From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-fsdevel@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org, darrick.wong@oracle.com, hch@lst.de,
linux-xfs@vger.kernel.org, Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: [PATCH 05/15] btrfs: Add CoW in iomap based writes
Date: Thu, 5 Sep 2019 10:06:40 -0500 [thread overview]
Message-ID: <20190905150650.21089-6-rgoldwyn@suse.de> (raw)
In-Reply-To: <20190905150650.21089-1-rgoldwyn@suse.de>
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Set iomap->flags to IOMAP_F_COW and fill up the source map in case
the I/O is not page aligned.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
fs/btrfs/iomap.c | 42 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/iomap.c b/fs/btrfs/iomap.c
index 025ccbf471bf..f8fa34105838 100644
--- a/fs/btrfs/iomap.c
+++ b/fs/btrfs/iomap.c
@@ -165,6 +165,35 @@ static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
return 0;
}
+/*
+ * get_iomap: Get the block map and fill the iomap structure
+ * @pos: file position
+ * @length: I/O length
+ * @iomap: The iomap structure to fill
+ */
+
+static int get_iomap(struct inode *inode, loff_t pos, loff_t length,
+ struct iomap *iomap)
+{
+ struct extent_map *em;
+ iomap->addr = IOMAP_NULL_ADDR;
+ em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+ /* XXX Do we need to check for em->flags here? */
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ iomap->type = IOMAP_HOLE;
+ } else {
+ iomap->addr = em->block_start;
+ iomap->type = IOMAP_MAPPED;
+ }
+ iomap->offset = em->start;
+ iomap->bdev = em->bdev;
+ iomap->length = em->len;
+ free_extent_map(em);
+ return 0;
+}
+
static void btrfs_buffered_page_done(struct inode *inode, loff_t pos,
unsigned copied, struct page *page,
struct iomap *iomap)
@@ -190,6 +219,7 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos,
int ret;
size_t write_bytes = length;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ size_t end;
size_t sector_offset = pos & (fs_info->sectorsize - 1);
struct btrfs_iomap *bi;
@@ -257,8 +287,18 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos,
iomap->private = bi;
iomap->length = round_up(write_bytes, fs_info->sectorsize);
iomap->offset = round_down(pos, fs_info->sectorsize);
+ end = pos + write_bytes;
+ /* Set IOMAP_F_COW if start/end is not page aligned */
+ if (((pos & (PAGE_SIZE - 1)) || (end & (PAGE_SIZE - 1)))) {
+ iomap->flags = IOMAP_F_COW;
+ ret = get_iomap(inode, pos, length, srcmap);
+ if (ret < 0)
+ goto release;
+ } else {
+ iomap->type = IOMAP_DELALLOC;
+ }
+
iomap->addr = IOMAP_NULL_ADDR;
- iomap->type = IOMAP_DELALLOC;
iomap->bdev = fs_info->fs_devices->latest_bdev;
iomap->page_ops = &btrfs_buffered_page_ops;
return 0;
--
2.16.4
next prev parent reply other threads:[~2019-09-05 15:07 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 15:06 [PATCH v4 0/15] CoW support for iomap Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 01/15] iomap: Use a srcmap for a read-modify-write I/O Goldwyn Rodrigues
2019-09-05 23:23 ` Darrick J. Wong
2019-09-05 15:06 ` [PATCH 02/15] iomap: Read page from srcmap if IOMAP_F_COW is set Goldwyn Rodrigues
2019-09-05 16:37 ` Christoph Hellwig
2019-09-05 20:28 ` Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 03/15] btrfs: Eliminate PagePrivate for btrfs data pages Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 04/15] btrfs: Add a simple buffered iomap write Goldwyn Rodrigues
2019-09-05 16:23 ` Christoph Hellwig
2019-09-05 20:42 ` Goldwyn Rodrigues
2019-09-06 5:54 ` Christoph Hellwig
2019-09-05 15:06 ` Goldwyn Rodrigues [this message]
2019-09-05 15:06 ` [PATCH 06/15] btrfs: remove buffered write code made unnecessary Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 07/15] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 08/15] btrfs: basic direct read operation Goldwyn Rodrigues
2019-09-05 16:25 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 09/15] btrfs: Carve out btrfs_get_extent_map_write() out of btrfs_get_blocks_write() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 10/15] btrfs: Rename __endio_write_update_ordered() to btrfs_update_ordered_extent() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 11/15] iomap: use a function pointer for dio submits Goldwyn Rodrigues
2019-09-05 16:27 ` Christoph Hellwig
2019-09-05 23:24 ` Darrick J. Wong
2019-09-05 15:06 ` [PATCH 12/15] btrfs: Use iomap_dio_rw for performing direct I/O writes Goldwyn Rodrigues
2019-09-05 16:31 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 13/15] btrfs: Remove btrfs_dio_data and __btrfs_direct_write Goldwyn Rodrigues
2019-09-05 16:32 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 14/15] btrfs: update inode size during bio completion Goldwyn Rodrigues
2019-09-05 16:33 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 15/15] xfs: Use the new iomap infrastructure for CoW Goldwyn Rodrigues
2019-09-06 16:55 ` Christoph Hellwig
2019-09-06 23:28 ` Dave Chinner
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