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Merge tag 'fsnotify_for_v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify updates from Jan Kara:
- support for limited fanotify functionality for unpriviledged users
- faster merging of fanotify events
- a few smaller fsnotify improvements
* tag 'fsnotify_for_v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
shmem: allow reporting fanotify events with file handles on tmpfs
fs: introduce a wrapper uuid_to_fsid()
fanotify_user: use upper_32_bits() to verify mask
fanotify: support limited functionality for unprivileged users
fanotify: configurable limits via sysfs
fanotify: limit number of event merge attempts
fsnotify: use hash table for faster events merge
fanotify: mix event info and pid into merge key hash
fanotify: reduce event objectid to 29-bit hash
fsnotify: allow fsnotify_{peek,remove}_first_event with empty queue
This commit is contained in:
Linus Torvalds
commit
3644286f6c
@ -1399,7 +1399,6 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
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struct super_block *sb = dentry->d_sb;
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struct ext2_sb_info *sbi = EXT2_SB(sb);
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struct ext2_super_block *es = sbi->s_es;
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u64 fsid;
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spin_lock(&sbi->s_lock);
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@ -1453,9 +1452,7 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
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buf->f_ffree = ext2_count_free_inodes(sb);
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es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
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buf->f_namelen = EXT2_NAME_LEN;
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fsid = le64_to_cpup((void *)es->s_uuid) ^
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le64_to_cpup((void *)es->s_uuid + sizeof(u64));
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buf->f_fsid = u64_to_fsid(fsid);
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buf->f_fsid = uuid_to_fsid(es->s_uuid);
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spin_unlock(&sbi->s_lock);
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return 0;
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}
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@ -6153,7 +6153,6 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct ext4_super_block *es = sbi->s_es;
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ext4_fsblk_t overhead = 0, resv_blocks;
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u64 fsid;
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s64 bfree;
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resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
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@ -6174,9 +6173,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
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buf->f_files = le32_to_cpu(es->s_inodes_count);
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buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
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buf->f_namelen = EXT4_NAME_LEN;
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fsid = le64_to_cpup((void *)es->s_uuid) ^
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le64_to_cpup((void *)es->s_uuid + sizeof(u64));
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buf->f_fsid = u64_to_fsid(fsid);
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buf->f_fsid = uuid_to_fsid(es->s_uuid);
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#ifdef CONFIG_QUOTA
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if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
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@ -14,6 +14,7 @@
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#include <linux/audit.h>
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#include <linux/sched/mm.h>
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#include <linux/statfs.h>
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#include <linux/stringhash.h>
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#include "fanotify.h"
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@ -22,12 +23,24 @@ static bool fanotify_path_equal(struct path *p1, struct path *p2)
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return p1->mnt == p2->mnt && p1->dentry == p2->dentry;
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}
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static unsigned int fanotify_hash_path(const struct path *path)
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{
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return hash_ptr(path->dentry, FANOTIFY_EVENT_HASH_BITS) ^
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hash_ptr(path->mnt, FANOTIFY_EVENT_HASH_BITS);
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}
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static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
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__kernel_fsid_t *fsid2)
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{
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return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];
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}
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static unsigned int fanotify_hash_fsid(__kernel_fsid_t *fsid)
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{
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return hash_32(fsid->val[0], FANOTIFY_EVENT_HASH_BITS) ^
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hash_32(fsid->val[1], FANOTIFY_EVENT_HASH_BITS);
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}
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static bool fanotify_fh_equal(struct fanotify_fh *fh1,
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struct fanotify_fh *fh2)
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{
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@ -38,6 +51,16 @@ static bool fanotify_fh_equal(struct fanotify_fh *fh1,
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!memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len);
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}
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static unsigned int fanotify_hash_fh(struct fanotify_fh *fh)
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{
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long salt = (long)fh->type | (long)fh->len << 8;
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/*
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* full_name_hash() works long by long, so it handles fh buf optimally.
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*/
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return full_name_hash((void *)salt, fanotify_fh_buf(fh), fh->len);
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}
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static bool fanotify_fid_event_equal(struct fanotify_fid_event *ffe1,
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struct fanotify_fid_event *ffe2)
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{
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@ -88,16 +111,12 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
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return fanotify_info_equal(info1, info2);
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}
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static bool fanotify_should_merge(struct fsnotify_event *old_fsn,
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struct fsnotify_event *new_fsn)
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static bool fanotify_should_merge(struct fanotify_event *old,
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struct fanotify_event *new)
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{
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struct fanotify_event *old, *new;
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pr_debug("%s: old=%p new=%p\n", __func__, old, new);
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pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn);
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old = FANOTIFY_E(old_fsn);
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new = FANOTIFY_E(new_fsn);
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if (old_fsn->objectid != new_fsn->objectid ||
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if (old->hash != new->hash ||
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old->type != new->type || old->pid != new->pid)
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return false;
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@ -129,14 +148,20 @@ static bool fanotify_should_merge(struct fsnotify_event *old_fsn,
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return false;
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}
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/* and the list better be locked by something too! */
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static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
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{
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struct fsnotify_event *test_event;
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struct fanotify_event *new;
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/* Limit event merges to limit CPU overhead per event */
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#define FANOTIFY_MAX_MERGE_EVENTS 128
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pr_debug("%s: list=%p event=%p\n", __func__, list, event);
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new = FANOTIFY_E(event);
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/* and the list better be locked by something too! */
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static int fanotify_merge(struct fsnotify_group *group,
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struct fsnotify_event *event)
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{
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struct fanotify_event *old, *new = FANOTIFY_E(event);
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unsigned int bucket = fanotify_event_hash_bucket(group, new);
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struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket];
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int i = 0;
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pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,
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group, event, bucket);
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/*
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* Don't merge a permission event with any other event so that we know
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@ -146,9 +171,11 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
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if (fanotify_is_perm_event(new->mask))
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return 0;
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list_for_each_entry_reverse(test_event, list, list) {
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if (fanotify_should_merge(test_event, event)) {
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FANOTIFY_E(test_event)->mask |= new->mask;
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hlist_for_each_entry(old, hlist, merge_list) {
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if (++i > FANOTIFY_MAX_MERGE_EVENTS)
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break;
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if (fanotify_should_merge(old, new)) {
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old->mask |= new->mask;
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return 1;
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}
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}
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@ -184,8 +211,11 @@ static int fanotify_get_response(struct fsnotify_group *group,
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return ret;
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}
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/* Event not yet reported? Just remove it. */
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if (event->state == FAN_EVENT_INIT)
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if (event->state == FAN_EVENT_INIT) {
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fsnotify_remove_queued_event(group, &event->fae.fse);
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/* Permission events are not supposed to be hashed */
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WARN_ON_ONCE(!hlist_unhashed(&event->fae.merge_list));
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}
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/*
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* Event may be also answered in case signal delivery raced
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* with wakeup. In that case we have nothing to do besides
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@ -329,7 +359,8 @@ static int fanotify_encode_fh_len(struct inode *inode)
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* Return 0 on failure to encode.
