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author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2017-06-20 15:05:43 +0300 |
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committer | Jens Axboe <axboe@kernel.dk> | 2017-06-20 16:12:03 +0300 |
commit | b745fafaf70c0a98a2e1e7ac8cb14542889ceb0e (patch) | |
tree | 10a7b6f647945c63f17c6d55c346e84d99130ac3 /include/uapi | |
parent | 9830f4be159b29399d107bffb99e0132bc5aedd4 (diff) | |
download | linux-b745fafaf70c0a98a2e1e7ac8cb14542889ceb0e.tar.xz |
fs: Introduce RWF_NOWAIT and FMODE_AIO_NOWAIT
RWF_NOWAIT informs kernel to bail out if an AIO request will block
for reasons such as file allocations, or a writeback triggered,
or would block while allocating requests while performing
direct I/O.
RWF_NOWAIT is translated to IOCB_NOWAIT for iocb->ki_flags.
FMODE_AIO_NOWAIT is a flag which identifies the file opened is capable
of returning -EAGAIN if the AIO call will block. This must be set by
supporting filesystems in the ->open() call.
Filesystems xfs, btrfs and ext4 would be supported in the following patches.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/uapi')
-rw-r--r-- | include/uapi/linux/fs.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 937c3e39650a..27d8c36c04af 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -360,7 +360,9 @@ struct fscrypt_key { #define RWF_HIPRI 0x00000001 /* high priority request, poll if possible */ #define RWF_DSYNC 0x00000002 /* per-IO O_DSYNC */ #define RWF_SYNC 0x00000004 /* per-IO O_SYNC */ +#define RWF_NOWAIT 0x00000008 /* per-IO, return -EAGAIN if operation would block */ -#define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC) +#define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC |\ + RWF_NOWAIT) #endif /* _UAPI_LINUX_FS_H */ |