From 68da9f055755ee2609a1686722e6d6a7980019ee Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 25 Jul 2011 17:12:34 -0700 Subject: [PATCH] tmpfs: pass gfp to shmem_getpage_gfp Make shmem_getpage() a wrapper, passing mapping_gfp_mask() down to shmem_getpage_gfp(), which in turn passes gfp down to shmem_swp_alloc(). Change shmem_read_mapping_page_gfp() to use shmem_getpage_gfp() in the CONFIG_SHMEM case; but leave tiny !SHMEM using read_cache_page_gfp(). Add a BUG_ON() in case anyone happens to call this on a non-shmem mapping; though we might later want to let that case route to read_cache_page_gfp(). It annoys me to have these two almost-redundant args, gfp and fault_type: I can't find a better way; but initialize fault_type only in shmem_fault(). Note that before, read_cache_page_gfp() was allocating i915_gem's pages with __GFP_NORETRY as intended; but the corresponding swap vector pages got allocated without it, leaving a small possibility of OOM. Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 67 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 44 insertions(+), 23 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index f96614526d1c..f6c94ba87808 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -127,8 +127,15 @@ static unsigned long shmem_default_max_inodes(void) } #endif -static int shmem_getpage(struct inode *inode, unsigned long idx, - struct page **pagep, enum sgp_type sgp, int *type); +static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, + struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type); + +static inline int shmem_getpage(struct inode *inode, pgoff_t index, + struct page **pagep, enum sgp_type sgp, int *fault_type) +{ + return shmem_getpage_gfp(inode, index, pagep, sgp, + mapping_gfp_mask(inode->i_mapping), fault_type); +} static inline struct page *shmem_dir_alloc(gfp_t gfp_mask) { @@ -404,10 +411,12 @@ static void shmem_swp_set(struct shmem_inode_info *info, swp_entry_t *entry, uns * @info: info structure for the inode * @index: index of the page to find * @sgp: check and recheck i_size? skip allocation? + * @gfp: gfp mask to use for any page allocation * * If the entry does not exist, allocate it. */ -static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long index, enum sgp_type sgp) +static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, + unsigned long index, enum sgp_type sgp, gfp_t gfp) { struct inode *inode = &info->vfs_inode; struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); @@ -435,7 +444,7 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long } spin_unlock(&info->lock); - page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping)); + page = shmem_dir_alloc(gfp); spin_lock(&info->lock); if (!page) { @@ -1225,14 +1234,14 @@ static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) #endif /* - * shmem_getpage - either get the page from swap or allocate a new one + * shmem_getpage_gfp - find page in cache, or get from swap, or allocate * * If we allocate a new one we do not mark it dirty. That's up to the * vm. If we swap it in we mark it dirty since we also free the swap * entry since a page cannot live in both the swap and page cache */ -static int shmem_getpage(struct inode *inode, unsigned long idx, - struct page **pagep, enum sgp_type sgp, int *type) +static int shmem_getpage_gfp(struct inode *inode, pgoff_t idx, + struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type) { struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info = SHMEM_I(inode); @@ -1242,15 +1251,11 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page *prealloc_page = NULL; swp_entry_t *entry; swp_entry_t swap; - gfp_t gfp; int error; if (idx >= SHMEM_MAX_INDEX) return -EFBIG; - if (type) - *type = 0; - /* * Normally, filepage is NULL on entry, and either found * uptodate immediately, or allocated and zeroed, or read @@ -1264,13 +1269,12 @@ repeat: filepage = find_lock_page(mapping, idx); if (filepage && PageUptodate(filepage)) goto done; - gfp = mapping_gfp_mask(mapping); if (!filepage) { /* * Try to preload while we can wait, to not make a habit of * draining atomic reserves; but don't latch on to this cpu. */ - error = radix_tree_preload(gfp & ~__GFP_HIGHMEM); + error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); if (error) goto failed; radix_tree_preload_end(); @@ -1290,7 +1294,7 @@ repeat: spin_lock(&info->lock); shmem_recalc_inode(inode); - entry = shmem_swp_alloc(info, idx, sgp); + entry = shmem_swp_alloc(info, idx, sgp, gfp); if (IS_ERR(entry)) { spin_unlock(&info->lock); error = PTR_ERR(entry); @@ -1305,12 +1309,12 @@ repeat: shmem_swp_unmap(entry); spin_unlock(&info->lock); /* here we actually do the io */ - if (type) - *type |= VM_FAULT_MAJOR; + if (fault_type) + *fault_type |= VM_FAULT_MAJOR; swappage = shmem_swapin(swap, gfp, info, idx); if (!swappage) { spin_lock(&info->lock); - entry = shmem_swp_alloc(info, idx, sgp); + entry = shmem_swp_alloc(info, idx, sgp, gfp); if (IS_ERR(entry)) error = PTR_ERR(entry); else { @@ -1461,7 +1465,7 @@ repeat: SetPageSwapBacked(filepage); } - entry = shmem_swp_alloc(info, idx, sgp); + entry = shmem_swp_alloc(info, idx, sgp, gfp); if (IS_ERR(entry)) error = PTR_ERR(entry); else { @@ -1539,7 +1543,7 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct inode *inode = vma->vm_file->f_path.dentry->d_inode; int error; - int ret; + int ret = VM_FAULT_LOCKED; if (((loff_t)vmf->pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode)) return VM_FAULT_SIGBUS; @@ -1547,11 +1551,12 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); if (error) return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); + if (ret & VM_FAULT_MAJOR) { count_vm_event(PGMAJFAULT); mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); } - return ret | VM_FAULT_LOCKED; + return ret; } #ifdef CONFIG_NUMA @@ -3162,13 +3167,29 @@ int shmem_zero_setup(struct vm_area_struct *vma) * suit tmpfs, since it may have pages in swapcache, and needs to find those * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. * - * Provide a stub for those callers to start using now, then later - * flesh it out to call shmem_getpage() with additional gfp mask, when - * shmem_file_splice_read() is added and shmem_readpage() is removed. + * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in + * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. */ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, pgoff_t index, gfp_t gfp) { +#ifdef CONFIG_SHMEM + struct inode *inode = mapping->host; + struct page *page = NULL; + int error; + + BUG_ON(mapping->a_ops != &shmem_aops); + error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, gfp, NULL); + if (error) + page = ERR_PTR(error); + else + unlock_page(page); + return page; +#else + /* + * The tiny !SHMEM case uses ramfs without swap + */ return read_cache_page_gfp(mapping, index, gfp); +#endif } EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp);