linux-ext4 - [PATCH v5 10/12] ext4: move inode extension check out from ext4_iomap

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Message-ID: <a2bf8283b42f49e3549f92b9170d56d3a740c521.1571647180.git.mbobrowski@mbobrowski.org>
Date:   Mon, 21 Oct 2019 20:20:37 +1100
From:   Matthew Bobrowski <mbobrowski@...browski.org>
To:     tytso@....edu, jack@...e.cz, adilger.kernel@...ger.ca
Cc:     linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        hch@...radead.org, david@...morbit.com, darrick.wong@...cle.com
Subject: [PATCH v5 10/12] ext4: move inode extension check out from
 ext4_iomap_alloc()

Lift the inode extension/orphan list handling code out from
ext4_iomap_alloc() and apply it within the ext4_dax_write_iter()
function.

Signed-off-by: Matthew Bobrowski <mbobrowski@...browski.org>
Reviewed-by: Jan Kara <jack@...e.cz>
Reviewed-by: Ritesh Harjani <riteshh@...ux.ibm.com>
---
 fs/ext4/file.c  | 21 ++++++++++++++++++++-
 fs/ext4/inode.c | 22 ----------------------
 2 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 6ddf00265988..65e758ae02d0 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -304,6 +304,8 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	ssize_t ret;
 	size_t count;
 	loff_t offset;
+	handle_t *handle;
+	bool extend = false;
 	struct inode *inode = file_inode(iocb->ki_filp);
 
 	if (!inode_trylock(inode)) {
@@ -323,8 +325,25 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	offset = iocb->ki_pos;
 	count = iov_iter_count(from);
+	if (offset + count > EXT4_I(inode)->i_disksize) {
+		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			goto out;
+		}
+
+		ret = ext4_orphan_add(handle, inode);
+		if (ret) {
+			ext4_journal_stop(handle);
+			goto out;
+		}
+		extend = true;
+		ext4_journal_stop(handle);
+	}
+
 	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
-	ret = ext4_handle_inode_extension(inode, ret, offset, count);
+	if (extend)
+		ret = ext4_handle_inode_extension(inode, ret, offset, count);
 out:
 	inode_unlock(inode);
 	if (ret > 0)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f79d15e8d3c6..a37112efe3fb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3443,7 +3443,6 @@ static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map,
 			    unsigned int flags)
 {
 	handle_t *handle;
-	u8 blkbits = inode->i_blkbits;
 	int ret, dio_credits, retries = 0;
 
 	/*
@@ -3466,28 +3465,7 @@ static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map,
 		return PTR_ERR(handle);
 
 	ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO);
-	if (ret < 0)
-		goto journal_stop;
-
-	/*
-	 * If we have allocated blocks beyond EOF, we need to ensure that
-	 * they're truncated if we crash before updating the inode size
-	 * metadata within ext4_iomap_end(). For faults, we don't need to do
-	 * that (and cannot due to the orphan list operations needing an
-	 * inode_lock()). If we happen to instantiate blocks beyond EOF, it is
-	 * because we race with a truncate operation, which already has added
-	 * the inode onto the orphan list.
-	 */
-	if (!(flags & IOMAP_FAULT) && map->m_lblk + map->m_len >
-	    (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) {
-		int err;
-
-		err = ext4_orphan_add(handle, inode);
-		if (err < 0)
-			ret = err;
-	}
 
-journal_stop:
 	ext4_journal_stop(handle);
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
-- 
2.20.1

--<M>--