ext4: allow unlocked direct IO when pages are cached (4b0524aa) · Commits · 戴 / test

Currently we do not allow unlocked (meaning without inode_lock) direct IO when the file has any pages cached. This check is not needed anymore as we keep inode lock until ext4_direct_IO_write() and thus can happily writeback and evict any pages conflicting with current direct IO write. Signed-off-by:

Jan Kara <jack@suse.cz> Signed-off-by:

Theodore Ts'o <tytso@mit.edu>

fs/ext4/file.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -91,7 +91,6 @@ ext4_unaligned_aio(struct inode inode, struct iov_iter from, loff_t pos)
		static ssize_t
		ext4_file_write_iter(struct kiocb iocb, struct iov_iter from)
		{
		struct file *file = iocb->ki_filp;
		struct inode *inode = file_inode(iocb->ki_filp);
		struct blk_plug plug;
		int o_direct = iocb->ki_flags & IOCB_DIRECT;
		@@ -138,7 +137,7 @@ ext4_file_write_iter(struct kiocb iocb, struct iov_iter from)

		/* check whether we do a DIO overwrite or not */
		if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
		!file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
		pos + length <= i_size_read(inode)) {
		struct ext4_map_blocks map;
		unsigned int blkbits = inode->i_blkbits;
		int err, len;

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