This commit moves ext4/readpage.c to crypto/readpage.c and adds new
functionality to enable reading encrypted files in blocksize less than
pagesize setup.
Ext4 now uses the new fscrypt API when CONFIG_EXT4_FS_ENCRYPTION is
enabled. Otherwise it invokes mpage_readpage[s]() functions.
Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx>
---
fs/crypto/Makefile | 2 +-
fs/crypto/bio.c | 18 +-
fs/crypto/fscrypt_private.h | 3 +
fs/crypto/readpage.c | 461 ++++++++++++++++++++++++++++++++++++++++
fs/ext4/Makefile | 2 +-
fs/ext4/ext4.h | 5 -
fs/ext4/inode.c | 13 +-
fs/ext4/readpage.c | 294 -------------------------
include/linux/fscrypt.h | 1 +
include/linux/fscrypt_notsupp.h | 3 +-
include/linux/fscrypt_supp.h | 9 +-
11 files changed, 502 insertions(+), 309 deletions(-)
create mode 100644 fs/crypto/readpage.c
delete mode 100644 fs/ext4/readpage.c
diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile
index cb49698..84400e9 100644
--- a/fs/crypto/Makefile
+++ b/fs/crypto/Makefile
@@ -1,4 +1,4 @@
obj-$(CONFIG_FS_ENCRYPTION) += fscrypto.o
fscrypto-y := crypto.o fname.o hooks.o keyinfo.o policy.o
-fscrypto-$(CONFIG_BLOCK) += bio.o
+fscrypto-$(CONFIG_BLOCK) += bio.o readpage.o
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 4d0d14f..265cba3 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -70,9 +70,23 @@ static void completion_pages(struct work_struct *work)
bio_put(bio);
}
-void fscrypt_decrypt_bio_blocks(struct fscrypt_ctx *ctx, struct bio *bio)
+bool fscrypt_bio_encrypted(struct bio *bio)
{
- INIT_WORK(&ctx->r.work, completion_pages);
+ if (bio->bi_vcnt) {
+ struct inode *inode = bio->bi_io_vec->bv_page->mapping->host;
+
+ if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
+ return true;
+ }
+
+ return false;
+}
+
+void fscrypt_decrypt_bio_blocks(struct fscrypt_ctx *ctx, struct bio *bio,
+ void (*process_bio)(struct work_struct *))
+{
+ INIT_WORK(&ctx->r.work,
+ process_bio ? process_bio : completion_pages);
ctx->r.bio = bio;
queue_work(fscrypt_read_workqueue, &ctx->r.work);
}
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 9821e97..63e2b10 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -71,6 +71,9 @@ typedef enum {
#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
+/* bio.c */
+extern bool fscrypt_bio_encrypted(struct bio *bio);
+
/* crypto.c */
extern int fscrypt_initialize(unsigned int cop_flags);
extern struct workqueue_struct *fscrypt_read_workqueue;
diff --git a/fs/crypto/readpage.c b/fs/crypto/readpage.c
new file mode 100644
index 0000000..7372173
--- /dev/null
+++ b/fs/crypto/readpage.c
@@ -0,0 +1,461 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/crypto/readpage.c
+ *
+ * Copyright (C) 2002, Linus Torvalds.
+ * Copyright (C) 2015, Google, Inc.
