c82ee6d3beaa4 (Thomas Gleixner 2019-05-19 15:51:48 +0200 1) // SPDX-License-Identifier: GPL-2.0-or-later
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 2) /*
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 3) * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 4) */
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 5)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 6) #include <linux/dcache.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 7) #include <linux/fs.h>
5a0e3ad6af866 (Tejun Heo 2010-03-24 17:04:11 +0900 8) #include <linux/gfp.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 9) #include <linux/init.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 10) #include <linux/module.h>
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 11) #include <linux/mount.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 12) #include <linux/srcu.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 13)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 14) #include <linux/fsnotify_backend.h>
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 15) #include "fsnotify.h"
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 16)
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 17) /*
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 18) * Clear all of the marks on an inode when it is being evicted from core
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 19) */
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 20) void __fsnotify_inode_delete(struct inode *inode)
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 21) {
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 22) fsnotify_clear_marks_by_inode(inode);
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 23) }
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 24) EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
3be25f49b9d6a (Eric Paris 2009-05-21 17:01:26 -0400 25)
ca9c726eea013 (Andreas Gruenbacher 2009-12-17 21:24:27 -0500 26) void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
ca9c726eea013 (Andreas Gruenbacher 2009-12-17 21:24:27 -0500 27) {
ca9c726eea013 (Andreas Gruenbacher 2009-12-17 21:24:27 -0500 28) fsnotify_clear_marks_by_mount(mnt);
ca9c726eea013 (Andreas Gruenbacher 2009-12-17 21:24:27 -0500 29) }
ca9c726eea013 (Andreas Gruenbacher 2009-12-17 21:24:27 -0500 30)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 31) /**
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 32) * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 33) * @sb: superblock being unmounted.
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 34) *
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 35) * Called during unmount with no locks held, so needs to be safe against
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 36) * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 37) */
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 38) static void fsnotify_unmount_inodes(struct super_block *sb)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 39) {
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 40) struct inode *inode, *iput_inode = NULL;
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 41)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 42) spin_lock(&sb->s_inode_list_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 43) list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 44) /*
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 45) * We cannot __iget() an inode in state I_FREEING,
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 46) * I_WILL_FREE, or I_NEW which is fine because by that point
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 47) * the inode cannot have any associated watches.
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 48) */
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 49) spin_lock(&inode->i_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 50) if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 51) spin_unlock(&inode->i_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 52) continue;
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 53) }
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 54)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 55) /*
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 56) * If i_count is zero, the inode cannot have any watches and
1751e8a6cb935 (Linus Torvalds 2017-11-27 13:05:09 -0800 57) * doing an __iget/iput with SB_ACTIVE clear would actually
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 58) * evict all inodes with zero i_count from icache which is
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 59) * unnecessarily violent and may in fact be illegal to do.
1edc8eb2e9313 (Eric Sandeen 2019-12-06 10:55:59 -0600 60) * However, we should have been called /after/ evict_inodes
1edc8eb2e9313 (Eric Sandeen 2019-12-06 10:55:59 -0600 61) * removed all zero refcount inodes, in any case. Test to
1edc8eb2e9313 (Eric Sandeen 2019-12-06 10:55:59 -0600 62) * be sure.
