On Mon, Sep 09, 2019 at 08:27:04PM +0200, Christoph Hellwig wrote: > The documentation for IOMAP_F_* is a bit disorganized, and doesn't > mention the fact that most flags are set by the file system and consumed > by the iomap core, while IOMAP_F_SIZE_CHANGED is set by the core and > consumed by the file system. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Wooooooo, Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --D > --- > include/linux/iomap.h | 31 +++++++++++++++++++++++-------- > 1 file changed, 23 insertions(+), 8 deletions(-) > > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index e79af6b28410..8adcc8dd4498 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -30,21 +30,36 @@ struct vm_fault; > #define IOMAP_INLINE 0x05 /* data inline in the inode */ > > /* > - * Flags for all iomap mappings: > + * Flags reported by the file system from iomap_begin: > + * > + * IOMAP_F_NEW indicates that the blocks have been newly allocated and need > + * zeroing for areas that no data is copied to. > * > * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access > * written data and requires fdatasync to commit them to persistent storage. > + * > + * IOMAP_F_SHARED indicates that the blocks are shared, and will need to be > + * unshared as part a write. > + * > + * IOMAP_F_MERGED indicates that the iomap contains the merge of multiple block > + * mappings. > + * > + * IOMAP_F_BUFFER_HEAD indicates that the file system requires the use of > + * buffer heads for this mapping. > */ > -#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ > -#define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ > -#define IOMAP_F_BUFFER_HEAD 0x04 /* file system requires buffer heads */ > -#define IOMAP_F_SIZE_CHANGED 0x08 /* file size has changed */ > +#define IOMAP_F_NEW 0x01 > +#define IOMAP_F_DIRTY 0x02 > +#define IOMAP_F_SHARED 0x04 > +#define IOMAP_F_MERGED 0x08 > +#define IOMAP_F_BUFFER_HEAD 0x10 > > /* > - * Flags that only need to be reported for IOMAP_REPORT requests: > + * Flags set by the core iomap code during operations: > + * > + * IOMAP_F_SIZE_CHANGED indicates to the iomap_end method that the file size > + * has changed as the result of this write operation. > */ > -#define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ > -#define IOMAP_F_SHARED 0x20 /* block shared with another file */ > +#define IOMAP_F_SIZE_CHANGED 0x100 > > /* > * Flags from 0x1000 up are for file system specific usage: > -- > 2.20.1 >
