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 233b9a1b977SAmir Goldstein static int fsnotify_handle_event(struct fsnotify_group *group, __u32 mask, 234b9a1b977SAmir Goldstein const void *data, int data_type, 235b9a1b977SAmir Goldstein struct inode *dir, const struct qstr *name, 236b9a1b977SAmir Goldstein u32 cookie, struct fsnotify_iter_info *iter_info) 237b9a1b977SAmir Goldstein { 238b9a1b977SAmir Goldstein struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info); 239b9a1b977SAmir Goldstein struct fsnotify_mark *child_mark = fsnotify_iter_child_mark(iter_info); 240b9a1b977SAmir Goldstein struct inode *inode = fsnotify_data_inode(data, data_type); 241b9a1b977SAmir Goldstein const struct fsnotify_ops *ops = group->ops; 242b9a1b977SAmir Goldstein int ret; 243b9a1b977SAmir Goldstein 244b9a1b977SAmir Goldstein if (WARN_ON_ONCE(!ops->handle_inode_event)) 245b9a1b977SAmir Goldstein return 0; 246b9a1b977SAmir Goldstein 247b9a1b977SAmir Goldstein if (WARN_ON_ONCE(fsnotify_iter_sb_mark(iter_info)) || 248b9a1b977SAmir Goldstein WARN_ON_ONCE(fsnotify_iter_vfsmount_mark(iter_info))) 249b9a1b977SAmir Goldstein return 0; 250b9a1b977SAmir Goldstein 251b9a1b977SAmir Goldstein /* 252b9a1b977SAmir Goldstein * An event can be sent on child mark iterator instead of inode mark 253b9a1b977SAmir Goldstein * iterator because of other groups that have interest of this inode 254b9a1b977SAmir Goldstein * and have marks on both parent and child. We can simplify this case. 255b9a1b977SAmir Goldstein */ 256b9a1b977SAmir Goldstein if (!inode_mark) { 257b9a1b977SAmir Goldstein inode_mark = child_mark; 258b9a1b977SAmir Goldstein child_mark = NULL; 259b9a1b977SAmir Goldstein dir = NULL; 260b9a1b977SAmir Goldstein name = NULL; 261b9a1b977SAmir Goldstein } 262b9a1b977SAmir Goldstein 263b9a1b977SAmir Goldstein ret = ops->handle_inode_event(inode_mark, mask, inode, dir, name); 264b9a1b977SAmir Goldstein if (ret || !child_mark) 265b9a1b977SAmir Goldstein return ret; 266b9a1b977SAmir Goldstein 267b9a1b977SAmir Goldstein /* 268b9a1b977SAmir Goldstein * Some events can be sent on both parent dir and child marks 269b9a1b977SAmir Goldstein * (e.g. FS_ATTRIB). If both parent dir and child are watching, 270b9a1b977SAmir Goldstein * report the event once to parent dir with name and once to child 271b9a1b977SAmir Goldstein * without name. 272b9a1b977SAmir Goldstein */ 273b9a1b977SAmir Goldstein return ops->handle_inode_event(child_mark, mask, inode, NULL, NULL); 274b9a1b977SAmir Goldstein } 275b9a1b977SAmir Goldstein 276b54cecf5SAmir Goldstein static int send_to_group(__u32 mask, const void *data, int data_type, 277b54cecf5SAmir Goldstein struct inode *dir, const struct qstr *file_name, 278b54cecf5SAmir Goldstein u32 cookie, struct fsnotify_iter_info *iter_info) 2797131485aSEric Paris { 280faa9560aSEric Paris struct fsnotify_group *group = NULL; 281007d1e83SAmir Goldstein __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS); 28292183a42SAmir Goldstein __u32 marks_mask = 0; 28392183a42SAmir Goldstein __u32 marks_ignored_mask = 0; 2843dca1a74SAmir Goldstein struct fsnotify_mark *mark; 2853dca1a74SAmir Goldstein int type; 286613a807fSEric Paris 2875b0457adSAmir Goldstein if (WARN_ON(!iter_info->report_mask)) 288faa9560aSEric Paris return 0; 2895ba08e2eSEric Paris 290ce8f76fbSEric Paris /* clear ignored on inode modification */ 291ce8f76fbSEric Paris if (mask & FS_MODIFY) { 2923dca1a74SAmir Goldstein fsnotify_foreach_obj_type(type) { 2933dca1a74SAmir Goldstein if (!fsnotify_iter_should_report_type(iter_info, type)) 2943dca1a74SAmir Goldstein continue; 2953dca1a74SAmir Goldstein mark = iter_info->marks[type]; 2963dca1a74SAmir Goldstein if (mark && 2973dca1a74SAmir Goldstein !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) 2983dca1a74SAmir Goldstein mark->ignored_mask = 0; 2993dca1a74SAmir Goldstein } 300ce8f76fbSEric Paris } 301613a807fSEric Paris 3023dca1a74SAmir Goldstein fsnotify_foreach_obj_type(type) { 3033dca1a74SAmir Goldstein if (!fsnotify_iter_should_report_type(iter_info, type)) 3043dca1a74SAmir Goldstein continue; 3053dca1a74SAmir Goldstein mark = iter_info->marks[type]; 3063dca1a74SAmir Goldstein /* does the object mark tell us to do something? */ 3073dca1a74SAmir Goldstein if (mark) { 3083dca1a74SAmir Goldstein group = mark->group; 3093dca1a74SAmir Goldstein marks_mask |= mark->mask; 3103dca1a74SAmir Goldstein marks_ignored_mask |= mark->ignored_mask; 3113dca1a74SAmir Goldstein } 312ce8f76fbSEric Paris } 313ce8f76fbSEric Paris 314b54cecf5SAmir 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", 315b54cecf5SAmir Goldstein __func__, group, mask, marks_mask, marks_ignored_mask, 316b54cecf5SAmir Goldstein data, data_type, dir, cookie); 317faa9560aSEric Paris 31892183a42SAmir Goldstein if (!(test_mask & marks_mask & ~marks_ignored_mask)) 319613a807fSEric Paris return 0; 320613a807fSEric Paris 321b9a1b977SAmir Goldstein if (group->ops->handle_event) { 322b54cecf5SAmir Goldstein return group->ops->handle_event(group, mask, data, data_type, dir, 3239385a84dSJan Kara file_name, cookie, iter_info); 3247131485aSEric Paris } 3257131485aSEric Paris 326b9a1b977SAmir Goldstein return fsnotify_handle_event(group, mask, data, data_type, dir, 327b9a1b977SAmir Goldstein file_name, cookie, iter_info); 328b9a1b977SAmir Goldstein } 329b9a1b977SAmir Goldstein 3303427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp) 3313427ce71SMiklos Szeredi { 3323427ce71SMiklos Szeredi struct fsnotify_mark_connector *conn; 3333427ce71SMiklos Szeredi struct hlist_node *node = NULL; 3343427ce71SMiklos Szeredi 3353427ce71SMiklos Szeredi conn = srcu_dereference(*connp, &fsnotify_mark_srcu); 3363427ce71SMiklos Szeredi if (conn) 3373427ce71SMiklos Szeredi node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu); 3383427ce71SMiklos Szeredi 3393427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 3403427ce71SMiklos Szeredi } 3413427ce71SMiklos Szeredi 3423427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark) 3433427ce71SMiklos Szeredi { 3443427ce71SMiklos Szeredi struct hlist_node *node = NULL; 3453427ce71SMiklos Szeredi 3463427ce71SMiklos Szeredi if (mark) 3473427ce71SMiklos Szeredi node = srcu_dereference(mark->obj_list.next, 3483427ce71SMiklos Szeredi &fsnotify_mark_srcu); 3493427ce71SMiklos Szeredi 3503427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 3513427ce71SMiklos Szeredi } 3523427ce71SMiklos Szeredi 353c28f7e56SEric Paris /* 354d9a6f30bSAmir Goldstein * iter_info is a multi head priority queue of marks. 