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 iput(iput_inode); 74ebb3b47eSJan Kara 75ebb3b47eSJan Kara /* for each watch, send FS_UNMOUNT and then remove it */ 7682ace1efSAmir Goldstein fsnotify_inode(inode, FS_UNMOUNT); 77ebb3b47eSJan Kara 78ebb3b47eSJan Kara fsnotify_inode_delete(inode); 79ebb3b47eSJan Kara 80ebb3b47eSJan Kara iput_inode = inode; 81ebb3b47eSJan Kara 8204646aebSEric Sandeen cond_resched(); 83ebb3b47eSJan Kara spin_lock(&sb->s_inode_list_lock); 84ebb3b47eSJan Kara } 85ebb3b47eSJan Kara spin_unlock(&sb->s_inode_list_lock); 86ebb3b47eSJan Kara 87ebb3b47eSJan Kara iput(iput_inode); 88ebb3b47eSJan Kara } 89ebb3b47eSJan Kara 901e6cb723SAmir Goldstein void fsnotify_sb_delete(struct super_block *sb) 911e6cb723SAmir Goldstein { 921e6cb723SAmir Goldstein fsnotify_unmount_inodes(sb); 931e6cb723SAmir Goldstein fsnotify_clear_marks_by_sb(sb); 94ec44610fSAmir Goldstein /* Wait for outstanding object references from connectors */ 95ec44610fSAmir Goldstein wait_var_event(&sb->s_fsnotify_connectors, 96ec44610fSAmir Goldstein !atomic_long_read(&sb->s_fsnotify_connectors)); 971e6cb723SAmir Goldstein } 981e6cb723SAmir Goldstein 993be25f49SEric Paris /* 100c28f7e56SEric Paris * Given an inode, first check if we care what happens to our children. Inotify 101c28f7e56SEric Paris * and dnotify both tell their parents about events. If we care about any event 102c28f7e56SEric Paris * on a child we run all of our children and set a dentry flag saying that the 103c28f7e56SEric Paris * parent cares. Thus when an event happens on a child it can quickly tell if 104c28f7e56SEric Paris * if there is a need to find a parent and send the event to the parent. 105c28f7e56SEric Paris */ 106c28f7e56SEric Paris void __fsnotify_update_child_dentry_flags(struct inode *inode) 107c28f7e56SEric Paris { 108c28f7e56SEric Paris struct dentry *alias; 109c28f7e56SEric Paris int watched; 110c28f7e56SEric Paris 111c28f7e56SEric Paris if (!S_ISDIR(inode->i_mode)) 112c28f7e56SEric Paris return; 113c28f7e56SEric Paris 114c28f7e56SEric Paris /* determine if the children should tell inode about their events */ 115c28f7e56SEric Paris watched = fsnotify_inode_watches_children(inode); 116c28f7e56SEric Paris 117873feea0SNick Piggin spin_lock(&inode->i_lock); 118c28f7e56SEric Paris /* run all of the dentries associated with this inode. Since this is a 119c28f7e56SEric Paris * directory, there damn well better only be one item on this list */ 120946e51f2SAl Viro hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { 121c28f7e56SEric Paris struct dentry *child; 122c28f7e56SEric Paris 123c28f7e56SEric Paris /* run all of the children of the original inode and fix their 124c28f7e56SEric Paris * d_flags to indicate parental interest (their parent is the 125c28f7e56SEric Paris * original inode) */ 1262fd6b7f5SNick Piggin spin_lock(&alias->d_lock); 127946e51f2SAl Viro list_for_each_entry(child, &alias->d_subdirs, d_child) { 128c28f7e56SEric Paris if (!child->d_inode) 129c28f7e56SEric Paris continue; 130c28f7e56SEric Paris 1312fd6b7f5SNick Piggin spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); 132c28f7e56SEric Paris if (watched) 133c28f7e56SEric Paris child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; 134c28f7e56SEric Paris else 135c28f7e56SEric Paris child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; 136c28f7e56SEric Paris spin_unlock(&child->d_lock); 137c28f7e56SEric Paris } 1382fd6b7f5SNick Piggin spin_unlock(&alias->d_lock); 139c28f7e56SEric Paris } 140873feea0SNick Piggin spin_unlock(&inode->i_lock); 141c28f7e56SEric Paris } 142c28f7e56SEric Paris 