Commit 051d2525 authored by David Howells's avatar David Howells
Browse files

afs: Add some callback management tracepoints 



Add a couple of tracepoints to track callback management:

 (1) afs_cb_miss - Logs when we were unable to apply a callback, either due
     to the inode being discarded or due to a competing thread applying a
     callback first.

 (2) afs_cb_break - Logs when we attempted to clear the noted callback
     promise, either due to the server explicitly breaking the callback,
     the callback promise lapsing or a local event obsoleting it.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent fa59f52f

fs/afs/callback.c

+12 −4
Original line number Diff line number Diff line
@@ -212,7 +212,7 @@ void afs_init_callback_state(struct afs_server *server) 
/*

 * actually break a callback

 */

void __afs_break_callback(struct afs_vnode *vnode)

void __afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)

{

	_enter("");
@@ -223,13 +223,17 @@ void __afs_break_callback(struct afs_vnode *vnode) 


		if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)

			afs_lock_may_be_available(vnode);



		trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, true);

	} else {

		trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, false);

	}

}



void afs_break_callback(struct afs_vnode *vnode)

void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)

{

	write_seqlock(&vnode->cb_lock);

	__afs_break_callback(vnode);

	__afs_break_callback(vnode, reason);

	write_sequnlock(&vnode->cb_lock);

}
@@ -277,6 +281,8 @@ static void afs_break_one_callback(struct afs_server *server, 


			write_lock(&volume->cb_v_break_lock);

			volume->cb_v_break++;

			trace_afs_cb_break(fid, volume->cb_v_break,

					   afs_cb_break_for_volume_callback, false);

			write_unlock(&volume->cb_v_break_lock);

		} else {

			data.volume = NULL;
@@ -285,8 +291,10 @@ static void afs_break_one_callback(struct afs_server *server, 
						afs_iget5_test, &data);

			if (inode) {

				vnode = AFS_FS_I(inode);

				afs_break_callback(vnode);

				afs_break_callback(vnode, afs_cb_break_for_callback);

				iput(inode);

			} else {

				trace_afs_cb_miss(fid, afs_cb_break_for_callback);

			}

		}

	}

fs/afs/dir.c

+2 −2
Original line number Diff line number Diff line
@@ -1367,12 +1367,12 @@ static int afs_dir_remove_link(struct afs_vnode *dvnode, struct dentry *dentry, 
			drop_nlink(&vnode->vfs_inode);

			if (vnode->vfs_inode.i_nlink == 0) {

				set_bit(AFS_VNODE_DELETED, &vnode->flags);

				__afs_break_callback(vnode);

				__afs_break_callback(vnode, afs_cb_break_for_unlink);

			}

			write_sequnlock(&vnode->cb_lock);

			ret = 0;

		} else {

			afs_break_callback(vnode);

			afs_break_callback(vnode, afs_cb_break_for_unlink);



			if (test_bit(AFS_VNODE_DELETED, &vnode->flags))

				kdebug("AFS_VNODE_DELETED");

fs/afs/inode.c

+10 −7
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ void afs_vnode_commit_status(struct afs_fs_cursor *fc, 
		if (scb->status.abort_code == VNOVNODE) {

			set_bit(AFS_VNODE_DELETED, &vnode->flags);

			clear_nlink(&vnode->vfs_inode);

			__afs_break_callback(vnode);

			__afs_break_callback(vnode, afs_cb_break_for_deleted);

		}

	} else {

		if (scb->have_status)
@@ -594,8 +594,9 @@ bool afs_check_validity(struct afs_vnode *vnode) 
	struct afs_cb_interest *cbi;

	struct afs_server *server;

	struct afs_volume *volume = vnode->volume;

	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;

	time64_t now = ktime_get_real_seconds();

	bool valid, need_clear = false;

	bool valid;

	unsigned int cb_break, cb_s_break, cb_v_break;

	int seq = 0;
@@ -613,13 +614,13 @@ bool afs_check_validity(struct afs_vnode *vnode) 
			    vnode->cb_v_break != cb_v_break) {

				vnode->cb_s_break = cb_s_break;

				vnode->cb_v_break = cb_v_break;

				need_clear = true;

				need_clear = afs_cb_break_for_vsbreak;

				valid = false;

			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {

				need_clear = true;

				need_clear = afs_cb_break_for_zap;

				valid = false;

			} else if (vnode->cb_expires_at - 10 <= now) {

				need_clear = true;

				need_clear = afs_cb_break_for_lapsed;

				valid = false;

			} else {

				valid = true;
@@ -635,10 +636,12 @@ bool afs_check_validity(struct afs_vnode *vnode) 


	done_seqretry(&vnode->cb_lock, seq);



	if (need_clear) {

	if (need_clear != afs_cb_break_no_break) {

		write_seqlock(&vnode->cb_lock);

		if (cb_break == vnode->cb_break)