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*/
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static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
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unsigned int fh_len, gfp_t gfp)
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unsigned int fh_len, unsigned int *hash,
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gfp_t gfp)
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{
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int dwords, type = 0;
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char *ext_buf = NULL;
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@ -372,6 +403,9 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
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fh->type = type;
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fh->len = fh_len;
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/* Mix fh into event merge key */
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*hash ^= fanotify_hash_fh(fh);
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return FANOTIFY_FH_HDR_LEN + fh_len;
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out_err:
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@ -425,6 +459,7 @@ static struct inode *fanotify_dfid_inode(u32 event_mask, const void *data,
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}
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static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
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unsigned int *hash,
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gfp_t gfp)
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{
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struct fanotify_path_event *pevent;
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@ -435,6 +470,7 @@ static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
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pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH;
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pevent->path = *path;
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*hash ^= fanotify_hash_path(path);
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path_get(path);
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return &pevent->fae;
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@ -460,6 +496,7 @@ static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
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static struct fanotify_event *fanotify_alloc_fid_event(struct inode *id,
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__kernel_fsid_t *fsid,
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unsigned int *hash,
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gfp_t gfp)
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{
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struct fanotify_fid_event *ffe;
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@ -470,16 +507,18 @@ static struct fanotify_event *fanotify_alloc_fid_event(struct inode *id,
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ffe->fae.type = FANOTIFY_EVENT_TYPE_FID;
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ffe->fsid = *fsid;
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*hash ^= fanotify_hash_fsid(fsid);
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fanotify_encode_fh(&ffe->object_fh, id, fanotify_encode_fh_len(id),
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gfp);
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hash, gfp);
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return &ffe->fae;
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}
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static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
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__kernel_fsid_t *fsid,
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const struct qstr *file_name,
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const struct qstr *name,
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struct inode *child,
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unsigned int *hash,
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gfp_t gfp)
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{
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struct fanotify_name_event *fne;
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@ -492,24 +531,30 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
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size = sizeof(*fne) + FANOTIFY_FH_HDR_LEN + dir_fh_len;
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if (child_fh_len)
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size += FANOTIFY_FH_HDR_LEN + child_fh_len;
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if (file_name)
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size += file_name->len + 1;
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if (name)
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size += name->len + 1;
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fne = kmalloc(size, gfp);
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if (!fne)
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return NULL;
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fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;
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fne->fsid = *fsid;
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*hash ^= fanotify_hash_fsid(fsid);
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info = &fne->info;
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fanotify_info_init(info);
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dfh = fanotify_info_dir_fh(info);
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info->dir_fh_totlen = fanotify_encode_fh(dfh, id, dir_fh_len, 0);
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info->dir_fh_totlen = fanotify_encode_fh(dfh, id, dir_fh_len, hash, 0);
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if (child_fh_len) {
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ffh = fanotify_info_file_fh(info);
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info->file_fh_totlen = fanotify_encode_fh(ffh, child, child_fh_len, 0);
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info->file_fh_totlen = fanotify_encode_fh(ffh, child,
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child_fh_len, hash, 0);
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}
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if (name) {
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long salt = name->len;
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fanotify_info_copy_name(info, name);
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*hash ^= full_name_hash((void *)salt, name->name, name->len);
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}
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if (file_name)
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fanotify_info_copy_name(info, file_name);
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|
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pr_debug("%s: ino=%lu size=%u dir_fh_len=%u child_fh_len=%u name_len=%u name='%.*s'\n",
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__func__, id->i_ino, size, dir_fh_len, child_fh_len,
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@ -533,6 +578,9 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
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struct mem_cgroup *old_memcg;
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struct inode *child = NULL;
|
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bool name_event = false;
|
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unsigned int hash = 0;
|
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bool ondir = mask & FAN_ONDIR;
|
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struct pid *pid;
|
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|
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if ((fid_mode & FAN_REPORT_DIR_FID) && dirid) {
|
||||
/*
|
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@ -540,8 +588,7 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
|
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* report the child fid for events reported on a non-dir child
|
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* in addition to reporting the parent fid and maybe child name.
|
||||
*/
|
||||
if ((fid_mode & FAN_REPORT_FID) &&
|
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id != dirid && !(mask & FAN_ONDIR))
|
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if ((fid_mode & FAN_REPORT_FID) && id != dirid && !ondir)
|
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child = id;
|
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|
||||
id = dirid;
|
||||
@ -562,8 +609,7 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
|
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if (!(fid_mode & FAN_REPORT_NAME)) {
|
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name_event = !!child;
|
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file_name = NULL;
|
||||
} else if ((mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
|
||||
!(mask & FAN_ONDIR)) {
|
||||
} else if ((mask & ALL_FSNOTIFY_DIRENT_EVENTS) || !ondir) {
|
||||
name_event = true;
|
||||
}
|
||||
}
|
||||
@ -586,26 +632,25 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
|
||||
event = fanotify_alloc_perm_event(path, gfp);
|
||||
} else if (name_event && (file_name || child)) {
|
||||
event = fanotify_alloc_name_event(id, fsid, file_name, child,
|
||||
gfp);
|
||||
&hash, gfp);
|
||||
} else if (fid_mode) {
|
||||
event = fanotify_alloc_fid_event(id, fsid, gfp);
|
||||
event = fanotify_alloc_fid_event(id, fsid, &hash, gfp);
|
||||
} else {
|
||||
event = fanotify_alloc_path_event(path, gfp);
|
||||
event = fanotify_alloc_path_event(path, &hash, gfp);
|
||||
}
|
||||
|
||||
if (!event)
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* Use the victim inode instead of the watching inode as the id for
|
||||
* event queue, so event reported on parent is merged with event
|
||||
* reported on child when both directory and child watches exist.
|
||||
*/
|
||||
fanotify_init_event(event, (unsigned long)id, mask);
|
||||
if (FAN_GROUP_FLAG(group, FAN_REPORT_TID))
|
||||
event->pid = get_pid(task_pid(current));
|
||||
pid = get_pid(task_pid(current));
|
||||
else
|
||||
event->pid = get_pid(task_tgid(current));
|
||||
pid = get_pid(task_tgid(current));
|
||||
|
||||
/* Mix event info, FAN_ONDIR flag and pid into event merge key */
|
||||
hash ^= hash_long((unsigned long)pid | ondir, FANOTIFY_EVENT_HASH_BITS);
|
||||
fanotify_init_event(event, hash, mask);
|
||||
event->pid = pid;
|
||||
|
||||
out:
|
||||
set_active_memcg(old_memcg);
|
||||
@ -645,6 +690,24 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info)
|
||||
return fsid;
|
||||
}
|
||||
|
||||
/*
|
||||
* Add an event to hash table for faster merge.