1439b93f331SAmir Goldstein /* Are inode/sb/mount interested in parent and name info with this event? */ 1449b93f331SAmir Goldstein static bool fsnotify_event_needs_parent(struct inode *inode, struct mount *mnt, 1459b93f331SAmir Goldstein __u32 mask) 1469b93f331SAmir Goldstein { 1479b93f331SAmir Goldstein __u32 marks_mask = 0; 1489b93f331SAmir Goldstein 1499b93f331SAmir Goldstein /* We only send parent/name to inode/sb/mount for events on non-dir */ 1509b93f331SAmir Goldstein if (mask & FS_ISDIR) 1519b93f331SAmir Goldstein return false; 1529b93f331SAmir Goldstein 153fecc4559SAmir Goldstein /* 154fecc4559SAmir Goldstein * All events that are possible on child can also may be reported with 155fecc4559SAmir Goldstein * parent/name info to inode/sb/mount. Otherwise, a watching parent 156fecc4559SAmir Goldstein * could result in events reported with unexpected name info to sb/mount. 157fecc4559SAmir Goldstein */ 158fecc4559SAmir Goldstein BUILD_BUG_ON(FS_EVENTS_POSS_ON_CHILD & ~FS_EVENTS_POSS_TO_PARENT); 159fecc4559SAmir Goldstein 1609b93f331SAmir Goldstein /* Did either inode/sb/mount subscribe for events with parent/name? */ 1619b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(inode->i_fsnotify_mask); 1629b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(inode->i_sb->s_fsnotify_mask); 1639b93f331SAmir Goldstein if (mnt) 1649b93f331SAmir Goldstein marks_mask |= fsnotify_parent_needed_mask(mnt->mnt_fsnotify_mask); 1659b93f331SAmir Goldstein 1669b93f331SAmir Goldstein /* Did they subscribe for this event with parent/name info? */ 1679b93f331SAmir Goldstein return mask & marks_mask; 1689b93f331SAmir Goldstein } 1699b93f331SAmir Goldstein 170c738fbabSAmir Goldstein /* 171c738fbabSAmir Goldstein * Notify this dentry's parent about a child's events with child name info 1729b93f331SAmir Goldstein * if parent is watching or if inode/sb/mount are interested in events with 1739b93f331SAmir Goldstein * parent and name info. 1749b93f331SAmir Goldstein * 1759b93f331SAmir Goldstein * Notify only the child without name info if parent is not watching and 1769b93f331SAmir Goldstein * inode/sb/mount are not interested in events with parent and name info. 177c738fbabSAmir Goldstein */ 17871d73410SMel Gorman int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 179017de65fSAmir Goldstein int data_type) 180c28f7e56SEric Paris { 1819b93f331SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 1829b93f331SAmir Goldstein struct mount *mnt = path ? real_mount(path->mnt) : NULL; 183497b0c5aSAmir Goldstein struct inode *inode = d_inode(dentry); 184c28f7e56SEric Paris struct dentry *parent; 1859b93f331SAmir Goldstein bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED; 1867372e79cSAmir Goldstein bool parent_needed, parent_interested; 1879b93f331SAmir Goldstein __u32 p_mask; 18840a100d3SAmir Goldstein struct inode *p_inode = NULL; 189497b0c5aSAmir Goldstein struct name_snapshot name; 190497b0c5aSAmir Goldstein struct qstr *file_name = NULL; 19152420392SEric Paris int ret = 0; 192c28f7e56SEric Paris 1939b93f331SAmir Goldstein /* 1949b93f331SAmir Goldstein * Do inode/sb/mount care about parent and name info on non-dir? 1959b93f331SAmir Goldstein * Do they care about any event at all? 1969b93f331SAmir Goldstein */ 1979b93f331SAmir Goldstein if (!inode->i_fsnotify_marks && !inode->i_sb->s_fsnotify_marks && 1989b93f331SAmir Goldstein (!mnt || !mnt->mnt_fsnotify_marks) && !parent_watched) 1999b93f331SAmir Goldstein return 0; 2009b93f331SAmir Goldstein 201497b0c5aSAmir Goldstein parent = NULL; 2027372e79cSAmir Goldstein parent_needed = fsnotify_event_needs_parent(inode, mnt, mask); 2037372e79cSAmir Goldstein if (!parent_watched && !parent_needed) 204497b0c5aSAmir Goldstein goto notify; 205c28f7e56SEric Paris 2069b93f331SAmir Goldstein /* Does parent inode care about events on children? */ 2074d4eb366SChristoph Hellwig parent = dget_parent(dentry); 208c28f7e56SEric Paris p_inode = parent->d_inode; 2099b93f331SAmir Goldstein p_mask = fsnotify_inode_watches_children(p_inode); 2109b93f331SAmir Goldstein if (unlikely(parent_watched && !p_mask)) 2114d4eb366SChristoph Hellwig __fsnotify_update_child_dentry_flags(p_inode); 2129b93f331SAmir Goldstein 2139b93f331SAmir Goldstein /* 2149b93f331SAmir Goldstein * Include parent/name in notification either if some notification 2157372e79cSAmir Goldstein * groups require parent info or the parent is interested in this event. 2169b93f331SAmir Goldstein */ 2177372e79cSAmir Goldstein parent_interested = mask & p_mask & ALL_FSNOTIFY_EVENTS; 2187372e79cSAmir Goldstein if (parent_needed || parent_interested) { 219497b0c5aSAmir Goldstein /* When notifying parent, child should be passed as data */ 220497b0c5aSAmir Goldstein WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type)); 22149d31c2fSAl Viro 222497b0c5aSAmir Goldstein /* Notify both parent and child with child name info */ 22349d31c2fSAl Viro take_dentry_name_snapshot(&name, dentry); 224497b0c5aSAmir Goldstein file_name = &name.name; 2257372e79cSAmir Goldstein if (parent_interested) 226497b0c5aSAmir Goldstein mask |= FS_EVENT_ON_CHILD; 227c28f7e56SEric Paris } 228c28f7e56SEric Paris 229497b0c5aSAmir Goldstein notify: 23040a100d3SAmir Goldstein ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0); 231497b0c5aSAmir Goldstein 232497b0c5aSAmir Goldstein if (file_name) 233497b0c5aSAmir Goldstein release_dentry_name_snapshot(&name); 234c28f7e56SEric Paris dput(parent); 23552420392SEric Paris 23652420392SEric Paris return ret; 237c28f7e56SEric Paris } 23871d73410SMel Gorman EXPORT_SYMBOL_GPL(__fsnotify_parent); 239c28f7e56SEric Paris 240950cc0d2SAmir Goldstein static int fsnotify_handle_inode_event(struct fsnotify_group *group, 241950cc0d2SAmir Goldstein struct fsnotify_mark *inode_mark, 242950cc0d2SAmir Goldstein u32 mask, const void *data, int data_type, 243950cc0d2SAmir Goldstein struct inode *dir, const struct qstr *name, 244950cc0d2SAmir Goldstein u32 cookie) 245950cc0d2SAmir Goldstein { 246950cc0d2SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 247950cc0d2SAmir Goldstein struct inode *inode = fsnotify_data_inode(data, data_type); 248950cc0d2SAmir Goldstein const struct fsnotify_ops *ops = group->ops; 249950cc0d2SAmir Goldstein 250950cc0d2SAmir Goldstein if (WARN_ON_ONCE(!ops->handle_inode_event)) 251950cc0d2SAmir Goldstein return 0; 252950cc0d2SAmir Goldstein 25324dca905SGabriel Krisman Bertazi if (WARN_ON_ONCE(!inode && !dir)) 25424dca905SGabriel Krisman Bertazi return 0; 25524dca905SGabriel Krisman Bertazi 25638035c04SAmir Goldstein if ((inode_mark->flags & FSNOTIFY_MARK_FLAG_EXCL_UNLINK) && 257950cc0d2SAmir Goldstein path && d_unlinked(path->dentry)) 258950cc0d2SAmir Goldstein return 0; 259950cc0d2SAmir Goldstein 260fecc4559SAmir Goldstein /* Check interest of this mark in case event was sent with two marks */ 261fecc4559SAmir Goldstein if (!