+ *
+ * This was originally taken from fs/ext4/readpage.c which in turn was
+ * taken from fs/mpage.c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/kdev_t.h>
+#include <linux/gfp.h>
+#include <linux/bio.h>
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
+#include <linux/highmem.h>
+#include <linux/prefetch.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/cleancache.h>
+
+#include "fscrypt_private.h"
+
+static void fscrypt_complete_block(struct work_struct *work)
+{
+ struct fscrypt_ctx *ctx =
+ container_of(work, struct fscrypt_ctx, r.work);
+ struct buffer_head *bh;
+ struct bio *bio;
+ struct bio_vec *bv;
+ struct page *page;
+ struct inode *inode;
+ u64 blk_nr;
+ int ret;
+
+ bio = ctx->r.bio;
+ BUG_ON(bio->bi_vcnt != 1);
+
+ bv = bio->bi_io_vec;
+ page = bv->bv_page;
+ inode = page->mapping->host;
+
+ BUG_ON(bv->bv_len != i_blocksize(inode));
+
+ blk_nr = page->index << (PAGE_SHIFT - inode->i_blkbits);
+ blk_nr += bv->bv_offset >> inode->i_blkbits;
+
+ bh = ctx->r.bh;
+
+ ret = fscrypt_decrypt_block(inode, page, bv->bv_len,
+ bv->bv_offset, blk_nr);
+
+ end_buffer_async_read(bh, !ret);
+
+ fscrypt_release_ctx(ctx);
+ bio_put(bio);
+}
+
+static void fscrypt_block_end_io(struct bio *bio)
+{
+ struct buffer_head *bh;
+
+ if (fscrypt_bio_encrypted(bio)) {
+ struct fscrypt_ctx *ctx = bio->bi_private;
+
+ bh = ctx->r.bh;
+
+ if (bio->bi_status) {
+ fscrypt_release_ctx(ctx);
+ } else {
+ fscrypt_decrypt_bio_blocks(ctx, bio,
+ fscrypt_complete_block);
+ return;
+ }
+ } else {
+ bh = bio->bi_private;
+ }
+
+ end_buffer_async_read(bh, !bio->bi_status);
+}
+
+/*
+ * I/O completion handler for multipage BIOs.
+ *
+ * The mpage code never puts partial pages into a BIO (except for end-of-file).
+ * If a page does not map to a contiguous run of blocks then it simply falls
+ * back to block_read_full_page().
+ *
+ * Why is this? If a page's completion depends on a number of different BIOs
+ * which can complete in any order (or at the same time) then determining the
+ * status of that page is hard. See end_buffer_async_read() for the details.
+ * There is no point in duplicating all that complexity.
+ */
+static void fscrypt_mpage_end_io(struct bio *bio)
+{
+ struct bio_vec *bv;
+ int i;
+
+ if (fscrypt_bio_encrypted(bio)) {
+ if (bio->bi_status) {
+ fscrypt_release_ctx(bio->bi_private);
+ } else {
+ fscrypt_decrypt_bio_blocks(bio->bi_private, bio, NULL);
+ return;
+ }
+ }
+ bio_for_each_segment_all(bv, bio, i) {
+ struct page *page = bv->bv_page;
+
+ if (!bio->bi_status) {
+ SetPageUptodate(page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+ unlock_page(page);
+ }
+
+ bio_put(bio);
+}
+
+static int fscrypt_block_read_full_page(struct page *page, get_block_t *get_block)
+{
+ struct inode *inode = page->mapping->host;
+ struct fscrypt_ctx *ctx;
+ struct bio *bio;
+ sector_t iblock, lblock;
+ struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
+ unsigned int blocksize, bbits;
+ int nr, i;
+ int fully_mapped = 1;
+ int ret;
+
+ head = create_page_buffers(page, inode, 0);
+ blocksize = head->b_size;
+ bbits = inode->i_blkbits;
+
+ iblock = (sector_t)page->index << (PAGE_SHIFT - bbits);
+ lblock = (i_size_read(inode)+blocksize-1) >> bbits;
+ bh = head;
+ nr = 0;
+ i = 0;
+
+ do {
+ if (buffer_uptodate(bh))
+ continue;
+
+ if (!buffer_mapped(bh)) {
+ int err = 0;
+
+ fully_mapped = 0;
+ if (iblock < lblock) {
+ WARN_ON(bh->b_size != blocksize);
+ err = get_block(inode, iblock, bh, 0);
+ if (err)
+ SetPageError(page);
+ }
+ if (!buffer_mapped(bh)) {
+ zero_user(page, i << bbits, blocksize);
+ if (!err)
+ set_buffer_uptodate(bh);
+ continue;
+ }
+ /*
+ * get_block() might have updated the buffer
+ * synchronously
+ */
+ if (buffer_uptodate(bh))
+ continue;
+ }
+ arr[nr++] = bh;
+ } while (i++, iblock++, (bh = bh->b_this_page) != head);
+
+ if (fully_mapped)
+ SetPageMappedToDisk(page);
+
+ if (!nr) {
+ /*
+ * All buffers are uptodate - we can set the page uptodate
+ * as well. But not if ext4_get_block() returned an error.
+ */
+ if (!PageError(page))
+ SetPageUptodate(page);
+ unlock_page(page);
+ return 0;
+ }
+
+ /* Stage two: lock the buffers */
+ for (i = 0; i < nr; i++) {
+ bh = arr[i];
+ lock_buffer(bh);
+ set_buffer_async_read(bh);
+ }
+
+ /*
+ * Stage 3: start the IO. Check for uptodateness
+ * inside the buffer lock in case another process reading
+ * the underlying blockdev brought it uptodate (the sct fix).
+ */
+ for (i = 0; i < nr; i++) {
+ ctx = NULL;
+ bh = arr[i];
+
+ if (buffer_uptodate(bh)) {
+ end_buffer_async_read(bh, 1);
+ continue;
+ }
+
+ if (IS_ENCRYPTED(inode)
+ && S_ISREG(inode->i_mode)) {
+ ctx = fscrypt_get_ctx(inode, GFP_NOFS);
+ if (IS_ERR(ctx)) {
+ set_page_error:
+ zero_user_segment(page, bh_offset(bh),
+ blocksize);
+ end_buffer_async_read(bh, 0);
+ continue;
+ }
+ ctx->r.bh = bh;
+ }
+
+ bio = bio_alloc(GFP_NOIO, 1);
+ if (!bio) {
+ if (ctx)
+ fscrypt_release_ctx(ctx);
+ goto set_page_error;
+ }
+
+ bio->bi_iter.bi_sector = bh->b_blocknr * (blocksize >> 9);
+ bio_set_dev(bio, bh->b_bdev);
+ bio->bi_write_hint = 0;
+
+ ret = bio_add_page(bio, bh->b_page, blocksize, bh_offset(bh));
+ BUG_ON(bio->bi_iter.bi_size != blocksize);
+
+ bio->bi_end_io = fscrypt_block_end_io;
+ if (ctx)
+ bio->bi_private = ctx;
+ else
+ bio->bi_private = bh;
+ bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+ submit_bio(bio);
+ }
+
+ return 0;
+}
+
+int fscrypt_mpage_readpages(struct address_space *mapping,
+ struct list_head *pages, struct page *page,
+ unsigned nr_pages, get_block_t get_block)
+{
+ struct bio *bio = NULL;
+ sector_t last_block_in_bio = 0;
+
+ struct inode *inode = mapping->host;
+ const unsigned blkbits = inode->i_blkbits;
+ const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
+ const unsigned blocksize = 1 << blkbits;
+ sector_t block_in_file;
+ sector_t last_block;
+ sector_t last_block_in_file;
+ sector_t blocks[MAX_BUF_PER_PAGE];
+ unsigned page_block;
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ int length;
+ unsigned relative_block = 0;
+ struct buffer_head map_bh;
+ unsigned int nblocks;
+ unsigned long first_logical_block = 0;
+
+ map_bh.b_state = 0;
+ map_bh.b_size = 0;
+
+ for (; nr_pages; nr_pages--) {
+ int fully_mapped = 1;
+ unsigned first_hole = blocks_per_page;
+
+ prefetchw(&page->flags);
+ if (pages) {
+ page = list_entry(pages->prev, struct page, lru);
+ list_del(&page->lru);
+ if (add_to_page_cache_lru(page, mapping, page->index,
+ readahead_gfp_mask(mapping)))
+ goto next_page;
+ }
+
+ if (page_has_buffers(page))
+ goto confused;
+
+ block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits);
+ last_block = block_in_file + nr_pages * blocks_per_page;
+ last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;
+ if (last_block > last_block_in_file)
+ last_block = last_block_in_file;
+ page_block = 0;
+
+ /*
+ * Map blocks using the previous result first.
+ */
+ nblocks = map_bh.b_size >> blkbits;
+ if (buffer_mapped(&map_bh) &&
+ block_in_file > first_logical_block &&
+ block_in_file < (first_logical_block + nblocks)) {
+ unsigned map_offset = block_in_file - first_logical_block;
+ unsigned last = nblocks - map_offset;
+
+ for (relative_block = 0; ; relative_block++) {
+ if (relative_block == last) {
+ /* needed? */
+ clear_buffer_mapped(&map_bh);
+ break;
+ }
+ if (page_block == blocks_per_page)
+ break;
+ blocks[page_block] = map_bh.b_blocknr + map_offset +
+ relative_block;
+ page_block++;
+ block_in_file++;
+ }
+ }
+
+ /*
+ * Then do more get_blocks() calls until we are
+ * done with this page.
