diff --git a/Documentation/admin-guide/filesystem-monitoring.rst b/Documentation/admin-guide/filesystem-monitoring.rst
new file mode 100644
index 0000000000000000000000000000000000000000..ab8dba76283c5caf2ccc84f9f559dd00283acb85
--- /dev/null
+++ b/Documentation/admin-guide/filesystem-monitoring.rst
@@ -0,0 +1,78 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================================
+File system Monitoring with fanotify
+====================================
+
+File system Error Reporting
+===========================
+
+Fanotify supports the FAN_FS_ERROR event type for file system-wide error
+reporting. It is meant to be used by file system health monitoring
+daemons, which listen for these events and take actions (notify
+sysadmin, start recovery) when a file system problem is detected.
+
+By design, a FAN_FS_ERROR notification exposes sufficient information
+for a monitoring tool to know a problem in the file system has happened.
+It doesn't necessarily provide a user space application with semantics
+to verify an IO operation was successfully executed. That is out of
+scope for this feature. Instead, it is only meant as a framework for
+early file system problem detection and reporting recovery tools.
+
+When a file system operation fails, it is common for dozens of kernel
+errors to cascade after the initial failure, hiding the original failure
+log, which is usually the most useful debug data to troubleshoot the
+problem. For this reason, FAN_FS_ERROR tries to report only the first
+error that occurred for a file system since the last notification, and
+it simply counts additional errors. This ensures that the most
+important pieces of information are never lost.
+
+FAN_FS_ERROR requires the fanotify group to be setup with the
+FAN_REPORT_FID flag.
+
+At the time of this writing, the only file system that emits FAN_FS_ERROR
+notifications is Ext4.
+
+A FAN_FS_ERROR Notification has the following format::
+
+ ::
+
+ [ Notification Metadata (Mandatory) ]
+ [ Generic Error Record (Mandatory) ]
+ [ FID record (Mandatory) ]
+
+The order of records is not guaranteed, and new records might be added
+in the future. Therefore, applications must not rely on the order and
+must be prepared to skip over unknown records. Please refer to
+``samples/fanotify/fs-monitor.c`` for an example parser.
+
+Generic error record
+--------------------
+
+The generic error record provides enough information for a file system
+agnostic tool to learn about a problem in the file system, without
+providing any additional details about the problem. This record is
+identified by ``struct fanotify_event_info_header.info_type`` being set
+to FAN_EVENT_INFO_TYPE_ERROR.
+
+ ::
+
+ struct fanotify_event_info_error {
+ struct fanotify_event_info_header hdr;
+ __s32 error;
+ __u32 error_count;
+ };
+
+The `error` field identifies the type of error using errno values.
+`error_count` tracks the number of errors that occurred and were
+suppressed to preserve the original error information, since the last
+notification.
+
+FID record
+----------
+
+The FID record can be used to uniquely identify the inode that triggered
+the error through the combination of fsid and file handle. A file system
+specific application can use that information to attempt a recovery
+procedure. Errors that are not related to an inode are reported with an
+empty file handle of type FILEID_INVALID.
diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
index dc00afcabb95f90da2a7562d9f443c0b4ba6eae6..1bedab498104af95a2f52257fe0ee728276fc092 100644
--- a/Documentation/admin-guide/index.rst
+++ b/Documentation/admin-guide/index.rst
@@ -82,6 +82,7 @@ configure specific aspects of kernel behavior to your liking.
edid
efi-stub
ext4
+ filesystem-monitoring
nfs/index
gpio/index
highuid
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 79b6a0c47f6fdbc04a7e6cf1cd5550526b4ce90d..a320c54202d95e0ee56c1daf571d0896c7821e69 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -46,6 +46,7 @@
#include <linux/part_stat.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
+#include <linux/fsnotify.h>
#include "ext4.h"
#include "ext4_extents.h" /* Needed for trace points definition */
@@ -759,6 +760,8 @@ void __ext4_error(struct super_block *sb, const char *function,
sb->s_id, function, line, current->comm, &vaf);
va_end(args);
}
+ fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
+
ext4_handle_error(sb, force_ro, error, 0, block, function, line);
}
@@ -789,6 +792,8 @@ void __ext4_error_inode(struct inode *inode, const char *function,
current->comm, &vaf);
va_end(args);
}
+ fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
+
ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
function, line);
}
@@ -827,6 +832,8 @@ void __ext4_error_file(struct file *file, const char *function,
current->comm, path, &vaf);
va_end(args);
}
+ fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
+
ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
function, line);
}
@@ -894,6 +901,7 @@ void __ext4_std_error(struct super_block *sb, const char *function,
printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
sb->s_id, function, line, errstr);
}
+ fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
ext4_handle_error(sb, false, -errno, 0, 0, function, line);
}
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index be3c1aad50ea3974433f39b3e6f362f2f0839155..fdf89fcf1a0ca17ac03ab3027b1b36512c408aa0 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -602,6 +602,9 @@ nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask,
struct inode *inode, struct inode *dir,
const struct qstr *name, u32 cookie)
{
+ if (WARN_ON_ONCE(!inode))
+ return 0;
+
trace_nfsd_file_fsnotify_handle_event(inode, mask);
/* Should be no marks on non-regular files */
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 057abd2cf8875ad8786acd496c30ec8add429834..b6091775aa6efe3677e9e83e50cc664dfa15a0df 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -111,6 +111,16 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
return fanotify_info_equal(info1, info2);
}
+static bool fanotify_error_event_equal(struct fanotify_error_event *fee1,
+ struct fanotify_error_event *fee2)
+{
+ /* Error events against the same file system are always merged. */
+ if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))
+ return false;
+
+ return true;
+}
+
static bool fanotify_should_merge(struct fanotify_event *old,
struct fanotify_event *new)
{
@@ -141,6 +151,9 @@ static bool fanotify_should_merge(struct fanotify_event *old,
case FANOTIFY_EVENT_TYPE_FID_NAME:
return fanotify_name_event_equal(FANOTIFY_NE(old),
FANOTIFY_NE(new));
+ case FANOTIFY_EVENT_TYPE_FS_ERROR:
+ return fanotify_error_event_equal(FANOTIFY_EE(old),
+ FANOTIFY_EE(new));
default:
WARN_ON_ONCE(1);
}
@@ -176,6 +189,10 @@ static int fanotify_merge(struct fsnotify_group *group,
break;
if (fanotify_should_merge(old, new)) {
old->mask |= new->mask;
+
+ if (fanotify_is_error_event(old->mask))
+ FANOTIFY_EE(old)->err_count++;
+
return 1;
}
}
@@ -343,13 +360,23 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
static int fanotify_encode_fh_len(struct inode *inode)
{
int dwords = 0;
+ int fh_len;
if (!inode)
return 0;
exportfs_encode_inode_fh(inode, NULL, &dwords, NULL);
+ fh_len = dwords << 2;
+
+ /*
+ * struct fanotify_error_event might be preallocated and is
+ * limited to MAX_HANDLE_SZ. This should never happen, but
+ * safeguard by forcing an invalid file handle.
