1c82ee6d3SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 290586523SEric Paris /* 390586523SEric Paris * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> 490586523SEric Paris */ 590586523SEric Paris 690586523SEric Paris #include <linux/dcache.h> 790586523SEric Paris #include <linux/fs.h> 85a0e3ad6STejun Heo #include <linux/gfp.h> 990586523SEric Paris #include <linux/init.h> 1090586523SEric Paris #include <linux/module.h> 117131485aSEric Paris #include <linux/mount.h> 1290586523SEric Paris #include <linux/srcu.h> 1390586523SEric Paris 1490586523SEric Paris #include <linux/fsnotify_backend.h> 1590586523SEric Paris #include "fsnotify.h" 1690586523SEric Paris 1790586523SEric Paris /* 183be25f49SEric Paris * Clear all of the marks on an inode when it is being evicted from core 193be25f49SEric Paris */ 203be25f49SEric Paris void __fsnotify_inode_delete(struct inode *inode) 213be25f49SEric Paris { 223be25f49SEric Paris fsnotify_clear_marks_by_inode(inode); 233be25f49SEric Paris } 243be25f49SEric Paris EXPORT_SYMBOL_GPL(__fsnotify_inode_delete); 253be25f49SEric Paris 26ca9c726eSAndreas Gruenbacher void __fsnotify_vfsmount_delete(struct vfsmount *mnt) 27ca9c726eSAndreas Gruenbacher { 28ca9c726eSAndreas Gruenbacher fsnotify_clear_marks_by_mount(mnt); 29ca9c726eSAndreas Gruenbacher } 30ca9c726eSAndreas Gruenbacher 31ebb3b47eSJan Kara /** 32ebb3b47eSJan Kara * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes. 33ebb3b47eSJan Kara * @sb: superblock being unmounted. 34ebb3b47eSJan Kara * 35ebb3b47eSJan Kara * Called during unmount with no locks held, so needs to be safe against 36ebb3b47eSJan Kara * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block. 37ebb3b47eSJan Kara */ 381e6cb723SAmir Goldstein static void fsnotify_unmount_inodes(struct super_block *sb) 39ebb3b47eSJan Kara { 40ebb3b47eSJan Kara struct inode *inode, *iput_inode = NULL; 41ebb3b47eSJan Kara 42ebb3b47eSJan Kara spin_lock(&sb->s_inode_list_lock); 43ebb3b47eSJan Kara list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 44ebb3b47eSJan Kara /* 45ebb3b47eSJan Kara * We cannot __iget() an inode in state I_FREEING, 46ebb3b47eSJan Kara * I_WILL_FREE, or I_NEW which is fine because by that point 47ebb3b47eSJan Kara * the inode cannot have any associated watches. 48ebb3b47eSJan Kara */ 49ebb3b47eSJan Kara spin_lock(&inode->i_lock); 50ebb3b47eSJan Kara if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) { 51ebb3b47eSJan Kara spin_unlock(&inode->i_lock); 52ebb3b47eSJan Kara continue; 53ebb3b47eSJan Kara } 54ebb3b47eSJan Kara 55ebb3b47eSJan Kara /* 56ebb3b47eSJan Kara * If i_count is zero, the inode cannot have any watches and 571751e8a6SLinus Torvalds * doing an __iget/iput with SB_ACTIVE clear would actually 58ebb3b47eSJan Kara * evict all inodes with zero i_count from icache which is 59ebb3b47eSJan Kara * unnecessarily violent and may in fact be illegal to do. 601edc8eb2SEric Sandeen * However, we should have been called /after/ evict_inodes 611edc8eb2SEric Sandeen * removed all zero refcount inodes, in any case. Test to 621edc8eb2SEric Sandeen * be sure. 63ebb3b47eSJan Kara */ 64ebb3b47eSJan Kara if (!atomic_read(&inode->i_count)) { 65ebb3b47eSJan Kara spin_unlock(&inode->i_lock); 66ebb3b47eSJan Kara continue; 67ebb3b47eSJan Kara } 68ebb3b47eSJan Kara 69ebb3b47eSJan Kara __iget(inode); 70ebb3b47eSJan Kara spin_unlock(&inode->i_lock); 71ebb3b47eSJan Kara spin_unlock(&sb->s_inode_list_lock); 72ebb3b47eSJan Kara 73ebb3b47eSJan Kara if (iput_inode) 74ebb3b47eSJan Kara iput(iput_inode); 75ebb3b47eSJan Kara 76ebb3b47eSJan Kara /* for each watch, send FS_UNMOUNT and then remove it */ 7782ace1efSAmir