This adds basic O_DIRECT read and write support. In the write case, we
just do a normal buffered write followed by a cache flush. O_DIRECT +
O_SYNC are required to trigger metadata syncs.
In the read case, there is a basic btrfs_get_block call for use by
the generic O_DIRECT code. This does honor multi-volume mapping rules
but it skips all checksumming.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Yan Zheng noticed that we don't clear the extent state tree dirty and delalloc
bits when we clear the dirty bits on the page during file write.
This leads to csum errors later on.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A few codes were not properly updated for changes of extent map. This
may be the causes of "no csum found for inode" issue.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Now that delayed allocation accounting works, i_blocks accounting is changed
to only modify i_blocks when extents inserted or removed.
The fillattr call is changed to include the delayed allocation byte count
in the i_blocks result.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When truncating a inline extent, btrfs_drop_extents doesn't properly
handle the case "key.offset > inline_limit". This bug can only happen
when max line size is larger than 8K.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.
The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller. This allows a few performance
optimizations and is easier to use.
A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There were a few places that could cause duplicate extent insertion,
this adjusts the code that creates holes to avoid it.
lookup_extent_map is changed to correctly return all of the extents in a
range, even when there are none matching at the start of the range.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This forces file data extents down the disk along with the metadata that
references them. The current implementation is fairly simple, and just
writes out all of the dirty pages in an inode before the commit.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This is intended to prevent accidentally filling the drive. A determined
user can still make things oops.
It includes some accounting of the current bytes under delayed allocation,
but this will change as things get optimized
Signed-off-by: Chris Mason <chris.mason@oracle.com>
One of my old patches introduces a new bug to
btrfs_drop_extents(changeset 275). Inline extents are not truncated
properly when "extent_end == end", it can trigger the BUG_ON at
file.c:600. I hope I don't introduce new bug this time.
---
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Don't set hint_byte to EXTENT_MAP_INLINE when 'end == extent_end' or
'start == key.offset' . The inline extent will be truncated in these
cases.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When calculating the size of inline extent, inode->i_size should also
be take into consideration, otherwise sys_write may drop some data
silently. You can test this bug by:
#dd if=/dev/zero bs=4k count=1 of=test_file
#dd if=/dev/zero bs=2k count=1 of=test_file conv=notrunc
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The fixes do a number of things:
1) Most btrfs_drop_extent callers will try to leave the inline extents in
place. It can truncate bytes off the beginning of the inline extent if
required.
2) writepage can now update the inline extent, allowing mmap writes to
go directly into the inline extent.
3) btrfs_truncate_in_transaction truncates inline extents
4) extent_map.c fixed to not merge inline extent mappings and hole
mappings together
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This modifies inline extent size calculation, so that
insert_inline_extent can handle the case that parameter 'offset' is
not zero; it also a few codes to zero uninitialized area in inline
extent.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_btree_balance_dirty is changed to pass the number of pages dirtied
for more accurate dirty throttling. This lets the VM make better decisions
about when to force some writeback.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
No reason to grab the BKL before calling into the btrfs ioctl code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
File data checksums are only done during writepage, so we have to make sure
all pages are written when the snapshot is taken. This also adds some
locking so that new writes don't race in and add new dirty pages.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Chris Mason