+ */
+ if (WARN_ON_ONCE(fh_len > MAX_HANDLE_SZ))
+ return 0;
- return dwords << 2;
+ return fh_len;
}
/*
@@ -370,8 +397,14 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
fh->type = FILEID_ROOT;
fh->len = 0;
fh->flags = 0;
+
+ /*
+ * Invalid FHs are used by FAN_FS_ERROR for errors not
+ * linked to any inode. The f_handle won't be reported
+ * back to userspace.
+ */
if (!inode)
- return 0;
+ goto out;
/*
* !gpf means preallocated variable size fh, but fh_len could
@@ -403,8 +436,13 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
fh->type = type;
fh->len = fh_len;
- /* Mix fh into event merge key */
- *hash ^= fanotify_hash_fh(fh);
+out:
+ /*
+ * Mix fh into event merge key. Hash might be NULL in case of
+ * unhashed FID events (i.e. FAN_FS_ERROR).
+ */
+ if (hash)
+ *hash ^= fanotify_hash_fh(fh);
return FANOTIFY_FH_HDR_LEN + fh_len;
@@ -452,7 +490,7 @@ static struct inode *fanotify_dfid_inode(u32 event_mask, const void *data,
if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS)
return dir;
- if (S_ISDIR(inode->i_mode))
+ if (inode && S_ISDIR(inode->i_mode))
return inode;
return dir;
@@ -563,6 +601,44 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
return &fne->fae;
}
+static struct fanotify_event *fanotify_alloc_error_event(
+ struct fsnotify_group *group,
+ __kernel_fsid_t *fsid,
+ const void *data, int data_type,
+ unsigned int *hash)
+{
+ struct fs_error_report *report =
+ fsnotify_data_error_report(data, data_type);
+ struct inode *inode;
+ struct fanotify_error_event *fee;
+ int fh_len;
+
+ if (WARN_ON_ONCE(!report))
+ return NULL;
+
+ fee = mempool_alloc(&group->fanotify_data.error_events_pool, GFP_NOFS);
+ if (!fee)
+ return NULL;
+
+ fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
+ fee->error = report->error;
+ fee->err_count = 1;
+ fee->fsid = *fsid;
+
+ inode = report->inode;
+ fh_len = fanotify_encode_fh_len(inode);
+
+ /* Bad fh_len. Fallback to using an invalid fh. Should never happen. */
+ if (!fh_len && inode)
+ inode = NULL;
+
+ fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0);
+
+ *hash ^= fanotify_hash_fsid(fsid);
+
+ return &fee->fae;
+}
+
static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
u32 mask, const void *data,
int data_type, struct inode *dir,
@@ -630,6 +706,9 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
if (fanotify_is_perm_event(mask)) {
event = fanotify_alloc_perm_event(path, 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 || child)) {
event = fanotify_alloc_name_event(id, fsid, file_name, child,
&hash, gfp);
@@ -702,6 +781,9 @@ static void fanotify_insert_event(struct fsnotify_group *group,
assert_spin_locked(&group->notification_lock);
+ if (!fanotify_is_hashed_event(event->mask))
+ return;
+
pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,
group, event, bucket);
@@ -738,8 +820,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
BUILD_BUG_ON(FAN_OPEN_EXEC != FS_OPEN_EXEC);
BUILD_BUG_ON(FAN_OPEN_EXEC_PERM != FS_OPEN_EXEC_PERM);
+ BUILD_BUG_ON(FAN_FS_ERROR != FS_ERROR);
- BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 19);
+ BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 20);
mask = fanotify_group_event_mask(group, iter_info, mask, data,
data_type, dir);
@@ -778,9 +861,8 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
}
fsn_event = &event->fse;
- ret = fsnotify_add_event(group, fsn_event, fanotify_merge,
- fanotify_is_hashed_event(mask) ?
- fanotify_insert_event : NULL);
+ ret = fsnotify_insert_event(group, fsn_event, fanotify_merge,
+ fanotify_insert_event);
if (ret) {
/* Permission events shouldn't be merged */
BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS);
@@ -805,6 +887,9 @@ static void fanotify_free_group_priv(struct fsnotify_group *group)
if (group->fanotify_data.ucounts)
dec_ucount(group->fanotify_data.ucounts,
UCOUNT_FANOTIFY_GROUPS);
+
+ if (mempool_initialized(&group->fanotify_data.error_events_pool))
+ mempool_exit(&group->fanotify_data.error_events_pool);
}
static void fanotify_free_path_event(struct fanotify_event *event)
@@ -833,7 +918,16 @@ static void fanotify_free_name_event(struct fanotify_event *event)
kfree(FANOTIFY_NE(event));
}
-static void fanotify_free_event(struct fsnotify_event *fsn_event)
+static void fanotify_free_error_event(struct fsnotify_group *group,
+ struct fanotify_event *event)
+{
+ struct fanotify_error_event *fee = FANOTIFY_EE(event);
+
+ mempool_free(fee, &group->fanotify_data.error_events_pool);
+}
+
+static void fanotify_free_event(struct fsnotify_group *group,
+ struct fsnotify_event *fsn_event)
{
struct fanotify_event *event;
@@ -855,6 +949,9 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event)
case FANOTIFY_EVENT_TYPE_OVERFLOW:
kfree(event);
break;
+ case FANOTIFY_EVENT_TYPE_FS_ERROR:
+ fanotify_free_error_event(group, event);
+ break;
default:
WARN_ON_ONCE(1);
}
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 4a5e555dc3d25d4f33104f35c9750409e4225713..d25f500bf7e79a4fb3e8e7af939b0911507f6518 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -141,6 +141,7 @@ enum fanotify_event_type {
FANOTIFY_EVENT_TYPE_PATH,
FANOTIFY_EVENT_TYPE_PATH_PERM,
FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
+ FANOTIFY_EVENT_TYPE_FS_ERROR, /* struct fanotify_error_event */
__FANOTIFY_EVENT_TYPE_NUM
};
@@ -170,12 +171,18 @@ static inline void fanotify_init_event(struct fanotify_event *event,
