diff options
| -rw-r--r-- | mm/shmem.c | 57 | ||||
| -rw-r--r-- | mm/swapfile.c | 23 |
2 files changed, 45 insertions, 35 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 2e03d6031c2..a0126c43710 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -838,10 +838,8 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, s if (size > SHMEM_NR_DIRECT) size = SHMEM_NR_DIRECT; offset = shmem_find_swp(entry, ptr, ptr+size); - if (offset >= 0) { - shmem_swp_balance_unmap(); + if (offset >= 0) goto found; - } if (!info->i_indirect) goto lost2; @@ -879,11 +877,11 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, s if (size > ENTRIES_PER_PAGE) size = ENTRIES_PER_PAGE; offset = shmem_find_swp(entry, ptr, ptr+size); + shmem_swp_unmap(ptr); if (offset >= 0) { shmem_dir_unmap(dir); goto found; } - shmem_swp_unmap(ptr); } } lost1: @@ -893,10 +891,25 @@ lost2: return 0; found: idx += offset; - inode = &info->vfs_inode; - error = add_to_page_cache(page, inode->i_mapping, idx, GFP_ATOMIC); + inode = igrab(&info->vfs_inode); + spin_unlock(&info->lock); + + /* move head to start search for next from here */ + list_move_tail(&shmem_swaplist, &info->swaplist); + mutex_unlock(&shmem_swaplist_mutex); + + error = 1; + if (!inode) + goto out; + + spin_lock(&info->lock); + ptr = shmem_swp_entry(info, idx, NULL); + if (ptr && ptr->val == entry.val) + error = add_to_page_cache(page, inode->i_mapping, + idx, GFP_ATOMIC); if (error == -EEXIST) { struct page *filepage = find_get_page(inode->i_mapping, idx); + error = 1; if (filepage) { /* * There might be a more uptodate page coming down @@ -911,16 +924,18 @@ found: delete_from_swap_cache(page); set_page_dirty(page); info->flags |= SHMEM_PAGEIN; - shmem_swp_set(info, ptr + offset, 0); + shmem_swp_set(info, ptr, 0); + swap_free(entry); + error = 1; /* not an error, but entry was found */ } - shmem_swp_unmap(ptr); + if (ptr) + shmem_swp_unmap(ptr); spin_unlock(&info->lock); - /* - * Decrement swap count even when the entry is left behind: - * try_to_unuse will skip over mms, then reincrement count. - */ - swap_free(entry); - return 1; +out: + unlock_page(page); + page_cache_release(page); + iput(inode); /* allows for NULL */ + return error; } /* @@ -935,18 +950,16 @@ int shmem_unuse(swp_entry_t entry, struct page *page) mutex_lock(&shmem_swaplist_mutex); list_for_each_safe(p, next, &shmem_swaplist) { info = list_entry(p, struct shmem_inode_info, swaplist); - if (!info->swapped) + if (info->swapped) + found = shmem_unuse_inode(info, entry, page); + else list_del_init(&info->swaplist); - else if (shmem_unuse_inode(info, entry, page)) { - /* move head to start search for next from here */ - list_move_tail(&shmem_swaplist, &info->swaplist); - found = 1; - break; - } cond_resched(); + if (found) + goto out; } mutex_unlock(&shmem_swaplist_mutex); - return found; +out: return found; /* 0 or 1 or -ENOMEM */ } /* diff --git a/mm/swapfile.c b/mm/swapfile.c index 14bc4f28a8c..eade24da931 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -814,7 +814,7 @@ static int try_to_unuse(unsigned int type) atomic_inc(&new_start_mm->mm_users); atomic_inc(&prev_mm->mm_users); spin_lock(&mmlist_lock); - while (*swap_map > 1 && !retval && + while (*swap_map > 1 && !retval && !shmem && (p = p->next) != &start_mm->mmlist) { mm = list_entry(p, struct mm_struct, mmlist); if (!atomic_inc_not_zero(&mm->mm_users)) @@ -846,6 +846,13 @@ static int try_to_unuse(unsigned int type) mmput(start_mm); start_mm = new_start_mm; } + if (shmem) { + /* page has already been unlocked and released */ + if (shmem > 0) + continue; + retval = shmem; + break; + } if (retval) { unlock_page(page); page_cache_release(page); @@ -884,12 +891,6 @@ static int try_to_unuse(unsigned int type) * read from disk into another page. Splitting into two * pages would be incorrect if swap supported "shared * private" pages, but they are handled by tmpfs files. - * - * Note shmem_unuse already deleted a swappage from - * the swap cache, unless the move to filepage failed: - * in which case it left swappage in cache, lowered its - * swap count to pass quickly through the loops above, - * and now we must reincrement count to try again later. */ if ((*swap_map > 1) && PageDirty(page) && PageSwapCache(page)) { struct writeback_control wbc = { @@ -900,12 +901,8 @@ static int try_to_unuse(unsigned int type) lock_page(page); wait_on_page_writeback(page); } - if (PageSwapCache(page)) { - if (shmem) - swap_duplicate(entry); - else - delete_from_swap_cache(page); - } + if (PageSwapCache(page)) + delete_from_swap_cache(page); /* * So we could skip searching mms once swap count went |