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| author |   Joe Perches <joe@perches.com> | 2014-09-29 16:08:21 -0700 |
|---|---|---|
| committer |   Steven Rostedt <rostedt@goodmis.org> | 2014-10-29 20:26:06 -0400 |
| commit | 1f33c41c03daece85a84b8dcea5733f3efe3e2b0 (patch) | |
| tree | dc20bd3893f3756d30c9281c2aafc5c1170bdaee /Documentation/filesystems | |
| parent | Linux 3.18-rc1 (diff) | |
| download | linux-dev-1f33c41c03daece85a84b8dcea5733f3efe3e2b0.tar.xz linux-dev-1f33c41c03daece85a84b8dcea5733f3efe3e2b0.zip | |
seq_file: Rename seq_overflow() to seq_has_overflowed() and make public
The return values of seq_printf/puts/putc are frequently misused.
Start down a path to remove all the return value uses of these
functions.
Move the seq_overflow() to a global inlined function called
seq_has_overflowed() that can be used by the users of seq_file() calls.
Update the documentation to not show return types for seq_printf
et al. Add a description of seq_has_overflowed().
Link: http://lkml.kernel.org/p/848ac7e3d1c31cddf638a8526fa3c59fa6fdeb8a.1412031505.git.joe@perches.com
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Joe Perches <joe@perches.com>
[ Reworked the original patch from Joe ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/seq_file.txt | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt index 8ea3e90ace07..b797ed38de46 100644 --- a/Documentation/filesystems/seq_file.txt +++ b/Documentation/filesystems/seq_file.txt @@ -180,23 +180,19 @@ output must be passed to the seq_file code. Some utility functions have been defined which make this task easy. Most code will simply use seq_printf(), which works pretty much like -printk(), but which requires the seq_file pointer as an argument. It is -common to ignore the return value from seq_printf(), but a function -producing complicated output may want to check that value and quit if -something non-zero is returned; an error return means that the seq_file -buffer has been filled and further output will be discarded. +printk(), but which requires the seq_file pointer as an argument. For straight character output, the following functions may be used: - int seq_putc(struct seq_file *m, char c); - int seq_puts(struct seq_file *m, const char *s); - int seq_escape(struct seq_file *m, const char *s, const char *esc); + seq_putc(struct seq_file *m, char c); + seq_puts(struct seq_file *m, const char *s); + seq_escape(struct seq_file *m, const char *s, const char *esc); 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. -There is also a pair of functions for printing filenames: +There are also a pair of functions for printing filenames: int seq_path(struct seq_file *m, struct path *path, char *esc); int seq_path_root(struct seq_file *m, struct path *path, @@ -209,6 +205,14 @@ 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. +A function producing complicated output may want to check + bool seq_has_overflowed(struct seq_file *m); +and avoid further seq_<output> calls if true is returned. + +A true return from seq_has_overflowed means that the seq_file buffer will +be discarded and the seq_show function will attempt to allocate a larger +buffer and retry printing. + Making it all work |