|
||||
*/
|
||||
static void fanotify_insert_event(struct fsnotify_group *group,
|
||||
struct fsnotify_event *fsn_event)
|
||||
{
|
||||
struct fanotify_event *event = FANOTIFY_E(fsn_event);
|
||||
unsigned int bucket = fanotify_event_hash_bucket(group, event);
|
||||
struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket];
|
||||
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
|
||||
pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,
|
||||
group, event, bucket);
|
||||
|
||||
hlist_add_head(&event->merge_list, hlist);
|
||||
}
|
||||
|
||||
static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
|
||||
const void *data, int data_type,
|
||||
struct inode *dir,
|
||||
@ -715,7 +778,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
|
||||
}
|
||||
|
||||
fsn_event = &event->fse;
|
||||
ret = fsnotify_add_event(group, fsn_event, fanotify_merge);
|
||||
ret = fsnotify_add_event(group, fsn_event, fanotify_merge,
|
||||
fanotify_is_hashed_event(mask) ?
|
||||
fanotify_insert_event : NULL);
|
||||
if (ret) {
|
||||
/* Permission events shouldn't be merged */
|
||||
BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS);
|
||||
@ -736,11 +801,10 @@ finish:
|
||||
|
||||
static void fanotify_free_group_priv(struct fsnotify_group *group)
|
||||
{
|
||||
struct user_struct *user;
|
||||
|
||||
user = group->fanotify_data.user;
|
||||
atomic_dec(&user->fanotify_listeners);
|
||||
free_uid(user);
|
||||
kfree(group->fanotify_data.merge_hash);
|
||||
if (group->fanotify_data.ucounts)
|
||||
dec_ucount(group->fanotify_data.ucounts,
|
||||
UCOUNT_FANOTIFY_GROUPS);
|
||||
}
|
||||
|
||||
static void fanotify_free_path_event(struct fanotify_event *event)
|
||||
@ -796,6 +860,13 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event)
|
||||
}
|
||||
}
|
||||
|
||||
static void fanotify_freeing_mark(struct fsnotify_mark *mark,
|
||||
struct fsnotify_group *group)
|
||||
{
|
||||
if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS))
|
||||
dec_ucount(group->fanotify_data.ucounts, UCOUNT_FANOTIFY_MARKS);
|
||||
}
|
||||
|
||||
static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
|
||||
{
|
||||
kmem_cache_free(fanotify_mark_cache, fsn_mark);
|
||||
@ -805,5 +876,6 @@ const struct fsnotify_ops fanotify_fsnotify_ops = {
|
||||
.handle_event = fanotify_handle_event,
|
||||
.free_group_priv = fanotify_free_group_priv,
|
||||
.free_event = fanotify_free_event,
|
||||
.freeing_mark = fanotify_freeing_mark,
|
||||
.free_mark = fanotify_free_mark,
|
||||
};
|
||||
|
||||
@ -3,6 +3,7 @@
|
||||
#include <linux/path.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/exportfs.h>
|
||||
#include <linux/hashtable.h>
|
||||
|
||||
extern struct kmem_cache *fanotify_mark_cache;
|
||||
extern struct kmem_cache *fanotify_fid_event_cachep;
|
||||
@ -115,6 +116,11 @@ static inline void fanotify_info_init(struct fanotify_info *info)
|
||||
info->name_len = 0;
|
||||
}
|
||||
|
||||
static inline unsigned int fanotify_info_len(struct fanotify_info *info)
|
||||
{
|
||||
return info->dir_fh_totlen + info->file_fh_totlen + info->name_len;
|
||||
}
|
||||
|
||||
static inline void fanotify_info_copy_name(struct fanotify_info *info,
|
||||
const struct qstr *name)
|
||||
{
|
||||
@ -135,19 +141,31 @@ enum fanotify_event_type {
|
||||
FANOTIFY_EVENT_TYPE_PATH,
|
||||
FANOTIFY_EVENT_TYPE_PATH_PERM,
|
||||
FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
|
||||
__FANOTIFY_EVENT_TYPE_NUM
|
||||
};
|
||||
|
||||
#define FANOTIFY_EVENT_TYPE_BITS \
|
||||
(ilog2(__FANOTIFY_EVENT_TYPE_NUM - 1) + 1)
|
||||
#define FANOTIFY_EVENT_HASH_BITS \
|
||||
(32 - FANOTIFY_EVENT_TYPE_BITS)
|
||||
|
||||
struct fanotify_event {
|
||||
struct fsnotify_event fse;
|
||||
struct hlist_node merge_list; /* List for hashed merge */
|
||||
u32 mask;
|
||||
enum fanotify_event_type type;
|
||||
struct {
|
||||
unsigned int type : FANOTIFY_EVENT_TYPE_BITS;
|
||||
unsigned int hash : FANOTIFY_EVENT_HASH_BITS;
|
||||
};
|
||||
struct pid *pid;
|
||||
};
|
||||
|
||||
static inline void fanotify_init_event(struct fanotify_event *event,
|
||||
unsigned long id, u32 mask)
|
||||
unsigned int hash, u32 mask)
|
||||
{
|
||||
fsnotify_init_event(&event->fse, id);
|
||||
fsnotify_init_event(&event->fse);
|
||||
INIT_HLIST_NODE(&event->merge_list);
|
||||
event->hash = hash;
|
||||
event->mask = mask;
|
||||
event->pid = NULL;
|
||||
}
|
||||
@ -284,3 +302,25 @@ static inline struct path *fanotify_event_path(struct fanotify_event *event)
|
||||
else
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Use 128 size hash table to speed up events merge.
|
||||
*/
|
||||
#define FANOTIFY_HTABLE_BITS (7)
|
||||
#define FANOTIFY_HTABLE_SIZE (1 << FANOTIFY_HTABLE_BITS)
|
||||
#define FANOTIFY_HTABLE_MASK (FANOTIFY_HTABLE_SIZE - 1)
|
||||
|
||||
/*
|
||||
* Permission events and overflow event do not get merged - don't hash them.
|
||||
*/
|
||||
static inline bool fanotify_is_hashed_event(u32 mask)
|
||||
{
|
||||
return !fanotify_is_perm_event(mask) && !(mask & FS_Q_OVERFLOW);
|
||||
}
|
||||
|
||||
static inline unsigned int fanotify_event_hash_bucket(
|
||||
struct fsnotify_group *group,
|
||||
struct fanotify_event *event)
|
||||
{
|
||||
return event->hash & FANOTIFY_HTABLE_MASK;
|
||||
}
|
||||
|
||||
@ -27,8 +27,61 @@
|
||||
#include "fanotify.h"
|
||||
|
||||
#define FANOTIFY_DEFAULT_MAX_EVENTS 16384
|
||||
#define FANOTIFY_DEFAULT_MAX_MARKS 8192
|
||||
#define FANOTIFY_DEFAULT_MAX_LISTENERS 128
|
||||
#define FANOTIFY_OLD_DEFAULT_MAX_MARKS 8192
|
||||
#define FANOTIFY_DEFAULT_MAX_GROUPS 128
|
||||
|
||||
/*
|
||||
* Legacy fanotify marks limits (8192) is per group and we introduced a tunable
|
||||
* limit of marks per user, similar to inotify. Effectively, the legacy limit
|
||||
* of fanotify marks per user is <max marks per group> * <max groups per user>.