event->pid = NULL;
}
+#define FANOTIFY_INLINE_FH(name, size) \
+struct { \
+ struct fanotify_fh (name); \
+ /* Space for object_fh.buf[] - access with fanotify_fh_buf() */ \
+ unsigned char _inline_fh_buf[(size)]; \
+}
+
struct fanotify_fid_event {
struct fanotify_event fae;
__kernel_fsid_t fsid;
- struct fanotify_fh object_fh;
- /* Reserve space in object_fh.buf[] - access with fanotify_fh_buf() */
- unsigned char _inline_fh_buf[FANOTIFY_INLINE_FH_LEN];
+
+ FANOTIFY_INLINE_FH(object_fh, FANOTIFY_INLINE_FH_LEN);
};
static inline struct fanotify_fid_event *
@@ -196,12 +203,30 @@ FANOTIFY_NE(struct fanotify_event *event)
return container_of(event, struct fanotify_name_event, fae);
}
+struct fanotify_error_event {
+ struct fanotify_event fae;
+ s32 error; /* Error reported by the Filesystem. */
+ u32 err_count; /* Suppressed errors count */
+
+ __kernel_fsid_t fsid; /* FSID this error refers to. */
+
+ FANOTIFY_INLINE_FH(object_fh, MAX_HANDLE_SZ);
+};
+
+static inline struct fanotify_error_event *
+FANOTIFY_EE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_error_event, fae);
+}
+
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)
return &FANOTIFY_NE(event)->fsid;
+ else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return &FANOTIFY_EE(event)->fsid;
else
return NULL;
}
@@ -213,6 +238,8 @@ static inline struct fanotify_fh *fanotify_event_object_fh(
return &FANOTIFY_FE(event)->object_fh;
else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
return fanotify_info_file_fh(&FANOTIFY_NE(event)->info);
+ else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return &FANOTIFY_EE(event)->object_fh;
else
return NULL;
}
@@ -244,6 +271,19 @@ static inline int fanotify_event_dir_fh_len(struct fanotify_event *event)
return info ? fanotify_info_dir_fh_len(info) : 0;
}
+static inline bool fanotify_event_has_object_fh(struct fanotify_event *event)
+{
+ /* For error events, even zeroed fh are reported. */
+ if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return true;
+ return fanotify_event_object_fh_len(event) > 0;
+}
+
+static inline bool fanotify_event_has_dir_fh(struct fanotify_event *event)
+{
+ return fanotify_event_dir_fh_len(event) > 0;
+}
+
struct fanotify_path_event {
struct fanotify_event fae;
struct path path;
@@ -287,6 +327,11 @@ static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse)
return container_of(fse, struct fanotify_event, fse);
}
+static inline bool fanotify_is_error_event(u32 mask)
+{
+ return mask & FAN_FS_ERROR;
+}
+
static inline bool fanotify_event_has_path(struct fanotify_event *event)
{
return event->type == FANOTIFY_EVENT_TYPE_PATH ||
@@ -315,7 +360,8 @@ static inline struct path *fanotify_event_path(struct fanotify_event *event)
*/
static inline bool fanotify_is_hashed_event(u32 mask)
{
- return !fanotify_is_perm_event(mask) && !(mask & FS_Q_OVERFLOW);
+ return !(fanotify_is_perm_event(mask) ||
+ fsnotify_is_overflow_event(mask));
}
static inline unsigned int fanotify_event_hash_bucket(
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 6facdf476255d13c7ff7dc9aa36def05fcfdf896..559bc1e9926d6a4e41bf7265977f4cfffbba8360 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -30,6 +30,7 @@
#define FANOTIFY_DEFAULT_MAX_EVENTS 16384
#define FANOTIFY_OLD_DEFAULT_MAX_MARKS 8192
#define FANOTIFY_DEFAULT_MAX_GROUPS 128
+#define FANOTIFY_DEFAULT_FEE_POOL_SIZE 32
/*
* Legacy fanotify marks limits (8192) is per group and we introduced a tunable
@@ -114,6 +115,8 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
(sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle))
#define FANOTIFY_PIDFD_INFO_HDR_LEN \
sizeof(struct fanotify_event_info_pidfd)
+#define FANOTIFY_ERROR_INFO_LEN \
+ (sizeof(struct fanotify_event_info_error))
static int fanotify_fid_info_len(int fh_len, int name_len)
{
@@ -126,17 +129,26 @@ static int fanotify_fid_info_len(int fh_len, int name_len)
FANOTIFY_EVENT_ALIGN);
}
-static int fanotify_event_info_len(unsigned int info_mode,
- struct fanotify_event *event)
+static size_t fanotify_event_len(unsigned int info_mode,
+ struct fanotify_event *event)
{
- struct fanotify_info *info = fanotify_event_info(event);
- int dir_fh_len = fanotify_event_dir_fh_len(event);
- int fh_len = fanotify_event_object_fh_len(event);
- int info_len = 0;
+ size_t event_len = FAN_EVENT_METADATA_LEN;
+ struct fanotify_info *info;
+ int dir_fh_len;
+ int fh_len;
int dot_len = 0;
- if (dir_fh_len) {
- info_len += fanotify_fid_info_len(dir_fh_len, info->name_len);
+ if (!info_mode)
+ return event_len;
+
+ if (fanotify_is_error_event(event->mask))
+ event_len += FANOTIFY_ERROR_INFO_LEN;
+
+ info = fanotify_event_info(event);
+
+ if (fanotify_event_has_dir_fh(event)) {
+ dir_fh_len = fanotify_event_dir_fh_len(event);
+ event_len += fanotify_fid_info_len(dir_fh_len, info->name_len);
} else if ((info_mode & FAN_REPORT_NAME) &&
(event->mask & FAN_ONDIR)) {
/*
@@ -147,12 +159,14 @@ static int fanotify_event_info_len(unsigned int info_mode,
}
if (info_mode & FAN_REPORT_PIDFD)
- info_len += FANOTIFY_PIDFD_INFO_HDR_LEN;
+ event_len += FANOTIFY_PIDFD_INFO_HDR_LEN;
- if (fh_len)
- info_len += fanotify_fid_info_len(fh_len, dot_len);
+ if (fanotify_event_has_object_fh(event)) {
+ fh_len = fanotify_event_object_fh_len(event);
+ event_len += fanotify_fid_info_len(fh_len, dot_len);
+ }
- return info_len;
+ return event_len;
}
/*
