Limit max_pages for insane devices

Intel SSDs have a limit of 0xffff as queue_max_hw_sectors(q).  Such a
limit may make sense from a hardware pov, but it causes bio_alloc() to
return NULL.

Signed-off-by: Joern Engel <joern@logfs.org>

diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index 9718c22..f99f5dc 100644 (file)
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -97,8 +97,10 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
        unsigned int max_pages = queue_max_hw_sectors(q) >> (PAGE_SHIFT - 9);
        int i;
 
+       if (max_pages > BIO_MAX_PAGES)
+               max_pages = BIO_MAX_PAGES;
        bio = bio_alloc(GFP_NOFS, max_pages);
-       BUG_ON(!bio); /* FIXME: handle this */
+       BUG_ON(!bio);
 
        for (i = 0; i < nr_pages; i++) {
                if (i >= max_pages) {
@@ -191,8 +193,10 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
        unsigned int max_pages = queue_max_hw_sectors(q) >> (PAGE_SHIFT - 9);
        int i;
 
+       if (max_pages > BIO_MAX_PAGES)
+               max_pages = BIO_MAX_PAGES;
        bio = bio_alloc(GFP_NOFS, max_pages);
-       BUG_ON(!bio); /* FIXME: handle this */
+       BUG_ON(!bio);
 
        for (i = 0; i < nr_pages; i++) {
                if (i >= max_pages) {