355d9a6f30bSAmir Goldstein * Pick a subset of marks from queue heads, all with the 356d9a6f30bSAmir Goldstein * same group and set the report_mask for selected subset. 357d9a6f30bSAmir Goldstein * Returns the report_mask of the selected subset. 358d9a6f30bSAmir Goldstein */ 359d9a6f30bSAmir Goldstein static unsigned int fsnotify_iter_select_report_types( 360d9a6f30bSAmir Goldstein struct fsnotify_iter_info *iter_info) 361d9a6f30bSAmir Goldstein { 36247d9c7ccSAmir Goldstein struct fsnotify_group *max_prio_group = NULL; 36347d9c7ccSAmir Goldstein struct fsnotify_mark *mark; 36447d9c7ccSAmir Goldstein int type; 365d9a6f30bSAmir Goldstein 36647d9c7ccSAmir Goldstein /* Choose max prio group among groups of all queue heads */ 36747d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 36847d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 36947d9c7ccSAmir Goldstein if (mark && 37047d9c7ccSAmir Goldstein fsnotify_compare_groups(max_prio_group, mark->group) > 0) 37147d9c7ccSAmir Goldstein max_prio_group = mark->group; 372d9a6f30bSAmir Goldstein } 373d9a6f30bSAmir Goldstein 37447d9c7ccSAmir Goldstein if (!max_prio_group) 37547d9c7ccSAmir Goldstein return 0; 37647d9c7ccSAmir Goldstein 37747d9c7ccSAmir Goldstein /* Set the report mask for marks from same group as max prio group */ 378d9a6f30bSAmir Goldstein iter_info->report_mask = 0; 37947d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 38047d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 38147d9c7ccSAmir Goldstein if (mark && 38247d9c7ccSAmir Goldstein fsnotify_compare_groups(max_prio_group, mark->group) == 0) 38347d9c7ccSAmir Goldstein fsnotify_iter_set_report_type(iter_info, type); 38447d9c7ccSAmir Goldstein } 385d9a6f30bSAmir Goldstein 386d9a6f30bSAmir Goldstein return iter_info->report_mask; 387d9a6f30bSAmir Goldstein } 388d9a6f30bSAmir Goldstein 389d9a6f30bSAmir Goldstein /* 390d9a6f30bSAmir Goldstein * Pop from iter_info multi head queue, the marks that were iterated in the 391d9a6f30bSAmir Goldstein * current iteration step. 392d9a6f30bSAmir Goldstein */ 393d9a6f30bSAmir Goldstein static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) 394d9a6f30bSAmir Goldstein { 39547d9c7ccSAmir Goldstein int type; 396d9a6f30bSAmir Goldstein 39747d9c7ccSAmir Goldstein fsnotify_foreach_obj_type(type) { 39847d9c7ccSAmir Goldstein if (fsnotify_iter_should_report_type(iter_info, type)) 39947d9c7ccSAmir Goldstein iter_info->marks[type] = 40047d9c7ccSAmir Goldstein fsnotify_next_mark(iter_info->marks[type]); 40147d9c7ccSAmir Goldstein } 402d9a6f30bSAmir Goldstein } 403d9a6f30bSAmir Goldstein 404d9a6f30bSAmir Goldstein /* 40540a100d3SAmir Goldstein * fsnotify - This is the main call to fsnotify. 40640a100d3SAmir Goldstein * 40740a100d3SAmir Goldstein * The VFS calls into hook specific functions in linux/fsnotify.h. 40840a100d3SAmir Goldstein * Those functions then in turn call here. Here will call out to all of the 40940a100d3SAmir Goldstein * registered fsnotify_group. Those groups can then use the notification event 41040a100d3SAmir Goldstein * in whatever means they feel necessary. 