1 files changed, 48 insertions, 9 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 140ebda9640f..20e5642e9f9f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -151,6 +151,7 @@ void remove_from_page_cache(struct page *page)
         spin_unlock_irq(&mapping->tree_lock);
         mem_cgroup_uncharge_cache_page(page);
 }
+EXPORT_SYMBOL(remove_from_page_cache);
 
 static int sync_page(void *word)
 {
@@ -441,7 +442,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
         /*
          * Splice_read and readahead add shmem/tmpfs pages into the page cache
          * before shmem_readpage has a chance to mark them as SwapBacked: they
-         * need to go on the active_anon lru below, and mem_cgroup_cache_charge
+         * need to go on the anon lru below, and mem_cgroup_cache_charge
          * (called in add_to_page_cache) needs to know where they're going too.
          */
         if (mapping_cap_swap_backed(mapping))
@@ -452,7 +453,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
                 if (page_is_file_cache(page))
                         lru_cache_add_file(page);
                 else
-                        lru_cache_add_active_anon(page);
+                        lru_cache_add_anon(page);
         }
         return ret;
 }
@@ -461,9 +462,15 @@ EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
 #ifdef CONFIG_NUMA
 struct page *__page_cache_alloc(gfp_t gfp)
 {
+        int n;
+        struct page *page;
+
         if (cpuset_do_page_mem_spread()) {
-                int n = cpuset_mem_spread_node();
-                return alloc_pages_exact_node(n, gfp, 0);
+                get_mems_allowed();
+                n = cpuset_mem_spread_node();
+                page = alloc_pages_exact_node(n, gfp, 0);
+                put_mems_allowed();
+                return page;
         }
         return alloc_pages(gfp, 0);
 }
@@ -1099,6 +1106,12 @@ page_not_up_to_date_locked:
                 }
 
 readpage:
+                /*
+                 * A previous I/O error may have been due to temporary
+                 * failures, eg. multipath errors.
+                 * PG_error will be set again if readpage fails.
+                 */
+                ClearPageError(page);
                 /* Start the actual read. The read will unlock the page. */
                 error = mapping->a_ops->readpage(filp, page);
 
@@ -1263,7 +1276,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 {
         struct file *filp = iocb->ki_filp;
         ssize_t retval;
-        unsigned long seg;
+        unsigned long seg = 0;
         size_t count;
         loff_t *ppos = &iocb->ki_pos;
 
@@ -1290,21 +1303,47 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
                                 retval = mapping->a_ops->direct_IO(READ, iocb,
                                                         iov, pos, nr_segs);
                         }
-                        if (retval > 0)
+                        if (retval > 0) {
                                 *ppos = pos + retval;
-                        if (retval) {
+                                count -= retval;
+                        }
+
+                        /*
+                         * Btrfs can have a short DIO read if we encounter
+                         * compressed extents, so if there was an error, or if
+                         * we've already read everything we wanted to, or if
+                         * there was a short read because we hit EOF, go ahead
+                         * and return.  Otherwise fallthrough to buffered io for
+                         * the rest of the read.
+                         */
+                        if (retval < 0 || !count || *ppos >= size) {
                                 file_accessed(filp);
                                 goto out;
                         }
                 }
         }
 
+        count = retval;
         for (seg = 0; seg < nr_segs; seg++) {
                 read_descriptor_t desc;
+                loff_t offset = 0;
+
+                /*
+                 * If we did a short DIO read we need to skip the section of the
+                 * iov that we've already read data into.
+                 */
+                if (count) {
+                        if (count > iov[seg].iov_len) {
+                                count -= iov[seg].iov_len;
+                                continue;
+                        }
+                        offset = count;
+                        count = 0;
+                }
 
                 desc.written = 0;
-                desc.arg.buf = iov[seg].iov_base;
-                desc.count = iov[seg].iov_len;
+                desc.arg.buf = iov[seg].iov_base + offset;
+                desc.count = iov[seg].iov_len - offset;
                 if (desc.count == 0)
                         continue;
                 desc.error = 0;