On Fri, Oct 15, 2021 at 12:39 AM Gabriel Krisman Bertazi
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
Plumb the pieces to add a FID report to error records. Since all error
event memory must be pre-allocated, we pre-allocate the maximum file
handle size possible, such that it should always fit.
For errors that don't expose a file handle report it with an invalid
FID.
Signed-off-by: Gabriel Krisman Bertazi <redacted>
---
Changes since v6:
- pass fsid from handle_events
Changes since v5:
- Use preallocated MAX_HANDLE_SZ FH buffer
- Report superblock errors with a zerolength INVALID FID (jan, amir)
---
fs/notify/fanotify/fanotify.c | 15 +++++++++++++++
fs/notify/fanotify/fanotify.h | 8 ++++++++
2 files changed, 23 insertions(+)
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 7032083df62a..8a60c96f5fb2 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -611,7 +611,9 @@ static struct fanotify_event *fanotify_alloc_error_event(
{
struct fs_error_report *report =
fsnotify_data_error_report(data, data_type);
+ struct inode *inode = report->inode;
struct fanotify_error_event *fee;
+ int fh_len;
if (WARN_ON(!report))
return NULL;@@ -622,6 +624,19 @@ static struct fanotify_event *fanotify_alloc_error_event(
fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
fee->err_count = 1;
+ fee->fsid = *fsid;
+
+ fh_len = fanotify_encode_fh_len(inode);
+ if (WARN_ON(fh_len > MAX_HANDLE_SZ)) {
WARN_ON_ONCE please and I rather that this sanity check is moved inside
fanotify_encode_fh_len() where it will return 0 for encoding failure.
quoted hunk ↗ jump to hunk
+ /*
+ * Fallback to reporting the error against the super
+ * block. It should never happen.
+ */
+ inode = NULL;
+ fh_len = fanotify_encode_fh_len(NULL);
+ }
+
+ fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0);
*hash ^= fanotify_hash_fsid(fsid);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 2b032b79d5b0..b58400926f92 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -202,6 +202,10 @@ struct fanotify_error_event {
u32 err_count; /* Suppressed errors count */
__kernel_fsid_t fsid; /* FSID this error refers to. */
+ /* object_fh must be followed by the inline handle buffer. */
+ struct fanotify_fh object_fh;
+ /* Reserve space in object_fh.buf[] - access with fanotify_fh_buf() */
+ unsigned char _inline_fh_buf[MAX_HANDLE_SZ];
};
This struct duplicates most of struct fanotify_fid_event.
How about:
#define FANOTIFY_ERROR_FH_LEN \
(MAX_HANDLE_SZ - FANOTIFY_INLINE_FH_LEN)
struct fanotify_error_event {
u32 err_count; /* Suppressed errors count */
struct fanotify_event ffe;
/* Reserve space in ffe.object_fh.buf[] - access with
fanotify_fh_buf() */
unsigned char _fh_buf[FANOTIFY_ERROR_FH_LEN];
}
Or leaving out the struct padding and passing
FANOTIFY_ERROR_EVENT_SIZE as mempool object size?
#define FANOTIFY_ERROR_EVENT_SIZE \
(sizeof(struct fanotify_error_event) + FANOTIFY_ERROR_FH_LEN)
You do not have to make this change - it is a proposal that can have
supporters and objectors, so let's wait to see what you and other reviewers
have to say.
Thanks,
Amir.