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 63) */
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 64) if (!atomic_read(&inode->i_count)) {
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 65) spin_unlock(&inode->i_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 66) continue;
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 67) }
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 68)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 69) __iget(inode);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 70) spin_unlock(&inode->i_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 71) spin_unlock(&sb->s_inode_list_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 72)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 73) if (iput_inode)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 74) iput(iput_inode);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 75)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 76) /* for each watch, send FS_UNMOUNT and then remove it */
82ace1efb3cb1 (Amir Goldstein 2020-07-22 15:58:44 +0300 77) fsnotify_inode(inode, FS_UNMOUNT);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 78)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 79) fsnotify_inode_delete(inode);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 80)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 81) iput_inode = inode;
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 82)
04646aebd30b9 (Eric Sandeen 2019-12-06 10:54:23 -0600 83) cond_resched();
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 84) spin_lock(&sb->s_inode_list_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 85) }
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 86) spin_unlock(&sb->s_inode_list_lock);
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 87)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 88) if (iput_inode)
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 89) iput(iput_inode);
721fb6fbfd213 (Jan Kara 2018-10-17 13:07:05 +0200 90) /* Wait for outstanding inode references from connectors */
721fb6fbfd213 (Jan Kara 2018-10-17 13:07:05 +0200 91) wait_var_event(&sb->s_fsnotify_inode_refs,
721fb6fbfd213 (Jan Kara 2018-10-17 13:07:05 +0200 92) !atomic_long_read(&sb->s_fsnotify_inode_refs));
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 93) }
ebb3b47e37a4c (Jan Kara 2016-12-21 16:40:48 +0100 94)
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 95) void fsnotify_sb_delete(struct super_block *sb)
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 96) {
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 97) fsnotify_unmount_inodes(sb);
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 98) fsnotify_clear_marks_by_sb(sb);
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 99) }
1e6cb72399fd5 (Amir Goldstein 2018-09-01 10:41:11 +0300 100)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 101) /*
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 102) * Given an inode, first check if we care what happens to our children. Inotify
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 103) * and dnotify both tell their parents about events. If we care about any event
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 104) * on a child we run all of our children and set a dentry flag saying that the
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 105) * parent cares. Thus when an event happens on a child it can quickly tell if
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 106) * if there is a need to find a parent and send the event to the parent.
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 107) */
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 108) void __fsnotify_update_child_dentry_flags(struct inode *inode)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 109) {
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 110) struct dentry *alias;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 111) int watched;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 112)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 113) if (!S_ISDIR(inode->i_mode))
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 114) return;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 115)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 116) /* determine if the children should tell inode about their events */
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 117) watched = fsnotify_inode_watches_children(inode);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 118)
873feea09ebc9 (Nicholas Piggin 2011-01-07 17:50:06 +1100 119) spin_lock(&inode->i_lock);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 120) /* run all of the dentries associated with this inode. Since this is a
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 121) * directory, there damn well better only be one item on this list */
946e51f2bf37f (Al Viro 2014-10-26 19:19:16 -0400 122) hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 123) struct dentry *child;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 124)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 125) /* run all of the children of the original inode and fix their
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 126) * d_flags to indicate parental interest (their parent is the
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 127) * original inode) */
2fd6b7f50797f (Nicholas Piggin 2011-01-07 17:49:34 +1100 128) spin_lock(&alias->d_lock);
946e51f2bf37f (Al Viro 2014-10-26 19:19:16 -0400 129) list_for_each_entry(child, &alias->d_subdirs, d_child) {
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 130) if (!child->d_inode)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 131) continue;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 132)
2fd6b7f50797f (Nicholas Piggin 2011-01-07 17:49:34 +1100 133) spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 134) if (watched)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 135) child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 136) else
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 137) child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 138) spin_unlock(&child->d_lock);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 139) }
2fd6b7f50797f (Nicholas Piggin 2011-01-07 17:49:34 +1100 140) spin_unlock(&alias->d_lock);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 141) }
873feea09ebc9 (Nicholas Piggin 2011-01-07 17:50:06 +1100 142) spin_unlock(&inode->i_lock);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 143) }
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 144)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 145) /* Are inode/sb/mount interested in parent and name info with this event? */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 146) static bool fsnotify_event_needs_parent(struct inode *inode, struct mount *mnt,
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 147) __u32 mask)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 148) {
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 149) __u32 marks_mask = 0;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 150)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 151) /* We only send parent/name to inode/sb/mount for events on non-dir */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 152) if (mask & FS_ISDIR)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 153) return false;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 154)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 155) /*
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 156) * All events that are possible on child can also may be reported with
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 157) * parent/name info to inode/sb/mount. Otherwise, a watching parent
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 158) * could result in events reported with unexpected name info to sb/mount.
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 159) */
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 160) BUILD_BUG_ON(FS_EVENTS_POSS_ON_CHILD & ~FS_EVENTS_POSS_TO_PARENT);
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 161)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 162) /* Did either inode/sb/mount subscribe for events with parent/name? */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 163) marks_mask |= fsnotify_parent_needed_mask(inode->i_fsnotify_mask);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 164) marks_mask |= fsnotify_parent_needed_mask(inode->i_sb->s_fsnotify_mask);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 165) if (mnt)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 166) marks_mask |= fsnotify_parent_needed_mask(mnt->mnt_fsnotify_mask);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 167)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 168) /* Did they subscribe for this event with parent/name info? */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 169) return mask & marks_mask;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 170) }
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 171)
c738fbabb0ff6 (Amir Goldstein 2020-07-08 14:11:37 +0300 172) /*
c738fbabb0ff6 (Amir Goldstein 2020-07-08 14:11:37 +0300 173) * Notify this dentry's parent about a child's events with child name info
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 174) * if parent is watching or if inode/sb/mount are interested in events with
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 175) * parent and name info.
