ext4: add read support for inline data
Let readpage and readpages handle the case when we want to read an
inlined file.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index bec68b3..e4a41d5 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -454,6 +454,67 @@
return error;
}
+static int ext4_read_inline_page(struct inode *inode, struct page *page)
+{
+ void *kaddr;
+ int ret = 0;
+ size_t len;
+ struct ext4_iloc iloc;
+
+ BUG_ON(!PageLocked(page));
+ BUG_ON(!ext4_has_inline_data(inode));
+ BUG_ON(page->index);
+
+ if (!EXT4_I(inode)->i_inline_off) {
+ ext4_warning(inode->i_sb, "inode %lu doesn't have inline data.",
+ inode->i_ino);
+ goto out;
+ }
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ goto out;
+
+ len = min_t(size_t, ext4_get_inline_size(inode), i_size_read(inode));
+ kaddr = kmap_atomic(page);
+ ret = ext4_read_inline_data(inode, kaddr, len, &iloc);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ zero_user_segment(page, len, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ brelse(iloc.bh);
+
+out:
+ return ret;
+}
+
+int ext4_readpage_inline(struct inode *inode, struct page *page)
+{
+ int ret = 0;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return -EAGAIN;
+ }
+
+ /*
+ * Current inline data can only exist in the 1st page,
+ * So for all the other pages, just set them uptodate.
+ */
+ if (!page->index)
+ ret = ext4_read_inline_page(inode, page);
+ else if (!PageUptodate(page)) {
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ }
+
+ up_read(&EXT4_I(inode)->xattr_sem);
+
+ unlock_page(page);
+ return ret >= 0 ? 0 : ret;
+}
+
int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
{
int ret;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e23f114..1668abf 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -649,6 +649,9 @@
int ret = 0, started = 0;
int dio_credits;
+ if (ext4_has_inline_data(inode))
+ return -ERANGE;
+
map.m_lblk = iblock;
map.m_len = bh->b_size >> inode->i_blkbits;
@@ -2687,6 +2690,12 @@
journal_t *journal;
int err;
+ /*
+ * We can get here for an inline file via the FIBMAP ioctl
+ */
+ if (ext4_has_inline_data(inode))
+ return 0;
+
if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
test_opt(inode->i_sb, DELALLOC)) {
/*
@@ -2732,14 +2741,30 @@
static int ext4_readpage(struct file *file, struct page *page)
{
+ int ret = -EAGAIN;
+ struct inode *inode = page->mapping->host;
+
trace_ext4_readpage(page);
- return mpage_readpage(page, ext4_get_block);
+
+ if (ext4_has_inline_data(inode))
+ ret = ext4_readpage_inline(inode, page);
+
+ if (ret == -EAGAIN)
+ return mpage_readpage(page, ext4_get_block);
+
+ return ret;
}
static int
ext4_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
+ struct inode *inode = mapping->host;
+
+ /* If the file has inline data, no need to do readpages. */
+ if (ext4_has_inline_data(inode))
+ return 0;
+
return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
}
@@ -3078,6 +3103,10 @@
if (ext4_should_journal_data(inode))
return 0;
+ /* Let buffer I/O handle the inline data case. */
+ if (ext4_has_inline_data(inode))
+ return 0;
+
trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 7ae0d05..646c9b9 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -139,6 +139,8 @@
extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
unsigned int len);
extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
+
+extern int ext4_readpage_inline(struct inode *inode, struct page *page);
# else /* CONFIG_EXT4_FS_XATTR */
static inline int
@@ -255,6 +257,11 @@
{
return 0;
}
+
+static inline int ext4_readpage_inline(struct inode *inode, struct page *page)
+{
+ return 0;
+}
# endif /* CONFIG_EXT4_FS_XATTR */
#ifdef CONFIG_EXT4_FS_SECURITY