+ */
+ while (page_block < blocks_per_page) {
+ if (block_in_file < last_block) {
+ /*
+ * map.m_lblk = block_in_file;
+ * map.m_len = last_block - block_in_file;
+ */
+ map_bh.b_state = 0;
+ map_bh.b_size = (last_block - block_in_file) << blkbits;
+
+ if (get_block(inode, block_in_file, &map_bh, 0)) {
+ set_error_page:
+ SetPageError(page);
+ zero_user_segment(page, 0,
+ PAGE_SIZE);
+ unlock_page(page);
+ goto next_page;
+ }
+ first_logical_block = block_in_file;
+ }
+
+ if (!buffer_mapped(&map_bh)) {
+ fully_mapped = 0;
+ if (first_hole == blocks_per_page)
+ first_hole = page_block;
+ page_block++;
+ block_in_file++;
+ continue;
+ }
+ if (first_hole != blocks_per_page)
+ goto confused; /* hole -> non-hole */
+
+ /* Contiguous blocks? */
+ if (page_block && blocks[page_block-1] != map_bh.b_blocknr-1)
+ goto confused;
+ nblocks = map_bh.b_size >> blkbits;
+ for (relative_block = 0; ; relative_block++) {
+ if (relative_block == nblocks) {
+ /* needed? */
+ clear_buffer_mapped(&map_bh);
+ break;
+ } else if (page_block == blocks_per_page)
+ break;
+ blocks[page_block] = map_bh.b_blocknr+relative_block;
+ page_block++;
+ block_in_file++;
+ }
+ }
+ if (first_hole != blocks_per_page) {
+ zero_user_segment(page, first_hole << blkbits,
+ PAGE_SIZE);
+ if (first_hole == 0) {
+ SetPageUptodate(page);
+ unlock_page(page);
+ goto next_page;
+ }
+ } else if (fully_mapped) {
+ SetPageMappedToDisk(page);
+ }
+ if (fully_mapped && blocks_per_page == 1 &&
+ !PageUptodate(page) && cleancache_get_page(page) == 0) {
+ SetPageUptodate(page);
+ goto confused;
+ }
+
+ /*
+ * This page will go to BIO. Do we need to send this
+ * BIO off first?
+ */
+ if (bio && (last_block_in_bio != blocks[0] - 1)) {
+ submit_and_realloc:
+ submit_bio(bio);
+ bio = NULL;
+ }
+ if (bio == NULL) {
+ struct fscrypt_ctx *ctx = NULL;
+ if (IS_ENCRYPTED(inode) &&
+ S_ISREG(inode->i_mode)) {
+ ctx = fscrypt_get_ctx(inode, GFP_NOFS);
+ if (IS_ERR(ctx))
+ goto set_error_page;
+ }
+ bio = bio_alloc(GFP_KERNEL,
+ min_t(int, nr_pages, BIO_MAX_PAGES));
+ if (!bio) {
+ if (ctx)
+ fscrypt_release_ctx(ctx);
+ goto set_error_page;
+ }
+ bio_set_dev(bio, bdev);
+ bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
+ bio->bi_end_io = fscrypt_mpage_end_io;
+ bio->bi_private = ctx;
+ bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ }
+
+ length = first_hole << blkbits;
+ if (bio_add_page(bio, page, length, 0) < length)
+ goto submit_and_realloc;
+
+ relative_block = block_in_file - first_logical_block;
+ if ((buffer_boundary(&map_bh) && relative_block == nblocks) ||
+ (first_hole != blocks_per_page)) {
+ submit_bio(bio);
+ bio = NULL;
+ } else {
+ last_block_in_bio = blocks[blocks_per_page - 1];
+ }
+ goto next_page;
+ confused:
+ if (bio) {
+ submit_bio(bio);
+ bio = NULL;
+ }
+ if (!PageUptodate(page))
+ fscrypt_block_read_full_page(page, get_block);
+ else
+ unlock_page(page);
+ next_page:
+ if (pages)
+ put_page(page);
+ }
+ BUG_ON(pages && !list_empty(pages));
+ if (bio)
+ submit_bio(bio);
+ return 0;
+}
+EXPORT_SYMBOL(fscrypt_mpage_readpages);
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 8fdfcd3..7c38803 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -8,7 +8,7 @@ obj-$(CONFIG_EXT4_FS) += ext4.o
ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \
extents_status.o file.o fsmap.o fsync.o hash.o ialloc.o \
indirect.o inline.o inode.o ioctl.o mballoc.o migrate.o \
- mmp.o move_extent.o namei.o page-io.o readpage.o resize.o \
+ mmp.o move_extent.o namei.o page-io.o resize.o \
super.o symlink.o sysfs.o xattr.o xattr_trusted.o xattr_user.o
ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 4e091eae..98c1b83 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3053,11 +3053,6 @@ static inline void ext4_set_de_type(struct super_block *sb,
