]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - fs/xfs/xfs_aops.c
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[karo-tx-linux.git] / fs / xfs / xfs_aops.c
index 7575cfc3ad15671b7b6242a241cca2c54b7d111d..0f56fcd3a5d51517b93c391bb3d97a58f205a544 100644 (file)
 #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>
 #include <linux/writeback.h>
 
-/* flags for direct write completions */
-#define XFS_DIO_FLAG_UNWRITTEN (1 << 0)
-#define XFS_DIO_FLAG_APPEND    (1 << 1)
-
 /*
  * structure owned by writepages passed to individual writepage calls
  */
@@ -200,7 +197,7 @@ xfs_setfilesize_trans_alloc(
  * 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,
@@ -225,6 +222,23 @@ xfs_setfilesize(
        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,
@@ -247,7 +261,7 @@ xfs_setfilesize_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);
 }
 
 /*
@@ -269,6 +283,25 @@ xfs_end_io(
        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.
@@ -284,7 +317,8 @@ xfs_end_io(
        } 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:
@@ -298,7 +332,7 @@ xfs_end_bio(
        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);
@@ -324,6 +358,7 @@ xfs_map_blocks(
        if (XFS_FORCED_SHUTDOWN(mp))
                return -EIO;
 
+       ASSERT(type != XFS_IO_COW);
        if (type == XFS_IO_UNWRITTEN)
                bmapi_flags |= XFS_BMAPI_IGSTATE;
 
@@ -338,6 +373,13 @@ xfs_map_blocks(
        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)
@@ -345,7 +387,8 @@ xfs_map_blocks(
 
        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;
@@ -447,8 +490,8 @@ xfs_submit_ioend(
 
        ioend->io_bio->bi_private = ioend;
        ioend->io_bio->bi_end_io = xfs_end_bio;
-       bio_set_op_attrs(ioend->io_bio, REQ_OP_WRITE,
-                        (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0);
+       ioend->io_bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc);
+
        /*
         * If we are failing the IO now, just mark the ioend with an
         * error and finish it. This will run IO completion immediately
@@ -519,8 +562,7 @@ xfs_chain_bio(
 
        bio_chain(ioend->io_bio, new);
        bio_get(ioend->io_bio);         /* for xfs_destroy_ioend */
-       bio_set_op_attrs(ioend->io_bio, REQ_OP_WRITE,
-                         (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0);
+       ioend->io_bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc);
        submit_bio(ioend->io_bio);
        ioend->io_bio = new;
 }
@@ -720,6 +762,56 @@ out_invalidate:
        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;
+       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);
+       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 (isnullstartblock(imap.br_startblock)) {
+               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
@@ -752,6 +844,7 @@ xfs_writepage_map(
        int                     error = 0;
        int                     count = 0;
        int                     uptodate = 1;
+       unsigned int            new_type;
 
        bh = head = page_buffers(page);
        offset = page_offset(page);
@@ -772,22 +865,13 @@ xfs_writepage_map(
                        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));
                        /*
@@ -800,6 +884,17 @@ xfs_writepage_map(
                        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);
@@ -1074,39 +1169,6 @@ xfs_vm_releasepage(
        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)
-{
-       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);
-
-       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);
-       }
-}
-
 /*
  * 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.
@@ -1147,14 +1209,12 @@ xfs_map_trim_size(
        bh_result->b_size = mapping_size;
 }
 
-STATIC int
-__xfs_get_blocks(
+static int
+xfs_get_blocks(
        struct inode            *inode,
        sector_t                iblock,
        struct buffer_head      *bh_result,
-       int                     create,
-       bool                    direct,
-       bool                    dax_fault)
+       int                     create)
 {
        struct xfs_inode        *ip = XFS_I(inode);
        struct xfs_mount        *mp = ip->i_mount;
@@ -1165,9 +1225,8 @@ __xfs_get_blocks(
        int                     nimaps = 1;
        xfs_off_t               offset;
        ssize_t                 size;
-       int                     new = 0;
 
-       BUG_ON(create && !direct);
+       BUG_ON(create);
 
        if (XFS_FORCED_SHUTDOWN(mp))
                return -EIO;
@@ -1176,7 +1235,7 @@ __xfs_get_blocks(
        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;
 
        /*
@@ -1196,29 +1255,7 @@ __xfs_get_blocks(
        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);
@@ -1228,12 +1265,6 @@ __xfs_get_blocks(
                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);
 
@@ -1243,42 +1274,14 @@ __xfs_get_blocks(
         */
        if (imap.br_startblock != HOLESTARTBLOCK &&
            imap.br_startblock != DELAYSTARTBLOCK &&
-           (create || !ISUNWRITTEN(&imap))) {
+           !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) {
-                       if (dax_fault)
-                               ASSERT(!ISUNWRITTEN(&imap));
-                       else
-                               xfs_map_direct(inode, bh_result, &imap, offset);
-               }
-       }
 
        /*
         * 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:
@@ -1286,113 +1289,6 @@ 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, 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, false);
-}
-
-int
-xfs_get_blocks_dax_fault(
-       struct inode            *inode,
-       sector_t                iblock,
-       struct buffer_head      *bh_result,
-       int                     create)
-{
-       return __xfs_get_blocks(inode, iblock, bh_result, create, true, 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);
-       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))
-               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_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;
-
-               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);
-       }
-
-       return error;
-}
-
 STATIC ssize_t
 xfs_vm_direct_IO(
        struct kiocb            *iocb,
@@ -1413,9 +1309,17 @@ xfs_vm_bmap(
        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
+        * bypasseŃ• 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))
+               return 0;
+
        filemap_write_and_wait(mapping);
-       xfs_iunlock(ip, XFS_IOLOCK_SHARED);
        return generic_block_bmap(mapping, block, xfs_get_blocks);
 }