diff options
Diffstat (limited to 'fs/cramfs')
| -rw-r--r-- | fs/cramfs/README | 8 | ||||
| -rw-r--r-- | fs/cramfs/inode.c | 24 |
2 files changed, 12 insertions, 20 deletions
diff --git a/fs/cramfs/README b/fs/cramfs/README index d71b27e0ff15..778df5c4d70b 100644 --- a/fs/cramfs/README +++ b/fs/cramfs/README @@ -115,7 +115,7 @@ Block Size (Block size in cramfs refers to the size of input data that is compressed at a time. It's intended to be somewhere around -PAGE_SIZE for cramfs_readpage's convenience.) +PAGE_SIZE for cramfs_read_folio's convenience.) The superblock ought to indicate the block size that the fs was written for, since comments in <linux/pagemap.h> indicate that @@ -161,7 +161,7 @@ size. The options are: PAGE_SIZE. It's easy enough to change the kernel to use a smaller value than -PAGE_SIZE: just make cramfs_readpage read multiple blocks. +PAGE_SIZE: just make cramfs_read_folio read multiple blocks. The cost of option 1 is that kernels with a larger PAGE_SIZE value don't get as good compression as they can. @@ -173,9 +173,9 @@ they don't mind their cramfs being inaccessible to kernels with smaller PAGE_SIZE values. Option 3 is easy to implement if we don't mind being CPU-inefficient: -e.g. get readpage to decompress to a buffer of size MAX_BLKSIZE (which +e.g. get read_folio to decompress to a buffer of size MAX_BLKSIZE (which must be no larger than 32KB) and discard what it doesn't need. -Getting readpage to read into all the covered pages is harder. +Getting read_folio to read into all the covered pages is harder. The main advantage of option 3 over 1, 2, is better compression. The cost is greater complexity. Probably not worth it, but I hope someone diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index 666aa380011e..61ccf7722fc3 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -183,6 +183,7 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, unsigned int len) { struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; + struct file_ra_state ra; struct page *pages[BLKS_PER_BUF]; unsigned i, blocknr, buffer; unsigned long devsize; @@ -212,6 +213,9 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, devsize = bdev_nr_bytes(sb->s_bdev) >> PAGE_SHIFT; /* Ok, read in BLKS_PER_BUF pages completely first. */ + file_ra_state_init(&ra, mapping); + page_cache_sync_readahead(mapping, &ra, NULL, blocknr, BLKS_PER_BUF); + for (i = 0; i < BLKS_PER_BUF; i++) { struct page *page = NULL; @@ -224,19 +228,6 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, pages[i] = page; } - for (i = 0; i < BLKS_PER_BUF; i++) { - struct page *page = pages[i]; - - if (page) { - wait_on_page_locked(page); - if (!PageUptodate(page)) { - /* asynchronous error */ - put_page(page); - pages[i] = NULL; - } - } - } - buffer = next_buffer; next_buffer = NEXT_BUFFER(buffer); buffer_blocknr[buffer] = blocknr; @@ -414,7 +405,7 @@ static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma) /* * Let's create a mixed map if we can't map it all. * The normal paging machinery will take care of the - * unpopulated ptes via cramfs_readpage(). + * unpopulated ptes via cramfs_read_folio(). */ int i; vma->vm_flags |= VM_MIXEDMAP; @@ -814,8 +805,9 @@ out: return d_splice_alias(inode, dentry); } -static int cramfs_readpage(struct file *file, struct page *page) +static int cramfs_read_folio(struct file *file, struct folio *folio) { + struct page *page = &folio->page; struct inode *inode = page->mapping->host; u32 maxblock; int bytes_filled; @@ -925,7 +917,7 @@ err: } static const struct address_space_operations cramfs_aops = { - .readpage = cramfs_readpage + .read_folio = cramfs_read_folio }; /* |