| Message ID | 162609464716.3133237.10354897554363093252.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | afs: Miscellaneous fixes | expand |
On Mon, Jul 12, 2021 at 9:57 AM David Howells <dhowells@redhat.com> wrote: > > From: Tom Rix <trix@redhat.com> > > Static analysis reports this problem > > write.c:773:29: warning: Assigned value is garbage or undefined > mapping->writeback_index = next; > ^ ~~~~ > The call to afs_writepages_region() can return without setting > next. So check the function return before using next. > > Fixes: e87b03f5830e ("afs: Prepare for use of THPs") > Signed-off-by: Tom Rix <trix@redhat.com> > Signed-off-by: David Howells <dhowells@redhat.com> > Link: https://lore.kernel.org/r/20210430155031.3287870-1-trix@redhat.com > --- > > fs/afs/write.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/afs/write.c b/fs/afs/write.c > index 3104b62c2082..2794147f82ff 100644 > --- a/fs/afs/write.c > +++ b/fs/afs/write.c > @@ -777,7 +777,7 @@ int afs_writepages(struct address_space *mapping, > mapping->writeback_index = next / PAGE_SIZE; Isn't there the same issue with the use of next here. > } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { > ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next); > - if (wbc->nr_to_write > 0) > + if (wbc->nr_to_write > 0 && ret == 0) > mapping->writeback_index = next; Unrelated to this patch, but since next is a byte offset, should this also divide by PAGE_SIZE as above. > } else { > ret = afs_writepages_region(mapping, wbc, > > Marc
Marc Dionne <marc.c.dionne@gmail.com> wrote: > > @@ -777,7 +777,7 @@ int afs_writepages(struct address_space *mapping, > > mapping->writeback_index = next / PAGE_SIZE; > > Isn't there the same issue with the use of next here. Good point. > > mapping->writeback_index = next; > > Unrelated to this patch, but since next is a byte offset, should this > also divide by PAGE_SIZE as above. Also a good point. I'll whip up a separate patch for that. David
diff --git a/fs/afs/write.c b/fs/afs/write.c index 3104b62c2082..2794147f82ff 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -777,7 +777,7 @@ int afs_writepages(struct address_space *mapping, mapping->writeback_index = next / PAGE_SIZE; } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next); - if (wbc->nr_to_write > 0) + if (wbc->nr_to_write > 0 && ret == 0) mapping->writeback_index = next; } else { ret = afs_writepages_region(mapping, wbc,