(mask & inode_mark->mask & ALL_FSNOTIFY_EVENTS)) 262fecc4559SAmir Goldstein return 0; 263fecc4559SAmir Goldstein 264950cc0d2SAmir Goldstein return ops->handle_inode_event(inode_mark, mask, inode, dir, name, cookie); 265950cc0d2SAmir Goldstein } 266950cc0d2SAmir Goldstein 267b9a1b977SAmir Goldstein static int fsnotify_handle_event(struct fsnotify_group *group, __u32 mask, 268b9a1b977SAmir Goldstein const void *data, int data_type, 269b9a1b977SAmir Goldstein struct inode *dir, const struct qstr *name, 270b9a1b977SAmir Goldstein u32 cookie, struct fsnotify_iter_info *iter_info) 271b9a1b977SAmir Goldstein { 272b9a1b977SAmir Goldstein struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info); 273fecc4559SAmir Goldstein struct fsnotify_mark *parent_mark = fsnotify_iter_parent_mark(iter_info); 274b9a1b977SAmir Goldstein int ret; 275b9a1b977SAmir Goldstein 276b9a1b977SAmir Goldstein if (WARN_ON_ONCE(fsnotify_iter_sb_mark(iter_info)) || 277b9a1b977SAmir Goldstein WARN_ON_ONCE(fsnotify_iter_vfsmount_mark(iter_info))) 278b9a1b977SAmir Goldstein return 0; 279b9a1b977SAmir Goldstein 280e54183faSAmir Goldstein /* 281e54183faSAmir Goldstein * For FS_RENAME, 'dir' is old dir and 'data' is new dentry. 282e54183faSAmir Goldstein * The only ->handle_inode_event() backend that supports FS_RENAME is 283e54183faSAmir Goldstein * dnotify, where it means file was renamed within same parent. 284e54183faSAmir Goldstein */ 285e54183faSAmir Goldstein if (mask & FS_RENAME) { 286e54183faSAmir Goldstein struct dentry *moved = fsnotify_data_dentry(data, data_type); 287e54183faSAmir Goldstein 288e54183faSAmir Goldstein if (dir != moved->d_parent->d_inode) 289e54183faSAmir Goldstein return 0; 290e54183faSAmir Goldstein } 291e54183faSAmir Goldstein 292fecc4559SAmir Goldstein if (parent_mark) { 293fecc4559SAmir Goldstein ret = fsnotify_handle_inode_event(group, parent_mark, mask, 294fecc4559SAmir Goldstein data, data_type, dir, name, 0); 295fecc4559SAmir Goldstein if (ret) 296fecc4559SAmir Goldstein return ret; 297fecc4559SAmir Goldstein } 298e730558aSAmir Goldstein 299fecc4559SAmir Goldstein if (!inode_mark) 300fecc4559SAmir Goldstein return 0; 301fecc4559SAmir Goldstein 302fecc4559SAmir Goldstein if (mask & FS_EVENT_ON_CHILD) { 303fecc4559SAmir Goldstein /* 304fecc4559SAmir Goldstein * Some events can be sent on both parent dir and child marks 305fecc4559SAmir Goldstein * (e.g. FS_ATTRIB). If both parent dir and child are 306fecc4559SAmir Goldstein * watching, report the event once to parent dir with name (if 307fecc4559SAmir Goldstein * interested) and once to child without name (if interested). 308fecc4559SAmir Goldstein * The child watcher is expecting an event without a file name 309fecc4559SAmir Goldstein * and without the FS_EVENT_ON_CHILD flag. 310fecc4559SAmir Goldstein */ 311fecc4559SAmir Goldstein mask &= ~FS_EVENT_ON_CHILD; 312b9a1b977SAmir Goldstein dir = NULL; 313b9a1b977SAmir Goldstein name = NULL; 314b9a1b977SAmir Goldstein } 315b9a1b977SAmir Goldstein 316fecc4559SAmir Goldstein return fsnotify_handle_inode_event(group, inode_mark, mask, data, data_type, 317950cc0d2SAmir Goldstein dir, name, cookie); 318b9a1b977SAmir Goldstein } 319b9a1b977SAmir Goldstein 320b54cecf5SAmir Goldstein static int send_to_group(__u32 mask, const void *data, int data_type, 321b54cecf5SAmir Goldstein struct inode *dir, const struct qstr *file_name, 322b54cecf5SAmir Goldstein u32 cookie, struct fsnotify_iter_info *iter_info) 3237131485aSEric Paris { 324faa9560aSEric Paris struct fsnotify_group *group = NULL; 325007d1e83SAmir Goldstein __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS); 32692183a42SAmir Goldstein __u32 marks_mask = 0; 327*31a371e4SAmir Goldstein __u32 marks_ignore_mask = 0; 328*31a371e4SAmir Goldstein bool is_dir = mask & FS_ISDIR; 3293dca1a74SAmir Goldstein struct fsnotify_mark *mark; 3303dca1a74SAmir Goldstein int type; 331613a807fSEric Paris 33214362a25SAmir Goldstein if (!iter_info->report_mask) 333faa9560aSEric Paris return 0; 3345ba08e2eSEric Paris 335ce8f76fbSEric Paris /* clear ignored on inode modification */ 336ce8f76fbSEric Paris if (mask & FS_MODIFY) { 33714362a25SAmir Goldstein fsnotify_foreach_iter_mark_type(iter_info, mark, type) { 33814362a25SAmir Goldstein if (!