de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
}
-/* readpages.c */
-extern int ext4_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages);
-
/* symlink.c */
extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
extern const struct inode_operations ext4_symlink_inode_operations;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index aac0e04..66b768c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3342,7 +3342,11 @@ static int ext4_readpage(struct file *file, struct page *page)
ret = ext4_readpage_inline(inode, page);
if (ret == -EAGAIN)
- return ext4_mpage_readpages(page->mapping, NULL, page, 1);
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ return fscrypt_mpage_readpages(page->mapping, NULL, page, 1, ext4_get_block);
+#else
+ return mpage_readpage(page, ext4_get_block);
+#endif
return ret;
}
@@ -3356,8 +3360,11 @@ ext4_readpages(struct file *file, struct address_space *mapping,
/* If the file has inline data, no need to do readpages. */
if (ext4_has_inline_data(inode))
return 0;
-
- return ext4_mpage_readpages(mapping, pages, NULL, nr_pages);
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ return fscrypt_mpage_readpages(mapping, pages, NULL, nr_pages, ext4_get_block);
+#else
+ return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
+#endif
}
static void ext4_invalidatepage(struct page *page, unsigned int offset,
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
deleted file mode 100644
index 8b2789f..0000000
--- a/fs/ext4/readpage.c
+++ /dev/null
@@ -1,294 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/fs/ext4/readpage.c
- *
- * Copyright (C) 2002, Linus Torvalds.
- * Copyright (C) 2015, Google, Inc.
- *
- * This was originally taken from fs/mpage.c
- *
- * The intent is the ext4_mpage_readpages() function here is intended
- * to replace mpage_readpages() in the general case, not just for
- * encrypted files. It has some limitations (see below), where it
- * will fall back to read_block_full_page(), but these limitations
- * should only be hit when page_size != block_size.
- *
- * This will allow us to attach a callback function to support ext4
- * encryption.
- *
- * If anything unusual happens, such as:
- *
- * - encountering a page which has buffers
- * - encountering a page which has a non-hole after a hole
- * - encountering a page with non-contiguous blocks
- *
- * then this code just gives up and calls the buffer_head-based read function.
- * It does handle a page which has holes at the end - that is a common case:
- * the end-of-file on blocksize < PAGE_SIZE setups.
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/mm.h>
-#include <linux/kdev_t.h>
-#include <linux/gfp.h>
-#include <linux/bio.h>
-#include <linux/fs.h>
-#include <linux/buffer_head.h>
-#include <linux/blkdev.h>
-#include <linux/highmem.h>
-#include <linux/prefetch.h>
-#include <linux/mpage.h>
-#include <linux/writeback.h>
-#include <linux/backing-dev.h>
-#include <linux/pagevec.h>
-#include <linux/cleancache.h>
-
-#include "ext4.h"
-
-static inline bool ext4_bio_encrypted(struct bio *bio)
-{
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- return unlikely(bio->bi_private != NULL);
-#else
- return false;
-#endif
-}
-
-/*
- * I/O completion handler for multipage BIOs.
- *
- * The mpage code never puts partial pages into a BIO (except for end-of-file).
- * If a page does not map to a contiguous run of blocks then it simply falls
- * back to block_read_full_page().
- *
- * Why is this? If a page's completion depends on a number of different BIOs
- * which can complete in any order (or at the same time) then determining the
- * status of that page is hard. See end_buffer_async_read() for the details.