Goldstein fsnotify_inode(inode, FS_UNMOUNT); 78ebb3b47eSJan Kara 79ebb3b47eSJan Kara fsnotify_inode_delete(inode); 80ebb3b47eSJan Kara 81ebb3b47eSJan Kara iput_inode = inode; 82ebb3b47eSJan Kara 8304646aebSEric Sandeen cond_resched(); 84ebb3b47eSJan Kara spin_lock(&sb->s_inode_list_lock); 85ebb3b47eSJan Kara } 86ebb3b47eSJan Kara spin_unlock(&sb->s_inode_list_lock); 87ebb3b47eSJan Kara 88ebb3b47eSJan Kara if (iput_inode) 89ebb3b47eSJan Kara iput(iput_inode); 90721fb6fbSJan Kara /* Wait for outstanding inode references from connectors */ 91721fb6fbSJan Kara wait_var_event(&sb->s_fsnotify_inode_refs, 92721fb6fbSJan Kara !atomic_long_read(&sb->s_fsnotify_inode_refs)); 93ebb3b47eSJan Kara } 94ebb3b47eSJan Kara 951e6cb723SAmir Goldstein void fsnotify_sb_delete(struct super_block *sb) 961e6cb723SAmir Goldstein { 971e6cb723SAmir Goldstein fsnotify_unmount_inodes(sb); 981e6cb723SAmir Goldstein fsnotify_clear_marks_by_sb(sb); 991e6cb723SAmir Goldstein } 1001e6cb723SAmir Goldstein 1013be25f49SEric Paris /* 102c28f7e56SEric Paris * Given an inode, first check if we care what happens to our children. Inotify 103c28f7e56SEric Paris * and dnotify both tell their parents about events. If we care about any event 104c28f7e56SEric Paris * on a child we run all of our children and set a dentry flag saying that the 105c28f7e56SEric Paris * parent cares. Thus when an event happens on a child it can quickly tell if 106c28f7e56SEric Paris * if there is a need to find a parent and send the event to the parent. 107c28f7e56SEric Paris */ 108c28f7e56SEric Paris void __fsnotify_update_child_dentry_flags(struct inode *inode) 109c28f7e56SEric Paris { 110c28f7e56SEric Paris struct dentry *alias; 111c28f7e56SEric Paris int watched; 112c28f7e56SEric Paris 113c28f7e56SEric Paris if (!S_ISDIR(inode->i_mode)) 114c28f7e56SEric Paris return; 115c28f7e56SEric Paris 116c28f7e56SEric Paris /* determine if the children should tell inode about their events */ 117c28f7e56SEric Paris watched = fsnotify_inode_watches_children(inode); 118c28f7e56SEric Paris 119873feea0SNick Piggin spin_lock(&inode->i_lock); 120c28f7e56SEric Paris /* run all of the dentries associated with this inode. Since this is a 121c28f7e56SEric Paris * directory, there damn well better only be one item on this list */ 122946e51f2SAl Viro hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { 123c28f7e56SEric Paris struct dentry *child; 124c28f7e56SEric Paris 125c28f7e56SEric Paris /* run all of the children of the original inode and fix their 126c28f7e56SEric Paris * d_flags to indicate parental interest (their parent is the 127c28f7e56SEric Paris * original inode) */ 1282fd6b7f5SNick Piggin spin_lock(&alias->d_lock); 129946e51f2SAl Viro list_for_each_entry(child, &alias->d_subdirs, d_child) { 130c28f7e56SEric Paris if (!child->d_inode) 131c28f7e56SEric Paris continue; 132c28f7e56SEric Paris 1332fd6b7f5SNick Piggin spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); 134c28f7e56SEric Paris if (watched) 135c28f7e56SEric Paris child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; 136c28f7e56SEric Paris else 137c28f7e56SEric Paris child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; 138c28f7e56SEric Paris spin_unlock(&child->d_lock); 139c28f7e56SEric Paris } 1402fd6b7f5SNick Piggin spin_unlock(&alias->d_lock); 141c28f7e56SEric Paris } 142873feea0SNick Piggin spin_unlock(&inode->i_lock); 143c28f7e56SEric Paris } 144c28f7e56SEric Paris 1459b93f331SAmir Goldstein /* Are inode/sb/mount interested in parent and name info with this event? */ 1469b93f331SAmir Goldstein static bool fsnotify_event_needs_parent(struct inode *inode, struct mount *mnt, 1479b93f331SAmir Goldstein __u32 mask) 1489b93f331SAmir Goldstein { 1499b93f331SAmir Goldstein __u32 marks_mask = 0; 1509b93f331SAmir Goldstein 1519b93f331SAmir Goldstein /* We only send parent/name to inode/sb/mount for events on non-dir */ 1529b93f331SAmir Goldstein if (mask & FS_ISDIR) 1539b93f331SAmir Goldstein return false; 1549b93f331SAmir Goldstein 1559b93f331SAmir Goldstein /* Did either inode/sb/mount subscribe for events with parent/name? */ 1569b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(inode->i_fsnotify_mask); 1579b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(inode->i_sb->s_fsnotify_mask); 1589b93f331SAmir Goldstein if (mnt) 1599b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(mnt->mnt_fsnotify_mask); 1609b93f331SAmir Goldstein 1619b93f331SAmir Goldstein /* Did they subscribe for this event with parent/name info? */ 1629b93f331SAmir Goldstein return mask & marks_mask; 1639b93f331SAmir Goldstein } 1649b93f331SAmir Goldstein 165c738fbabSAmir Goldstein /* 166c738fbabSAmir Goldstein * Notify this dentry's parent about a child's events with child name info 1679b93f331SAmir Goldstein * if parent is watching or if inode/sb/mount are interested in events with 1689b93f331SAmir Goldstein * parent and name info. 1699b93f331SAmir Goldstein * 1709b93f331SAmir Goldstein * Notify only the child without name info if parent is not watching and 1719b93f331SAmir Goldstein * inode/sb/mount are not interested in events with parent and name info. 172c738fbabSAmir Goldstein */ 17371d73410SMel Gorman int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 174017de65fSAmir Goldstein int data_type) 175c28f7e56SEric Paris { 1769b93f331SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 1779b93f331SAmir Goldstein struct mount *mnt = path ? real_mount(path->mnt) : NULL; 178497b0c5aSAmir Goldstein struct inode *inode = d_inode(dentry); 179c28f7e56SEric Paris struct dentry *parent; 1809b93f331SAmir Goldstein bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED; 1819b93f331SAmir Goldstein __u32 p_mask; 18240a100d3SAmir Goldstein struct inode *p_inode = NULL; 183497b0c5aSAmir Goldstein struct name_snapshot name; 184497b0c5aSAmir Goldstein struct qstr *file_name = NULL; 18552420392SEric Paris int ret = 0; 186c28f7e56SEric Paris 1879b93f331SAmir Goldstein /* 1889b93f331SAmir Goldstein * Do inode/sb/mount care about parent and name info on non-dir? 1899b93f331SAmir Goldstein * Do they care about any event at all? 1909b93f331SAmir Goldstein */ 1919b93f331SAmir Goldstein if (!inode->i_fsnotify_marks && !inode->i_sb->s_fsnotify_marks && 1929b93f331SAmir Goldstein (!mnt || !mnt->mnt_fsnotify_marks) && !parent_watched) 1939b93f331SAmir Goldstein return 0; 1949b93f331SAmir Goldstein 195497b0c5aSAmir Goldstein parent = NULL; 1969b93f331SAmir Goldstein if (!parent_watched && !fsnotify_event_needs_parent(inode, mnt, mask)) 197497b0c5aSAmir Goldstein goto notify; 198c28f7e56SEric Paris 1999b93f331SAmir Goldstein /* Does parent inode care about events on children? */ 2004d4eb366SChristoph Hellwig parent = dget_parent(dentry); 201c28f7e56SEric Paris p_inode = parent->d_inode; 2029b93f331SAmir Goldstein p_mask = fsnotify_inode_watches_children(p_inode); 2039b93f331SAmir Goldstein if (unlikely(parent_watched && !p_mask)) 2044d4eb366SChristoph Hellwig __fsnotify_update_child_dentry_flags(p_inode); 2059b93f331SAmir Goldstein 2069b93f331SAmir Goldstein /* 2079b93f331SAmir Goldstein * Include parent/name in notification either if some notification 2089b93f331SAmir Goldstein * groups require parent info (!parent_watched case) or the parent is 2099b93f331SAmir Goldstein * interested in this event. 