(mark->flags & 33914362a25SAmir Goldstein FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) 340*31a371e4SAmir Goldstein mark->ignore_mask = 0; 3413dca1a74SAmir Goldstein } 342ce8f76fbSEric Paris } 343613a807fSEric Paris 34414362a25SAmir Goldstein /* Are any of the group marks interested in this event? */ 34514362a25SAmir Goldstein fsnotify_foreach_iter_mark_type(iter_info, mark, type) { 3463dca1a74SAmir Goldstein group = mark->group; 3473dca1a74SAmir Goldstein marks_mask |= mark->mask; 348*31a371e4SAmir Goldstein marks_ignore_mask |= 349*31a371e4SAmir Goldstein fsnotify_effective_ignore_mask(mark, is_dir, type); 3503dca1a74SAmir Goldstein } 351ce8f76fbSEric Paris 352*31a371e4SAmir Goldstein pr_debug("%s: group=%p mask=%x marks_mask=%x marks_ignore_mask=%x data=%p data_type=%d dir=%p cookie=%d\n", 353*31a371e4SAmir Goldstein __func__, group, mask, marks_mask, marks_ignore_mask, 354b54cecf5SAmir Goldstein data, data_type, dir, cookie); 355faa9560aSEric Paris 356*31a371e4SAmir Goldstein if (!(test_mask & marks_mask & ~marks_ignore_mask)) 357613a807fSEric Paris return 0; 358613a807fSEric Paris 359b9a1b977SAmir Goldstein if (group->ops->handle_event) { 360b54cecf5SAmir Goldstein return group->ops->handle_event(group, mask, data, data_type, dir, 3619385a84dSJan Kara file_name, cookie, iter_info); 3627131485aSEric Paris } 3637131485aSEric Paris 364b9a1b977SAmir Goldstein return fsnotify_handle_event(group, mask, data, data_type, dir, 365b9a1b977SAmir Goldstein file_name, cookie, iter_info); 366b9a1b977SAmir Goldstein } 367b9a1b977SAmir Goldstein 3683427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp) 3693427ce71SMiklos Szeredi { 3703427ce71SMiklos Szeredi struct fsnotify_mark_connector *conn; 3713427ce71SMiklos Szeredi struct hlist_node *node = NULL; 3723427ce71SMiklos Szeredi 3733427ce71SMiklos Szeredi conn = srcu_dereference(*connp, &fsnotify_mark_srcu); 3743427ce71SMiklos Szeredi if (conn) 3753427ce71SMiklos Szeredi node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu); 3763427ce71SMiklos Szeredi 3773427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 3783427ce71SMiklos Szeredi } 3793427ce71SMiklos Szeredi 3803427ce71SMiklos Szeredi static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark) 3813427ce71SMiklos Szeredi { 3823427ce71SMiklos Szeredi struct hlist_node *node = NULL; 3833427ce71SMiklos Szeredi 3843427ce71SMiklos Szeredi if (mark) 3853427ce71SMiklos Szeredi node = srcu_dereference(mark->obj_list.next, 3863427ce71SMiklos Szeredi &fsnotify_mark_srcu); 3873427ce71SMiklos Szeredi 3883427ce71SMiklos Szeredi return hlist_entry_safe(node, struct fsnotify_mark, obj_list); 3893427ce71SMiklos Szeredi } 3903427ce71SMiklos Szeredi 391c28f7e56SEric Paris /* 392d9a6f30bSAmir Goldstein * iter_info is a multi head priority queue of marks. 39314362a25SAmir Goldstein * Pick a subset of marks from queue heads, all with the same group 39414362a25SAmir Goldstein * and set the report_mask to a subset of the selected marks. 39514362a25SAmir Goldstein * Returns false if there are no more groups to iterate. 