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().

Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/fd5c84db25d5d0da87d97ed4c36fd844f57da759.1572949325.git.mbobrowski@mbobrowski.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index ec54fec..83ef9c9 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -323,6 +323,8 @@ 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)) {
@@ -342,8 +344,28 @@ 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, offset, ret, count);
+
+       if (extend)
+               ret = ext4_handle_inode_extension(inode, offset, ret, count);
 out:
        inode_unlock(inode);
        if (ret > 0)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 071a1f9..392085a 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3494,7 +3494,6 @@ 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;
 
        /*
@@ -3517,28 +3516,7 @@ retry:
                return PTR_ERR(handle);
 
        ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO);
-       if (ret < 0)
-               goto journal_stop;
-
-       /*
-        * If we've 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 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;