2109b93f331SAmir Goldstein */ 2119b93f331SAmir Goldstein if (!parent_watched || (mask & p_mask & ALL_FSNOTIFY_EVENTS)) { 212497b0c5aSAmir Goldstein /* When notifying parent, child should be passed as data */ 213497b0c5aSAmir Goldstein WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type)); 21449d31c2fSAl Viro 215497b0c5aSAmir Goldstein /* Notify both parent and child with child name info */ 21649d31c2fSAl Viro take_dentry_name_snapshot(&name, dentry); 217497b0c5aSAmir Goldstein file_name = &name.name; 2189b93f331SAmir Goldstein if (parent_watched) 219497b0c5aSAmir Goldstein mask |= FS_EVENT_ON_CHILD; 220c28f7e56SEric Paris } 221c28f7e56SEric Paris 222497b0c5aSAmir Goldstein notify: 22340a100d3SAmir Goldstein ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0); 224497b0c5aSAmir Goldstein 225497b0c5aSAmir Goldstein if (file_name) 226497b0c5aSAmir Goldstein release_dentry_name_snapshot(&name); 227c28f7e56SEric Paris dput(parent); 22852420392SEric Paris 22952420392SEric Paris return ret; 230c28f7e56SEric Paris } 23171d73410SMel Gorman EXPORT_SYMBOL_GPL(__fsnotify_parent); 232c28f7e56SEric Paris 233b54cecf5SAmir Goldstein static int send_to_group(__u32 mask, const void *data, int data_type, 234b54cecf5SAmir Goldstein struct inode *dir, const struct qstr *file_name, 235b54cecf5SAmir Goldstein u32 cookie, struct fsnotify_iter_info *iter_info) 2367131485aSEric Paris { 237faa9560aSEric Paris struct fsnotify_group *group = NULL; 238007d1e83SAmir Goldstein __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS); 23992183a42SAmir Goldstein __u32 marks_mask = 0; 24092183a42SAmir Goldstein __u32 marks_ignored_mask = 0; 2413dca1a74SAmir Goldstein struct fsnotify_mark *mark; 2423dca1a74SAmir Goldstein int type; 243613a807fSEric Paris 2445b0457adSAmir Goldstein if (WARN_ON(!iter_info->report_mask)) 245faa9560aSEric Paris return 0; 2465ba08e2eSEric Paris 247ce8f76fbSEric Paris /* clear ignored on inode modification */ 248ce8f76fbSEric Paris if (mask & FS_MODIFY) { 2493dca1a74SAmir Goldstein fsnotify_foreach_obj_type(type) { 2503dca1a74SAmir Goldstein if (!fsnotify_iter_should_report_type(iter_info, type)) 2513dca1a74SAmir Goldstein continue; 2523dca1a74SAmir Goldstein mark = iter_info->marks[type]; 2533dca1a74SAmir Goldstein if (mark && 2543dca1a74SAmir Goldstein !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) 2553dca1a74SAmir Goldstein mark->ignored_mask = 0; 2563dca1a74SAmir Goldstein } 257ce8f76fbSEric Paris } 258613a807fSEric Paris 2593dca1a74SAmir Goldstein fsnotify_foreach_obj_type(type) { 2603dca1a74SAmir Goldstein if (!fsnotify_iter_should_report_type(iter_info, type)) 2613dca1a74SAmir Goldstein continue; 2623dca1a74SAmir Goldstein mark = iter_info->marks[type]; 2633dca1a74SAmir Goldstein /* does the object mark tell us to do something? */ 2643dca1a74SAmir Goldstein if (mark) { 2653dca1a74SAmir Goldstein group = mark->group; 2663dca1a74SAmir Goldstein marks_mask |= mark->mask; 2673dca1a74SAmir Goldstein marks_ignored_mask |= mark->ignored_mask; 2683dca1a74SAmir Goldstein } 269ce8f76fbSEric Paris } 270ce8f76fbSEric Paris 271b54cecf5SAmir Goldstein pr_debug("%s: group=%p mask=%x marks_mask=%x marks_ignored_mask=%x data=%p data_type=%d dir=%p cookie=%d\n", 272b54cecf5SAmir Goldstein __func__, group, mask, marks_mask, marks_ignored_mask, 273b54cecf5SAmir Goldstein data, data_type, dir, cookie); 274faa9560aSEric Paris 27592183a42SAmir Goldstein if (!(test_mask & marks_mask & ~marks_ignored_mask)) 276613a807fSEric Paris return 0; 277613a807fSEric Paris 278b54cecf5SAmir Goldstein return group->ops->handle_event(group, mask, data, data_type, dir, 2799385a84dSJan Kara file_name, cookie, iter_info); 2807131485aSEric Paris } 2817131485aSEric Paris 2823427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp) 2833427ce71SMiklos Szeredi { 2843427ce71SMiklos Szeredi struct fsnotify_mark_connector *conn; 2853427ce71SMiklos Szeredi struct hlist_node *node = NULL; 2863427ce71SMiklos Szeredi 2873427ce71SMiklos Szeredi conn = srcu_dereference(*connp, &fsnotify_mark_srcu); 2883427ce71SMiklos Szeredi if (conn) 2893427ce71SMiklos Szeredi node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu); 2903427ce71SMiklos Szeredi 2913427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 2923427ce71SMiklos Szeredi } 2933427ce71SMiklos Szeredi 2943427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark) 2953427ce71SMiklos Szeredi { 2963427ce71SMiklos Szeredi struct hlist_node *node = NULL; 2973427ce71SMiklos Szeredi 2983427ce71SMiklos Szeredi if (mark) 2993427ce71SMiklos Szeredi node = srcu_dereference(mark->obj_list.next, 3003427ce71SMiklos Szeredi &fsnotify_mark_srcu); 3013427ce71SMiklos Szeredi 3023427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 3033427ce71SMiklos Szeredi } 3043427ce71SMiklos Szeredi 305c28f7e56SEric Paris /* 306d9a6f30bSAmir Goldstein * iter_info is a multi head priority queue of marks. 307d9a6f30bSAmir Goldstein * Pick a subset of marks from queue heads, all with the 308d9a6f30bSAmir Goldstein * same group and set the report_mask for selected subset. 309d9a6f30bSAmir Goldstein * Returns the report_mask of the selected subset. 310d9a6f30bSAmir Goldstein */ 311d9a6f30bSAmir Goldstein static unsigned int fsnotify_iter_select_report_types( 312d9a6f30bSAmir Goldstein struct fsnotify_iter_info *iter_info) 313d9a6f30bSAmir Goldstein { 31447d9c7ccSAmir Goldstein struct fsnotify_group *max_prio_group = NULL; 31547d9c7ccSAmir Goldstein struct fsnotify_mark *mark; 31647d9c7ccSAmir Goldstein int type; 317d9a6f30bSAmir Goldstein 31847d9c7ccSAmir Goldstein /* Choose max prio group among groups of all queue heads */ 31947d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 32047d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 32147d9c7ccSAmir Goldstein if (mark && 32247d9c7ccSAmir Goldstein fsnotify_compare_groups(max_prio_group, mark->group) > 0) 32347d9c7ccSAmir Goldstein max_prio_group = mark->group; 324d9a6f30bSAmir Goldstein } 325d9a6f30bSAmir Goldstein 32647d9c7ccSAmir Goldstein if (!max_prio_group) 32747d9c7ccSAmir Goldstein return 0; 32847d9c7ccSAmir Goldstein 32947d9c7ccSAmir Goldstein /* Set the report mask for marks from same group as max prio group */ 330d9a6f30bSAmir Goldstein iter_info->report_mask = 0; 33147d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 33247d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 33347d9c7ccSAmir Goldstein if (mark && 33447d9c7ccSAmir Goldstein fsnotify_compare_groups(max_prio_group, mark->group) == 0) 33547d9c7ccSAmir Goldstein fsnotify_iter_set_report_type(iter_info, type); 33647d9c7ccSAmir Goldstein } 337d9a6f30bSAmir Goldstein 338d9a6f30bSAmir Goldstein return iter_info->report_mask; 339d9a6f30bSAmir Goldstein } 340d9a6f30bSAmir Goldstein 341d9a6f30bSAmir Goldstein /* 342d9a6f30bSAmir Goldstein * Pop from iter_info multi head queue, the marks that were iterated in the 343d9a6f30bSAmir Goldstein * current iteration step. 344d9a6f30bSAmir Goldstein */ 345d9a6f30bSAmir Goldstein static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) 346d9a6f30bSAmir Goldstein { 34747d9c7ccSAmir Goldstein int type; 348d9a6f30bSAmir Goldstein 34947d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 35047d9c7ccSAmir Goldstein if (fsnotify_iter_should_report_type(iter_info, type)) 35147d9c7ccSAmir Goldstein iter_info->marks[type] = 35247d9c7ccSAmir Goldstein fsnotify_next_mark(iter_info->marks[type]); 35347d9c7ccSAmir Goldstein } 354d9a6f30bSAmir Goldstein } 355d9a6f30bSAmir Goldstein 356d9a6f30bSAmir Goldstein /* 35740a100d3SAmir Goldstein * fsnotify - This is the main call to fsnotify. 