#include <linux/pagevec.h>
#include <linux/writeback.h>
-/* flags for direct write completions */
-#define XFS_DIO_FLAG_UNWRITTEN (1 << 0)
-#define XFS_DIO_FLAG_APPEND (1 << 1)
-#define XFS_DIO_FLAG_COW (1 << 2)
-
/*
* structure owned by writepages passed to individual writepage calls
*/
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_bmbt_irec imap;
- bool is_cow = false, need_alloc = false;
+ bool is_cow = false;
int error;
/*
* Else we need to check if there is a COW mapping at this offset.
*/
xfs_ilock(ip, XFS_ILOCK_SHARED);
- is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap, &need_alloc);
+ is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (!is_cow)
* And if the COW mapping has a delayed extent here we need to
* allocate real space for it now.
*/
- if (need_alloc) {
+ if (isnullstartblock(imap.br_startblock)) {
error = xfs_iomap_write_allocate(ip, XFS_COW_FORK, offset,
&imap);
if (error)
return try_to_free_buffers(page);
}
-/*
- * When we map a DIO buffer, we may need to pass flags to
- * xfs_end_io_direct_write to tell it what kind of write IO we are doing.
- *
- * Note that for DIO, an IO to the highest supported file block offset (i.e.
- * 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64
- * bit variable. Hence if we see this overflow, we have to assume that the IO is
- * extending the file size. We won't know for sure until IO completion is run
- * and the actual max write offset is communicated to the IO completion
- * routine.
- */
-static void
-xfs_map_direct(
- struct inode *inode,
- struct buffer_head *bh_result,
- struct xfs_bmbt_irec *imap,
- xfs_off_t offset,
- bool is_cow)
-{
- uintptr_t *flags = (uintptr_t *)&bh_result->b_private;
- xfs_off_t size = bh_result->b_size;
-
- trace_xfs_get_blocks_map_direct(XFS_I(inode), offset, size,
- ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : is_cow ? XFS_IO_COW :
- XFS_IO_OVERWRITE, imap);
-
- if (ISUNWRITTEN(imap)) {
- *flags |= XFS_DIO_FLAG_UNWRITTEN;
- set_buffer_defer_completion(bh_result);
- } else if (is_cow) {
- *flags |= XFS_DIO_FLAG_COW;
- set_buffer_defer_completion(bh_result);
- }
- if (offset + size > i_size_read(inode) || offset + size < 0) {
- *flags |= XFS_DIO_FLAG_APPEND;
- set_buffer_defer_completion(bh_result);
- }
-}
-
/*
* If this is O_DIRECT or the mpage code calling tell them how large the mapping
* is, so that we can avoid repeated get_blocks calls.
bh_result->b_size = mapping_size;
}
-/* Bounce unaligned directio writes to the page cache. */
static int
-xfs_bounce_unaligned_dio_write(
- struct xfs_inode *ip,
- xfs_fileoff_t offset_fsb,
- struct xfs_bmbt_irec *imap)
-{
- struct xfs_bmbt_irec irec;
- xfs_fileoff_t delta;
- bool shared;
- bool x;
- int error;
-
- irec = *imap;
- if (offset_fsb > irec.br_startoff) {
- delta = offset_fsb - irec.br_startoff;
- irec.br_blockcount -= delta;
- irec.br_startblock += delta;
- irec.br_startoff = offset_fsb;
- }
- error = xfs_reflink_trim_around_shared(ip, &irec, &shared, &x);
- if (error)
- return error;
-
- /*
- * We're here because we're trying to do a directio write to a
- * region that isn't aligned to a filesystem block. If any part
- * of the extent is shared, fall back to buffered mode to handle
- * the RMW. This is done by returning -EREMCHG ("remote addr
- * changed"), which is caught further up the call stack.