41140a100d3SAmir Goldstein * 41240a100d3SAmir Goldstein * @mask: event type and flags 41340a100d3SAmir Goldstein * @data: object that event happened on 41440a100d3SAmir Goldstein * @data_type: type of object for fanotify_data_XXX() accessors 41540a100d3SAmir Goldstein * @dir: optional directory associated with event - 41640a100d3SAmir Goldstein * if @file_name is not NULL, this is the directory that 41740a100d3SAmir Goldstein * @file_name is relative to 41840a100d3SAmir Goldstein * @file_name: optional file name associated with event 41940a100d3SAmir Goldstein * @inode: optional inode associated with event - 42040a100d3SAmir Goldstein * either @dir or @inode must be non-NULL. 42140a100d3SAmir Goldstein * if both are non-NULL event may be reported to both. 42240a100d3SAmir Goldstein * @cookie: inotify rename cookie 42390586523SEric Paris */ 42440a100d3SAmir Goldstein int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir, 42540a100d3SAmir Goldstein const struct qstr *file_name, struct inode *inode, u32 cookie) 42690586523SEric Paris { 427b54cecf5SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 4283427ce71SMiklos Szeredi struct fsnotify_iter_info iter_info = {}; 42940a100d3SAmir Goldstein struct super_block *sb; 43060f7ed8cSAmir Goldstein struct mount *mnt = NULL; 431497b0c5aSAmir Goldstein struct inode *child = NULL; 4329385a84dSJan Kara int ret = 0; 43371d73410SMel Gorman __u32 test_mask, marks_mask; 43490586523SEric Paris 43571d73410SMel Gorman if (path) 436aa93bdc5SAmir Goldstein mnt = real_mount(path->mnt); 437613a807fSEric Paris 43840a100d3SAmir Goldstein if (!inode) { 43940a100d3SAmir Goldstein /* Dirent event - report on TYPE_INODE to dir */ 44040a100d3SAmir Goldstein inode = dir; 44140a100d3SAmir Goldstein } else if (mask & FS_EVENT_ON_CHILD) { 44240a100d3SAmir Goldstein /* 4439b93f331SAmir Goldstein * Event on child - report on TYPE_INODE to dir if it is 4449b93f331SAmir Goldstein * watching children and on TYPE_CHILD to child. 44540a100d3SAmir Goldstein */ 44640a100d3SAmir Goldstein child = inode; 44740a100d3SAmir Goldstein inode = dir; 44840a100d3SAmir Goldstein } 44940a100d3SAmir Goldstein sb = inode->i_sb; 450497b0c5aSAmir Goldstein 451613a807fSEric Paris /* 4527c49b861SDave Hansen * Optimization: srcu_read_lock() has a memory barrier which can 4537c49b861SDave Hansen * be expensive. It protects walking the *_fsnotify_marks lists. 4547c49b861SDave Hansen * However, if we do not walk the lists, we do not have to do 4557c49b861SDave Hansen * SRCU because we have no references to any objects and do not 4567c49b861SDave Hansen * need SRCU to keep them "alive". 4577c49b861SDave Hansen */ 4589b93f331SAmir Goldstein if (!sb->s_fsnotify_marks && 459497b0c5aSAmir Goldstein (!mnt || !mnt->mnt_fsnotify_marks) && 4609b93f331SAmir Goldstein (!inode || !inode->i_fsnotify_marks) && 461497b0c5aSAmir Goldstein (!child || !child->i_fsnotify_marks)) 4627c49b861SDave Hansen return 0; 46371d73410SMel Gorman 4649b93f331SAmir Goldstein marks_mask = sb->s_fsnotify_mask; 46571d73410SMel Gorman if (mnt) 46671d73410SMel Gorman marks_mask |= mnt->mnt_fsnotify_mask; 4679b93f331SAmir Goldstein if (inode) 4689b93f331SAmir Goldstein marks_mask |= inode->i_fsnotify_mask; 469497b0c5aSAmir Goldstein if (child) 470497b0c5aSAmir Goldstein marks_mask |= child->i_fsnotify_mask; 471497b0c5aSAmir Goldstein 47271d73410SMel Gorman 4737c49b861SDave Hansen /* 474613a807fSEric Paris * if this is a modify event we may need to clear the ignored masks 475497b0c5aSAmir Goldstein * otherwise return if none of the marks care about this type of event. 