- * There is no point in duplicating all that complexity.
- */
-static void mpage_end_io(struct bio *bio)
-{
- struct bio_vec *bv;
- int i;
-
- if (ext4_bio_encrypted(bio)) {
- if (bio->bi_status) {
- fscrypt_release_ctx(bio->bi_private);
- } else {
- fscrypt_decrypt_bio_blocks(bio->bi_private, bio);
- return;
- }
- }
- bio_for_each_segment_all(bv, bio, i) {
- struct page *page = bv->bv_page;
-
- if (!bio->bi_status) {
- SetPageUptodate(page);
- } else {
- ClearPageUptodate(page);
- SetPageError(page);
- }
- unlock_page(page);
- }
-
- bio_put(bio);
-}
-
-int ext4_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages)
-{
- struct bio *bio = NULL;
- sector_t last_block_in_bio = 0;
-
- struct inode *inode = mapping->host;
- const unsigned blkbits = inode->i_blkbits;
- const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
- const unsigned blocksize = 1 << blkbits;
- sector_t block_in_file;
- sector_t last_block;
- sector_t last_block_in_file;
- sector_t blocks[MAX_BUF_PER_PAGE];
- unsigned page_block;
- struct block_device *bdev = inode->i_sb->s_bdev;
- int length;
- unsigned relative_block = 0;
- struct ext4_map_blocks map;
-
- map.m_pblk = 0;
- map.m_lblk = 0;
- map.m_len = 0;
- map.m_flags = 0;
-
- for (; nr_pages; nr_pages--) {
- int fully_mapped = 1;
- unsigned first_hole = blocks_per_page;
-
- prefetchw(&page->flags);
- if (pages) {
- page = list_entry(pages->prev, struct page, lru);
- list_del(&page->lru);
- if (add_to_page_cache_lru(page, mapping, page->index,
- readahead_gfp_mask(mapping)))
- goto next_page;
- }
-
- if (page_has_buffers(page))
- goto confused;
-
- block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits);
- last_block = block_in_file + nr_pages * blocks_per_page;
- last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;
- if (last_block > last_block_in_file)
- last_block = last_block_in_file;
- page_block = 0;
-
- /*
- * Map blocks using the previous result first.
- */
- if ((map.m_flags & EXT4_MAP_MAPPED) &&
- block_in_file > map.m_lblk &&
- block_in_file < (map.m_lblk + map.m_len)) {
- unsigned map_offset = block_in_file - map.m_lblk;
- unsigned last = map.m_len - map_offset;
-
- for (relative_block = 0; ; relative_block++) {
- if (relative_block == last) {
- /* needed? */
- map.m_flags &= ~EXT4_MAP_MAPPED;
- break;
- }
- if (page_block == blocks_per_page)
- break;
- blocks[page_block] = map.m_pblk + map_offset +
- relative_block;
- page_block++;
- block_in_file++;
- }
- }
-
- /*
- * Then do more ext4_map_blocks() calls until we are
- * done with this page.
- */
- while (page_block < blocks_per_page) {
- if (block_in_file < last_block) {
- map.m_lblk = block_in_file;
- map.m_len = last_block - block_in_file;
-
- if (ext4_map_blocks(NULL, inode, &map, 0) < 0) {
- set_error_page:
- SetPageError(page);
- zero_user_segment(page, 0,
- PAGE_SIZE);
- unlock_page(page);
- goto next_page;
- }
- }
- if ((map.m_flags & EXT4_MAP_MAPPED) == 0) {
- fully_mapped = 0;
- if (first_hole == blocks_per_page)
- first_hole = page_block;
- page_block++;
- block_in_file++;
- continue;
- }
- if (first_hole != blocks_per_page)
- goto confused; /* hole -> non-hole */
-
- /* Contiguous blocks? */
- if (page_block && blocks[page_block-1] != map.m_pblk-1)
- goto confused;
- for (relative_block = 0; ; relative_block++) {
- if (relative_block == map.m_len) {
- /* needed? */
- map.m_flags &= ~EXT4_MAP_MAPPED;
- break;
- } else if (page_block == blocks_per_page)
- break;
- blocks[page_block] = map.m_pblk+relative_block;
- page_block++;
- block_in_file++;
- }
- }
- if (first_hole != blocks_per_page) {
- zero_user_segment(page, first_hole << blkbits,
- PAGE_SIZE);
- if (first_hole == 0) {
- SetPageUptodate(page);
- unlock_page(page);
- goto next_page;
- }
- } else if (fully_mapped) {
- SetPageMappedToDisk(page);
- }
- if (fully_mapped && blocks_per_page == 1 &&
- !PageUptodate(page) && cleancache_get_page(page) == 0) {
- SetPageUptodate(page);
- goto confused;
- }
-
- /*
- * This page will go to BIO. Do we need to send this
- * BIO off first?
