Module Name: src
Committed By: riastradh
Date: Tue Mar 31 21:08:06 UTC 2015
Modified Files:
src/share/man/man9: fstrans.9
Log Message:
More details on what may sleep and what won't sleep when.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/share/man/man9/fstrans.9
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/fstrans.9
diff -u src/share/man/man9/fstrans.9:1.19 src/share/man/man9/fstrans.9:1.20
--- src/share/man/man9/fstrans.9:1.19 Tue Mar 31 20:50:29 2015
+++ src/share/man/man9/fstrans.9 Tue Mar 31 21:08:06 2015
@@ -1,4 +1,4 @@
-.\" $NetBSD: fstrans.9,v 1.19 2015/03/31 20:50:29 riastradh Exp $
+.\" $NetBSD: fstrans.9,v 1.20 2015/03/31 21:08:06 riastradh Exp $
.\"
.\" Copyright (c) 2007 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -167,6 +167,8 @@ in
Return zero on success, or error code if
.Xr vfs_busy 9
fails.
+.Pp
+May sleep.
.It Fn fstrans_unmount "mp"
Finalize the
.Nm
@@ -176,8 +178,10 @@ Clears
in
.Fa mp Ns Li "->mnt_iflag" .
Caller is responsible for ensuring that no transactions are active.
+.Pp
+May sleep.
.It Fn fstrans_start "mp" "lock_type"
-Begin a transaction of type
+Enter a transaction of type
.Fa lock_type
on the file system
.Fa mp
@@ -194,6 +198,14 @@ If the file system is suspended, wait un
Intended for operations needed to sync the file system to its backing
store in order to suspend it.
.El
+.Pp
+However, if the current thread is already in a transaction on
+.Fa mp ,
+.Fn fstrans_start
+will enter a nested transaction and return immediately without
+waiting.
+.Pp
+May sleep.
.It Fn fstrans_start_nowait "mp" "lock_type"
Like
.Fn fstrans_start ,
@@ -277,9 +289,13 @@ where
is true if and only if the buffer
.Fa bp
has not yet been modified.
+.Pp
+May sleep.
.It Fn fscow_disestablish "mp" "func" "cookie"
Disestablish a copy-on-write callback established with
.Fn fscow_establish .
+.Pp
+May sleep.
.It Fn fscow_run "bp" "data_valid"
Run all copy-on-write callbacks established for the file system this buffer
belongs to, if they have not already been run for this buffer.
@@ -288,6 +304,8 @@ If
is
.Dv true
the buffer data has not yet been modified.
+.Pp
+May sleep.
.El
.Sh EXAMPLES
The following is an example of a file system suspend operation.