@@ -181,7 +195,7 @@ static void fanotify_unhash_event(struct fsnotify_group *group,
static struct fanotify_event *get_one_event(struct fsnotify_group *group,
size_t count)
{
- size_t event_size = FAN_EVENT_METADATA_LEN;
+ size_t event_size;
struct fanotify_event *event = NULL;
struct fsnotify_event *fsn_event;
unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES);
@@ -194,8 +208,7 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
goto out;
event = FANOTIFY_E(fsn_event);
- if (info_mode)
- event_size += fanotify_event_info_len(info_mode, event);
+ event_size = fanotify_event_len(info_mode, event);
if (event_size > count) {
event = ERR_PTR(-EINVAL);
@@ -316,6 +329,28 @@ static int process_access_response(struct fsnotify_group *group,
return -ENOENT;
}
+static size_t copy_error_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_error info;
+ struct fanotify_error_event *fee = FANOTIFY_EE(event);
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_ERROR;
+ info.hdr.pad = 0;
+ info.hdr.len = FANOTIFY_ERROR_INFO_LEN;
+
+ if (WARN_ON(count < info.hdr.len))
+ return -EFAULT;
+
+ info.error = fee->error;
+ info.error_count = fee->err_count;
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ return -EFAULT;
+
+ return info.hdr.len;
+}
+
static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
int info_type, const char *name,
size_t name_len,
@@ -331,9 +366,6 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n",
__func__, fh_len, name_len, info_len, count);
- if (!fh_len)
- return 0;
-
if (WARN_ON_ONCE(len < sizeof(info) || len > count))
return -EFAULT;
@@ -368,6 +400,11 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
handle.handle_type = fh->type;
handle.handle_bytes = fh_len;
+
+ /* Mangle handle_type for bad file_handle */
+ if (!fh_len)
+ handle.handle_type = FILEID_INVALID;
+
if (copy_to_user(buf, &handle, sizeof(handle)))
return -EFAULT;
@@ -444,7 +481,7 @@ static int copy_info_records_to_user(struct fanotify_event *event,
/*
* Event info records order is as follows: dir fid + name, child fid.
*/
- if (fanotify_event_dir_fh_len(event)) {
+ if (fanotify_event_has_dir_fh(event)) {
info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
FAN_EVENT_INFO_TYPE_DFID;
ret = copy_fid_info_to_user(fanotify_event_fsid(event),
@@ -460,7 +497,7 @@ static int copy_info_records_to_user(struct fanotify_event *event,
total_bytes += ret;
}
- if (fanotify_event_object_fh_len(event)) {
+ if (fanotify_event_has_object_fh(event)) {
const char *dot = NULL;
int dot_len = 0;
@@ -520,6 +557,15 @@ static int copy_info_records_to_user(struct fanotify_event *event,
total_bytes += ret;
}
+ if (fanotify_is_error_event(event->mask)) {
+ ret = copy_error_info_to_user(event, buf, count);
+ if (ret < 0)
+ return ret;
+ buf += ret;
+ count -= ret;
+ total_bytes += ret;
+ }
+
return total_bytes;
}
@@ -537,8 +583,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- metadata.event_len = FAN_EVENT_METADATA_LEN +
- fanotify_event_info_len(info_mode, event);
+ metadata.event_len = fanotify_event_len(info_mode, event);
metadata.metadata_len = FAN_EVENT_METADATA_LEN;
metadata.vers = FANOTIFY_METADATA_VERSION;
metadata.reserved = 0;
@@ -1049,6 +1094,15 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
return ERR_PTR(ret);
}
+static int fanotify_group_init_error_pool(struct fsnotify_group *group)
+{
+ if (mempool_initialized(&group->fanotify_data.error_events_pool))
+ return 0;
+
+ return mempool_init_kmalloc_pool(&group->fanotify_data.error_events_pool,
+ FANOTIFY_DEFAULT_FEE_POOL_SIZE,
+ sizeof(struct fanotify_error_event));
+}
static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, unsigned int type,
@@ -1057,6 +1111,7 @@ static int fanotify_add_mark(struct fsnotify_group *group,
{
struct fsnotify_mark *fsn_mark;
__u32 added;
+ int ret = 0;
mutex_lock(&group->mark_mutex);
fsn_mark = fsnotify_find_mark(connp, group);
@@ -1067,13 +1122,26 @@ static int fanotify_add_mark(struct fsnotify_group *group,
return PTR_ERR(fsn_mark);
}
}
+
+ /*
+ * Error events are pre-allocated per group, only if strictly
+ * needed (i.e. FAN_FS_ERROR was requested).
+ */
+ if (!(flags & FAN_MARK_IGNORED_MASK) && (mask & FAN_FS_ERROR)) {
+ ret = fanotify_group_init_error_pool(group);
+ if (ret)
+ goto out;
+ }
+
added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
if (added & ~fsnotify_conn_mask(fsn_mark->connector))
fsnotify_recalc_mask(fsn_mark->connector);
+
+out:
mutex_unlock(&group->mark_mutex);
fsnotify_put_mark(fsn_mark);
- return 0;
+ return ret;
}
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
@@ -1295,16 +1363,15 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
return fd;
}
-/* Check if filesystem can encode a unique fid */
-static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
+static int fanotify_test_fsid(struct dentry *dentry, __kernel_fsid_t *fsid)
{
__kernel_fsid_t root_fsid;
int err;
/*
- * Make sure path is not in filesystem with zero fsid (e.g. tmpfs).
+ * Make sure dentry is not of a filesystem with zero fsid (e.g. fuse).
*/
- err = vfs_get_fsid(path->dentry, fsid);
+ err = vfs_get_fsid(dentry, fsid);
if (err)
return err;
@@ -1312,10 +1379,10 @@ static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
return -ENODEV;
/*
- * Make sure path is not inside a filesystem subvolume (e.g. btrfs)
+ * Make sure dentry is not of a filesystem subvolume (e.g. btrfs)
* which uses a different fsid than sb root.
