Commit 5eec54fc authored by Ian Abbott's avatar Ian Abbott Committed by Jan Kara
Browse files

UDF: Add support for O_DIRECT 



Add support for the O_DIRECT flag.  There are two cases to deal with:

1. Small files stored in the ICB (inode control block?): just return 0
from the new udf_adinicb_direct_IO() handler to fall back to buffered
I/O.

2. Larger files, not stored in the ICB: nothing special here.  Just call
blockdev_direct_IO() from our new udf_direct_IO() handler and tidy up
any blocks instantiated outside i_size on error.  This is pretty
standard.  Factor error handling code out of udf_write_begin() into new
function udf_write_failed() so it can also be called by udf_direct_IO().

Also change the whitespace in udf_aops to make it a bit neater.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 3f6bba82

arch/um/os-Linux/time.c

+1 −1
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ static void deliver_alarm(void) 
	skew += this_tick - last_tick;



	while (skew >= one_tick) {

		alarm_handler(SIGVTALRM, NULL);

		alarm_handler(SIGVTALRM, NULL, NULL);

		skew -= one_tick;

	}

fs/udf/file.c

+9 −0
Original line number Diff line number Diff line
@@ -118,11 +118,20 @@ static int udf_adinicb_write_end(struct file *file, 
	return simple_write_end(file, mapping, pos, len, copied, page, fsdata);

}



static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb,

				     const struct iovec *iov,

				     loff_t offset, unsigned long nr_segs)

{

	/* Fallback to buffered I/O. */

	return 0;

}



const struct address_space_operations udf_adinicb_aops = {

	.readpage	= udf_adinicb_readpage,

	.writepage	= udf_adinicb_writepage,

	.write_begin	= udf_adinicb_write_begin,

	.write_end	= udf_adinicb_write_end,

	.direct_IO	= udf_adinicb_direct_IO,

};



static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,

fs/udf/inode.c

+36 −16
Original line number Diff line number Diff line
@@ -95,6 +95,22 @@ void udf_evict_inode(struct inode *inode) 
	}

}



static void udf_write_failed(struct address_space *mapping, loff_t to)

{

	struct inode *inode = mapping->host;

	struct udf_inode_info *iinfo = UDF_I(inode);

	loff_t isize = inode->i_size;



	if (to > isize) {

		truncate_pagecache(inode, to, isize);

		if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {

			down_write(&iinfo->i_data_sem);

			udf_truncate_extents(inode);

			up_write(&iinfo->i_data_sem);

		}

	}

}



static int udf_writepage(struct page *page, struct writeback_control *wbc)

{

	return block_write_full_page(page, udf_get_block, wbc);
@@ -124,21 +140,24 @@ static int udf_write_begin(struct file *file, struct address_space *mapping, 
	int ret;



	ret = block_write_begin(mapping, pos, len, flags, pagep, udf_get_block);

	if (unlikely(ret)) {

		struct inode *inode = mapping->host;

		struct udf_inode_info *iinfo = UDF_I(inode);

		loff_t isize = inode->i_size;



		if (pos + len > isize) {

			truncate_pagecache(inode, pos + len, isize);

			if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {

				down_write(&iinfo->i_data_sem);

				udf_truncate_extents(inode);

				up_write(&iinfo->i_data_sem);

			}

		}

	if (unlikely(ret))

		udf_write_failed(mapping, pos + len);

	return ret;

}



static ssize_t udf_direct_IO(int rw, struct kiocb *iocb,

			     const struct iovec *iov,

			     loff_t offset, unsigned long nr_segs)

{

	struct file *file = iocb->ki_filp;

	struct address_space *mapping = file->f_mapping;

	struct inode *inode = mapping->host;

	ssize_t ret;



	ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,

				  udf_get_block);

	if (unlikely(ret < 0 && (rw & WRITE)))

		udf_write_failed(mapping, offset + iov_length(iov, nr_segs));

	return ret;

}
@@ -154,6 +173,7 @@ const struct address_space_operations udf_aops = { 
	.writepages	= udf_writepages,

	.write_begin	= udf_write_begin,

	.write_end	= generic_write_end,

	.direct_IO	= udf_direct_IO,

	.bmap		= udf_bmap,

};

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