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authorAmir Goldstein <amir73il@gmail.com>2019-01-10 19:04:34 +0200
committerJan Kara <jack@suse.cz>2019-02-07 16:38:34 +0100
commite9e0c8903009477b630e37a8b6364b26a00720da (patch)
tree26abd52b6da51386edcea7f96237f3cdd803fc62 /include
parentbb2f7b4542c7a1d023d516af37dc70bb49db0438 (diff)
downloadlinux-e9e0c8903009477b630e37a8b6364b26a00720da.tar.bz2
fanotify: encode file identifier for FAN_REPORT_FID
When user requests the flag FAN_REPORT_FID in fanotify_init(), a unique file identifier of the event target object will be reported with the event. The file identifier includes the filesystem's fsid (i.e. from statfs(2)) and an NFS file handle of the file (i.e. from name_to_handle_at(2)). The file identifier makes holding the path reference and passing a file descriptor to user redundant, so those are disabled in a group with FAN_REPORT_FID. Encode fid and store it in event for a group with FAN_REPORT_FID. Up to 12 bytes of file handle on 32bit arch (16 bytes on 64bit arch) are stored inline in fanotify_event struct. Larger file handles are stored in an external allocated buffer. On failure to encode fid, we print a warning and queue the event without the fid information. [JK: Fold part of later patched into this one to use exportfs_encode_inode_fh() right away] Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'include')
-rw-r--r--include/uapi/linux/fanotify.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 909c98fcace2..d07f3cbc2786 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -44,6 +44,7 @@
/* Flags to determine fanotify event format */
#define FAN_REPORT_TID 0x00000100 /* event->pid is thread id */
+#define FAN_REPORT_FID 0x00000200 /* Report unique file id */
/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC | FAN_NONBLOCK | \