396d9a6f30bSAmir Goldstein */ 39714362a25SAmir Goldstein static bool fsnotify_iter_select_report_types( 398d9a6f30bSAmir Goldstein struct fsnotify_iter_info *iter_info) 399d9a6f30bSAmir Goldstein { 40047d9c7ccSAmir Goldstein struct fsnotify_group *max_prio_group = NULL; 40147d9c7ccSAmir Goldstein struct fsnotify_mark *mark; 40247d9c7ccSAmir Goldstein int type; 403d9a6f30bSAmir Goldstein 40447d9c7ccSAmir Goldstein /* Choose max prio group among groups of all queue heads */ 4051c9007d6SAmir Goldstein fsnotify_foreach_iter_type(type) { 40647d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 40747d9c7ccSAmir Goldstein if (mark && 40847d9c7ccSAmir Goldstein fsnotify_compare_groups(max_prio_group, mark->group) > 0) 40947d9c7ccSAmir Goldstein max_prio_group = mark->group; 410d9a6f30bSAmir Goldstein } 411d9a6f30bSAmir Goldstein 41247d9c7ccSAmir Goldstein if (!max_prio_group) 41314362a25SAmir Goldstein return false; 41447d9c7ccSAmir Goldstein 41547d9c7ccSAmir Goldstein /* Set the report mask for marks from same group as max prio group */ 41614362a25SAmir Goldstein iter_info->current_group = max_prio_group; 417d9a6f30bSAmir Goldstein iter_info->report_mask = 0; 4181c9007d6SAmir Goldstein fsnotify_foreach_iter_type(type) { 41947d9c7ccSAmir Goldstein mark = iter_info->marks[type]; 420e730558aSAmir Goldstein if (mark && mark->group == iter_info->current_group) { 421e730558aSAmir Goldstein /* 422e730558aSAmir Goldstein * FSNOTIFY_ITER_TYPE_PARENT indicates that this inode 423e730558aSAmir Goldstein * is watching children and interested in this event, 424e730558aSAmir Goldstein * which is an event possible on child. 425e730558aSAmir Goldstein * But is *this mark* watching children? 426e730558aSAmir Goldstein */ 427e730558aSAmir Goldstein if (type == FSNOTIFY_ITER_TYPE_PARENT && 428*31a371e4SAmir Goldstein !(mark->mask & FS_EVENT_ON_CHILD) && 429*31a371e4SAmir Goldstein !(fsnotify_ignore_mask(mark) & FS_EVENT_ON_CHILD)) 430e730558aSAmir Goldstein continue; 431e730558aSAmir Goldstein 43247d9c7ccSAmir Goldstein fsnotify_iter_set_report_type(iter_info, type); 43347d9c7ccSAmir Goldstein } 434e730558aSAmir Goldstein } 435d9a6f30bSAmir Goldstein 43614362a25SAmir Goldstein return true; 437d9a6f30bSAmir Goldstein } 438d9a6f30bSAmir Goldstein 439d9a6f30bSAmir Goldstein /* 44014362a25SAmir Goldstein * Pop from iter_info multi head queue, the marks that belong to the group of 441d9a6f30bSAmir Goldstein * current iteration step. 442d9a6f30bSAmir Goldstein */ 443d9a6f30bSAmir Goldstein static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) 444d9a6f30bSAmir Goldstein { 44514362a25SAmir Goldstein struct fsnotify_mark *mark; 44647d9c7ccSAmir Goldstein int type; 447d9a6f30bSAmir Goldstein 44814362a25SAmir Goldstein /* 44914362a25SAmir Goldstein * We cannot use fsnotify_foreach_iter_mark_type() here because we 45014362a25SAmir Goldstein * may need to advance a mark of type X that belongs to current_group 45114362a25SAmir Goldstein * but was not selected for reporting. 45214362a25SAmir Goldstein */ 4531c9007d6SAmir Goldstein fsnotify_foreach_iter_type(type) { 45414362a25SAmir Goldstein mark = iter_info->marks[type]; 45514362a25SAmir Goldstein if (mark && mark->group == iter_info->current_group) 45647d9c7ccSAmir Goldstein iter_info->marks[type] = 45747d9c7ccSAmir Goldstein fsnotify_next_mark(iter_info->marks[type]); 45847d9c7ccSAmir Goldstein } 459d9a6f30bSAmir Goldstein } 460d9a6f30bSAmir Goldstein 461d9a6f30bSAmir Goldstein /* 46240a100d3SAmir Goldstein * fsnotify - This is the main call to fsnotify. 46340a100d3SAmir Goldstein * 46440a100d3SAmir Goldstein * The VFS calls into hook specific functions in linux/fsnotify.h. 46540a100d3SAmir Goldstein * Those functions then in turn call here. Here will call out to all of the 46640a100d3SAmir Goldstein * registered fsnotify_group. Those groups can then use the notification event 46740a100d3SAmir Goldstein * in whatever means they feel necessary. 