|
||||
* This default limit (1M) also happens to match the increased limit of inotify
|
||||
* max_user_watches since v5.10.
|
||||
*/
|
||||
#define FANOTIFY_DEFAULT_MAX_USER_MARKS \
|
||||
(FANOTIFY_OLD_DEFAULT_MAX_MARKS * FANOTIFY_DEFAULT_MAX_GROUPS)
|
||||
|
||||
/*
|
||||
* Most of the memory cost of adding an inode mark is pinning the marked inode.
|
||||
* The size of the filesystem inode struct is not uniform across filesystems,
|
||||
* so double the size of a VFS inode is used as a conservative approximation.
|
||||
*/
|
||||
#define INODE_MARK_COST (2 * sizeof(struct inode))
|
||||
|
||||
/* configurable via /proc/sys/fs/fanotify/ */
|
||||
static int fanotify_max_queued_events __read_mostly;
|
||||
|
||||
#ifdef CONFIG_SYSCTL
|
||||
|
||||
#include <linux/sysctl.h>
|
||||
|
||||
struct ctl_table fanotify_table[] = {
|
||||
{
|
||||
.procname = "max_user_groups",
|
||||
.data = &init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS],
|
||||
.maxlen = sizeof(int),
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec_minmax,
|
||||
.extra1 = SYSCTL_ZERO,
|
||||
},
|
||||
{
|
||||
.procname = "max_user_marks",
|
||||
.data = &init_user_ns.ucount_max[UCOUNT_FANOTIFY_MARKS],
|
||||
.maxlen = sizeof(int),
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec_minmax,
|
||||
.extra1 = SYSCTL_ZERO,
|
||||
},
|
||||
{
|
||||
.procname = "max_queued_events",
|
||||
.data = &fanotify_max_queued_events,
|
||||
.maxlen = sizeof(int),
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec_minmax,
|
||||
.extra1 = SYSCTL_ZERO
|
||||
},
|
||||
{ }
|
||||
};
|
||||
#endif /* CONFIG_SYSCTL */
|
||||
|
||||
/*
|
||||
* All flags that may be specified in parameter event_f_flags of fanotify_init.
|
||||
@ -89,6 +142,23 @@ static int fanotify_event_info_len(unsigned int fid_mode,
|
||||
return info_len;
|
||||
}
|
||||
|
||||
/*
|
||||
* Remove an hashed event from merge hash table.
|
||||
*/
|
||||
static void fanotify_unhash_event(struct fsnotify_group *group,
|
||||
struct fanotify_event *event)
|
||||
{
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
|
||||
pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,
|
||||
group, event, fanotify_event_hash_bucket(group, event));
|
||||
|
||||
if (WARN_ON_ONCE(hlist_unhashed(&event->merge_list)))
|
||||
return;
|
||||
|
||||
hlist_del_init(&event->merge_list);
|
||||
}
|
||||
|
||||
/*
|
||||
* Get an fanotify notification event if one exists and is small
|
||||
* enough to fit in "count". Return an error pointer if the count
|
||||
@ -100,26 +170,34 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
|
||||
{
|
||||
size_t event_size = FAN_EVENT_METADATA_LEN;
|
||||
struct fanotify_event *event = NULL;
|
||||
struct fsnotify_event *fsn_event;
|
||||
unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
|
||||
|
||||
pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
|
||||
|
||||
spin_lock(&group->notification_lock);
|
||||
if (fsnotify_notify_queue_is_empty(group))
|
||||
fsn_event = fsnotify_peek_first_event(group);
|
||||
if (!fsn_event)
|
||||
goto out;
|
||||
|
||||
if (fid_mode) {
|
||||
event_size += fanotify_event_info_len(fid_mode,
|
||||
FANOTIFY_E(fsnotify_peek_first_event(group)));
|
||||
}
|
||||
event = FANOTIFY_E(fsn_event);
|
||||
if (fid_mode)
|
||||
event_size += fanotify_event_info_len(fid_mode, event);
|
||||
|
||||
if (event_size > count) {
|
||||
event = ERR_PTR(-EINVAL);
|
||||
goto out;
|
||||
}
|
||||
event = FANOTIFY_E(fsnotify_remove_first_event(group));
|
||||
|
||||
/*
|
||||
* Held the notification_lock the whole time, so this is the
|
||||
* same event we peeked above.
|
||||
*/
|
||||
fsnotify_remove_first_event(group);
|
||||
if (fanotify_is_perm_event(event->mask))
|
||||
FANOTIFY_PERM(event)->state = FAN_EVENT_REPORTED;
|
||||
if (fanotify_is_hashed_event(event->mask))
|
||||
fanotify_unhash_event(group, event);
|
||||
out:
|
||||
spin_unlock(&group->notification_lock);
|
||||
return event;
|
||||
@ -341,6 +419,14 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
|
||||
metadata.reserved = 0;
|
||||
metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
|
||||
metadata.pid = pid_vnr(event->pid);
|
||||
/*
|
||||
* For an unprivileged listener, event->pid can be used to identify the
|
||||
* events generated by the listener process itself, without disclosing
|
||||
* the pids of other processes.
|
||||
*/
|
||||
if (!capable(CAP_SYS_ADMIN) &&
|
||||
task_tgid(current) != event->pid)
|
||||
metadata.pid = 0;
|
||||
|
||||
if (path && path->mnt && path->dentry) {
|
||||
fd = create_fd(group, path, &f);
|
||||
@ -573,6 +659,7 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t
|
||||
static int fanotify_release(struct inode *ignored, struct file *file)
|
||||
{
|
||||
struct fsnotify_group *group = file->private_data;
|
||||
struct fsnotify_event *fsn_event;
|
||||
|
||||
/*
|
||||
* Stop new events from arriving in the notification queue. since
|
||||
@ -601,13 +688,12 @@ static int fanotify_release(struct inode *ignored, struct file *file)
|
||||
* dequeue them and set the response. They will be freed once the
|
||||
* response is consumed and fanotify_get_response() returns.
|
||||
*/
|
||||
while (!fsnotify_notify_queue_is_empty(group)) {
|
||||
struct fanotify_event *event;
|
||||
while ((fsn_event = fsnotify_remove_first_event(group))) {
|
||||
struct fanotify_event *event = FANOTIFY_E(fsn_event);
|
||||
|
||||
event = FANOTIFY_E(fsnotify_remove_first_event(group));
|
||||
if (!(event->mask & FANOTIFY_PERM_EVENTS)) {
|
||||
spin_unlock(&group->notification_lock);
|
||||
fsnotify_destroy_event(group, &event->fse);
|
||||
fsnotify_destroy_event(group, fsn_event);
|
||||
} else {
|
||||
finish_permission_event(group, FANOTIFY_PERM(event),
|
||||
FAN_ALLOW);
|
||||
@ -822,24 +908,38 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
|
||||
unsigned int type,
|
||||
__kernel_fsid_t *fsid)
|
||||
{
|
||||
struct ucounts *ucounts = group->fanotify_data.ucounts;
|
||||
struct fsnotify_mark *mark;
|
||||
int ret;
|
||||
|
||||
if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
|
||||
/*
|
||||
* Enforce per user marks limits per user in all containing user ns.
