#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_bmap_btree.h"
+#include "xfs_reflink.h"
#include <linux/gfp.h>
#include <linux/mpage.h>
#include <linux/pagevec.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
* Update on-disk file size now that data has been written to disk.
*/
STATIC int
-xfs_setfilesize(
+__xfs_setfilesize(
struct xfs_inode *ip,
struct xfs_trans *tp,
xfs_off_t offset,
return xfs_trans_commit(tp);
}
+int
+xfs_setfilesize(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ size_t size)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ int error;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
+ if (error)
+ return error;
+
+ return __xfs_setfilesize(ip, tp, offset, size);
+}
+
STATIC int
xfs_setfilesize_ioend(
struct xfs_ioend *ioend,
return error;
}
- return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
+ return __xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
}
/*
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
error = -EIO;
+ /*
+ * For a CoW extent, we need to move the mapping from the CoW fork
+ * to the data fork. If instead an error happened, just dump the
+ * new blocks.
+ */
+ if (ioend->io_type == XFS_IO_COW) {
+ if (error)
+ goto done;
+ if (ioend->io_bio->bi_error) {
+ error = xfs_reflink_cancel_cow_range(ip,
+ ioend->io_offset, ioend->io_size);
+ goto done;
+ }
+ error = xfs_reflink_end_cow(ip, ioend->io_offset,
+ ioend->io_size);
+ if (error)
+ goto done;
+ }
+
/*
* For unwritten extents we need to issue transactions to convert a
* range to normal written extens after the data I/O has finished.
} else if (ioend->io_append_trans) {
error = xfs_setfilesize_ioend(ioend, error);
} else {
- ASSERT(!xfs_ioend_is_append(ioend));
+ ASSERT(!xfs_ioend_is_append(ioend) ||
+ ioend->io_type == XFS_IO_COW);
}
done:
struct xfs_ioend *ioend = bio->bi_private;
struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
- if (ioend->io_type == XFS_IO_UNWRITTEN)
+ if (ioend->io_type == XFS_IO_UNWRITTEN || ioend->io_type == XFS_IO_COW)
queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
else if (ioend->io_append_trans)
queue_work(mp->m_data_workqueue, &ioend->io_work);
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
+ ASSERT(type != XFS_IO_COW);
if (type == XFS_IO_UNWRITTEN)
bmapi_flags |= XFS_BMAPI_IGSTATE;
offset_fsb = XFS_B_TO_FSBT(mp, offset);
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
imap, &nimaps, bmapi_flags);
+ /*
+ * Truncate an overwrite extent if there's a pending CoW
+ * reservation before the end of this extent. This forces us
+ * to come back to writepage to take care of the CoW.
+ */
+ if (nimaps && type == XFS_IO_OVERWRITE)
+ xfs_reflink_trim_irec_to_next_cow(ip, offset_fsb, imap);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (error)
if (type == XFS_IO_DELALLOC &&
(!nimaps || isnullstartblock(imap->br_startblock))) {
- error = xfs_iomap_write_allocate(ip, offset, imap);
+ error = xfs_iomap_write_allocate(ip, XFS_DATA_FORK, offset,
+ imap);
if (!error)
trace_xfs_map_blocks_alloc(ip, offset, count, type, imap);
return error;
return;
}
+static int
+xfs_map_cow(
+ struct xfs_writepage_ctx *wpc,
+ struct inode *inode,
+ loff_t offset,
+ unsigned int *new_type)
+{
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_bmbt_irec imap;
+ bool is_cow = false, need_alloc = false;
+ int error;
+
+ /*
+ * If we already have a valid COW mapping keep using it.
+ */
+ if (wpc->io_type == XFS_IO_COW) {
+ wpc->imap_valid = xfs_imap_valid(inode, &wpc->imap, offset);
+ if (wpc->imap_valid) {
+ *new_type = XFS_IO_COW;
+ return 0;
+ }
+ }
+
+ /*
+ * 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);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ if (!is_cow)
+ return 0;
+
+ /*
+ * And if the COW mapping has a delayed extent here we need to
+ * allocate real space for it now.