			__afs_break_callback(vnode);

			__afs_break_callback(vnode, need_clear);

		else

			trace_afs_cb_miss(&vnode->fid, need_clear);

		write_sequnlock(&vnode->cb_lock);

		valid = false;

	}

fs/afs/internal.h

+4 −4
Original line number Diff line number Diff line
@@ -848,8 +848,8 @@ extern struct fscache_cookie_def afs_vnode_cache_index_def; 
 * callback.c

 */

extern void afs_init_callback_state(struct afs_server *);

extern void __afs_break_callback(struct afs_vnode *);

extern void afs_break_callback(struct afs_vnode *);

extern void __afs_break_callback(struct afs_vnode *, enum afs_cb_break_reason);

extern void afs_break_callback(struct afs_vnode *, enum afs_cb_break_reason);

extern void afs_break_callbacks(struct afs_server *, size_t, struct afs_callback_break *);



extern int afs_register_server_cb_interest(struct afs_vnode *,
@@ -1438,7 +1438,7 @@ static inline void afs_check_for_remote_deletion(struct afs_fs_cursor *fc, 
{

	if (fc->ac.error == -ENOENT) {

		set_bit(AFS_VNODE_DELETED, &vnode->flags);

		afs_break_callback(vnode);

		afs_break_callback(vnode, afs_cb_break_for_deleted);

	}

}

include/trace/events/afs.h

+69 −0
Original line number Diff line number Diff line
@@ -195,6 +195,17 @@ enum afs_flock_operation { 
	afs_flock_op_wake,

};



enum afs_cb_break_reason {

	afs_cb_break_no_break,

	afs_cb_break_for_callback,

	afs_cb_break_for_deleted,

	afs_cb_break_for_lapsed,

	afs_cb_break_for_unlink,

	afs_cb_break_for_vsbreak,

	afs_cb_break_for_volume_callback,

	afs_cb_break_for_zap,

};



#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */



/*
@@ -374,6 +385,16 @@ enum afs_flock_operation { 
	EM(afs_flock_op_unlock,			"UNLOCK  ")		\

	E_(afs_flock_op_wake,			"WAKE    ")



#define afs_cb_break_reasons						\

	EM(afs_cb_break_no_break,		"no-break")		\

	EM(afs_cb_break_for_callback,		"break-cb")		\

	EM(afs_cb_break_for_deleted,		"break-del")		\

	EM(afs_cb_break_for_lapsed,		"break-lapsed")		\

	EM(afs_cb_break_for_unlink,		"break-unlink")		\

	EM(afs_cb_break_for_vsbreak,		"break-vs")		\

	EM(afs_cb_break_for_volume_callback,	"break-v-cb")		\

	E_(afs_cb_break_for_zap,		"break-zap")



/*

 * Export enum symbols via userspace.

 */
@@ -392,6 +413,7 @@ afs_io_errors; 
afs_file_errors;

afs_flock_types;

afs_flock_operations;

afs_cb_break_reasons;



/*

 * Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -1171,6 +1193,53 @@ TRACE_EVENT(afs_get_tree, 
		      __entry->cell, __entry->volume, __entry->vid)

	    );



TRACE_EVENT(afs_cb_break,

	    TP_PROTO(struct afs_fid *fid, unsigned int cb_break,

		     enum afs_cb_break_reason reason, bool skipped),



	    TP_ARGS(fid, cb_break, reason, skipped),



	    TP_STRUCT__entry(

		    __field_struct(struct afs_fid,	fid		)

		    __field(unsigned int,		cb_break	)

		    __field(enum afs_cb_break_reason,	reason		)

		    __field(bool,			skipped		)

			     ),



	    TP_fast_assign(

		    __entry->fid	= *fid;

		    __entry->cb_break	= cb_break;

		    __entry->reason	= reason;

		    __entry->skipped	= skipped;

			   ),



	    TP_printk("%llx:%llx:%x b=%x s=%u %s",

		      __entry->fid.vid, __entry->fid.vnode, __entry->fid.unique,

		      __entry->cb_break,

		      __entry->skipped,

		      __print_symbolic(__entry->reason, afs_cb_break_reasons))

	    );



TRACE_EVENT(afs_cb_miss,

	    TP_PROTO(struct afs_fid *fid, enum afs_cb_break_reason reason),



	    TP_ARGS(fid, reason),



	    TP_STRUCT__entry(

		    __field_struct(struct afs_fid,	fid		)

		    __field(enum afs_cb_break_reason,	reason		)

			     ),



	    TP_fast_assign(

		    __entry->fid	= *fid;

		    __entry->reason	= reason;

			   ),



	    TP_printk(" %llx:%llx:%x %s",

		      __entry->fid.vid, __entry->fid.vnode, __entry->fid.unique,

		      __print_symbolic(__entry->reason, afs_cb_break_reasons))

	    );



#endif /* _TRACE_AFS_H */



/* This part must be outside protection */

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