*/
- err = vfs_get_fsid(path->dentry->d_sb->s_root, &root_fsid);
+ err = vfs_get_fsid(dentry->d_sb->s_root, &root_fsid);
if (err)
return err;
@@ -1323,6 +1390,12 @@ static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
root_fsid.val[1] != fsid->val[1])
return -EXDEV;
+ return 0;
+}
+
+/* Check if filesystem can encode a unique fid */
+static int fanotify_test_fid(struct dentry *dentry)
+{
/*
* We need to make sure that the file system supports at least
* encoding a file handle so user can use name_to_handle_at() to
@@ -1330,8 +1403,8 @@ static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
* objects. However, name_to_handle_at() requires that the
* filesystem also supports decoding file handles.
*/
- if (!path->dentry->d_sb->s_export_op ||
- !path->dentry->d_sb->s_export_op->fh_to_dentry)
+ if (!dentry->d_sb->s_export_op ||
+ !dentry->d_sb->s_export_op->fh_to_dentry)
return -EOPNOTSUPP;
return 0;
@@ -1447,15 +1520,19 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
group->priority == FS_PRIO_0)
goto fput_and_out;
+ if (mask & FAN_FS_ERROR &&
+ mark_type != FAN_MARK_FILESYSTEM)
+ goto fput_and_out;
+
/*
- * Events with data type inode do not carry enough information to report
- * event->fd, so we do not allow setting a mask for inode events unless
- * group supports reporting fid.
- * inode events are not supported on a mount mark, because they do not
- * carry enough information (i.e. path) to be filtered by mount point.
+ * Events that do not carry enough information to report
+ * event->fd require a group that supports reporting fid. Those
+ * events are not supported on a mount mark, because they do not
+ * carry enough information (i.e. path) to be filtered by mount
+ * point.
*/
fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
- if (mask & FANOTIFY_INODE_EVENTS &&
+ if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_EVENT_FLAGS) &&
(!fid_mode || mark_type == FAN_MARK_MOUNT))
goto fput_and_out;
@@ -1482,7 +1559,11 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
}
if (fid_mode) {
- ret = fanotify_test_fid(&path, &__fsid);
+ ret = fanotify_test_fsid(path.dentry, &__fsid);
+ if (ret)
+ goto path_put_and_out;
+
+ ret = fanotify_test_fid(path.dentry);
if (ret)
goto path_put_and_out;
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 963e6ce75b96113c5739a68698082b2aea7f3195..4034ca566f95cedcb01480b0640be4b770539eec 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -252,6 +252,9 @@ static int fsnotify_handle_inode_event(struct fsnotify_group *group,
if (WARN_ON_ONCE(!ops->handle_inode_event))
return 0;
+ if (WARN_ON_ONCE(!inode && !dir))
+ return 0;
+
if ((inode_mark->mask & FS_EXCL_UNLINK) &&
path && d_unlinked(path->dentry))
return 0;
@@ -455,16 +458,16 @@ static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
* @file_name is relative to
* @file_name: optional file name associated with event
* @inode: optional inode associated with event -
- * either @dir or @inode must be non-NULL.
- * if both are non-NULL event may be reported to both.
+ * If @dir and @inode are both non-NULL, event may be
+ * reported to both.
* @cookie: inotify rename cookie
*/
int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
const struct qstr *file_name, struct inode *inode, u32 cookie)
{
const struct path *path = fsnotify_data_path(data, data_type);
+ struct super_block *sb = fsnotify_data_sb(data, data_type);
struct fsnotify_iter_info iter_info = {};
- struct super_block *sb;
struct mount *mnt = NULL;
struct inode *parent = NULL;
int ret = 0;
@@ -483,7 +486,6 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
*/
parent = dir;
}
- sb = inode->i_sb;
/*
* Optimization: srcu_read_lock() has a memory barrier which can
diff --git a/fs/notify/group.c b/fs/notify/group.c
index fb89c351295d6ee1e8156c176417915e60969812..6a297efc478874b10346b1d8ac0e8a9c941d6bd3 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -88,7 +88,7 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
* that deliberately ignores overflow events.
*/
if (group->overflow_event)
- group->ops->free_event(group->overflow_event);
+ group->ops->free_event(group, group->overflow_event);
fsnotify_put_group(group);
}
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index d1a64daa0171ec851903be87cd7357bf4ecba556..d92d7b0adc9a2764f16923fbf797df68730c0e7d 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -116,7 +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, NULL);
+ ret = fsnotify_add_event(group, fsn_event, inotify_merge);
if (ret) {
/* Our event wasn't used in the end. Free it. */
fsnotify_destroy_event(group, fsn_event);
@@ -177,7 +177,8 @@ static void inotify_free_group_priv(struct fsnotify_group *group)
dec_inotify_instances(group->inotify_data.ucounts);
}
-static void inotify_free_event(struct fsnotify_event *fsn_event)
+static void inotify_free_event(struct fsnotify_group *group,
+ struct fsnotify_event *fsn_event)
{
kfree(INOTIFY_E(fsn_event));
}
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 62051247f6d21d4b0fed55a914ccf37ae7e530c2..29fca3284bb5c83c25a669b213dfa3da870631ed 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -94,10 +94,10 @@ static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
__u32 mask;
/*
- * Everything should accept their own ignored and should receive events
- * when the inode is unmounted. All directories care about children.
+ * Everything should receive events when the inode is unmounted.
+ * All directories care about children.
*/
- mask = (FS_IN_IGNORED | FS_UNMOUNT);
+ mask = (FS_UNMOUNT);
if (S_ISDIR(inode->i_mode))
mask |= FS_EVENT_ON_CHILD;
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 32f45543b9c649bef2bfcf0ef78ad2681c05e89c..9022ae650cf863ea5276027204fcae754024cf62 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -64,7 +64,7 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
WARN_ON(!list_empty(&event->list));
spin_unlock(&group->notification_lock);
}
- group->ops->free_event(event);
+ group->ops->free_event(group, event);
}
/*
@@ -78,12 +78,12 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
* 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 fsnotify_group *,
- struct fsnotify_event *),
- void (*insert)(struct fsnotify_group *,
- struct fsnotify_event *))
+int fsnotify_insert_event(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ int (*merge)(struct fsnotify_group *,
+ struct fsnotify_event *),
+ void (*insert)(struct fsnotify_group *,
+ struct fsnotify_event *))
{
int ret = 0;
struct list_head *list = &group->notification_list;
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index eec3b7c40811528dfab87563cacffea4396a6021..616af2ea20f301067faccb5e18f2814750d8b046 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -84,13 +84,20 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */
*/
#define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE)
+/* Events that can be reported with event->fd */
+#define FANOTIFY_FD_EVENTS (FANOTIFY_PATH_EVENTS | FANOTIFY_PERM_EVENTS)
+
/* Events that can only be reported with data type FSNOTIFY_EVENT_INODE */
#define FANOTIFY_INODE_EVENTS (FANOTIFY_DIRENT_EVENTS | \
FAN_ATTRIB | FAN_MOVE_SELF | FAN_DELETE_SELF)
+/* Events that can only be reported with data type FSNOTIFY_EVENT_ERROR */
+#define FANOTIFY_ERROR_EVENTS (FAN_FS_ERROR)
+
/* Events that user can request to be notified on */
#define FANOTIFY_EVENTS (FANOTIFY_PATH_EVENTS | \
- FANOTIFY_INODE_EVENTS)
+ FANOTIFY_INODE_EVENTS | \
+ FANOTIFY_ERROR_EVENTS)
/* Events that require a permission response from user */
#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 12d3a7d308ab9ae40afd886b80cabb0a319f3e6e..787545e87eeb053d8016ebfecc1a5c67f806ff8b 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -26,20 +26,20 @@
* FS_EVENT_ON_CHILD mask on the parent inode and will not be reported if only
* the child is interested and not the parent.
