* [PATCH 7/7] nonblocking aio: btrfs [not found] <20170214024603.9563-1-rgoldwyn@suse.de> @ 2017-02-14 2:46 ` Goldwyn Rodrigues 2017-02-14 9:24 ` Nikolay Borisov 0 siblings, 1 reply; 2+ messages in thread From: Goldwyn Rodrigues @ 2017-02-14 2:46 UTC (permalink / raw) To: linux-fsdevel; +Cc: jack, Goldwyn Rodrigues, linux-btrfs From: Goldwyn Rodrigues <rgoldwyn@suse.com> Return EAGAIN if any of the following checks fail + i_rwsem is lockable + NODATACOW or PREALLOC is set + Can nocow at the desired location + Writing beyond end of file Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> --- 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)) || + 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) -- 2.10.2 ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 7/7] nonblocking aio: btrfs 2017-02-14 2:46 ` [PATCH 7/7] nonblocking aio: btrfs Goldwyn Rodrigues @ 2017-02-14 9:24 ` Nikolay Borisov 0 siblings, 0 replies; 2+ messages in thread From: Nikolay Borisov @ 2017-02-14 9:24 UTC (permalink / raw) To: Goldwyn Rodrigues, linux-fsdevel; +Cc: jack, linux-btrfs On 14.02.2017 04:46, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > 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 <rgoldwyn@suse.com> > --- > 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) > ^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-02-14 2:46 ` [PATCH 7/7] nonblocking aio: btrfs Goldwyn Rodrigues
2017-02-14 9:24 ` Nikolay Borisov
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