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 176) *
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 177) * Notify only the child without name info if parent is not watching and
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 178) * inode/sb/mount are not interested in events with parent and name info.
c738fbabb0ff6 (Amir Goldstein 2020-07-08 14:11:37 +0300 179) */
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 180) int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
c738fbabb0ff6 (Amir Goldstein 2020-07-08 14:11:37 +0300 181) int data_type)
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 182) {
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 183) const struct path *path = fsnotify_data_path(data, data_type);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 184) struct mount *mnt = path ? real_mount(path->mnt) : NULL;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 185) struct inode *inode = d_inode(dentry);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 186) struct dentry *parent;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 187) bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED;
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 188) bool parent_needed, parent_interested;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 189) __u32 p_mask;
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 190) struct inode *p_inode = NULL;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 191) struct name_snapshot name;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 192) struct qstr *file_name = NULL;
52420392c81c8 (Eric Paris 2010-10-28 17:21:56 -0400 193) int ret = 0;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 194)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 195) /*
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 196) * Do inode/sb/mount care about parent and name info on non-dir?
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 197) * Do they care about any event at all?
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 198) */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 199) if (!inode->i_fsnotify_marks && !inode->i_sb->s_fsnotify_marks &&
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 200) (!mnt || !mnt->mnt_fsnotify_marks) && !parent_watched)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 201) return 0;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 202)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 203) parent = NULL;
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 204) parent_needed = fsnotify_event_needs_parent(inode, mnt, mask);
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 205) if (!parent_watched && !parent_needed)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 206) goto notify;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 207)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 208) /* Does parent inode care about events on children? */
4d4eb36679adb (Christoph Hellwig 2010-10-10 05:36:30 -0400 209) parent = dget_parent(dentry);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 210) p_inode = parent->d_inode;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 211) p_mask = fsnotify_inode_watches_children(p_inode);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 212) if (unlikely(parent_watched && !p_mask))
4d4eb36679adb (Christoph Hellwig 2010-10-10 05:36:30 -0400 213) __fsnotify_update_child_dentry_flags(p_inode);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 214)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 215) /*
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 216) * Include parent/name in notification either if some notification
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 217) * groups require parent info or the parent is interested in this event.
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 218) */
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 219) parent_interested = mask & p_mask & ALL_FSNOTIFY_EVENTS;
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 220) if (parent_needed || parent_interested) {
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 221) /* When notifying parent, child should be passed as data */
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 222) WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type));
49d31c2f389ac (Al Viro 2017-07-07 14:51:19 -0400 223)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 224) /* Notify both parent and child with child name info */
49d31c2f389ac (Al Viro 2017-07-07 14:51:19 -0400 225) take_dentry_name_snapshot(&name, dentry);
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 226) file_name = &name.name;
7372e79c9eb9d (Amir Goldstein 2020-11-08 12:59:06 +0200 227) if (parent_interested)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 228) mask |= FS_EVENT_ON_CHILD;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 229) }
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 230)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 231) notify:
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 232) ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0);
52420392c81c8 (Eric Paris 2010-10-28 17:21:56 -0400 233)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 234) if (file_name)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 235) release_dentry_name_snapshot(&name);
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 236) dput(parent);
c738fbabb0ff6 (Amir Goldstein 2020-07-08 14:11:37 +0300 237)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 238) return ret;
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 239) }
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 240) EXPORT_SYMBOL_GPL(__fsnotify_parent);
c28f7e56e9d95 (Eric Paris 2009-05-21 17:01:29 -0400 241)
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 242) static int fsnotify_handle_inode_event(struct fsnotify_group *group,
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 243) struct fsnotify_mark *inode_mark,
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 244) u32 mask, const void *data, int data_type,
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 245) struct inode *dir, const struct qstr *name,
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 246) u32 cookie)
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 247) {
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 248) const struct path *path = fsnotify_data_path(data, data_type);
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 249) struct inode *inode = fsnotify_data_inode(data, data_type);
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 250) const struct fsnotify_ops *ops = group->ops;
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 251)
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 252) if (WARN_ON_ONCE(!ops->handle_inode_event))
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 253) return 0;
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 254)
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 255) if ((inode_mark->mask & FS_EXCL_UNLINK) &&
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 256) path && d_unlinked(path->dentry))