|
||||
* A group with FAN_UNLIMITED_MARKS does not contribute to mark count
|
||||
* in the limited groups account.
|
||||
*/
|
||||
if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS) &&
|
||||
!inc_ucount(ucounts->ns, ucounts->uid, UCOUNT_FANOTIFY_MARKS))
|
||||
return ERR_PTR(-ENOSPC);
|
||||
|
||||
mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
|
||||
if (!mark)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
if (!mark) {
|
||||
ret = -ENOMEM;
|
||||
goto out_dec_ucounts;
|
||||
}
|
||||
|
||||
fsnotify_init_mark(mark, group);
|
||||
ret = fsnotify_add_mark_locked(mark, connp, type, 0, fsid);
|
||||
if (ret) {
|
||||
fsnotify_put_mark(mark);
|
||||
return ERR_PTR(ret);
|
||||
goto out_dec_ucounts;
|
||||
}
|
||||
|
||||
return mark;
|
||||
|
||||
out_dec_ucounts:
|
||||
if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS))
|
||||
dec_ucount(ucounts, UCOUNT_FANOTIFY_MARKS);
|
||||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
|
||||
@ -919,20 +1019,41 @@ static struct fsnotify_event *fanotify_alloc_overflow_event(void)
|
||||
return &oevent->fse;
|
||||
}
|
||||
|
||||
static struct hlist_head *fanotify_alloc_merge_hash(void)
|
||||
{
|
||||
struct hlist_head *hash;
|
||||
|
||||
hash = kmalloc(sizeof(struct hlist_head) << FANOTIFY_HTABLE_BITS,
|
||||
GFP_KERNEL_ACCOUNT);
|
||||
if (!hash)
|
||||
return NULL;
|
||||
|
||||
__hash_init(hash, FANOTIFY_HTABLE_SIZE);
|
||||
|
||||
return hash;
|
||||
}
|
||||
|
||||
/* fanotify syscalls */
|
||||
SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
|
||||
{
|
||||
struct fsnotify_group *group;
|
||||
int f_flags, fd;
|
||||
struct user_struct *user;
|
||||
unsigned int fid_mode = flags & FANOTIFY_FID_BITS;
|
||||
unsigned int class = flags & FANOTIFY_CLASS_BITS;
|
||||
|
||||
pr_debug("%s: flags=%x event_f_flags=%x\n",
|
||||
__func__, flags, event_f_flags);
|
||||
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
if (!capable(CAP_SYS_ADMIN)) {
|
||||
/*
|
||||
* An unprivileged user can setup an fanotify group with
|
||||
* limited functionality - an unprivileged group is limited to
|
||||
* notification events with file handles and it cannot use
|
||||
* unlimited queue/marks.
|
||||
*/
|
||||
if ((flags & FANOTIFY_ADMIN_INIT_FLAGS) || !fid_mode)
|
||||
return -EPERM;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_AUDITSYSCALL
|
||||
if (flags & ~(FANOTIFY_INIT_FLAGS | FAN_ENABLE_AUDIT))
|
||||
@ -963,12 +1084,6 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
|
||||
if ((fid_mode & FAN_REPORT_NAME) && !(fid_mode & FAN_REPORT_DIR_FID))
|
||||
return -EINVAL;
|
||||
|
||||
user = get_current_user();
|
||||
if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
|
||||
free_uid(user);
|
||||
return -EMFILE;
|
||||
}
|
||||
|
||||
f_flags = O_RDWR | FMODE_NONOTIFY;
|
||||
if (flags & FAN_CLOEXEC)
|
||||
f_flags |= O_CLOEXEC;
|
||||
@ -978,15 +1093,27 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
|
||||
/* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
|
||||
group = fsnotify_alloc_user_group(&fanotify_fsnotify_ops);
|
||||
if (IS_ERR(group)) {
|
||||
free_uid(user);
|
||||
return PTR_ERR(group);
|
||||
}
|
||||
|
||||
group->fanotify_data.user = user;
|
||||
/* Enforce groups limits per user in all containing user ns */
|
||||
group->fanotify_data.ucounts = inc_ucount(current_user_ns(),
|
||||
current_euid(),
|
||||
UCOUNT_FANOTIFY_GROUPS);
|
||||
if (!group->fanotify_data.ucounts) {
|
||||
fd = -EMFILE;
|
||||
goto out_destroy_group;
|
||||
}
|
||||
|
||||
group->fanotify_data.flags = flags;
|
||||
atomic_inc(&user->fanotify_listeners);
|
||||
group->memcg = get_mem_cgroup_from_mm(current->mm);
|
||||
|
||||
group->fanotify_data.merge_hash = fanotify_alloc_merge_hash();
|
||||
if (!group->fanotify_data.merge_hash) {
|
||||
fd = -ENOMEM;
|
||||
goto out_destroy_group;
|
||||
}
|
||||
|
||||
group->overflow_event = fanotify_alloc_overflow_event();
|
||||
if (unlikely(!group->overflow_event)) {
|
||||
fd = -ENOMEM;
|
||||
@ -1019,16 +1146,13 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
|
||||
goto out_destroy_group;
|
||||
group->max_events = UINT_MAX;
|
||||
} else {
|
||||
group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
|
||||
group->max_events = fanotify_max_queued_events;
|
||||
}
|
||||
|
||||
if (flags & FAN_UNLIMITED_MARKS) {
|
||||
fd = -EPERM;
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
goto out_destroy_group;
|
||||
group->fanotify_data.max_marks = UINT_MAX;
|
||||
} else {
|
||||
group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
|
||||
}
|
||||
|
||||
if (flags & FAN_ENABLE_AUDIT) {
|
||||
@ -1126,7 +1250,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
|
||||
__func__, fanotify_fd, flags, dfd, pathname, mask);
|
||||
|
||||
/* we only use the lower 32 bits as of right now. */
|
||||
if (mask & ((__u64)0xffffffff << 32))
|
||||
if (upper_32_bits(mask))
|
||||
return -EINVAL;
|
||||
|
||||
if (flags & ~FANOTIFY_MARK_FLAGS)
|
||||
@ -1180,6 +1304,15 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
|
||||
goto fput_and_out;
|
||||
group = f.file->private_data;
|
||||
|
||||
/*
|
||||
* An unprivileged user is not allowed to watch a mount point nor
|
||||
* a filesystem.
