#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)
+
void
xfs_count_page_state(
struct page *page,
}
/*
- * When we map a DIO buffer, we may need to attach an ioend that describes the
- * type of write IO we are doing. This passes to the completion function the
- * operations it needs to perform. If the mapping is for an overwrite wholly
- * within the EOF then we don't need an ioend and so we don't allocate one.
- * This avoids the unnecessary overhead of allocating and freeing ioends for
- * workloads that don't require transactions on IO completion.
- *
- * If we get multiple mappings in a single IO, we might be mapping different
- * types. But because the direct IO can only have a single private pointer, we
- * need to ensure that:
- *
- * a) i) the ioend spans the entire region of unwritten mappings; or
- * ii) the ioend spans all the mappings that cross or are beyond EOF; and
- * b) if it contains unwritten extents, it is *permanently* marked as such
- *
- * We could do this by chaining ioends like buffered IO does, but we only
- * actually get one IO completion callback from the direct IO, and that spans
- * the entire IO regardless of how many mappings and IOs are needed to complete
- * the DIO. There is only going to be one reference to the ioend and its life
- * cycle is constrained by the DIO completion code. hence we don't need
- * reference counting here.
+ * 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
* 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.
- *
- * For DAX page faults, we are preparing to never see unwritten extents here,
- * nor should we ever extend the inode size. Hence we will soon have nothing to
- * do here for this case, ensuring we don't have to provide an IO completion
- * callback to free an ioend that we don't actually need for a fault into the
- * page at offset (2^63 - 1FSB) bytes.
*/
-
static void
xfs_map_direct(
struct inode *inode,
struct buffer_head *bh_result,
struct xfs_bmbt_irec *imap,
- xfs_off_t offset,
- bool dax_fault)
+ xfs_off_t offset)
{
- struct xfs_ioend *ioend;
+ uintptr_t *flags = (uintptr_t *)&bh_result->b_private;
xfs_off_t size = bh_result->b_size;
- int type;
-
- if (ISUNWRITTEN(imap))
- type = XFS_IO_UNWRITTEN;
- else
- type = XFS_IO_OVERWRITE;
-
- trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap);
-
- if (dax_fault) {
- ASSERT(type == XFS_IO_OVERWRITE);
- trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
- imap);
- return;
- }
- if (bh_result->b_private) {
- ioend = bh_result->b_private;
- ASSERT(ioend->io_size > 0);
- ASSERT(offset >= ioend->io_offset);
- if (offset + size > ioend->io_offset + ioend->io_size)
- ioend->io_size = offset - ioend->io_offset + size;
-
- if (type == XFS_IO_UNWRITTEN && type != ioend->io_type)
- ioend->io_type = XFS_IO_UNWRITTEN;
-
- trace_xfs_gbmap_direct_update(XFS_I(inode), ioend->io_offset,
- ioend->io_size, ioend->io_type,
- imap);
- } else if (type == XFS_IO_UNWRITTEN ||
- offset + size > i_size_read(inode) ||
- offset + size < 0) {
- ioend = xfs_alloc_ioend(inode, type);
- ioend->io_offset = offset;
- ioend->io_size = size;
+ trace_xfs_get_blocks_map_direct(XFS_I(inode), offset, size,
+ ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : XFS_IO_OVERWRITE, imap);
- bh_result->b_private = ioend;
+ 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) {
+ *flags |= XFS_DIO_FLAG_APPEND;
set_buffer_defer_completion(bh_result);
-
- trace_xfs_gbmap_direct_new(XFS_I(inode), offset, size, type,
- imap);
- } else {
- trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
- imap);
}
}
if (ISUNWRITTEN(&imap))
set_buffer_unwritten(bh_result);
/* direct IO needs special help */
- if (create && direct)
- xfs_map_direct(inode, bh_result, &imap, offset,
- dax_fault);
+ if (create && direct) {
+ if (dax_fault)
+ ASSERT(!ISUNWRITTEN(&imap));
+ else
+ xfs_map_direct(inode, bh_result, &imap, offset);
+ }
}
/*
return __xfs_get_blocks(inode, iblock, bh_result, create, true, true);
}
-static void
-__xfs_end_io_direct_write(
- struct inode *inode,
- struct xfs_ioend *ioend,
+/*
+ * 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).