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 257) return 0;
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 258)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 259) /* Check interest of this mark in case event was sent with two marks */
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 260) if (!(mask & inode_mark->mask & ALL_FSNOTIFY_EVENTS))
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 261) return 0;
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 262)
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 263) return ops->handle_inode_event(inode_mark, mask, inode, dir, name, cookie);
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 264) }
950cc0d2bef07 (Amir Goldstein 2020-12-02 14:07:07 +0200 265)
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 266) static int fsnotify_handle_event(struct fsnotify_group *group, __u32 mask,
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 267) const void *data, int data_type,
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 268) struct inode *dir, const struct qstr *name,
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 269) u32 cookie, struct fsnotify_iter_info *iter_info)
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 270) {
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 271) struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 272) struct fsnotify_mark *parent_mark = fsnotify_iter_parent_mark(iter_info);
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 273) int ret;
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 274)
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 275) if (WARN_ON_ONCE(fsnotify_iter_sb_mark(iter_info)) ||
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 276) WARN_ON_ONCE(fsnotify_iter_vfsmount_mark(iter_info)))
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 277) return 0;
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 278)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 279) if (parent_mark) {
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 280) /*
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 281) * parent_mark indicates that the parent inode is watching
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 282) * children and interested in this event, which is an event
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 283) * possible on child. But is *this mark* watching children and
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 284) * interested in this event?
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 285) */
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 286) if (parent_mark->mask & FS_EVENT_ON_CHILD) {
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 287) ret = fsnotify_handle_inode_event(group, parent_mark, mask,
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 288) data, data_type, dir, name, 0);
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 289) if (ret)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 290) return ret;
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 291) }
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 292) if (!inode_mark)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 293) return 0;
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 294) }
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 295)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 296) if (mask & FS_EVENT_ON_CHILD) {
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 297) /*
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 298) * Some events can be sent on both parent dir and child marks
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 299) * (e.g. FS_ATTRIB). If both parent dir and child are
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 300) * watching, report the event once to parent dir with name (if
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 301) * interested) and once to child without name (if interested).
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 302) * The child watcher is expecting an event without a file name
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 303) * and without the FS_EVENT_ON_CHILD flag.
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 304) */
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 305) mask &= ~FS_EVENT_ON_CHILD;
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 306) dir = NULL;
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 307) name = NULL;
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 308) }
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 309)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 310) return fsnotify_handle_inode_event(group, inode_mark, mask, data, data_type,
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 311) dir, name, cookie);
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 312) }
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 313)
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 314) static int send_to_group(__u32 mask, const void *data, int data_type,
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 315) struct inode *dir, const struct qstr *file_name,
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 316) u32 cookie, struct fsnotify_iter_info *iter_info)
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 317) {
faa9560ae76ef (Eric Paris 2010-08-18 12:25:49 -0400 318) struct fsnotify_group *group = NULL;
007d1e8395eaa (Amir Goldstein 2018-10-04 00:25:33 +0300 319) __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS);
92183a42898dc (Amir Goldstein 2018-04-05 16:18:03 +0300 320) __u32 marks_mask = 0;
92183a42898dc (Amir Goldstein 2018-04-05 16:18:03 +0300 321) __u32 marks_ignored_mask = 0;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 322) struct fsnotify_mark *mark;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 323) int type;
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 324)
5b0457ad021f3 (Amir Goldstein 2018-04-20 16:10:50 -0700 325) if (WARN_ON(!iter_info->report_mask))
faa9560ae76ef (Eric Paris 2010-08-18 12:25:49 -0400 326) return 0;
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 327)
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 328) /* clear ignored on inode modification */
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 329) if (mask & FS_MODIFY) {
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 330) fsnotify_foreach_obj_type(type) {
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 331) if (!fsnotify_iter_should_report_type(iter_info, type))
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 332) continue;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 333) mark = iter_info->marks[type];
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 334) if (mark &&
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 335) !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 336) mark->ignored_mask = 0;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 337) }
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 338) }
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 339)
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 340) fsnotify_foreach_obj_type(type) {
