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An update to fanotify fdinfo output

PATCH New Cyrill Gorcunov 1 participant 3 messages Dec 7, 2012

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Documentation Fsnotify: filesystem notification infrastructure
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Cyrill Gorcunov

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#0 lore raw

cover An update to fanotify fdinfo output

Hi Andrew, here is an update for fanotify fdinfo output.
I also update documentation to fit the current state of the output format. This should be the last bits we need for fdinfo. As always any comments are highly appreciated.

Cyrill

author
#1 lore raw

PATCH 1/2 fs, fanotify: Add @mflags field to fanotify output

The kernel keeps FAN_MARK_IGNORED_SURV_MODIFY bit separately from fsnotify_mark::mask|ignored_mask thus put it in @mflags (mark flags) field so the user-space reader will be able to detect if such bit were used on mark creation procedure.

 | pos:	0
 | flags:	04002
 | fanotify flags:10 event-flags:0
 | fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
 | fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
Signed-off-by Cyrill Gorcunov <[email protected]>
CC Pavel Emelyanov <[email protected]>
CC Oleg Nesterov <[email protected]>
CC Andrey Vagin <[email protected]>
CC Al Viro <[email protected]>
CC Alexey Dobriyan <[email protected]>
CC Andrew Morton <[email protected]>
CC James Bottomley <[email protected]>
CC "Aneesh Kumar K.V" <[email protected]>
CC Matthew Helsley <[email protected]>
CC "J. Bruce Fields" <[email protected]>
CC Tvrtko Ursulin <[email protected]>
---
 fs/notify/fdinfo.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
fs/notify/fdinfo.c +9 -5
Index: linux-2.6.git/fs/notify/fdinfo.c
===================================================================
@@ -111,29 +111,33 @@ int inotify_show_fdinfo(struct seq_file
 
 static int fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 {
+	unsigned int mflags = 0;
 	struct inode *inode;
 	int ret = 0;
 
 	if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE))
 		return 0;
 
+	if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
+		mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
+
 	if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
 		inode = igrab(mark->i.inode);
 		if (!inode)
 			goto out;
 		ret = seq_printf(m, "fanotify ino:%lx sdev:%x "
-				 "mask:%x ignored_mask:%x ",
+				 "mflags:%x mask:%x ignored_mask:%x ",
 				 inode->i_ino, inode->i_sb->s_dev,
-				 mark->mask, mark->ignored_mask);
+				 mflags, mark->mask, mark->ignored_mask);
 		ret |= show_mark_fhandle(m, inode);
 		ret |= seq_putc(m, '\n');
 		iput(inode);
 	} else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) {
 		struct mount *mnt = real_mount(mark->m.mnt);
 
-		ret = seq_printf(m, "fanotify mnt_id:%x mask:%x "
-				 "ignored_mask:%x\n",
-				 mnt->mnt_id, mark->mask, mark->ignored_mask);
+		ret = seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x "
+				 "ignored_mask:%x\n", mnt->mnt_id, mflags,
+				 mark->mask, mark->ignored_mask);
 	}
 out:
 	return ret;
author
#2 lore raw

PATCH 2/2 docs: Update documentation about /proc/<pid>/fdinfo/<fd> fanotify output

In reply to Cyrill Gorcunov
Signed-off-by Cyrill Gorcunov <[email protected]>
CC Pavel Emelyanov <[email protected]>
CC Oleg Nesterov <[email protected]>
CC Andrey Vagin <[email protected]>
CC Al Viro <[email protected]>
CC Alexey Dobriyan <[email protected]>
CC Andrew Morton <[email protected]>
CC James Bottomley <[email protected]>
CC "Aneesh Kumar K.V" <[email protected]>
CC Alexey Dobriyan <[email protected]>
CC Matthew Helsley <[email protected]>
CC "J. Bruce Fields" <[email protected]>
CC "Aneesh Kumar K.V" <[email protected]>
CC Tvrtko Ursulin <[email protected]>
---
 Documentation/filesystems/proc.txt |   26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)
Documentation/filesystems/proc.txt +16 -10
Index: linux-2.6.git/Documentation/filesystems/proc.txt
===================================================================
@@ -1696,21 +1696,27 @@ pair provide additional information part
 	If the kernel is built without exportfs support the file handle won't be
 	printed out.
 
-	For fanotify files the format is
+	If there is no inotify mark attached yet the 'inotify' line will be omitted.
 
-	pos:	0
-	flags:	02
-	fanotify ino:2 sdev:800013 mask:1 ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:0200000000000000
-
-	or
+	For fanotify files the format is
 
 	pos:	0
 	flags:	02
-	fanotify mnt_id:13 mask:1 ignored_mask:40000000
+	fanotify flags:10 event-flags:0
+	fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
+	fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
+
+	where fanotify 'flags' and 'event-flags' are values used in fanotify_init
+	call, 'mnt_id' is the mount point identifier, 'mflags' is the value of
+	flags associated with mark which are tracked separately from events
+	mask. 'ino', 'sdev' are target inode and device, 'mask' is the events
+	mask and 'ignored_mask' is the mask of events which are to be ignored.
+	All in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask'
+	does provide information about flags and mask used in fanotify_mark
+	call [see fsnotify manpage for details].
 
-	where 'ino', 'sdev' are target inode and device, 'mnt_id' is the mount
-	point identifier, 'mask' is the events mask used and 'ignored_mask' is
-	the mask of events which are to be ignored. All in hex format.
+	While the first three lines are mandatory and always printed, the rest is
+	optional and may be omitted if no marks created yet.
 
 
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