46840a100d3SAmir Goldstein * 46940a100d3SAmir Goldstein * @mask: event type and flags 47040a100d3SAmir Goldstein * @data: object that event happened on 47140a100d3SAmir Goldstein * @data_type: type of object for fanotify_data_XXX() accessors 47240a100d3SAmir Goldstein * @dir: optional directory associated with event - 47340a100d3SAmir Goldstein * if @file_name is not NULL, this is the directory that 47440a100d3SAmir Goldstein * @file_name is relative to 47540a100d3SAmir Goldstein * @file_name: optional file name associated with event 47640a100d3SAmir Goldstein * @inode: optional inode associated with event - 47729335033SGabriel Krisman Bertazi * If @dir and @inode are both non-NULL, event may be 47829335033SGabriel Krisman Bertazi * reported to both. 47940a100d3SAmir Goldstein * @cookie: inotify rename cookie 48090586523SEric Paris */ 48140a100d3SAmir Goldstein int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir, 48240a100d3SAmir Goldstein const struct qstr *file_name, struct inode *inode, u32 cookie) 48390586523SEric Paris { 484b54cecf5SAmir Goldstein const struct path *path = fsnotify_data_path(data, data_type); 48529335033SGabriel Krisman Bertazi struct super_block *sb = fsnotify_data_sb(data, data_type); 4863427ce71SMiklos Szeredi struct fsnotify_iter_info iter_info = {}; 48760f7ed8cSAmir Goldstein struct mount *mnt = NULL; 488e54183faSAmir Goldstein struct inode *inode2 = NULL; 489e54183faSAmir Goldstein struct dentry *moved; 490e54183faSAmir Goldstein int inode2_type; 4919385a84dSJan Kara int ret = 0; 49271d73410SMel Gorman __u32 test_mask, marks_mask; 49390586523SEric Paris 49471d73410SMel Gorman if (path) 495aa93bdc5SAmir Goldstein mnt = real_mount(path->mnt); 496613a807fSEric Paris 49740a100d3SAmir Goldstein if (!inode) { 49840a100d3SAmir Goldstein /* Dirent event - report on TYPE_INODE to dir */ 49940a100d3SAmir Goldstein inode = dir; 500e54183faSAmir Goldstein /* For FS_RENAME, inode is old_dir and inode2 is new_dir */ 501e54183faSAmir Goldstein if (mask & FS_RENAME) { 502e54183faSAmir Goldstein moved = fsnotify_data_dentry(data, data_type); 503e54183faSAmir Goldstein inode2 = moved->d_parent->d_inode; 504e54183faSAmir Goldstein inode2_type = FSNOTIFY_ITER_TYPE_INODE2; 505e54183faSAmir Goldstein } 50640a100d3SAmir Goldstein } else if (mask & FS_EVENT_ON_CHILD) { 50740a100d3SAmir Goldstein /* 508fecc4559SAmir Goldstein * Event on child - report on TYPE_PARENT to dir if it is 509fecc4559SAmir Goldstein * watching children and on TYPE_INODE to child. 51040a100d3SAmir Goldstein */ 511e54183faSAmir Goldstein inode2 = dir; 512e54183faSAmir Goldstein inode2_type = FSNOTIFY_ITER_TYPE_PARENT; 51340a100d3SAmir Goldstein } 514497b0c5aSAmir Goldstein 515613a807fSEric Paris /* 5167c49b861SDave Hansen * Optimization: srcu_read_lock() has a memory barrier which can 5177c49b861SDave Hansen * be expensive. It protects walking the *_fsnotify_marks lists. 5187c49b861SDave Hansen * However, if we do not walk the lists, we do not have to do 5197c49b861SDave Hansen * SRCU because we have no references to any objects and do not 5207c49b861SDave Hansen * need SRCU to keep them "alive". 