|
||||
*/
|
||||
ret = -EPERM;
|
||||
if (!capable(CAP_SYS_ADMIN) &&
|
||||
mark_type != FAN_MARK_INODE)
|
||||
goto fput_and_out;
|
||||
|
||||
/*
|
||||
* group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF. These are not
|
||||
* allowed to set permissions events.
|
||||
@ -1312,6 +1445,21 @@ SYSCALL32_DEFINE6(fanotify_mark,
|
||||
*/
|
||||
static int __init fanotify_user_setup(void)
|
||||
{
|
||||
struct sysinfo si;
|
||||
int max_marks;
|
||||
|
||||
si_meminfo(&si);
|
||||
/*
|
||||
* Allow up to 1% of addressable memory to be accounted for per user
|
||||
* marks limited to the range [8192, 1048576]. mount and sb marks are
|
||||
* a lot cheaper than inode marks, but there is no reason for a user
|
||||
* to have many of those, so calculate by the cost of inode marks.
|
||||
*/
|
||||
max_marks = (((si.totalram - si.totalhigh) / 100) << PAGE_SHIFT) /
|
||||
INODE_MARK_COST;
|
||||
max_marks = clamp(max_marks, FANOTIFY_OLD_DEFAULT_MAX_MARKS,
|
||||
FANOTIFY_DEFAULT_MAX_USER_MARKS);
|
||||
|
||||
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 10);
|
||||
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9);
|
||||
|
||||
@ -1326,6 +1474,11 @@ static int __init fanotify_user_setup(void)
|
||||
KMEM_CACHE(fanotify_perm_event, SLAB_PANIC);
|
||||
}
|
||||
|
||||
fanotify_max_queued_events = FANOTIFY_DEFAULT_MAX_EVENTS;
|
||||
init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS] =
|
||||
FANOTIFY_DEFAULT_MAX_GROUPS;
|
||||
init_user_ns.ucount_max[UCOUNT_FANOTIFY_MARKS] = max_marks;
|
||||
|
||||
return 0;
|
||||
}
|
||||
device_initcall(fanotify_user_setup);
|
||||
|
||||
@ -144,7 +144,8 @@ void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
|
||||
struct fsnotify_group *group = f->private_data;
|
||||
|
||||
seq_printf(m, "fanotify flags:%x event-flags:%x\n",
|
||||
group->fanotify_data.flags, group->fanotify_data.f_flags);
|
||||
group->fanotify_data.flags,
|
||||
group->fanotify_data.f_flags);
|
||||
|
||||
show_fdinfo(m, f, fanotify_fdinfo);
|
||||
}
|
||||
|
||||
@ -122,7 +122,6 @@ static struct fsnotify_group *__fsnotify_alloc_group(
|
||||
|
||||
/* set to 0 when there a no external references to this group */
|
||||
refcount_set(&group->refcnt, 1);
|
||||
atomic_set(&group->num_marks, 0);
|
||||
atomic_set(&group->user_waits, 0);
|
||||
|
||||
spin_lock_init(&group->notification_lock);
|
||||
|
||||
@ -46,9 +46,10 @@ static bool event_compare(struct fsnotify_event *old_fsn,
|
||||
return false;
|
||||
}
|
||||
|
||||
static int inotify_merge(struct list_head *list,
|
||||
static int inotify_merge(struct fsnotify_group *group,
|
||||
struct fsnotify_event *event)
|
||||
{
|
||||
struct list_head *list = &group->notification_list;
|
||||
struct fsnotify_event *last_event;
|
||||
|
||||
last_event = list_entry(list->prev, struct fsnotify_event, list);
|
||||
@ -107,7 +108,7 @@ int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask,
|
||||
mask &= ~IN_ISDIR;
|
||||
|
||||
fsn_event = &event->fse;
|
||||
fsnotify_init_event(fsn_event, 0);
|
||||
fsnotify_init_event(fsn_event);
|
||||
event->mask = mask;
|
||||
event->wd = i_mark->wd;
|
||||
event->sync_cookie = cookie;
|
||||
@ -115,7 +116,7 @@ int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask,
|
||||
if (len)
|
||||
strcpy(event->name, name->name);
|
||||
|
||||
ret = fsnotify_add_event(group, fsn_event, inotify_merge);
|
||||
ret = fsnotify_add_event(group, fsn_event, inotify_merge, NULL);
|
||||
if (ret) {
|
||||
/* Our event wasn't used in the end. Free it. */
|
||||
fsnotify_destroy_event(group, fsn_event);
|
||||
|
||||
@ -146,10 +146,9 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
|
||||
size_t event_size = sizeof(struct inotify_event);
|
||||
struct fsnotify_event *event;
|
||||
|
||||
if (fsnotify_notify_queue_is_empty(group))
|
||||
return NULL;
|
||||
|
||||
event = fsnotify_peek_first_event(group);
|
||||
if (!event)
|
||||
return NULL;
|
||||
|
||||
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
|
||||
|
||||
@ -642,7 +641,7 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
group->overflow_event = &oevent->fse;
|
||||
fsnotify_init_event(group->overflow_event, 0);
|
||||
fsnotify_init_event(group->overflow_event);
|
||||
oevent->mask = FS_Q_OVERFLOW;
|
||||
oevent->wd = -1;
|
||||
oevent->sync_cookie = 0;
|
||||
|
||||
@ -391,8 +391,6 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark)
|
||||
list_del_init(&mark->g_list);
|
||||
spin_unlock(&mark->lock);
|
||||
|
||||
atomic_dec(&group->num_marks);
|
||||
|
||||
/* Drop mark reference acquired in fsnotify_add_mark_locked() */
|
||||
fsnotify_put_mark(mark);
|
||||
}
|
||||
@ -656,7 +654,6 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
|
||||
mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_ATTACHED;
|
||||
|
||||
list_add(&mark->g_list, &group->marks_list);
|
||||
atomic_inc(&group->num_marks);
|
||||
fsnotify_get_mark(mark); /* for g_list */
|
||||
spin_unlock(&mark->lock);
|
||||
|
||||
@ -674,7 +671,6 @@ err:
|
||||
FSNOTIFY_MARK_FLAG_ATTACHED);
|
||||
list_del_init(&mark->g_list);
|
||||
spin_unlock(&mark->lock);
|
||||
atomic_dec(&group->num_marks);
|
||||
|
||||
fsnotify_put_mark(mark);
|
||||
return ret;
|
||||
|
||||
@ -47,13 +47,6 @@ u32 fsnotify_get_cookie(void)
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(fsnotify_get_cookie);
|
||||
|
||||
/* return true if the notify queue is empty, false otherwise */
|
||||
bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
|
||||
{
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
return list_empty(&group->notification_list) ? true : false;
|
||||
}
|
||||
|
||||
void fsnotify_destroy_event(struct fsnotify_group *group,
|
||||
struct fsnotify_event *event)
|
||||
{
|
||||
@ -75,15 +68,21 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
|
||||
}
|
||||
|
||||
/*
|
||||
* Add an event to the group notification queue. The group can later pull this
|
||||
* event off the queue to deal with. The function returns 0 if the event was
|
||||
* added to the queue, 1 if the event was merged with some other queued event,
|
||||
* Try to add an event to the notification queue.