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 341) if (!fsnotify_iter_should_report_type(iter_info, type))
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 342) continue;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 343) mark = iter_info->marks[type];
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 344) /* does the object mark tell us to do something? */
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 345) if (mark) {
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 346) group = mark->group;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 347) marks_mask |= mark->mask;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 348) marks_ignored_mask |= mark->ignored_mask;
3dca1a7494e32 (Amir Goldstein 2018-04-20 16:10:53 -0700 349) }
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 350) }
ce8f76fb73202 (Eric Paris 2010-07-28 10:18:39 -0400 351)
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 352) pr_debug("%s: group=%p mask=%x marks_mask=%x marks_ignored_mask=%x data=%p data_type=%d dir=%p cookie=%d\n",
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 353) __func__, group, mask, marks_mask, marks_ignored_mask,
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 354) data, data_type, dir, cookie);
faa9560ae76ef (Eric Paris 2010-08-18 12:25:49 -0400 355)
92183a42898dc (Amir Goldstein 2018-04-05 16:18:03 +0300 356) if (!(test_mask & marks_mask & ~marks_ignored_mask))
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 357) return 0;
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 358)
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 359) if (group->ops->handle_event) {
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 360) return group->ops->handle_event(group, mask, data, data_type, dir,
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 361) file_name, cookie, iter_info);
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 362) }
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 363)
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 364) return fsnotify_handle_event(group, mask, data, data_type, dir,
b9a1b9772509c (Amir Goldstein 2020-07-22 15:58:48 +0300 365) file_name, cookie, iter_info);
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 366) }
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 367)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 368) static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 369) {
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 370) struct fsnotify_mark_connector *conn;
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 371) struct hlist_node *node = NULL;
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 372)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 373) conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 374) if (conn)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 375) node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 376)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 377) return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 378) }
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 379)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 380) static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 381) {
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 382) struct hlist_node *node = NULL;
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 383)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 384) if (mark)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 385) node = srcu_dereference(mark->obj_list.next,
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 386) &fsnotify_mark_srcu);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 387)
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 388) return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 389) }
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 390)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 391) /*
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 392) * iter_info is a multi head priority queue of marks.
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 393) * Pick a subset of marks from queue heads, all with the
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 394) * same group and set the report_mask for selected subset.
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 395) * Returns the report_mask of the selected subset.
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 396) */
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 397) static unsigned int fsnotify_iter_select_report_types(
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 398) struct fsnotify_iter_info *iter_info)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 399) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 400) struct fsnotify_group *max_prio_group = NULL;
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 401) struct fsnotify_mark *mark;
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 402) int type;
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 403)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 404) /* Choose max prio group among groups of all queue heads */
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 405) fsnotify_foreach_obj_type(type) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 406) mark = iter_info->marks[type];
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 407) if (mark &&
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 408) fsnotify_compare_groups(max_prio_group, mark->group) > 0)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 409) max_prio_group = mark->group;
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 410) }
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 411)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 412) if (!max_prio_group)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 413) return 0;
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 414)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 415) /* Set the report mask for marks from same group as max prio group */
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 416) iter_info->report_mask = 0;
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 417) fsnotify_foreach_obj_type(type) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 418) mark = iter_info->marks[type];
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 419) if (mark &&
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 420) fsnotify_compare_groups(max_prio_group, mark->group) == 0)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 421) fsnotify_iter_set_report_type(iter_info, type);
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 422) }
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 423)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 424) return iter_info->report_mask;
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 425) }
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 426)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 427) /*
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 428) * Pop from iter_info multi head queue, the marks that were iterated in the
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 429) * current iteration step.