*/
-static inline void fsnotify_name(struct inode *dir, __u32 mask,
- struct inode *child,
- const struct qstr *name, u32 cookie)
+static inline int fsnotify_name(__u32 mask, const void *data, int data_type,
+ struct inode *dir, const struct qstr *name,
+ u32 cookie)
{
if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0)
- return;
+ return 0;
- fsnotify(mask, child, FSNOTIFY_EVENT_INODE, dir, name, NULL, cookie);
+ return fsnotify(mask, data, data_type, dir, name, NULL, cookie);
}
static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry,
__u32 mask)
{
- fsnotify_name(dir, mask, d_inode(dentry), &dentry->d_name, 0);
+ fsnotify_name(mask, dentry, FSNOTIFY_EVENT_DENTRY, dir, &dentry->d_name, 0);
}
static inline void fsnotify_inode(struct inode *inode, __u32 mask)
@@ -86,7 +86,7 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
*/
static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask)
{
- fsnotify_parent(dentry, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE);
+ fsnotify_parent(dentry, mask, dentry, FSNOTIFY_EVENT_DENTRY);
}
static inline int fsnotify_file(struct file *file, __u32 mask)
@@ -154,8 +154,10 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
new_dir_mask |= FS_ISDIR;
}
- fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie);
- fsnotify_name(new_dir, new_dir_mask, source, new_name, fs_cookie);
+ fsnotify_name(old_dir_mask, source, FSNOTIFY_EVENT_INODE,
+ old_dir, old_name, fs_cookie);
+ fsnotify_name(new_dir_mask, source, FSNOTIFY_EVENT_INODE,
+ new_dir, new_name, fs_cookie);
if (target)
fsnotify_link_count(target);
@@ -190,16 +192,22 @@ static inline void fsnotify_inoderemove(struct inode *inode)
/*
* fsnotify_create - 'name' was linked in
+ *
+ * Caller must make sure that dentry->d_name is stable.
+ * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate
+ * ->d_inode later
*/
-static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
+static inline void fsnotify_create(struct inode *dir, struct dentry *dentry)
{
- audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
+ audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE);
- fsnotify_dirent(inode, dentry, FS_CREATE);
+ fsnotify_dirent(dir, dentry, FS_CREATE);
}
/*
* fsnotify_link - new hardlink in 'inode' directory
+ *
+ * Caller must make sure that new_dentry->d_name is stable.
* Note: We have to pass also the linked inode ptr as some filesystems leave
* new_dentry->d_inode NULL and instantiate inode pointer later
*/
@@ -209,7 +217,8 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode,
fsnotify_link_count(inode);
audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
- fsnotify_name(dir, FS_CREATE, inode, &new_dentry->d_name, 0);
+ fsnotify_name(FS_CREATE, inode, FSNOTIFY_EVENT_INODE,
+ dir, &new_dentry->d_name, 0);
}
/*
@@ -227,12 +236,16 @@ static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry)
/*
* fsnotify_mkdir - directory 'name' was created
+ *
+ * Caller must make sure that dentry->d_name is stable.
+ * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate
+ * ->d_inode later
*/
-static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
+static inline void fsnotify_mkdir(struct inode *dir, struct dentry *dentry)
{
- audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
+ audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE);
- fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
+ fsnotify_dirent(dir, dentry, FS_CREATE | FS_ISDIR);
}
/*
@@ -326,4 +339,17 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
fsnotify_dentry(dentry, mask);
}
+static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode,
+ int error)
+{
+ struct fs_error_report report = {
+ .error = error,
+ .inode = inode,
+ .sb = sb,
+ };
+
+ return fsnotify(FS_ERROR, &report, FSNOTIFY_EVENT_ERROR,
+ NULL, NULL, NULL, 0);
+}
+
#endif /* _LINUX_FS_NOTIFY_H */
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 1ce66748a2d299dbfac1b3438ed7f1ac48f48527..51ef2b079bfa0c7ea4bf8a8f1d010cb67a546d95 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -19,6 +19,7 @@
#include <linux/atomic.h>
#include <linux/user_namespace.h>
#include <linux/refcount.h>
+#include <linux/mempool.h>
/*
* IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily
@@ -42,6 +43,12 @@
#define FS_UNMOUNT 0x00002000 /* inode on umount fs */
#define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
+#define FS_ERROR 0x00008000 /* Filesystem Error (fanotify) */
+
+/*
+ * FS_IN_IGNORED overloads FS_ERROR. It is only used internally by inotify
+ * which does not support FS_ERROR.
+ */
#define FS_IN_IGNORED 0x00008000 /* last inotify event here */
#define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */
@@ -95,7 +102,8 @@
#define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
FS_EVENTS_POSS_ON_CHILD | \
FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \
- FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED)
+ FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \
+ FS_ERROR)
/* Extra flags that may be reported with event or control handling of events */
#define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \
@@ -136,6 +144,7 @@ struct mem_cgroup;
* @dir: optional directory associated with event -
* if @file_name is not NULL, this is the directory that
* @file_name is relative to.
+ * Either @inode or @dir must be non-NULL.
* @file_name: optional file name associated with event
* @cookie: inotify rename cookie
*
@@ -155,7 +164,7 @@ struct fsnotify_ops {
const struct qstr *file_name, u32 cookie);
void (*free_group_priv)(struct fsnotify_group *group);
void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group);
- void (*free_event)(struct fsnotify_event *event);
+ void (*free_event)(struct fsnotify_group *group, struct fsnotify_event *event);
/* called on final put+free to free memory */
void (*free_mark)(struct fsnotify_mark *mark);
};
@@ -238,6 +247,7 @@ struct fsnotify_group {
int flags; /* flags from fanotify_init() */
int f_flags; /* event_f_flags from fanotify_init() */
struct ucounts *ucounts;
+ mempool_t error_events_pool;
} fanotify_data;
#endif /* CONFIG_FANOTIFY */
};
@@ -248,6 +258,14 @@ enum fsnotify_data_type {
FSNOTIFY_EVENT_NONE,
FSNOTIFY_EVENT_PATH,
FSNOTIFY_EVENT_INODE,
+ FSNOTIFY_EVENT_DENTRY,
+ FSNOTIFY_EVENT_ERROR,
+};
+
+struct fs_error_report {
+ int error;
+ struct inode *inode;
+ struct super_block *sb;
};
static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
@@ -255,8 +273,25 @@ static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
switch (data_type) {
case FSNOTIFY_EVENT_INODE:
return (struct inode *)data;
+ case FSNOTIFY_EVENT_DENTRY:
+ return d_inode(data);
case FSNOTIFY_EVENT_PATH:
return d_inode(((const struct path *)data)->dentry);
+ case FSNOTIFY_EVENT_ERROR:
+ return ((struct fs_error_report *)data)->inode;
+ default:
+ return NULL;
+ }
+}
+
+static inline struct dentry *fsnotify_data_dentry(const void *data, int data_type)
+{
+ switch (data_type) {
+ case FSNOTIFY_EVENT_DENTRY:
+ /* Non const is needed for dget() */
+ return (struct dentry *)data;
+ case FSNOTIFY_EVENT_PATH:
+ return ((const struct path *)data)->dentry;
default:
return NULL;
}
@@ -273,6 +308,35 @@ static inline const struct path *fsnotify_data_path(const void *data,
}
}
+static inline struct super_block *fsnotify_data_sb(const void *data,
+ int data_type)
+{
+ switch (data_type) {
+ case FSNOTIFY_EVENT_INODE:
+ return ((struct inode *)data)->i_sb;
+ case FSNOTIFY_EVENT_DENTRY:
+ return ((struct dentry *)data)->d_sb;
+ case FSNOTIFY_EVENT_PATH:
+ return ((const struct path *)data)->dentry->d_sb;
+ case FSNOTIFY_EVENT_ERROR:
+ return ((struct fs_error_report *) data)->sb;
+ default:
+ return NULL;
+ }
+}
+
+static inline struct fs_error_report *fsnotify_data_error_report(
+ const void *data,
+ int data_type)
+{
+ switch (data_type) {
+ case FSNOTIFY_EVENT_ERROR:
+ return (struct fs_error_report *) data;
+ default:
+ return NULL;
+ }
+}
+
enum fsnotify_obj_type {
FSNOTIFY_OBJ_TYPE_INODE,
FSNOTIFY_OBJ_TYPE_PARENT,
@@ -482,16 +546,30 @@ extern int fsnotify_fasync(int fd, struct file *file, int on);
extern void fsnotify_destroy_event(struct fsnotify_group *group,
struct fsnotify_event *event);
/* attach the event to the group notification queue */
-extern int fsnotify_add_event(struct fsnotify_group *group,
- struct fsnotify_event *event,
- int (*merge)(struct fsnotify_group *,
- struct fsnotify_event *),
- void (*insert)(struct fsnotify_group *,
- struct fsnotify_event *));
+extern int fsnotify_insert_event(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ int (*merge)(struct fsnotify_group *,
+ struct fsnotify_event *),
+ void (*insert)(struct fsnotify_group *,
+ struct fsnotify_event *));
+
+static inline int fsnotify_add_event(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ int (*merge)(struct fsnotify_group *,
+ struct fsnotify_event *))
+{
+ return fsnotify_insert_event(group, event, merge, NULL);
+}
+
/* 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, NULL);
+ fsnotify_add_event(group, group->overflow_event, NULL);
+}
+
+static inline bool fsnotify_is_overflow_event(u32 mask)
+{
+ return mask & FS_Q_OVERFLOW;
}
static inline bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 64553df9d7350d03b50e62f6419a78df1bbe64e3..bd1932c2074d52c74c7efa9f86ef48e3c8d39bb0 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -20,6 +20,7 @@
#define FAN_OPEN_EXEC 0x00001000 /* File was opened for exec */
#define FAN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
+#define FAN_FS_ERROR 0x00008000 /* Filesystem error */
#define FAN_OPEN_PERM 0x00010000 /* File open in perm check */
#define FAN_ACCESS_PERM 0x00020000 /* File accessed in perm check */
@@ -125,6 +126,7 @@ struct fanotify_event_metadata {
#define FAN_EVENT_INFO_TYPE_DFID_NAME 2
#define FAN_EVENT_INFO_TYPE_DFID 3
#define FAN_EVENT_INFO_TYPE_PIDFD 4
+#define FAN_EVENT_INFO_TYPE_ERROR 5
/* Variable length info record following event metadata */
struct fanotify_event_info_header {
@@ -159,6 +161,12 @@ struct fanotify_event_info_pidfd {
__s32 pidfd;
};
+struct fanotify_event_info_error {
+ struct fanotify_event_info_header hdr;
+ __s32 error;
+ __u32 error_count;
+};
+
struct fanotify_response {
__s32 fd;
__u32 response;
diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index 60739d5e3373f8da84e9732b93822a5b8007f8de..02348b48447cf72b906bf0195c6c42afb91da6f2 100644
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -160,8 +160,7 @@ static int audit_mark_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
- if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group) ||
- WARN_ON_ONCE(!inode))
+ if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group))
return 0;
if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 698b62b4a2ec1757a76f12a68b95c5a7940abdab..713b256be944c89402a2f6206d5adeafbb18b53c 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -473,8 +473,7 @@ static int audit_watch_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
parent = container_of(inode_mark, struct audit_parent, mark);
- if (WARN_ON_ONCE(inode_mark->group != audit_watch_group) ||
- WARN_ON_ONCE(!inode))
+ if (WARN_ON_ONCE(inode_mark->group != audit_watch_group))
return 0;
if (mask & (FS_CREATE|FS_MOVED_TO) && inode)
diff --git a/samples/Kconfig b/samples/Kconfig
index 5518a3e62292d7f8b28c155b75b38c46000a0384..bec3528aa2de1369619940999d300b1b9c1849d2 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -120,6 +120,15 @@ config SAMPLE_CONNECTOR
with it.