|
||||
* The group can later pull this event off the queue to deal with.
|
||||
* The group can use the @merge hook to merge the event with a queued event.
|
||||
* The group can use the @insert hook to insert the event into hash table.
|
||||
* The function returns:
|
||||
* 0 if the event was added to a queue
|
||||
* 1 if the event was merged with some other queued event
|
||||
* 2 if the event was not queued - either the queue of events has overflown
|
||||
* or the group is shutting down.
|
||||
*/
|
||||
int fsnotify_add_event(struct fsnotify_group *group,
|
||||
struct fsnotify_event *event,
|
||||
int (*merge)(struct list_head *,
|
||||
int (*merge)(struct fsnotify_group *,
|
||||
struct fsnotify_event *),
|
||||
void (*insert)(struct fsnotify_group *,
|
||||
struct fsnotify_event *))
|
||||
{
|
||||
int ret = 0;
|
||||
@ -111,7 +110,7 @@ int fsnotify_add_event(struct fsnotify_group *group,
|
||||
}
|
||||
|
||||
if (!list_empty(list) && merge) {
|
||||
ret = merge(list, event);
|
||||
ret = merge(group, event);
|
||||
if (ret) {
|
||||
spin_unlock(&group->notification_lock);
|
||||
return ret;
|
||||
@ -121,6 +120,8 @@ int fsnotify_add_event(struct fsnotify_group *group,
|
||||
queue:
|
||||
group->q_len++;
|
||||
list_add_tail(&event->list, list);
|
||||
if (insert)
|
||||
insert(group, event);
|
||||
spin_unlock(&group->notification_lock);
|
||||
|
||||
wake_up(&group->notification_waitq);
|
||||
@ -141,35 +142,38 @@ void fsnotify_remove_queued_event(struct fsnotify_group *group,
|
||||
}
|
||||
|
||||
/*
|
||||
* Remove and return the first event from the notification list. It is the
|
||||
* responsibility of the caller to destroy the obtained event
|
||||
*/
|
||||
struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)
|
||||
{
|
||||
struct fsnotify_event *event;
|
||||
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
|
||||
pr_debug("%s: group=%p\n", __func__, group);
|
||||
|
||||
event = list_first_entry(&group->notification_list,
|
||||
struct fsnotify_event, list);
|
||||
fsnotify_remove_queued_event(group, event);
|
||||
return event;
|
||||
}
|
||||
|
||||
/*
|
||||
* This will not remove the event, that must be done with
|
||||
* fsnotify_remove_first_event()
|
||||
* Return the first event on the notification list without removing it.
|
||||
* Returns NULL if the list is empty.
|
||||
*/
|
||||
struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group)
|
||||
{
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
|
||||
if (fsnotify_notify_queue_is_empty(group))
|
||||
return NULL;
|
||||
|
||||
return list_first_entry(&group->notification_list,
|
||||
struct fsnotify_event, list);
|
||||
}
|
||||
|
||||
/*
|
||||
* Remove and return the first event from the notification list. It is the
|
||||
* responsibility of the caller to destroy the obtained event
|
||||
*/
|
||||
struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)
|
||||
{
|
||||
struct fsnotify_event *event = fsnotify_peek_first_event(group);
|
||||
|
||||
if (!event)
|
||||
return NULL;
|
||||
|
||||
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
|
||||
|
||||
fsnotify_remove_queued_event(group, event);
|
||||
|
||||
return event;
|
||||
}
|
||||
|
||||
/*
|
||||
* Called when a group is being torn down to clean up any outstanding
|
||||
* event notifications.
|
||||
|
||||
@ -1177,7 +1177,6 @@ static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
||||
struct super_block *sb = dentry->d_sb;
|
||||
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
|
||||
enum zonefs_ztype t;
|
||||
u64 fsid;
|
||||
|
||||
buf->f_type = ZONEFS_MAGIC;
|
||||
buf->f_bsize = sb->s_blocksize;
|
||||
@ -1200,9 +1199,7 @@ static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
||||
|
||||
spin_unlock(&sbi->s_lock);
|
||||
|
||||
fsid = le64_to_cpup((void *)sbi->s_uuid.b) ^
|
||||
le64_to_cpup((void *)sbi->s_uuid.b + sizeof(u64));
|
||||
buf->f_fsid = u64_to_fsid(fsid);
|
||||
buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -2,8 +2,11 @@
|
||||
#ifndef _LINUX_FANOTIFY_H
|
||||
#define _LINUX_FANOTIFY_H
|
||||
|
||||
#include <linux/sysctl.h>
|
||||
#include <uapi/linux/fanotify.h>
|
||||
|
||||
extern struct ctl_table fanotify_table[]; /* for sysctl */
|
||||
|
||||
#define FAN_GROUP_FLAG(group, flag) \
|
||||
((group)->fanotify_data.flags & (flag))
|
||||
|
||||
@ -15,15 +18,38 @@
|
||||
* these constant, the programs may break if re-compiled with new uapi headers
|
||||
* and then run on an old kernel.
|
||||
*/
|
||||
#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
|
||||
|
||||
/* Group classes where permission events are allowed */
|
||||
#define FANOTIFY_PERM_CLASSES (FAN_CLASS_CONTENT | \
|
||||
FAN_CLASS_PRE_CONTENT)
|
||||
|
||||
#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF | FANOTIFY_PERM_CLASSES)
|
||||
|
||||
#define FANOTIFY_FID_BITS (FAN_REPORT_FID | FAN_REPORT_DFID_NAME)
|
||||
|
||||
#define FANOTIFY_INIT_FLAGS (FANOTIFY_CLASS_BITS | FANOTIFY_FID_BITS | \
|
||||
/*
|
||||
* fanotify_init() flags that require CAP_SYS_ADMIN.
|
||||
* We do not allow unprivileged groups to request permission events.
|
||||
* We do not allow unprivileged groups to get other process pid in events.
|
||||
* We do not allow unprivileged groups to use unlimited resources.
|
||||
*/
|
||||
#define FANOTIFY_ADMIN_INIT_FLAGS (FANOTIFY_PERM_CLASSES | \
|
||||
FAN_REPORT_TID | \
|
||||
FAN_CLOEXEC | FAN_NONBLOCK | \
|
||||
FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
|
||||
FAN_UNLIMITED_QUEUE | \
|
||||
FAN_UNLIMITED_MARKS)
|
||||
|
||||
/*
|
||||
* fanotify_init() flags that are allowed for user without CAP_SYS_ADMIN.
|
||||
* FAN_CLASS_NOTIF is the only class we allow for unprivileged group.
|
||||
* We do not allow unprivileged groups to get file descriptors in events,
|
||||
* so one of the flags for reporting file handles is required.