35840a100d3SAmir Goldstein * 35940a100d3SAmir Goldstein * The VFS calls into hook specific functions in linux/fsnotify.h. 36040a100d3SAmir Goldstein * Those functions then in turn call here. Here will call out to all of the 36140a100d3SAmir Goldstein * registered fsnotify_group. Those groups can then use the notification event 36240a100d3SAmir Goldstein * in whatever means they feel necessary. 36340a100d3SAmir Goldstein * 36440a100d3SAmir Goldstein * @mask: event type and flags 36540a100d3SAmir Goldstein * @data: object that event happened on 36640a100d3SAmir Goldstein * @data_type: type of object for fanotify_data_XXX() accessors 36740a100d3SAmir Goldstein * @dir: optional directory associated with event - 36840a100d3SAmir Goldstein * if @file_name is not NULL, this is the directory that 36940a100d3SAmir Goldstein * @file_name is relative to 37040a100d3SAmir Goldstein * @file_name: optional file name associated with event 37140a100d3SAmir Goldstein * @inode: optional inode associated with event - 37240a100d3SAmir Goldstein * either @dir or @inode must be non-NULL. 37340a100d3SAmir Goldstein * if both are non-NULL event may be reported to both. 37440a100d3SAmir Goldstein * @cookie: inotify rename cookie 37590586523SEric Paris */ 37640a100d3SAmir Goldstein int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir, 37740a100d3SAmir Goldstein const struct qstr *file_name, struct inode *inode, u32 cookie) 37890586523SEric Paris { 379b54cecf5SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 3803427ce71SMiklos Szeredi struct fsnotify_iter_info iter_info = {}; 38140a100d3SAmir Goldstein struct super_block *sb; 38260f7ed8cSAmir Goldstein struct mount *mnt = NULL; 383497b0c5aSAmir Goldstein struct inode *child = NULL; 3849385a84dSJan Kara int ret = 0; 38571d73410SMel Gorman __u32 test_mask, marks_mask; 38690586523SEric Paris 38771d73410SMel Gorman if (path) 388aa93bdc5SAmir Goldstein mnt = real_mount(path->mnt); 389613a807fSEric Paris 39040a100d3SAmir Goldstein if (!inode) { 39140a100d3SAmir Goldstein /* Dirent event - report on TYPE_INODE to dir */ 39240a100d3SAmir Goldstein inode = dir; 39340a100d3SAmir Goldstein } else if (mask & FS_EVENT_ON_CHILD) { 39440a100d3SAmir Goldstein /* 3959b93f331SAmir Goldstein * Event on child - report on TYPE_INODE to dir if it is 3969b93f331SAmir Goldstein * watching children and on TYPE_CHILD to child. 39740a100d3SAmir Goldstein */ 39840a100d3SAmir Goldstein child = inode; 39940a100d3SAmir Goldstein inode = dir; 40040a100d3SAmir Goldstein } 40140a100d3SAmir Goldstein sb = inode->i_sb; 402497b0c5aSAmir Goldstein 403613a807fSEric Paris /* 4047c49b861SDave Hansen * Optimization: srcu_read_lock() has a memory barrier which can 4057c49b861SDave Hansen * be expensive. It protects walking the *_fsnotify_marks lists. 4067c49b861SDave Hansen * However, if we do not walk the lists, we do not have to do 4077c49b861SDave Hansen * SRCU because we have no references to any objects and do not 4087c49b861SDave Hansen * need SRCU to keep them "alive". 