f2fs: fix to avoid triggering IO in write path

If we are in write IO path, we need to avoid using GFP_KERNEL.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/compress.c

@@ -656,7 +656,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
 		struct bio *bio = NULL;
 
 		ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
-						&last_block_in_bio, false);
+					&last_block_in_bio, false, true);
 		f2fs_destroy_compress_ctx(cc);
 		if (ret)
 			goto release_pages;

fs/f2fs/data.c

@@ -925,14 +925,15 @@ static inline bool f2fs_need_verity(const struct inode *inode, pgoff_t idx)
 
 static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
 				      unsigned nr_pages, unsigned op_flag,
-				      pgoff_t first_idx)
+				      pgoff_t first_idx, bool for_write)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct bio *bio;
 	struct bio_post_read_ctx *ctx;
 	unsigned int post_read_steps = 0;
 
-	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
+	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES),
+								for_write);
 	if (!bio)
 		return ERR_PTR(-ENOMEM);
 	f2fs_target_device(sbi, blkaddr, bio);
@@ -967,12 +968,12 @@ static void f2fs_release_read_bio(struct bio *bio)
 
 /* This can handle encryption stuffs */
 static int f2fs_submit_page_read(struct inode *inode, struct page *page,
-							block_t blkaddr)
+						block_t blkaddr, bool for_write)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct bio *bio;
 
-	bio = f2fs_grab_read_bio(inode, blkaddr, 1, 0, page->index);
+	bio = f2fs_grab_read_bio(inode, blkaddr, 1, 0, page->index, for_write);
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
 
@@ -1158,7 +1159,7 @@ struct page *f2fs_get_read_data_page(struct inode *inode, pgoff_t index,
 		return page;
 	}
 
-	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr);
+	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr, for_write);
 	if (err)
 		goto put_err;
 	return page;
@@ -1971,7 +1972,8 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
 	}
 	if (bio == NULL) {
 		bio = f2fs_grab_read_bio(inode, block_nr, nr_pages,
-				is_readahead ? REQ_RAHEAD : 0, page->index);
+				is_readahead ? REQ_RAHEAD : 0, page->index,
+				false);
 		if (IS_ERR(bio)) {
 			ret = PTR_ERR(bio);
 			bio = NULL;
@@ -2006,7 +2008,7 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 				unsigned nr_pages, sector_t *last_block_in_bio,
-				bool is_readahead)
+				bool is_readahead, bool for_write)
 {
 	struct dnode_of_data dn;
 	struct inode *inode = cc->inode;
@@ -2100,7 +2102,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 		if (!bio) {
 			bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages,
 					is_readahead ? REQ_RAHEAD : 0,
-					page->index);
+					page->index, for_write);
 			if (IS_ERR(bio)) {
 				ret = PTR_ERR(bio);
 				bio = NULL;
@@ -2201,7 +2203,7 @@ int f2fs_mpage_readpages(struct address_space *mapping,
 				ret = f2fs_read_multi_pages(&cc, &bio,
 							max_nr_pages,
 							&last_block_in_bio,
-							is_readahead);
+							is_readahead, false);
 				f2fs_destroy_compress_ctx(&cc);
 				if (ret)
 					goto set_error_page;
@@ -2244,7 +2246,7 @@ int f2fs_mpage_readpages(struct address_space *mapping,
 				ret = f2fs_read_multi_pages(&cc, &bio,
 							max_nr_pages,
 							&last_block_in_bio,
-							is_readahead);
+							is_readahead, false);
 				f2fs_destroy_compress_ctx(&cc);
 			}
 		}
@@ -3274,7 +3276,7 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 			err = -EFSCORRUPTED;
 			goto fail;
 		}
-		err = f2fs_submit_page_read(inode, page, blkaddr);
+		err = f2fs_submit_page_read(inode, page, blkaddr, true);
 		if (err)
 			goto fail;
 

fs/f2fs/f2fs.h

@@ -3796,7 +3796,7 @@ int f2fs_write_multi_pages(struct compress_ctx *cc,
 int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index);
 int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 				unsigned nr_pages, sector_t *last_block_in_bio,
-				bool is_readahead);
+				bool is_readahead, bool for_write);
 struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc);
 void f2fs_free_dic(struct decompress_io_ctx *dic);
 void f2fs_decompress_end_io(struct page **rpages,