xtensa: enforce slab alignment to maximum register width

[linux-2.6-omap-h63xx.git] / Documentation / filesystems / seq_file.txt

diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt
index cc6cdb95b73a64b361984ac26b931a7ca39cf293..b843743aa0b5928630771a0ba6e22ec65c206654 100644 (file)
--- a/Documentation/filesystems/seq_file.txt
+++ b/Documentation/filesystems/seq_file.txt
@@ -92,7 +92,7 @@ implementations; in most cases the start() function should check for a
 "past end of file" condition and return NULL if need be.
 
 For more complicated applications, the private field of the seq_file
 "past end of file" condition and return NULL if need be.
 
 For more complicated applications, the private field of the seq_file

-structure can be used. There is also a special value whch can be returned
+structure can be used. There is also a special value which can be returned

 by the start() function called SEQ_START_TOKEN; it can be used if you wish
 to instruct your show() function (described below) to print a header at the
 top of the output. SEQ_START_TOKEN should only be used if the offset is
 by the start() function called SEQ_START_TOKEN; it can be used if you wish
 to instruct your show() function (described below) to print a header at the
 top of the output. SEQ_START_TOKEN should only be used if the offset is


@@ -122,8 +122,7 @@ stop() is the place to free it.
        }
 
 Finally, the show() function should format the object currently pointed to
        }
 
 Finally, the show() function should format the object currently pointed to

-by the iterator for output. It should return zero, or an error code if
-something goes wrong. The example module's show() function is:
+by the iterator for output.  The example module's show() function is:

 
        static int ct_seq_show(struct seq_file *s, void *v)
        {
 
        static int ct_seq_show(struct seq_file *s, void *v)
        {


@@ -132,6 +131,12 @@ something goes wrong. The example module's show() function is:
                return 0;
        }
 
                return 0;
        }
 

+If all is well, the show() function should return zero.  A negative error
+code in the usual manner indicates that something went wrong; it will be
+passed back to user space.  This function can also return SEQ_SKIP, which
+causes the current item to be skipped; if the show() function has already
+generated output before returning SEQ_SKIP, that output will be dropped.
+

 We will look at seq_printf() in a moment. But first, the definition of the
 seq_file iterator is finished by creating a seq_operations structure with
 the four functions we have just defined:
 We will look at seq_printf() in a moment. But first, the definition of the
 seq_file iterator is finished by creating a seq_operations structure with
 the four functions we have just defined:


@@ -146,7 +151,7 @@ the four functions we have just defined:
 This structure will be needed to tie our iterator to the /proc file in
 a little bit.
 
 This structure will be needed to tie our iterator to the /proc file in
 a little bit.
 

-It's worth noting that the interator value returned by start() and
+It's worth noting that the iterator value returned by start() and

 manipulated by the other functions is considered to be completely opaque by
 the seq_file code. It can thus be anything that is useful in stepping
 through the data to be output. Counters can be useful, but it could also be
 manipulated by the other functions is considered to be completely opaque by
 the seq_file code. It can thus be anything that is useful in stepping
 through the data to be output. Counters can be useful, but it could also be


@@ -182,12 +187,18 @@ The first two output a single character and a string, just like one would
 expect. seq_escape() is like seq_puts(), except that any character in s
 which is in the string esc will be represented in octal form in the output.
 
 expect. seq_escape() is like seq_puts(), except that any character in s
 which is in the string esc will be represented in octal form in the output.
 

-There is also a function for printing filenames:
+There is also a pair of functions for printing filenames:

 
        int seq_path(struct seq_file *m, struct path *path, char *esc);
 
        int seq_path(struct seq_file *m, struct path *path, char *esc);

+       int seq_path_root(struct seq_file *m, struct path *path,
+                         struct path *root, char *esc)

 
 Here, path indicates the file of interest, and esc is a set of characters
 
 Here, path indicates the file of interest, and esc is a set of characters

-which should be escaped in the output.
+which should be escaped in the output.  A call to seq_path() will output
+the path relative to the current process's filesystem root.  If a different
+root is desired, it can be used with seq_path_root().  Note that, if it
+turns out that path cannot be reached from root, the value of root will be
+changed in seq_file_root() to a root which *does* work.

 
 
 Making it all work
 
 
 Making it all work


@@ -262,7 +273,7 @@ routines useful:
 
 These helpers will interpret pos as a position within the list and iterate
 accordingly.  Your start() and next() functions need only invoke the
 
 These helpers will interpret pos as a position within the list and iterate
 accordingly.  Your start() and next() functions need only invoke the

-seq_list_* helpers with a pointer to the appropriate list_head structure.  
+seq_list_* helpers with a pointer to the appropriate list_head structure.

 
 
 The extra-simple version
 
 
 The extra-simple version