generic_file_aio_read() cleanups
As akpm points out, there's really no need for generic_file_aio_read to
make a special case of count 0: just loop through nr_segs doing nothing.
And as Harvey Harrison points out, there's no need to reset retval to 0
where it's already 0.
Setting count (or ocount) to 0 before calling generic_segment_checks is
unnecessary too; but reluctantly I'll leave that removal to someone with a
wider range of gcc versions to hand - 4.1.2 and 4.2.1 don't warn about it,
but perhaps others do - I forget which are the warniest versions.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Tested-by: Lawrence Greenfield <leg@google.com>
Cc: Christoph Rohland <hans-christoph.rohland@sap.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index 6343f3c..7675b91 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1197,7 +1197,6 @@
mapping = filp->f_mapping;
inode = mapping->host;
- retval = 0;
if (!count)
goto out; /* skip atime */
size = i_size_read(inode);
@@ -1209,33 +1208,30 @@
}
if (retval > 0)
*ppos = pos + retval;
- }
- if (likely(retval != 0)) {
- file_accessed(filp);
- goto out;
+ if (retval) {
+ file_accessed(filp);
+ goto out;
+ }
}
}
- retval = 0;
- if (count) {
- for (seg = 0; seg < nr_segs; seg++) {
- read_descriptor_t desc;
+ for (seg = 0; seg < nr_segs; seg++) {
+ read_descriptor_t desc;
- desc.written = 0;
- desc.arg.buf = iov[seg].iov_base;
- desc.count = iov[seg].iov_len;
- if (desc.count == 0)
- continue;
- desc.error = 0;
- do_generic_file_read(filp,ppos,&desc,file_read_actor);
- retval += desc.written;
- if (desc.error) {
- retval = retval ?: desc.error;
- break;
- }
- if (desc.count > 0)
- break;
+ desc.written = 0;
+ desc.arg.buf = iov[seg].iov_base;
+ desc.count = iov[seg].iov_len;
+ if (desc.count == 0)
+ continue;
+ desc.error = 0;
+ do_generic_file_read(filp, ppos, &desc, file_read_actor);
+ retval += desc.written;
+ if (desc.error) {
+ retval = retval ?: desc.error;
+ break;
}
+ if (desc.count > 0)
+ break;
}
out:
return retval;