5217c49b861SDave Hansen */ 5229b93f331SAmir Goldstein if (!sb->s_fsnotify_marks && 523497b0c5aSAmir Goldstein (!mnt || !mnt->mnt_fsnotify_marks) && 5249b93f331SAmir Goldstein (!inode || !inode->i_fsnotify_marks) && 525e54183faSAmir Goldstein (!inode2 || !inode2->i_fsnotify_marks)) 5267c49b861SDave Hansen return 0; 52771d73410SMel Gorman 5289b93f331SAmir Goldstein marks_mask = sb->s_fsnotify_mask; 52971d73410SMel Gorman if (mnt) 53071d73410SMel Gorman marks_mask |= mnt->mnt_fsnotify_mask; 5319b93f331SAmir Goldstein if (inode) 5329b93f331SAmir Goldstein marks_mask |= inode->i_fsnotify_mask; 533e54183faSAmir Goldstein if (inode2) 534e54183faSAmir Goldstein marks_mask |= inode2->i_fsnotify_mask; 535497b0c5aSAmir Goldstein 53671d73410SMel Gorman 5377c49b861SDave Hansen /* 538*31a371e4SAmir Goldstein * If this is a modify event we may need to clear some ignore masks. 539*31a371e4SAmir Goldstein * In that case, the object with ignore masks will have the FS_MODIFY 54004e317baSAmir Goldstein * event in its mask. 54104e317baSAmir Goldstein * Otherwise, return if none of the marks care about this type of event. 542613a807fSEric Paris */ 54371d73410SMel Gorman test_mask = (mask & ALL_FSNOTIFY_EVENTS); 54404e317baSAmir Goldstein if (!(test_mask & marks_mask)) 545613a807fSEric Paris return 0; 5463a9fb89fSEric Paris 5479385a84dSJan Kara iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); 5487131485aSEric Paris 5491c9007d6SAmir Goldstein iter_info.marks[FSNOTIFY_ITER_TYPE_SB] = 55045a9fb37SAmir Goldstein fsnotify_first_mark(&sb->s_fsnotify_marks); 5519bdda4e9SAmir Goldstein if (mnt) { 5521c9007d6SAmir Goldstein iter_info.marks[FSNOTIFY_ITER_TYPE_VFSMOUNT] = 5533427ce71SMiklos Szeredi fsnotify_first_mark(&mnt->mnt_fsnotify_marks); 5547131485aSEric Paris } 5559b93f331SAmir Goldstein if (inode) { 5561c9007d6SAmir Goldstein iter_info.marks[FSNOTIFY_ITER_TYPE_INODE] = 5579b93f331SAmir Goldstein fsnotify_first_mark(&inode->i_fsnotify_marks); 5589b93f331SAmir Goldstein } 559e54183faSAmir Goldstein if (inode2) { 560e54183faSAmir Goldstein iter_info.marks[inode2_type] = 561e54183faSAmir Goldstein fsnotify_first_mark(&inode2->i_fsnotify_marks); 562497b0c5aSAmir Goldstein } 56375c1be48SEric Paris 5648edc6e16SJan Kara /* 56560f7ed8cSAmir Goldstein * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark 56660f7ed8cSAmir Goldstein * ignore masks are properly reflected for mount/sb mark notifications. 5678edc6e16SJan Kara * That's why this traversal is so complicated... 5688edc6e16SJan Kara */ 569d9a6f30bSAmir Goldstein while (fsnotify_iter_select_report_types(&iter_info)) { 570b54cecf5SAmir Goldstein ret = send_to_group(mask, data, data_type, dir, file_name, 571b54cecf5SAmir Goldstein cookie, &iter_info); 57284a5b68eSEric Paris 573ff8bcbd0SEric Paris if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) 574ff8bcbd0SEric Paris goto out; 575ff8bcbd0SEric Paris 576d9a6f30bSAmir Goldstein fsnotify_iter_next(&iter_info); 5777131485aSEric Paris } 578ff8bcbd0SEric Paris ret = 0; 579ff8bcbd0SEric Paris out: 5809385a84dSJan Kara srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx); 581c4ec54b4SEric Paris 58298b5c10dSJean-Christophe Dubois return ret; 58390586523SEric Paris } 58490586523SEric Paris EXPORT_SYMBOL_GPL(fsnotify); 58590586523SEric Paris 58690586523SEric Paris static __init int fsnotify_init(void) 58790586523SEric Paris { 58875c1be48SEric Paris int ret; 58975c1be48SEric Paris 59038035c04SAmir Goldstein BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 23); 59120dee624SEric Paris 59275c1be48SEric Paris ret = init_srcu_struct(&fsnotify_mark_srcu); 59375c1be48SEric Paris if (ret) 59475c1be48SEric Paris panic("initializing fsnotify_mark_srcu"); 59575c1be48SEric Paris 5969dd813c1SJan Kara fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector, 5979dd813c1SJan Kara SLAB_PANIC); 5989dd813c1SJan Kara 59975c1be48SEric Paris return 0; 60090586523SEric Paris } 60175c1be48SEric Paris core_initcall(fsnotify_init); 602