From: Ibrahim Jirdeh <ibrahimjirdeh@meta.com>
To: <ibrahimjirdeh@meta.com>
Cc: <jack@suse.cz>, <amir73il@gmail.com>, <josef@toxicpanda.com>,
<lesha@meta.com>, <linux-fsdevel@vger.kernel.org>,
<sargun@meta.com>
Subject: [PATCH v3 1/3] fanotify: add support for a variable length permission event
Date: Thu, 10 Jul 2025 19:36:02 -0700 [thread overview]
Message-ID: <20250711023604.593885-2-ibrahimjirdeh@meta.com> (raw)
In-Reply-To: <20250711023604.593885-1-ibrahimjirdeh@meta.com>
From: Amir Goldstein <amir73il@gmail.com>
In preparation for pre-content events that report fid info + name,
we need a new event type that is both variable length and can be
put on a user response wait list.
Create an event type FANOTIFY_EVENT_TYPE_FID_NAME_PERM with is a
combination of the variable length fanotify_name_event prefixed
with a fix length fanotify_perm_event and they share the common
fanotify_event memeber.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
fs/notify/fanotify/fanotify.c | 68 +++++++++++++++++++++++++++--------
fs/notify/fanotify/fanotify.h | 19 +++++++---
2 files changed, 67 insertions(+), 20 deletions(-)
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index bfe884d624e7..34acb7c16e8b 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -582,20 +582,13 @@ static struct fanotify_event *fanotify_alloc_mnt_event(u64 mnt_id, gfp_t gfp)
return &pevent->fae;
}
-static struct fanotify_event *fanotify_alloc_perm_event(const void *data,
- int data_type,
- gfp_t gfp)
+static void fanotify_init_perm_event(struct fanotify_perm_event *pevent,
+ const void *data, int data_type)
{
const struct path *path = fsnotify_data_path(data, data_type);
const struct file_range *range =
fsnotify_data_file_range(data, data_type);
- struct fanotify_perm_event *pevent;
-
- pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
- if (!pevent)
- return NULL;
- pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;
pevent->response = 0;
pevent->hdr.type = FAN_RESPONSE_INFO_NONE;
pevent->hdr.pad = 0;
@@ -606,6 +599,20 @@ static struct fanotify_event *fanotify_alloc_perm_event(const void *data,
pevent->ppos = range ? &range->pos : NULL;
pevent->count = range ? range->count : 0;
path_get(path);
+}
+
+static struct fanotify_event *fanotify_alloc_perm_event(const void *data,
+ int data_type,
+ gfp_t gfp)
+{
+ struct fanotify_perm_event *pevent;
+
+ pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
+ if (!pevent)
+ return NULL;
+
+ pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;
+ fanotify_init_perm_event(pevent, data, data_type);
return &pevent->fae;
}
@@ -636,11 +643,12 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *dir,
struct inode *child,
struct dentry *moved,
unsigned int *hash,
- gfp_t gfp)
+ gfp_t gfp, bool perm)
{
struct fanotify_name_event *fne;
struct fanotify_info *info;
struct fanotify_fh *dfh, *ffh;
+ struct fanotify_perm_event *pevent;
struct inode *dir2 = moved ? d_inode(moved->d_parent) : NULL;
const struct qstr *name2 = moved ? &moved->d_name : NULL;
unsigned int dir_fh_len = fanotify_encode_fh_len(dir);
@@ -658,11 +666,26 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *dir,
size += FANOTIFY_FH_HDR_LEN + dir2_fh_len;
if (child_fh_len)
size += FANOTIFY_FH_HDR_LEN + child_fh_len;
+ if (perm) {
+ BUILD_BUG_ON(offsetof(struct fanotify_perm_event, fae) +
+ sizeof(struct fanotify_event) != sizeof(*pevent));
+ size += offsetof(struct fanotify_perm_event, fae);
+ }
fne = kmalloc(size, gfp);
if (!fne)
return NULL;
- fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;
+ /*
+ * fanotify_name_event follows fanotify_perm_event and they share the
+ * fae member.