- */
- if (bio && (last_block_in_bio != blocks[0] - 1)) {
- submit_and_realloc:
- submit_bio(bio);
- bio = NULL;
- }
- if (bio == NULL) {
- struct fscrypt_ctx *ctx = NULL;
-
- if (ext4_encrypted_inode(inode) &&
- S_ISREG(inode->i_mode)) {
- ctx = fscrypt_get_ctx(inode, GFP_NOFS);
- if (IS_ERR(ctx))
- goto set_error_page;
- }
- bio = bio_alloc(GFP_KERNEL,
- min_t(int, nr_pages, BIO_MAX_PAGES));
- if (!bio) {
- if (ctx)
- fscrypt_release_ctx(ctx);
- goto set_error_page;
- }
- bio_set_dev(bio, bdev);
- bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
- bio->bi_end_io = mpage_end_io;
- bio->bi_private = ctx;
- bio_set_op_attrs(bio, REQ_OP_READ, 0);
- }
-
- length = first_hole << blkbits;
- if (bio_add_page(bio, page, length, 0) < length)
- goto submit_and_realloc;
-
- if (((map.m_flags & EXT4_MAP_BOUNDARY) &&
- (relative_block == map.m_len)) ||
- (first_hole != blocks_per_page)) {
- submit_bio(bio);
- bio = NULL;
- } else
- last_block_in_bio = blocks[blocks_per_page - 1];
- goto next_page;
- confused:
- if (bio) {
- submit_bio(bio);
- bio = NULL;
- }
- if (!PageUptodate(page))
- block_read_full_page(page, ext4_get_block);
- else
- unlock_page(page);
- next_page:
- if (pages)
- put_page(page);
- }
- BUG_ON(pages && !list_empty(pages));
- if (bio)
- submit_bio(bio);
- return 0;
-}
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 08b4b40..98c51eb 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -34,6 +34,7 @@ struct fscrypt_ctx {
} w;
struct {
struct bio *bio;
+ struct buffer_head *bh;
struct work_struct work;
} r;
struct list_head free_list; /* Free list */
diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h
index d726b53..aeb6b6d 100644
--- a/include/linux/fscrypt_notsupp.h
+++ b/include/linux/fscrypt_notsupp.h
@@ -162,7 +162,8 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
/* bio.c */
static inline void fscrypt_decrypt_bio_blocks(struct fscrypt_ctx *ctx,
- struct bio *bio)
+ struct bio *bio,
+ void (*process_bio)(struct work_struct *))
{
return;
}
diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h
index 7720e4a..b4c5231 100644
--- a/include/linux/fscrypt_supp.h
+++ b/include/linux/fscrypt_supp.h
@@ -139,7 +139,10 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
}
/* bio.c */
-extern void fscrypt_decrypt_bio_blocks(struct fscrypt_ctx *, struct bio *);
+
+extern void fscrypt_decrypt_bio_blocks(struct fscrypt_ctx *ctx, struct bio *bio,
+ void (*process_bio)(struct work_struct *));
+extern bool fscrypt_bio_encrypted(struct bio *bio);
extern void fscrypt_pullback_bio_page(struct page **, bool);
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
@@ -153,5 +156,7 @@ extern int __fscrypt_prepare_rename(struct inode *old_dir,
struct dentry *new_dentry,
unsigned int flags);
extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry);
-
+extern int fscrypt_mpage_readpages(struct address_space *mapping,
+ struct list_head *pages, struct page *page,
+ unsigned nr_pages, get_block_t get_block);
#endif /* _LINUX_FSCRYPT_SUPP_H */
--
2.9.5
