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| author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2017-06-20 07:05:49 -0500 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-06-20 07:12:03 -0600 |
| commit | edf064e7c6fec3646b06c944a8e35d1a3de5c2c3 (patch) | |
| tree | 861835f7c0ae787598be8e18eac67f623d90658e /fs/btrfs/file.c | |
| parent | 29a5d29ec181ebdc98a26cedbd76ce9870248892 (diff) | |
| download | lwn-edf064e7c6fec3646b06c944a8e35d1a3de5c2c3.tar.gz lwn-edf064e7c6fec3646b06c944a8e35d1a3de5c2c3.zip | |
btrfs: nowait aio support
Return EAGAIN if any of the following checks fail
+ i_rwsem is not lockable
+ NODATACOW or PREALLOC is not set
+ Cannot nocow at the desired location
+ Writing beyond end of file which is not allocated
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/btrfs/file.c')
| -rw-r--r-- | fs/btrfs/file.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index da1096eb1a40..59e2dccdf75b 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1875,12 +1875,29 @@ 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_NOWAIT) && + (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(BTRFS_I(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); @@ -1914,8 +1931,6 @@ 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, fs_info->sectorsize); oldsize = i_size_read(inode); if (start_pos > oldsize) { @@ -3071,13 +3086,19 @@ out: return offset; } +static int btrfs_file_open(struct inode *inode, struct file *filp) +{ + filp->f_mode |= FMODE_AIO_NOWAIT; + return generic_file_open(inode, filp); +} + const struct file_operations btrfs_file_operations = { .llseek = btrfs_file_llseek, .read_iter = generic_file_read_iter, .splice_read = generic_file_splice_read, .write_iter = btrfs_file_write_iter, .mmap = btrfs_file_mmap, - .open = generic_file_open, + .open = btrfs_file_open, .release = btrfs_release_file, .fsync = btrfs_sync_file, .fallocate = btrfs_fallocate, |