- */
- if (shared) {
- trace_xfs_reflink_bounce_dio_write(ip, imap);
- return -EREMCHG;
- }
- return 0;
-}
-
-STATIC int
-__xfs_get_blocks(
+xfs_get_blocks(
struct inode *inode,
sector_t iblock,
struct buffer_head *bh_result,
- int create,
- bool direct)
+ int create)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
int nimaps = 1;
xfs_off_t offset;
ssize_t size;
- int new = 0;
- bool is_cow = false;
- bool need_alloc = false;
- BUG_ON(create && !direct);
+ BUG_ON(create);
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
size = bh_result->b_size;
- if (!create && offset >= i_size_read(inode))
+ if (offset >= i_size_read(inode))
return 0;
/*
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- if (create && direct && xfs_is_reflink_inode(ip))
- is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap,
- &need_alloc);
- if (!is_cow) {
- error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
- &imap, &nimaps, XFS_BMAPI_ENTIRE);
- /*
- * Truncate an overwrite extent if there's a pending CoW
- * reservation before the end of this extent. This
- * forces us to come back to get_blocks to take care of
- * the CoW.
- */
- if (create && direct && nimaps &&
- imap.br_startblock != HOLESTARTBLOCK &&
- imap.br_startblock != DELAYSTARTBLOCK &&
- !ISUNWRITTEN(&imap))
- xfs_reflink_trim_irec_to_next_cow(ip, offset_fsb,
- &imap);
- }
- ASSERT(!need_alloc);
+ error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
+ &imap, &nimaps, XFS_BMAPI_ENTIRE);
if (error)
goto out_unlock;
- /* for DAX, we convert unwritten extents directly */
- if (create &&
- (!nimaps ||
- (imap.br_startblock == HOLESTARTBLOCK ||
- imap.br_startblock == DELAYSTARTBLOCK) ||
- (IS_DAX(inode) && ISUNWRITTEN(&imap)))) {
- /*
- * xfs_iomap_write_direct() expects the shared lock. It
- * is unlocked on return.
- */
- if (lockmode == XFS_ILOCK_EXCL)
- xfs_ilock_demote(ip, lockmode);
-
- error = xfs_iomap_write_direct(ip, offset, size,
- &imap, nimaps);
- if (error)
- return error;
- new = 1;
-
- trace_xfs_get_blocks_alloc(ip, offset, size,
- ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
- : XFS_IO_DELALLOC, &imap);
- } else if (nimaps) {
+ if (nimaps) {
trace_xfs_get_blocks_found(ip, offset, size,
ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
: XFS_IO_OVERWRITE, &imap);
goto out_unlock;
}
- if (IS_DAX(inode) && create) {
- ASSERT(!ISUNWRITTEN(&imap));
- /* zeroing is not needed at a higher layer */
- new = 0;
- }
-
/* trim mapping down to size requested */
xfs_map_trim_size(inode, iblock, bh_result, &imap, offset, size);
*/
if (imap.br_startblock != HOLESTARTBLOCK &&
imap.br_startblock != DELAYSTARTBLOCK &&
- (create || !ISUNWRITTEN(&imap))) {
- if (create && direct && !is_cow) {
- error = xfs_bounce_unaligned_dio_write(ip, offset_fsb,
- &imap);
- if (error)
- return error;
- }
-
+ !ISUNWRITTEN(&imap))
xfs_map_buffer(inode, bh_result, &imap, offset);
- if (ISUNWRITTEN(&imap))
- set_buffer_unwritten(bh_result);
- /* direct IO needs special help */
- if (create)
- xfs_map_direct(inode, bh_result, &imap, offset, is_cow);
- }
/*
* If this is a realtime file, data may be on a different device.
* to that pointed to from the buffer_head b_bdev currently.
*/
bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
-
- /*
- * If we previously allocated a block out beyond eof and we are now
- * coming back to use it then we will need to flag it as new even if it
- * has a disk address.