+ */
+ if (need_alloc) {
+ error = xfs_iomap_write_allocate(ip, XFS_COW_FORK, offset,
+ &imap);
+ if (error)
+ return error;
+ }
+
+ wpc->io_type = *new_type = XFS_IO_COW;
+ wpc->imap_valid = true;
+ wpc->imap = imap;
+ return 0;
+}
+
/*
* We implement an immediate ioend submission policy here to avoid needing to
* chain multiple ioends and hence nest mempool allocations which can violate
int error = 0;
int count = 0;
int uptodate = 1;
+ unsigned int new_type;
bh = head = page_buffers(page);
offset = page_offset(page);
continue;
}
- if (buffer_unwritten(bh)) {
- if (wpc->io_type != XFS_IO_UNWRITTEN) {
- wpc->io_type = XFS_IO_UNWRITTEN;
- wpc->imap_valid = false;
- }
- } else if (buffer_delay(bh)) {
- if (wpc->io_type != XFS_IO_DELALLOC) {
- wpc->io_type = XFS_IO_DELALLOC;
- wpc->imap_valid = false;
- }
- } else if (buffer_uptodate(bh)) {
- if (wpc->io_type != XFS_IO_OVERWRITE) {
- wpc->io_type = XFS_IO_OVERWRITE;
- wpc->imap_valid = false;
- }
- } else {
+ if (buffer_unwritten(bh))
+ new_type = XFS_IO_UNWRITTEN;
+ else if (buffer_delay(bh))
+ new_type = XFS_IO_DELALLOC;
+ else if (buffer_uptodate(bh))
+ new_type = XFS_IO_OVERWRITE;
+ else {
if (PageUptodate(page))
ASSERT(buffer_mapped(bh));
/*
continue;
}
+ if (xfs_is_reflink_inode(XFS_I(inode))) {
+ error = xfs_map_cow(wpc, inode, offset, &new_type);
+ if (error)
+ goto out;
+ }
+
+ if (wpc->io_type != new_type) {
+ wpc->io_type = new_type;
+ wpc->imap_valid = false;
+ }
+
if (wpc->imap_valid)
wpc->imap_valid = xfs_imap_valid(inode, &wpc->imap,
offset);
struct inode *inode,
struct buffer_head *bh_result,
struct xfs_bmbt_irec *imap,
- xfs_off_t offset)
+ 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 : XFS_IO_OVERWRITE, imap);
+ 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 (offset + size > i_size_read(inode) || offset + size < 0) {
+ } 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);
}
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(
struct inode *inode,
xfs_off_t offset;
ssize_t size;
int new = 0;
+ bool is_cow = false;
+ bool need_alloc = false;
BUG_ON(create && !direct);
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
- &imap, &nimaps, XFS_BMAPI_ENTIRE);
+ 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);
if (error)
goto out_unlock;
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;
+ }
+
xfs_map_buffer(inode, bh_result, &imap, offset);
if (ISUNWRITTEN(&imap))
set_buffer_unwritten(bh_result);
if (dax_fault)
ASSERT(!ISUNWRITTEN(&imap));
else
- xfs_map_direct(inode, bh_result, &imap, offset);
+ xfs_map_direct(inode, bh_result, &imap, offset,
+ is_cow);
}
}
{
struct inode *inode = file_inode(iocb->ki_filp);
struct xfs_inode *ip = XFS_I(inode);
- struct xfs_mount *mp = ip->i_mount;
uintptr_t flags = (uintptr_t)private;
int error = 0;
trace_xfs_end_io_direct_write(ip, offset, size);
- if (XFS_FORCED_SHUTDOWN(mp))
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
return -EIO;
if (size <= 0)
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);
- } else if (flags & XFS_DIO_FLAG_APPEND) {
- struct xfs_trans *tp;
-
+ }
+ if (flags & XFS_DIO_FLAG_APPEND) {
trace_xfs_end_io_direct_write_append(ip, offset, size);
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0,
- &tp);
- if (!error)
- error = xfs_setfilesize(ip, tp, offset, size);
+ error = xfs_setfilesize(ip, offset, size);
}
return error;
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
+ * bypasseѕ the file system for actual I/O. We really can't allow
+ * 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);
+ return 0;
+ }
filemap_write_and_wait(mapping);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return generic_block_bmap(mapping, block, xfs_get_blocks);
projects / cascardo / linux.git / blobdiff