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 430) */
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 431) static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 432) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 433) int type;
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 434)
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 435) fsnotify_foreach_obj_type(type) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 436) if (fsnotify_iter_should_report_type(iter_info, type))
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 437) iter_info->marks[type] =
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 438) fsnotify_next_mark(iter_info->marks[type]);
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 439) }
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 440) }
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 441)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 442) /*
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 443) * fsnotify - This is the main call to fsnotify.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 444) *
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 445) * The VFS calls into hook specific functions in linux/fsnotify.h.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 446) * Those functions then in turn call here. Here will call out to all of the
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 447) * registered fsnotify_group. Those groups can then use the notification event
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 448) * in whatever means they feel necessary.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 449) *
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 450) * @mask: event type and flags
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 451) * @data: object that event happened on
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 452) * @data_type: type of object for fanotify_data_XXX() accessors
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 453) * @dir: optional directory associated with event -
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 454) * if @file_name is not NULL, this is the directory that
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 455) * @file_name is relative to
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 456) * @file_name: optional file name associated with event
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 457) * @inode: optional inode associated with event -
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 458) * either @dir or @inode must be non-NULL.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 459) * if both are non-NULL event may be reported to both.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 460) * @cookie: inotify rename cookie
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 461) */
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 462) int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 463) const struct qstr *file_name, struct inode *inode, u32 cookie)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 464) {
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 465) const struct path *path = fsnotify_data_path(data, data_type);
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 466) struct fsnotify_iter_info iter_info = {};
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 467) struct super_block *sb;
60f7ed8c7c4d0 (Amir Goldstein 2018-09-01 10:41:12 +0300 468) struct mount *mnt = NULL;
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 469) struct inode *parent = NULL;
9385a84d7e1f6 (Jan Kara 2016-11-10 17:51:50 +0100 470) int ret = 0;
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 471) __u32 test_mask, marks_mask;
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 472)
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 473) if (path)
aa93bdc5500cc (Amir Goldstein 2020-03-19 17:10:12 +0200 474) mnt = real_mount(path->mnt);
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 475)
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 476) if (!inode) {
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 477) /* Dirent event - report on TYPE_INODE to dir */
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 478) inode = dir;
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 479) } else if (mask & FS_EVENT_ON_CHILD) {
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 480) /*
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 481) * Event on child - report on TYPE_PARENT to dir if it is
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 482) * watching children and on TYPE_INODE to child.
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 483) */
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 484) parent = dir;
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 485) }
40a100d3adc1a (Amir Goldstein 2020-07-22 15:58:46 +0300 486) sb = inode->i_sb;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 487)
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 488) /*
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 489) * Optimization: srcu_read_lock() has a memory barrier which can
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 490) * be expensive. It protects walking the *_fsnotify_marks lists.
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 491) * However, if we do not walk the lists, we do not have to do
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 492) * SRCU because we have no references to any objects and do not
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 493) * need SRCU to keep them "alive".
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 494) */
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 495) if (!sb->s_fsnotify_marks &&
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 496) (!mnt || !mnt->mnt_fsnotify_marks) &&
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 497) (!inode || !inode->i_fsnotify_marks) &&
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 498) (!parent || !parent->i_fsnotify_marks))
7c49b8616460e (Dave Hansen 2015-09-04 15:43:01 -0700 499) return 0;
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 500)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 501) marks_mask = sb->s_fsnotify_mask;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 502) if (mnt)
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 503) marks_mask |= mnt->mnt_fsnotify_mask;
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 504) if (inode)
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 505) marks_mask |= inode->i_fsnotify_mask;
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 506) if (parent)
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 507) marks_mask |= parent->i_fsnotify_mask;
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 508)
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 509)
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 510) /*
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 511) * if this is a modify event we may need to clear the ignored masks
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 512) * otherwise return if none of the marks care about this type of event.