- *
- * With sub-block writes into unwritten extents we also need to mark
- * the buffer as new so that the unwritten parts of the buffer gets
- * correctly zeroed.
- */
- if (create &&
- ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
- (offset >= i_size_read(inode)) ||
- (new || ISUNWRITTEN(&imap))))
- set_buffer_new(bh_result);
-
- BUG_ON(direct && imap.br_startblock == DELAYSTARTBLOCK);
-
return 0;
out_unlock:
return error;
}
-int
-xfs_get_blocks(
- struct inode *inode,
- sector_t iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return __xfs_get_blocks(inode, iblock, bh_result, create, false);
-}
-
-int
-xfs_get_blocks_direct(
- struct inode *inode,
- sector_t iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return __xfs_get_blocks(inode, iblock, bh_result, create, true);
-}
-
-/*
- * Complete a direct I/O write request.
- *
- * xfs_map_direct passes us some flags in the private data to tell us what to
- * do. If no flags are set, then the write IO is an overwrite wholly within
- * the existing allocated file size and so there is nothing for us to do.
- *
- * Note that in this case the completion can be called in interrupt context,
- * whereas if we have flags set we will always be called in task context
- * (i.e. from a workqueue).
- */
-int
-xfs_end_io_direct_write(
- struct kiocb *iocb,
- loff_t offset,
- ssize_t size,
- void *private)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- struct xfs_inode *ip = XFS_I(inode);
- uintptr_t flags = (uintptr_t)private;
- int error = 0;
-
- trace_xfs_end_io_direct_write(ip, offset, size);
-
- if (XFS_FORCED_SHUTDOWN(ip->i_mount))
- return -EIO;
-
- if (size <= 0)
- return size;
-
- /*
- * The flags tell us whether we are doing unwritten extent conversions
- * or an append transaction that updates the on-disk file size. These
- * cases are the only cases where we should *potentially* be needing
- * to update the VFS inode size.
- */
- if (flags == 0) {
- ASSERT(offset + size <= i_size_read(inode));
- return 0;
- }
-
- /*
- * We need to update the in-core inode size here so that we don't end up
- * with the on-disk inode size being outside the in-core inode size. We
- * have no other method of updating EOF for AIO, so always do it here
- * if necessary.
- *
- * We need to lock the test/set EOF update as we can be racing with
- * other IO completions here to update the EOF. Failing to serialise
- * here can result in EOF moving backwards and Bad Things Happen when
- * that occurs.
- */
- spin_lock(&ip->i_flags_lock);
- if (offset + size > i_size_read(inode))
- i_size_write(inode, offset + size);
- spin_unlock(&ip->i_flags_lock);
-
- if (flags & XFS_DIO_FLAG_COW)
- error = xfs_reflink_end_cow(ip, offset, size);
- if (flags & XFS_DIO_FLAG_UNWRITTEN) {
- trace_xfs_end_io_direct_write_unwritten(ip, offset, size);
-
- error = xfs_iomap_write_unwritten(ip, offset, size);
- }
- if (flags & XFS_DIO_FLAG_APPEND) {
- trace_xfs_end_io_direct_write_append(ip, offset, size);
-
- error = xfs_setfilesize(ip, offset, size);
- }
-
- return error;
-}
-
STATIC ssize_t
xfs_vm_direct_IO(
struct kiocb *iocb,
struct xfs_inode *ip = XFS_I(inode);
trace_xfs_vm_bmap(XFS_I(inode));
- xfs_ilock(ip, XFS_IOLOCK_SHARED);
/*
* The swap code (ab-)uses ->bmap to get a block mapping and then
* that on reflinks inodes, so we have to skip out here. And yes,
* 0 is the magic code for a bmap error..
*/
- if (xfs_is_reflink_inode(ip)) {
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ if (xfs_is_reflink_inode(ip))
return 0;
- }
+
filemap_write_and_wait(mapping);
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return generic_block_bmap(mapping, block, xfs_get_blocks);
}
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