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| author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2017-06-20 14:05:47 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-06-20 15:12:03 +0200 |
| commit | 728fbc0e10b7f3ce2ee043b32e3453fd5201c055 (patch) | |
| tree | eff612a5bd8832bb002d3adde66a9b6c5a475f6d /fs/ext4/file.c | |
| parent | block: return on congested block device (diff) | |
| download | linux-728fbc0e10b7f3ce2ee043b32e3453fd5201c055.tar.xz linux-728fbc0e10b7f3ce2ee043b32e3453fd5201c055.zip | |
ext4: nowait aio support
Return EAGAIN if any of the following checks fail for direct I/O:
+ i_rwsem is lockable
+ Writing beyond end of file (will trigger allocation)
+ Blocks are not allocated at the write location
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 02ce7e7bbdf5..58e2eeaa0bc4 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -37,7 +37,11 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) struct inode *inode = file_inode(iocb->ki_filp); ssize_t ret; - inode_lock_shared(inode); + if (!inode_trylock_shared(inode)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + inode_lock_shared(inode); + } /* * Recheck under inode lock - at this point we are sure it cannot * change anymore @@ -179,7 +183,11 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) struct inode *inode = file_inode(iocb->ki_filp); ssize_t ret; - inode_lock(inode); + if (!inode_trylock(inode)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + inode_lock(inode); + } ret = ext4_write_checks(iocb, from); if (ret <= 0) goto out; @@ -216,7 +224,12 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) return ext4_dax_write_iter(iocb, from); #endif - inode_lock(inode); + if (!inode_trylock(inode)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + inode_lock(inode); + } + ret = ext4_write_checks(iocb, from); if (ret <= 0) goto out; @@ -235,9 +248,15 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) iocb->private = &overwrite; /* Check whether we do a DIO overwrite or not */ - if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio && - ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) - overwrite = 1; + if (o_direct && !unaligned_aio) { + if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) { + if (ext4_should_dioread_nolock(inode)) + overwrite = 1; + } else if (iocb->ki_flags & IOCB_NOWAIT) { + ret = -EAGAIN; + goto out; + } + } ret = __generic_file_write_iter(iocb, from); inode_unlock(inode); @@ -435,6 +454,10 @@ static int ext4_file_open(struct inode * inode, struct file * filp) if (ret < 0) return ret; } + + /* Set the flags to support nowait AIO */ + filp->f_mode |= FMODE_AIO_NOWAIT; + return dquot_file_open(inode, filp); } |