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 513) */
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 514) test_mask = (mask & ALL_FSNOTIFY_EVENTS);
71d734103edfa (Mel Gorman 2020-07-08 14:11:36 +0300 515) if (!(mask & FS_MODIFY) && !(test_mask & marks_mask))
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 516) return 0;
3a9fb89f4cd04 (Eric Paris 2009-12-17 21:24:23 -0500 517)
9385a84d7e1f6 (Jan Kara 2016-11-10 17:51:50 +0100 518) iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 519)
45a9fb3725d88 (Amir Goldstein 2019-01-10 19:04:30 +0200 520) iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] =
45a9fb3725d88 (Amir Goldstein 2019-01-10 19:04:30 +0200 521) fsnotify_first_mark(&sb->s_fsnotify_marks);
9bdda4e9cf2dc (Amir Goldstein 2018-09-01 09:40:01 +0300 522) if (mnt) {
47d9c7cc457ad (Amir Goldstein 2018-04-20 16:10:52 -0700 523) iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] =
3427ce7155412 (Miklos Szeredi 2017-10-30 21:14:56 +0100 524) fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 525) }
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 526) if (inode) {
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 527) iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] =
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 528) fsnotify_first_mark(&inode->i_fsnotify_marks);
9b93f33105f5f (Amir Goldstein 2020-07-16 11:42:23 +0300 529) }
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 530) if (parent) {
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 531) iter_info.marks[FSNOTIFY_OBJ_TYPE_PARENT] =
fecc4559780d5 (Amir Goldstein 2020-12-02 14:07:09 +0200 532) fsnotify_first_mark(&parent->i_fsnotify_marks);
497b0c5a7c068 (Amir Goldstein 2020-07-16 11:42:22 +0300 533) }
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 534)
8edc6e1688fc8 (Jan Kara 2014-11-13 15:19:33 -0800 535) /*
60f7ed8c7c4d0 (Amir Goldstein 2018-09-01 10:41:12 +0300 536) * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark
60f7ed8c7c4d0 (Amir Goldstein 2018-09-01 10:41:12 +0300 537) * ignore masks are properly reflected for mount/sb mark notifications.
8edc6e1688fc8 (Jan Kara 2014-11-13 15:19:33 -0800 538) * That's why this traversal is so complicated...
8edc6e1688fc8 (Jan Kara 2014-11-13 15:19:33 -0800 539) */
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 540) while (fsnotify_iter_select_report_types(&iter_info)) {
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 541) ret = send_to_group(mask, data, data_type, dir, file_name,
b54cecf5e2293 (Amir Goldstein 2020-06-07 12:10:40 +0300 542) cookie, &iter_info);
613a807fe7c79 (Eric Paris 2010-07-28 10:18:39 -0400 543)
ff8bcbd03da88 (Eric Paris 2010-10-28 17:21:56 -0400 544) if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
ff8bcbd03da88 (Eric Paris 2010-10-28 17:21:56 -0400 545) goto out;
ff8bcbd03da88 (Eric Paris 2010-10-28 17:21:56 -0400 546)
d9a6f30bb8930 (Amir Goldstein 2018-04-20 16:10:51 -0700 547) fsnotify_iter_next(&iter_info);
7131485a93679 (Eric Paris 2009-12-17 21:24:23 -0500 548) }
ff8bcbd03da88 (Eric Paris 2010-10-28 17:21:56 -0400 549) ret = 0;
ff8bcbd03da88 (Eric Paris 2010-10-28 17:21:56 -0400 550) out:
9385a84d7e1f6 (Jan Kara 2016-11-10 17:51:50 +0100 551) srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx);
c4ec54b40d33f (Eric Paris 2009-12-17 21:24:34 -0500 552)
98b5c10d320ad (Jean-Christophe Dubois 2010-03-23 08:08:09 +0100 553) return ret;
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 554) }
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 555) EXPORT_SYMBOL_GPL(fsnotify);
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 556)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 557) static __init int fsnotify_init(void)
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 558) {
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 559) int ret;
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 560)
08b95c338e0c5 (Amir Goldstein 2020-07-08 14:11:52 +0300 561) BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25);
20dee624ca40d (Eric Paris 2010-07-28 10:18:37 -0400 562)
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 563) ret = init_srcu_struct(&fsnotify_mark_srcu);
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 564) if (ret)
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 565) panic("initializing fsnotify_mark_srcu");
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 566)
9dd813c15b2c1 (Jan Kara 2017-03-14 12:31:02 +0100 567) fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
9dd813c15b2c1 (Jan Kara 2017-03-14 12:31:02 +0100 568) SLAB_PANIC);
9dd813c15b2c1 (Jan Kara 2017-03-14 12:31:02 +0100 569)
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 570) return 0;
90586523eb4b3 (Eric Paris 2009-05-21 17:01:20 -0400 571) }
75c1be487a690 (Eric Paris 2010-07-28 10:18:38 -0400 572) core_initcall(fsnotify_init);
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
More than 9999 Commits
32 Branches
54 Tags