4097c49b861SDave Hansen */ 4109b93f331SAmir Goldstein if (!sb->s_fsnotify_marks && 411497b0c5aSAmir Goldstein (!mnt || !mnt->mnt_fsnotify_marks) && 4129b93f331SAmir Goldstein (!inode || !inode->i_fsnotify_marks) && 413497b0c5aSAmir Goldstein (!child || !child->i_fsnotify_marks)) 4147c49b861SDave Hansen return 0; 41571d73410SMel Gorman 4169b93f331SAmir Goldstein marks_mask = sb->s_fsnotify_mask; 41771d73410SMel Gorman if (mnt) 41871d73410SMel Gorman marks_mask |= mnt->mnt_fsnotify_mask; 4199b93f331SAmir Goldstein if (inode) 4209b93f331SAmir Goldstein marks_mask |= inode->i_fsnotify_mask; 421497b0c5aSAmir Goldstein if (child) 422497b0c5aSAmir Goldstein marks_mask |= child->i_fsnotify_mask; 423497b0c5aSAmir Goldstein 42471d73410SMel Gorman 4257c49b861SDave Hansen /* 426613a807fSEric Paris * if this is a modify event we may need to clear the ignored masks 427497b0c5aSAmir Goldstein * otherwise return if none of the marks care about this type of event. 428613a807fSEric Paris */ 42971d73410SMel Gorman test_mask = (mask & ALL_FSNOTIFY_EVENTS); 43071d73410SMel Gorman if (!(mask & FS_MODIFY) && !(test_mask & marks_mask)) 431613a807fSEric Paris return 0; 4323a9fb89fSEric Paris 4339385a84dSJan Kara iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); 4347131485aSEric Paris 43545a9fb37SAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] = 43645a9fb37SAmir Goldstein fsnotify_first_mark(&sb->s_fsnotify_marks); 4379bdda4e9SAmir Goldstein if (mnt) { 43847d9c7ccSAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] = 4393427ce71SMiklos Szeredi fsnotify_first_mark(&mnt->mnt_fsnotify_marks); 4407131485aSEric Paris } 4419b93f331SAmir Goldstein if (inode) { 4429b93f331SAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = 4439b93f331SAmir Goldstein fsnotify_first_mark(&inode->i_fsnotify_marks); 4449b93f331SAmir Goldstein } 445497b0c5aSAmir Goldstein if (child) { 446497b0c5aSAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_CHILD] = 447497b0c5aSAmir Goldstein fsnotify_first_mark(&child->i_fsnotify_marks); 448497b0c5aSAmir Goldstein } 44975c1be48SEric Paris 4508edc6e16SJan Kara /* 45160f7ed8cSAmir Goldstein * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark 45260f7ed8cSAmir Goldstein * ignore masks are properly reflected for mount/sb mark notifications. 4538edc6e16SJan Kara * That's why this traversal is so complicated... 4548edc6e16SJan Kara */ 455d9a6f30bSAmir Goldstein while (fsnotify_iter_select_report_types(&iter_info)) { 456b54cecf5SAmir Goldstein ret = send_to_group(mask, data, data_type, dir, file_name, 457b54cecf5SAmir Goldstein cookie, &iter_info); 45884a5b68eSEric Paris 459ff8bcbd0SEric Paris if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) 460ff8bcbd0SEric Paris goto out; 461ff8bcbd0SEric Paris 462d9a6f30bSAmir Goldstein fsnotify_iter_next(&iter_info); 4637131485aSEric Paris } 464ff8bcbd0SEric Paris ret = 0; 465ff8bcbd0SEric Paris out: 4669385a84dSJan Kara srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx); 467c4ec54b4SEric Paris 46898b5c10dSJean-Christophe Dubois return ret; 46990586523SEric Paris } 47090586523SEric Paris EXPORT_SYMBOL_GPL(fsnotify); 47190586523SEric Paris 47290586523SEric Paris static __init int fsnotify_init(void) 47390586523SEric Paris { 47475c1be48SEric Paris int ret; 47575c1be48SEric Paris 47608b95c33SAmir Goldstein BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25); 47720dee624SEric Paris 47875c1be48SEric Paris ret = init_srcu_struct(&fsnotify_mark_srcu); 47975c1be48SEric Paris if (ret) 48075c1be48SEric Paris panic("initializing fsnotify_mark_srcu"); 48175c1be48SEric Paris 4829dd813c1SJan Kara fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector, 4839dd813c1SJan Kara SLAB_PANIC); 4849dd813c1SJan Kara 48575c1be48SEric Paris return 0; 48690586523SEric Paris } 48775c1be48SEric Paris core_initcall(fsnotify_init); 488