summaryrefslogtreecommitdiffstats
path: root/fs/proc
diff options
context:
space:
mode:
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/generic.c98
1 files changed, 47 insertions, 51 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 5453f1c..a6a1cb5 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -71,59 +71,55 @@ __proc_file_read(struct file *file, char __user *buf, size_t nbytes,
count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
start = NULL;
- if (dp->read_proc) {
- /*
- * How to be a proc read function
- * ------------------------------
- * Prototype:
- * int f(char *buffer, char **start, off_t offset,
- * int count, int *peof, void *dat)
- *
- * Assume that the buffer is "count" bytes in size.
- *
- * If you know you have supplied all the data you
- * have, set *peof.
- *
- * You have three ways to return data:
- * 0) Leave *start = NULL. (This is the default.)
- * Put the data of the requested offset at that
- * offset within the buffer. Return the number (n)
- * of bytes there are from the beginning of the
- * buffer up to the last byte of data. If the
- * number of supplied bytes (= n - offset) is
- * greater than zero and you didn't signal eof
- * and the reader is prepared to take more data
- * you will be called again with the requested
- * offset advanced by the number of bytes
- * absorbed. This interface is useful for files
- * no larger than the buffer.
- * 1) Set *start = an unsigned long value less than
- * the buffer address but greater than zero.
- * Put the data of the requested offset at the
- * beginning of the buffer. Return the number of
- * bytes of data placed there. If this number is
- * greater than zero and you didn't signal eof
- * and the reader is prepared to take more data
- * you will be called again with the requested
- * offset advanced by *start. This interface is
- * useful when you have a large file consisting
- * of a series of blocks which you want to count
- * and return as wholes.
- * (Hack by Paul.Russell@rustcorp.com.au)
- * 2) Set *start = an address within the buffer.
- * Put the data of the requested offset at *start.
- * Return the number of bytes of data placed there.
- * If this number is greater than zero and you
- * didn't signal eof and the reader is prepared to
- * take more data you will be called again with the
- * requested offset advanced by the number of bytes
- * absorbed.
- */
- n = dp->read_proc(page, &start, *ppos,
- count, &eof, dp->data);
- } else
+ if (!dp->read_proc)
break;
+ /* How to be a proc read function
+ * ------------------------------
+ * Prototype:
+ * int f(char *buffer, char **start, off_t offset,
+ * int count, int *peof, void *dat)
+ *
+ * Assume that the buffer is "count" bytes in size.
+ *
+ * If you know you have supplied all the data you have, set
+ * *peof.
+ *
+ * You have three ways to return data:
+ *
+ * 0) Leave *start = NULL. (This is the default.) Put the
+ * data of the requested offset at that offset within the
+ * buffer. Return the number (n) of bytes there are from
+ * the beginning of the buffer up to the last byte of data.
+ * If the number of supplied bytes (= n - offset) is greater
+ * than zero and you didn't signal eof and the reader is
+ * prepared to take more data you will be called again with
+ * the requested offset advanced by the number of bytes
+ * absorbed. This interface is useful for files no larger
+ * than the buffer.
+ *
+ * 1) Set *start = an unsigned long value less than the buffer
+ * address but greater than zero. Put the data of the
+ * requested offset at the beginning of the buffer. Return
+ * the number of bytes of data placed there. If this number
+ * is greater than zero and you didn't signal eof and the
+ * reader is prepared to take more data you will be called
+ * again with the requested offset advanced by *start. This
+ * interface is useful when you have a large file consisting
+ * of a series of blocks which you want to count and return
+ * as wholes.
+ * (Hack by Paul.Russell@rustcorp.com.au)
+ *
+ * 2) Set *start = an address within the buffer. Put the data
+ * of the requested offset at *start. Return the number of
+ * bytes of data placed there. If this number is greater
+ * than zero and you didn't signal eof and the reader is
+ * prepared to take more data you will be called again with
+ * the requested offset advanced by the number of bytes
+ * absorbed.
+ */
+ n = dp->read_proc(page, &start, *ppos, count, &eof, dp->data);
+
if (n == 0) /* end of file */
break;
if (n < 0) { /* error */
OpenPOWER on IntegriCloud