } ret = 0; out: srcu_read_unlock(&fsnotify_mark_srcu, idx); return ret; }


eric pariseric paris40684.58%1872.00%
jan karajan kara387.92%28.00%
dave hansendave hansen275.62%14.00%
al viroal viro61.25%28.00%
linus torvaldslinus torvalds20.42%14.00%
jean-christophe duboisjean-christophe dubois10.21%14.00%

static __init int fsnotify_init(void) { int ret; BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23); ret = init_srcu_struct(&fsnotify_mark_srcu); if (ret) panic("initializing fsnotify_mark_srcu"); return 0; }


eric pariseric paris42100.00%3100.00%


Overall Contributors

eric pariseric paris101686.39%2555.56%
jan karajan kara504.25%48.89%
nick pigginnick piggin292.47%36.67%
dave hansendave hansen272.30%12.22%
andreas gruenbacherandreas gruenbacher171.45%24.44%
christoph hellwigchristoph hellwig131.11%12.22%
al viroal viro110.94%511.11%
linus torvaldslinus torvalds80.68%12.22%
tejun heotejun heo30.26%12.22%
jean-christophe duboisjean-christophe dubois10.09%12.22%
dan carpenterdan carpenter10.09%12.22%
Directory: fs/notify
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