+ */
+ if (perm) {
+ pevent = (void *)fne;
+ fne = FANOTIFY_NE(&pevent->fae);
+ fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME_PERM;
+ } else {
+ fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;
+ }
fne->fsid = *fsid;
*hash ^= fanotify_hash_fsid(fsid);
info = &fne->info;
@@ -757,6 +780,7 @@ static struct fanotify_event *fanotify_alloc_event(
struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir);
const struct path *path = fsnotify_data_path(data, data_type);
u64 mnt_id = fsnotify_data_mnt_id(data, data_type);
+ bool perm = fanotify_is_perm_event(mask);
struct mem_cgroup *old_memcg;
struct dentry *moved = NULL;
struct inode *child = NULL;
@@ -842,14 +866,18 @@ static struct fanotify_event *fanotify_alloc_event(
/* Whoever is interested in the event, pays for the allocation. */
old_memcg = set_active_memcg(group->memcg);
- if (fanotify_is_perm_event(mask)) {
+ if (name_event && (file_name || moved || child || perm)) {
+ event = fanotify_alloc_name_event(dirid, fsid, file_name, child,
+ moved, &hash, gfp, perm);
+ if (event && perm) {
+ fanotify_init_perm_event(FANOTIFY_PERM(event),
+ data, data_type);
+ }
+ } else if (perm) {
event = fanotify_alloc_perm_event(data, data_type, gfp);
} else if (fanotify_is_error_event(mask)) {
event = fanotify_alloc_error_event(group, fsid, data,
data_type, &hash);
- } else if (name_event && (file_name || moved || child)) {
- event = fanotify_alloc_name_event(dirid, fsid, file_name, child,
- moved, &hash, gfp);
} else if (fid_mode) {
event = fanotify_alloc_fid_event(id, fsid, &hash, gfp);
} else if (path) {
@@ -1037,6 +1065,13 @@ static void fanotify_free_perm_event(struct fanotify_event *event)
kmem_cache_free(fanotify_perm_event_cachep, FANOTIFY_PERM(event));
}
+static void fanotify_free_name_perm_event(struct fanotify_event *event)
+{
+ path_put(fanotify_event_path(event));
+ /* Variable length perm event */
+ kfree(FANOTIFY_PERM(event));
+}
+
static void fanotify_free_fid_event(struct fanotify_event *event)
{
struct fanotify_fid_event *ffe = FANOTIFY_FE(event);
@@ -1084,6 +1119,9 @@ static void fanotify_free_event(struct fsnotify_group *group,
case FANOTIFY_EVENT_TYPE_FID_NAME:
fanotify_free_name_event(event);
break;
+ case FANOTIFY_EVENT_TYPE_FID_NAME_PERM:
+ fanotify_free_name_perm_event(event);
+ break;
case FANOTIFY_EVENT_TYPE_OVERFLOW:
kfree(event);
break;
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index b78308975082..f6d25fcf8692 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -240,6 +240,7 @@ static inline void fanotify_info_copy_name2(struct fanotify_info *info,
enum fanotify_event_type {
FANOTIFY_EVENT_TYPE_FID, /* fixed length */
FANOTIFY_EVENT_TYPE_FID_NAME, /* variable length */
+ FANOTIFY_EVENT_TYPE_FID_NAME_PERM, /* variable length perm event */
FANOTIFY_EVENT_TYPE_PATH,
FANOTIFY_EVENT_TYPE_PATH_PERM,
FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
@@ -326,7 +327,8 @@ static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event)
{
if (event->type == FANOTIFY_EVENT_TYPE_FID)
return &FANOTIFY_FE(event)->fsid;
- else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME ||
+ event->type == FANOTIFY_EVENT_TYPE_FID_NAME_PERM)
return &FANOTIFY_NE(event)->fsid;
else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
return &FANOTIFY_EE(event)->fsid;
@@ -339,7 +341,8 @@ static inline struct fanotify_fh *fanotify_event_object_fh(
{
if (event->type == FANOTIFY_EVENT_TYPE_FID)
return &FANOTIFY_FE(event)->object_fh;
- else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME ||
+ event->type == FANOTIFY_EVENT_TYPE_FID_NAME_PERM)
return fanotify_info_file_fh(&FANOTIFY_NE(event)->info);
else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
return &FANOTIFY_EE(event)->object_fh;
@@ -350,7 +353,8 @@ static inline struct fanotify_fh *fanotify_event_object_fh(
static inline struct fanotify_info *fanotify_event_info(
struct fanotify_event *event)
{
- if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME ||
+ event->type == FANOTIFY_EVENT_TYPE_FID_NAME_PERM)
return &FANOTIFY_NE(event)->info;
else
return NULL;
@@ -435,7 +439,6 @@ FANOTIFY_ME(struct fanotify_event *event)
* user response.
*/
struct fanotify_perm_event {
- struct fanotify_event fae;
struct path path;
const loff_t *ppos; /* optional file range info */
size_t count;
@@ -446,6 +449,11 @@ struct fanotify_perm_event {
struct fanotify_response_info_header hdr;
struct fanotify_response_info_audit_rule audit_rule;
};
+ /*
+ * Overlaps with fanotify_name_event::fae when type is
+ * FANOTIFY_EVENT_TYPE_FID_NAME_PERM - Keep at the end!
+ */
+ struct fanotify_event fae;
};
static inline struct fanotify_perm_event *
@@ -487,7 +495,8 @@ static inline const struct path *fanotify_event_path(struct fanotify_event *even
{
if (event->type == FANOTIFY_EVENT_TYPE_PATH)
return &FANOTIFY_PE(event)->path;
- else if (event->type == FANOTIFY_EVENT_TYPE_PATH_PERM)
+ else if (event->type == FANOTIFY_EVENT_TYPE_PATH_PERM ||
+ event->type == FANOTIFY_EVENT_TYPE_FID_NAME_PERM)
return &FANOTIFY_PERM(event)->path;
else
return NULL;
--
2.47.1
next prev parent reply other threads:[~2025-07-11 2:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-11 2:36 [PATCH v3 0/3] fanotify: introduce response identifier Ibrahim Jirdeh
2025-07-11 2:36 ` Ibrahim Jirdeh [this message]
2025-07-11 2:36 ` [PATCH v3 2/3] fanotify: allow pre-content events with fid info Ibrahim Jirdeh
2025-07-11 2:36 ` [PATCH v3 3/3] fanotify: introduce event response identifier Ibrahim Jirdeh
2025-07-11 6:33 ` Amir Goldstein
2025-07-11 12:47 ` kernel test robot
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