diff options
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 118 |
1 files changed, 107 insertions, 11 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 89341b658bd0..03f9ba8fb8e5 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -910,25 +910,29 @@ static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { - struct mempolicy mpol, *spol; struct vm_area_struct pvma; - - spol = mpol_cond_copy(&mpol, - mpol_shared_policy_lookup(&info->policy, index)); + struct page *page; /* Create a pseudo vma that just contains the policy */ pvma.vm_start = 0; /* Bias interleave by inode number to distribute better across nodes */ pvma.vm_pgoff = index + info->vfs_inode.i_ino; pvma.vm_ops = NULL; - pvma.vm_policy = spol; - return swapin_readahead(swap, gfp, &pvma, 0); + pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); + + page = swapin_readahead(swap, gfp, &pvma, 0); + + /* Drop reference taken by mpol_shared_policy_lookup() */ + mpol_cond_put(pvma.vm_policy); + + return page; } static struct page *shmem_alloc_page(gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; + struct page *page; /* Create a pseudo vma that just contains the policy */ pvma.vm_start = 0; @@ -937,10 +941,12 @@ static struct page *shmem_alloc_page(gfp_t gfp, pvma.vm_ops = NULL; pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); - /* - * alloc_page_vma() will drop the shared policy reference - */ - return alloc_page_vma(gfp, &pvma, 0); + page = alloc_page_vma(gfp, &pvma, 0); + + /* Drop reference taken by mpol_shared_policy_lookup() */ + mpol_cond_put(pvma.vm_policy); + + return page; } #else /* !CONFIG_NUMA */ #ifdef CONFIG_TMPFS @@ -1709,6 +1715,96 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, return error; } +/* + * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. + */ +static pgoff_t shmem_seek_hole_data(struct address_space *mapping, + pgoff_t index, pgoff_t end, int origin) +{ + struct page *page; + struct pagevec pvec; + pgoff_t indices[PAGEVEC_SIZE]; + bool done = false; + int i; + + pagevec_init(&pvec, 0); + pvec.nr = 1; /* start small: we may be there already */ + while (!done) { + pvec.nr = shmem_find_get_pages_and_swap(mapping, index, + pvec.nr, pvec.pages, indices); + if (!pvec.nr) { + if (origin == SEEK_DATA) + index = end; + break; + } + for (i = 0; i < pvec.nr; i++, index++) { + if (index < indices[i]) { + if (origin == SEEK_HOLE) { + done = true; + break; + } + index = indices[i]; + } + page = pvec.pages[i]; + if (page && !radix_tree_exceptional_entry(page)) { + if (!PageUptodate(page)) + page = NULL; + } + if (index >= end || + (page && origin == SEEK_DATA) || + (!page && origin == SEEK_HOLE)) { + done = true; + break; + } + } + shmem_deswap_pagevec(&pvec); + pagevec_release(&pvec); + pvec.nr = PAGEVEC_SIZE; + cond_resched(); + } + return index; +} + +static loff_t shmem_file_llseek(struct file *file, loff_t offset, int origin) +{ + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + pgoff_t start, end; + loff_t new_offset; + + if (origin != SEEK_DATA && origin != SEEK_HOLE) + return generic_file_llseek_size(file, offset, origin, + MAX_LFS_FILESIZE, i_size_read(inode)); + mutex_lock(&inode->i_mutex); + /* We're holding i_mutex so we can access i_size directly */ + + if (offset < 0) + offset = -EINVAL; + else if (offset >= inode->i_size) + offset = -ENXIO; + else { + start = offset >> PAGE_CACHE_SHIFT; + end = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + new_offset = shmem_seek_hole_data(mapping, start, end, origin); + new_offset <<= PAGE_CACHE_SHIFT; + if (new_offset > offset) { + if (new_offset < inode->i_size) + offset = new_offset; + else if (origin == SEEK_DATA) + offset = -ENXIO; + else + offset = inode->i_size; + } + } + + if (offset >= 0 && offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + mutex_unlock(&inode->i_mutex); + return offset; +} + static long shmem_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { @@ -2580,7 +2676,7 @@ static const struct address_space_operations shmem_aops = { static const struct file_operations shmem_file_operations = { .mmap = shmem_mmap, #ifdef CONFIG_TMPFS - .llseek = generic_file_llseek, + .llseek = shmem_file_llseek, .read = do_sync_read, .write = do_sync_write, .aio_read = shmem_file_aio_read, |