See also Documentation/driver-api/connector.rst
+config SAMPLE_FANOTIFY_ERROR
+ bool "Build fanotify error monitoring sample"
+ depends on FANOTIFY && CC_CAN_LINK && HEADERS_INSTALL
+ help
+ When enabled, this builds an example code that uses the
+ FAN_FS_ERROR fanotify mechanism to monitor filesystem
+ errors.
+ See also Documentation/admin-guide/filesystem-monitoring.rst.
+
config SAMPLE_HIDRAW
bool "hidraw sample"
depends on CC_CAN_LINK && HEADERS_INSTALL
diff --git a/samples/Makefile b/samples/Makefile
index f06e5995019379732e35f5698a64169f6c2889e0..b7b98307c2b4051cb84e6bd0c38c3b6dc21fb864 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -5,6 +5,7 @@ subdir-$(CONFIG_SAMPLE_AUXDISPLAY) += auxdisplay
subdir-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs
obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs/
obj-$(CONFIG_SAMPLE_CONNECTOR) += connector/
+obj-$(CONFIG_SAMPLE_FANOTIFY_ERROR) += fanotify/
subdir-$(CONFIG_SAMPLE_HIDRAW) += hidraw
obj-$(CONFIG_SAMPLE_HW_BREAKPOINT) += hw_breakpoint/
obj-$(CONFIG_SAMPLE_KDB) += kdb/
diff --git a/samples/fanotify/Makefile b/samples/fanotify/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..e20db1bdde3b4c5a5916b541f91eaec96d645629
--- /dev/null
+++ b/samples/fanotify/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+userprogs-always-y += fs-monitor
+
+userccflags += -I usr/include -Wall
+
diff --git a/samples/fanotify/fs-monitor.c b/samples/fanotify/fs-monitor.c
new file mode 100644
index 0000000000000000000000000000000000000000..608db24c471e762e835a5567e89ca5d877a8e984
--- /dev/null
+++ b/samples/fanotify/fs-monitor.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021, Collabora Ltd.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <err.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/fanotify.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#ifndef FAN_FS_ERROR
+#define FAN_FS_ERROR 0x00008000
+#define FAN_EVENT_INFO_TYPE_ERROR 5
+
+struct fanotify_event_info_error {
+ struct fanotify_event_info_header hdr;
+ __s32 error;
+ __u32 error_count;
+};
+#endif
+
+#ifndef FILEID_INO32_GEN
+#define FILEID_INO32_GEN 1
+#endif
+
+#ifndef FILEID_INVALID
+#define FILEID_INVALID 0xff
+#endif
+
+static void print_fh(struct file_handle *fh)
+{
+ int i;
+ uint32_t *h = (uint32_t *) fh->f_handle;
+
+ printf("\tfh: ");
+ for (i = 0; i < fh->handle_bytes; i++)
+ printf("%hhx", fh->f_handle[i]);
+ printf("\n");
+
+ printf("\tdecoded fh: ");
+ if (fh->handle_type == FILEID_INO32_GEN)
+ printf("inode=%u gen=%u\n", h[0], h[1]);
+ else if (fh->handle_type == FILEID_INVALID && !fh->handle_bytes)
+ printf("Type %d (Superblock error)\n", fh->handle_type);
+ else
+ printf("Type %d (Unknown)\n", fh->handle_type);
+
+}
+
+static void handle_notifications(char *buffer, int len)
+{
+ struct fanotify_event_metadata *event =
+ (struct fanotify_event_metadata *) buffer;
+ struct fanotify_event_info_header *info;
+ struct fanotify_event_info_error *err;
+ struct fanotify_event_info_fid *fid;
+ int off;
+
+ for (; FAN_EVENT_OK(event, len); event = FAN_EVENT_NEXT(event, len)) {
+
+ if (event->mask != FAN_FS_ERROR) {
+ printf("unexpected FAN MARK: %llx\n",
+ (unsigned long long)event->mask);
+ goto next_event;
+ }
+
+ if (event->fd != FAN_NOFD) {
+ printf("Unexpected fd (!= FAN_NOFD)\n");
+ goto next_event;
+ }
+
+ printf("FAN_FS_ERROR (len=%d)\n", event->event_len);
+
+ for (off = sizeof(*event) ; off < event->event_len;
+ off += info->len) {
+ info = (struct fanotify_event_info_header *)
+ ((char *) event + off);
+
+ switch (info->info_type) {
+ case FAN_EVENT_INFO_TYPE_ERROR:
+ err = (struct fanotify_event_info_error *) info;
+
+ printf("\tGeneric Error Record: len=%d\n",
+ err->hdr.len);
+ printf("\terror: %d\n", err->error);
+ printf("\terror_count: %d\n", err->error_count);
+ break;
+
+ case FAN_EVENT_INFO_TYPE_FID:
+ fid = (struct fanotify_event_info_fid *) info;
+
+ printf("\tfsid: %x%x\n",
+ fid->fsid.val[0], fid->fsid.val[1]);
+ print_fh((struct file_handle *) &fid->handle);
+ break;
+
+ default:
+ printf("\tUnknown info type=%d len=%d:\n",
+ info->info_type, info->len);
+ }
+ }
+next_event:
+ printf("---\n\n");
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int fd;
+
+ char buffer[BUFSIZ];
+
+ if (argc < 2) {
+ printf("Missing path argument\n");
+ return 1;
+ }
+
+ fd = fanotify_init(FAN_CLASS_NOTIF|FAN_REPORT_FID, O_RDONLY);
+ if (fd < 0)
+ errx(1, "fanotify_init");
+
+ if (fanotify_mark(fd, FAN_MARK_ADD|FAN_MARK_FILESYSTEM,
+ FAN_FS_ERROR, AT_FDCWD, argv[1])) {
+ errx(1, "fanotify_mark");
+ }
+
+ while (1) {
+ int n = read(fd, buffer, BUFSIZ);
+
+ if (n < 0)
+ errx(1, "read");
+
+ handle_notifications(buffer, n);
+ }
+
+ return 0;
+}