On 14.02.2017 04:46, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <[email protected]> > > Return EAGAIN if any of the following checks fail > + i_rwsem is lockable > + NODATACOW or PREALLOC is set
perhaps you wanted to say "NODATACOW or PREALLOC is _not_ set"? See below > + Can nocow at the desired location > + Writing beyond end of file > > Signed-off-by: Goldwyn Rodrigues <[email protected]> > --- > fs/btrfs/file.c | 25 ++++++++++++++++++++----- > fs/btrfs/inode.c | 3 +++ > 2 files changed, 23 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index 3a14c87..f4dcc7a 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -1804,12 +1804,29 @@ static ssize_t btrfs_file_write_iter(struct kiocb > *iocb, > ssize_t num_written = 0; > bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); > ssize_t err; > - loff_t pos; > - size_t count; > + loff_t pos = iocb->ki_pos; > + size_t count = iov_iter_count(from); > loff_t oldsize; > int clean_page = 0; > > - inode_lock(inode); > + if ((iocb->ki_flags & IOCB_NONBLOCKING) && > + (iocb->ki_flags & IOCB_DIRECT)) { > + /* Don't sleep on inode rwsem */ > + if (!inode_trylock(inode)) > + return -EAGAIN; > + /* > + * We will allocate space in case nodatacow is not set, > + * so bail > + */ > + if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | > + BTRFS_INODE_PREALLOC)) || The first part of the condition will evaluate to true only when both btrfs_inode_nodatacow and btrfs_inodeprealloc are not set. The code contradicts your statement in the change log. > + check_can_nocow(inode, pos, &count) <= 0) { > + inode_unlock(inode); > + return -EAGAIN; > + } > + } else > + inode_lock(inode); > + > err = generic_write_checks(iocb, from); > if (err <= 0) { > inode_unlock(inode); > @@ -1843,8 +1860,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, > */ > update_time_for_write(inode); > > - pos = iocb->ki_pos; > - count = iov_iter_count(from); > start_pos = round_down(pos, root->sectorsize); > oldsize = i_size_read(inode); > if (start_pos > oldsize) { > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index be4da91..9911ebd 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -8690,6 +8690,9 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, > struct iov_iter *iter) > if (offset + count <= inode->i_size) { > inode_unlock(inode); > relock = true; > + } else if (iocb->ki_flags & IOCB_NONBLOCKING) { > + ret = -EAGAIN; > + goto out; > } > ret = btrfs_delalloc_reserve_space(inode, offset, count); > if (ret) > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