|
||||
*/
|
||||
#define FANOTIFY_USER_INIT_FLAGS (FAN_CLASS_NOTIF | \
|
||||
FANOTIFY_FID_BITS | \
|
||||
FAN_CLOEXEC | FAN_NONBLOCK)
|
||||
|
||||
#define FANOTIFY_INIT_FLAGS (FANOTIFY_ADMIN_INIT_FLAGS | \
|
||||
FANOTIFY_USER_INIT_FLAGS)
|
||||
|
||||
#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
|
||||
FAN_MARK_FILESYSTEM)
|
||||
|
||||
@ -167,7 +167,6 @@ struct fsnotify_ops {
|
||||
*/
|
||||
struct fsnotify_event {
|
||||
struct list_head list;
|
||||
unsigned long objectid; /* identifier for queue merges */
|
||||
};
|
||||
|
||||
/*
|
||||
@ -207,9 +206,6 @@ struct fsnotify_group {
|
||||
|
||||
/* stores all fastpath marks assoc with this group so they can be cleaned on unregister */
|
||||
struct mutex mark_mutex; /* protect marks_list */
|
||||
atomic_t num_marks; /* 1 for each mark and 1 for not being
|
||||
* past the point of no return when freeing
|
||||
* a group */
|
||||
atomic_t user_waits; /* Number of tasks waiting for user
|
||||
* response */
|
||||
struct list_head marks_list; /* all inode marks for this group */
|
||||
@ -234,13 +230,14 @@ struct fsnotify_group {
|
||||
#endif
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
struct fanotify_group_private_data {
|
||||
/* Hash table of events for merge */
|
||||
struct hlist_head *merge_hash;
|
||||
/* allows a group to block waiting for a userspace response */
|
||||
struct list_head access_list;
|
||||
wait_queue_head_t access_waitq;
|
||||
int flags; /* flags from fanotify_init() */
|
||||
int f_flags; /* event_f_flags from fanotify_init() */
|
||||
unsigned int max_marks;
|
||||
struct user_struct *user;
|
||||
struct ucounts *ucounts;
|
||||
} fanotify_data;
|
||||
#endif /* CONFIG_FANOTIFY */
|
||||
};
|
||||
@ -487,15 +484,23 @@ extern void fsnotify_destroy_event(struct fsnotify_group *group,
|
||||
/* attach the event to the group notification queue */
|
||||
extern int fsnotify_add_event(struct fsnotify_group *group,
|
||||
struct fsnotify_event *event,
|
||||
int (*merge)(struct list_head *,
|
||||
int (*merge)(struct fsnotify_group *,
|
||||
struct fsnotify_event *),
|
||||
void (*insert)(struct fsnotify_group *,
|
||||
struct fsnotify_event *));
|
||||
/* Queue overflow event to a notification group */
|
||||
static inline void fsnotify_queue_overflow(struct fsnotify_group *group)
|
||||
{
|
||||
fsnotify_add_event(group, group->overflow_event, NULL);
|
||||
fsnotify_add_event(group, group->overflow_event, NULL, NULL);
|
||||
}
|
||||
|
||||
static inline bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
|
||||
{
|
||||
assert_spin_locked(&group->notification_lock);
|
||||
|
||||
return list_empty(&group->notification_list);
|
||||
}
|
||||
|
||||
/* true if the group notification queue is empty */
|
||||
extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group);
|
||||
/* return, but do not dequeue the first event on the notification queue */
|
||||
extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group);
|
||||
@ -576,11 +581,9 @@ extern void fsnotify_put_mark(struct fsnotify_mark *mark);
|
||||
extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);
|
||||
extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info);
|
||||
|
||||
static inline void fsnotify_init_event(struct fsnotify_event *event,
|
||||
unsigned long objectid)
|
||||
static inline void fsnotify_init_event(struct fsnotify_event *event)
|
||||
{
|
||||
INIT_LIST_HEAD(&event->list);
|
||||
event->objectid = objectid;
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
@ -14,9 +14,6 @@ struct user_struct {
|
||||
refcount_t __count; /* reference count */
|
||||
atomic_t processes; /* How many processes does this user have? */
|
||||
atomic_t sigpending; /* How many pending signals does this user have? */
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
atomic_t fanotify_listeners;
|
||||
#endif
|
||||
#ifdef CONFIG_EPOLL
|
||||
atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
|
||||
#endif
|
||||
|
||||
@ -4,6 +4,7 @@
|
||||
|
||||
#include <linux/types.h>
|
||||
#include <asm/statfs.h>
|
||||
#include <asm/byteorder.h>
|
||||
|
||||
struct kstatfs {
|
||||
long f_type;
|
||||
@ -50,4 +51,11 @@ static inline __kernel_fsid_t u64_to_fsid(u64 v)
|
||||
return (__kernel_fsid_t){.val = {(u32)v, (u32)(v>>32)}};
|
||||
}
|
||||
|
||||
/* Fold 16 bytes uuid to 64 bit fsid */
|
||||
static inline __kernel_fsid_t uuid_to_fsid(__u8 *uuid)
|
||||
{
|
||||
return u64_to_fsid(le64_to_cpup((void *)uuid) ^
|
||||
le64_to_cpup((void *)(uuid + sizeof(u64))));
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
@ -49,6 +49,10 @@ enum ucount_type {
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
UCOUNT_INOTIFY_INSTANCES,
|
||||
UCOUNT_INOTIFY_WATCHES,
|
||||
#endif
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
UCOUNT_FANOTIFY_GROUPS,
|
||||
UCOUNT_FANOTIFY_MARKS,
|
||||
#endif
|
||||
UCOUNT_COUNTS,
|
||||
};
|
||||
|
||||
@ -148,6 +148,9 @@ static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
#include <linux/inotify.h>
|
||||
#endif
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
#include <linux/fanotify.h>
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_PROC_SYSCTL
|
||||
|
||||
@ -3165,6 +3168,13 @@ static struct ctl_table fs_table[] = {
|
||||
.child = inotify_table,
|
||||
},
|
||||
#endif
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
{
|
||||
.procname = "fanotify",
|
||||
.mode = 0555,
|
||||
.child = fanotify_table,
|
||||
},
|
||||
#endif
|
||||
#ifdef CONFIG_EPOLL
|
||||
{
|
||||
.procname = "epoll",
|
||||
|
||||
@ -73,6 +73,10 @@ static struct ctl_table user_table[] = {
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
UCOUNT_ENTRY("max_inotify_instances"),
|
||||
UCOUNT_ENTRY("max_inotify_watches"),
|
||||
#endif
|
||||
#ifdef CONFIG_FANOTIFY
|
||||
UCOUNT_ENTRY("max_fanotify_groups"),
|
||||
UCOUNT_ENTRY("max_fanotify_marks"),
|
||||
#endif
|
||||
{ }
|
||||
};
|
||||
|
||||
@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf)
|
||||
buf->f_ffree = sbinfo->free_inodes;
|
||||
}
|
||||
/* else leave those fields 0 like simple_statfs */
|
||||
|
||||
buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user