+ */
+STATIC int
+xfs_end_io_direct_write(
+ struct kiocb *iocb,
loff_t offset,
- ssize_t size)
+ ssize_t size,
+ void *private)
{
- struct xfs_mount *mp = XFS_I(inode)->i_mount;
+ 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;
- if (XFS_FORCED_SHUTDOWN(mp) || ioend->io_error)
- goto out_end_io;
+ trace_xfs_end_io_direct_write(ip, offset, size);
- /*
- * dio completion end_io functions are only called on writes if more
- * than 0 bytes was written.
- */
- ASSERT(size > 0);
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
- /*
- * The ioend only maps whole blocks, while the IO may be sector aligned.
- * Hence the ioend offset/size may not match the IO offset/size exactly.
- * Because we don't map overwrites within EOF into the ioend, the offset
- * may not match, but only if the endio spans EOF. Either way, write
- * the IO sizes into the ioend so that completion processing does the
- * right thing.
- */
- ASSERT(offset + size <= ioend->io_offset + ioend->io_size);
- ioend->io_size = size;
- ioend->io_offset = offset;
+ if (size <= 0)
+ return size;
/*
- * The ioend tells us whether we are doing unwritten extent conversion
+ * 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
* here can result in EOF moving backwards and Bad Things Happen when
* that occurs.
*/
- spin_lock(&XFS_I(inode)->i_flags_lock);
+ spin_lock(&ip->i_flags_lock);
if (offset + size > i_size_read(inode))
i_size_write(inode, offset + size);
- spin_unlock(&XFS_I(inode)->i_flags_lock);
+ spin_unlock(&ip->i_flags_lock);
- /*
- * If we are doing an append IO that needs to update the EOF on disk,
- * do the transaction reserve now so we can use common end io
- * processing. Stashing the error (if there is one) in the ioend will
- * result in the ioend processing passing on the error if it is
- * possible as we can't return it from here.
- */
- if (ioend->io_type == XFS_IO_OVERWRITE)
- ioend->io_error = xfs_setfilesize_trans_alloc(ioend);
+ if (flags & XFS_DIO_FLAG_UNWRITTEN) {
+ trace_xfs_end_io_direct_write_unwritten(ip, offset, size);
-out_end_io:
- xfs_end_io(&ioend->io_work);
- return;
-}
+ error = xfs_iomap_write_unwritten(ip, offset, size);
+ } else if (flags & XFS_DIO_FLAG_APPEND) {
+ struct xfs_trans *tp;
-/*
- * Complete a direct I/O write request.
- *
- * The ioend structure is passed from __xfs_get_blocks() to tell us what to do.
- * If no ioend exists (i.e. @private == NULL) then the write IO is an overwrite
- * wholly within the EOF 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 an
- * ioend we will always be called in task context (i.e. from a workqueue).
- */
-STATIC 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_ioend *ioend = private;
+ trace_xfs_end_io_direct_write_append(ip, offset, size);
- if (size <= 0)
- return 0;
-
- trace_xfs_gbmap_direct_endio(XFS_I(inode), offset, size,
- ioend ? ioend->io_type : 0, NULL);
-
- if (!ioend) {
- ASSERT(offset + size <= i_size_read(inode));
- return 0;
+ tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
+ error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
+ if (error) {
+ xfs_trans_cancel(tp);
+ return error;
+ }
+ error = xfs_setfilesize(ip, tp, offset, size);
}
- __xfs_end_io_direct_write(inode, ioend, offset, size);
- return 0;
+ return error;
}
static inline ssize_t
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff