btrfs: remove dio iomap DSYNC workaround

This effectively reverts 09745ff88d93 ("btrfs: dio iomap DSYNC
workaround") now that the iomap API has been updated to allow
iomap_dio_complete() not to be called under i_rwsem anymore.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6ee7252..d9188ec 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3068,7 +3068,6 @@ void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
 extern const struct iomap_dio_ops btrfs_dio_ops;
-extern const struct iomap_dio_ops btrfs_sync_dops;
 
 /* Inode locking type flags, by default the exclusive lock is taken */
 #define BTRFS_ILOCK_SHARED     (1U << 0)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 40b7886..5b93f0b 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2018,44 +2018,10 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
        if (sync)
                atomic_inc(&BTRFS_I(inode)->sync_writers);
 
-       if (iocb->ki_flags & IOCB_DIRECT) {
-               /*
-                * 1. We must always clear IOCB_DSYNC in order to not deadlock
-                *    in iomap, as it calls generic_write_sync() in this case.
-                * 2. If we are async, we can call iomap_dio_complete() either
-                *    in
-                *
-                *    2.1. A worker thread from the last bio completed.  In this
-                *         case we need to mark the btrfs_dio_data that it is
-                *         async in order to call generic_write_sync() properly.
-                *         This is handled by setting BTRFS_DIO_SYNC_STUB in the
-                *         current->journal_info.
-                *    2.2  The submitter context, because all IO completed
-                *         before we exited iomap_dio_rw().  In this case we can
-                *         just re-set the IOCB_DSYNC on the iocb and we'll do
-                *         the sync below.  If our ->end_io() gets called and
-                *         current->journal_info is set, then we know we're in
-                *         our current context and we will clear
-                *         current->journal_info to indicate that we need to
-                *         sync below.
-                */
-               if (sync) {
-                       ASSERT(current->journal_info == NULL);
-                       iocb->ki_flags &= ~IOCB_DSYNC;
-                       current->journal_info = BTRFS_DIO_SYNC_STUB;
-               }
+       if (iocb->ki_flags & IOCB_DIRECT)
                num_written = btrfs_direct_write(iocb, from);
-
-               /*
-                * As stated above, we cleared journal_info, so we need to do
-                * the sync ourselves.
-                */
-               if (sync && current->journal_info == NULL)
-                       iocb->ki_flags |= IOCB_DSYNC;
-               current->journal_info = NULL;
-       } else {
+       else
                num_written = btrfs_buffered_write(iocb, from);
-       }
 
        /*
         * We also have to set last_sub_trans to the current log transid,

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c4e0002..9c0bf69 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -62,7 +62,6 @@ struct btrfs_dio_data {
        loff_t length;
        ssize_t submitted;
        struct extent_changeset *data_reserved;
-       bool sync;
 };
 
 static const struct inode_operations btrfs_dir_inode_operations;
@@ -7431,17 +7430,6 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
        int ret = 0;
        u64 len = length;
        bool unlock_extents = false;
-       bool sync = (current->journal_info == BTRFS_DIO_SYNC_STUB);
-
-       /*
-        * We used current->journal_info here to see if we were sync, but
-        * there's a lot of tests in the enospc machinery to not do flushing if
-        * we have a journal_info set, so we need to clear this out and re-set
-        * it in iomap_end.
-        */
-       ASSERT(current->journal_info == NULL ||
-              current->journal_info == BTRFS_DIO_SYNC_STUB);
-       current->journal_info = NULL;
 
        if (!write)
                len = min_t(u64, len, fs_info->sectorsize);
@@ -7467,7 +7455,6 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
        if (!dio_data)
                return -ENOMEM;
 
-       dio_data->sync = sync;
        dio_data->length = length;
        if (write) {
                dio_data->reserve = round_up(length, fs_info->sectorsize);
@@ -7615,14 +7602,6 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
                extent_changeset_free(dio_data->data_reserved);
        }
 out:
-       /*
-        * We're all done, we can re-set the current->journal_info now safely
-        * for our endio.
-        */
-       if (dio_data->sync) {
-               ASSERT(current->journal_info == NULL);
-               current->journal_info = BTRFS_DIO_SYNC_STUB;
-       }
        kfree(dio_data);
        iomap->private = NULL;
 
@@ -7999,30 +7978,6 @@ out_err:
        return BLK_QC_T_NONE;
 }
 
-static inline int btrfs_maybe_fsync_end_io(struct kiocb *iocb, ssize_t size,
-                                          int error, unsigned flags)
-{
-       /*
-        * Now if we're still in the context of our submitter we know we can't
-        * safely run generic_write_sync(), so clear our flag here so that the
-        * caller knows to follow up with a sync.
-        */
-       if (current->journal_info == BTRFS_DIO_SYNC_STUB) {
-               current->journal_info = NULL;
-               return error;
-       }
-
-       if (error)
-               return error;
-
-       if (size) {
-               iocb->ki_flags |= IOCB_DSYNC;
-               return generic_write_sync(iocb, size);
-       }
-
-       return 0;
-}
-
 const struct iomap_ops btrfs_dio_iomap_ops = {
        .iomap_begin            = btrfs_dio_iomap_begin,
        .iomap_end              = btrfs_dio_iomap_end,
@@ -8032,11 +7987,6 @@ const struct iomap_dio_ops btrfs_dio_ops = {
        .submit_io              = btrfs_submit_direct,
 };
 
-const struct iomap_dio_ops btrfs_sync_dops = {
-       .submit_io              = btrfs_submit_direct,
-       .end_io                 = btrfs_maybe_fsync_end_io,
-};
-
 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                        u64 start, u64 len)
 {

diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 858d915..8241c05 100644 (file)
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -112,7 +112,6 @@ struct btrfs_transaction {
 #define TRANS_EXTWRITERS       (__TRANS_START | __TRANS_ATTACH)
 
 #define BTRFS_SEND_TRANS_STUB  ((void *)1)
-#define BTRFS_DIO_SYNC_STUB    ((void *)2)
 
 struct btrfs_trans_handle {
        u64 transid;