476613a807fSEric Paris */ 47771d73410SMel Gorman test_mask = (mask & ALL_FSNOTIFY_EVENTS); 47871d73410SMel Gorman if (!(mask & FS_MODIFY) && !(test_mask & marks_mask)) 479613a807fSEric Paris return 0; 4803a9fb89fSEric Paris 4819385a84dSJan Kara iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); 4827131485aSEric Paris 48345a9fb37SAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] = 48445a9fb37SAmir Goldstein fsnotify_first_mark(&sb->s_fsnotify_marks); 4859bdda4e9SAmir Goldstein if (mnt) { 48647d9c7ccSAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] = 4873427ce71SMiklos Szeredi fsnotify_first_mark(&mnt->mnt_fsnotify_marks); 4887131485aSEric Paris } 4899b93f331SAmir Goldstein if (inode) { 4909b93f331SAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = 4919b93f331SAmir Goldstein fsnotify_first_mark(&inode->i_fsnotify_marks); 4929b93f331SAmir Goldstein } 493497b0c5aSAmir Goldstein if (child) { 494497b0c5aSAmir Goldstein iter_info.marks[FSNOTIFY_OBJ_TYPE_CHILD] = 495497b0c5aSAmir Goldstein fsnotify_first_mark(&child->i_fsnotify_marks); 496497b0c5aSAmir Goldstein } 49775c1be48SEric Paris 4988edc6e16SJan Kara /* 49960f7ed8cSAmir Goldstein * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark 50060f7ed8cSAmir Goldstein * ignore masks are properly reflected for mount/sb mark notifications. 5018edc6e16SJan Kara * That's why this traversal is so complicated... 5028edc6e16SJan Kara */ 503d9a6f30bSAmir Goldstein while (fsnotify_iter_select_report_types(&iter_info)) { 504b54cecf5SAmir Goldstein ret = send_to_group(mask, data, data_type, dir, file_name, 505b54cecf5SAmir Goldstein cookie, &iter_info); 50684a5b68eSEric Paris 507ff8bcbd0SEric Paris if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) 508ff8bcbd0SEric Paris goto out; 509ff8bcbd0SEric Paris 510d9a6f30bSAmir Goldstein fsnotify_iter_next(&iter_info); 5117131485aSEric Paris } 512ff8bcbd0SEric Paris ret = 0; 513ff8bcbd0SEric Paris out: 5149385a84dSJan Kara srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx); 515c4ec54b4SEric Paris 51698b5c10dSJean-Christophe Dubois return ret; 51790586523SEric Paris } 51890586523SEric Paris EXPORT_SYMBOL_GPL(fsnotify); 51990586523SEric Paris 52090586523SEric Paris static __init int fsnotify_init(void) 52190586523SEric Paris { 52275c1be48SEric Paris int ret; 52375c1be48SEric Paris 52408b95c33SAmir Goldstein BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25); 52520dee624SEric Paris 52675c1be48SEric Paris ret = init_srcu_struct(&fsnotify_mark_srcu); 52775c1be48SEric Paris if (ret) 52875c1be48SEric Paris panic("initializing fsnotify_mark_srcu"); 52975c1be48SEric Paris 5309dd813c1SJan Kara fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector, 5319dd813c1SJan Kara SLAB_PANIC); 5329dd813c1SJan Kara 53375c1be48SEric Paris return 0; 53490586523SEric Paris } 53575c1be48SEric Paris core_initcall(fsnotify_init); 536