| Message ID | 20210819000055.149955-4-david@fromorbit.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | xfs: clean up buffer cache disk addressing | expand |
On Thu, Aug 19, 2021 at 10:00:55AM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > To stop external users from using b_bn as the disk address of the > buffer, rename it to b_rhash_key to indicate that it is the buffer > cache index, not the block number of the buffer. Code that needs the > disk address should use xfs_buf_daddr() to obtain it. > > Do the rename and clean up any of the remaining internal b_bn users. > Also clean up any remaining b_bn cruft that is now unused. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> Haaaa my brain didn't fall out! Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/xfs_buf.c | 19 +++++++++++-------- > fs/xfs/xfs_buf.h | 18 +----------------- > 2 files changed, 12 insertions(+), 25 deletions(-) > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index c1bb6e41595b..047bd6e3f389 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -251,7 +251,7 @@ _xfs_buf_alloc( > return error; > } > > - bp->b_bn = map[0].bm_bn; > + bp->b_rhash_key = map[0].bm_bn; > bp->b_length = 0; > for (i = 0; i < nmaps; i++) { > bp->b_maps[i].bm_bn = map[i].bm_bn; > @@ -459,7 +459,7 @@ _xfs_buf_obj_cmp( > */ > BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); > > - if (bp->b_bn != map->bm_bn) > + if (bp->b_rhash_key != map->bm_bn) > return 1; > > if (unlikely(bp->b_length != map->bm_len)) { > @@ -481,7 +481,7 @@ static const struct rhashtable_params xfs_buf_hash_params = { > .min_size = 32, /* empty AGs have minimal footprint */ > .nelem_hint = 16, > .key_len = sizeof(xfs_daddr_t), > - .key_offset = offsetof(struct xfs_buf, b_bn), > + .key_offset = offsetof(struct xfs_buf, b_rhash_key), > .head_offset = offsetof(struct xfs_buf, b_rhash_head), > .automatic_shrinking = true, > .obj_cmpfn = _xfs_buf_obj_cmp, > @@ -853,7 +853,9 @@ xfs_buf_readahead_map( > > /* > * Read an uncached buffer from disk. Allocates and returns a locked > - * buffer containing the disk contents or nothing. > + * buffer containing the disk contents or nothing. Uncached buffers always have > + * a cache index of XFS_BUF_DADDR_NULL so we can easily determine if the buffer > + * is cached or uncached during fault diagnosis. > */ > int > xfs_buf_read_uncached( > @@ -875,7 +877,7 @@ xfs_buf_read_uncached( > > /* set up the buffer for a read IO */ > ASSERT(bp->b_map_count == 1); > - bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ > + bp->b_rhash_key = XFS_BUF_DADDR_NULL; > bp->b_maps[0].bm_bn = daddr; > bp->b_flags |= XBF_READ; > bp->b_ops = ops; > @@ -1513,7 +1515,7 @@ _xfs_buf_ioapply( > SHUTDOWN_CORRUPT_INCORE); > return; > } > - } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { > + } else if (bp->b_rhash_key != XFS_BUF_DADDR_NULL) { > struct xfs_mount *mp = bp->b_mount; > > /* > @@ -1523,7 +1525,8 @@ _xfs_buf_ioapply( > if (xfs_has_crc(mp)) { > xfs_warn(mp, > "%s: no buf ops on daddr 0x%llx len %d", > - __func__, bp->b_bn, bp->b_length); > + __func__, xfs_buf_daddr(bp), > + bp->b_length); > xfs_hex_dump(bp->b_addr, > XFS_CORRUPTION_DUMP_LEN); > dump_stack(); > @@ -1793,7 +1796,7 @@ xfs_buftarg_drain( > xfs_buf_alert_ratelimited(bp, > "XFS: Corruption Alert", > "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", > - (long long)bp->b_bn); > + (long long)xfs_buf_daddr(bp)); > } > xfs_buf_rele(bp); > } > diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h > index 6db2fba44b46..6b0200b8007d 100644 > --- a/fs/xfs/xfs_buf.h > +++ b/fs/xfs/xfs_buf.h > @@ -134,11 +134,7 @@ struct xfs_buf { > */ > struct rhash_head b_rhash_head; /* pag buffer hash node */ > > - /* > - * b_bn is the cache index. Do not use directly, use b_maps[0].bm_bn > - * for the buffer disk address instead. > - */ > - xfs_daddr_t b_bn; > + xfs_daddr_t b_rhash_key; /* buffer cache index */ > int b_length; /* size of buffer in BBs */ > atomic_t b_hold; /* reference count */ > atomic_t b_lru_ref; /* lru reclaim ref count */ > @@ -301,18 +297,6 @@ extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); > extern int xfs_buf_init(void); > extern void xfs_buf_terminate(void); > > -/* > - * These macros use the IO block map rather than b_bn. b_bn is now really > - * just for the buffer cache index for cached buffers. As IO does not use b_bn > - * anymore, uncached buffers do not use b_bn at all and hence must modify the IO > - * map directly. Uncached buffers are not allowed to be discontiguous, so this > - * is safe to do. > - * > - * In future, uncached buffers will pass the block number directly to the io > - * request function and hence these macros will go away at that point. > - */ > -#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) > - > static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) > { > return bp->b_maps[0].bm_bn; > -- > 2.31.1 >
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index c1bb6e41595b..047bd6e3f389 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -251,7 +251,7 @@ _xfs_buf_alloc( return error; } - bp->b_bn = map[0].bm_bn; + bp->b_rhash_key = map[0].bm_bn; bp->b_length = 0; for (i = 0; i < nmaps; i++) { bp->b_maps[i].bm_bn = map[i].bm_bn; @@ -459,7 +459,7 @@ _xfs_buf_obj_cmp( */ BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); - if (bp->b_bn != map->bm_bn) + if (bp->b_rhash_key != map->bm_bn) return 1; if (unlikely(bp->b_length != map->bm_len)) { @@ -481,7 +481,7 @@ static const struct rhashtable_params xfs_buf_hash_params = { .min_size = 32, /* empty AGs have minimal footprint */ .nelem_hint = 16, .key_len = sizeof(xfs_daddr_t), - .key_offset = offsetof(struct xfs_buf, b_bn), + .key_offset = offsetof(struct xfs_buf, b_rhash_key), .head_offset = offsetof(struct xfs_buf, b_rhash_head), .automatic_shrinking = true, .obj_cmpfn = _xfs_buf_obj_cmp, @@ -853,7 +853,9 @@ xfs_buf_readahead_map( /* * Read an uncached buffer from disk. Allocates and returns a locked - * buffer containing the disk contents or nothing. + * buffer containing the disk contents or nothing. Uncached buffers always have + * a cache index of XFS_BUF_DADDR_NULL so we can easily determine if the buffer + * is cached or uncached during fault diagnosis. */ int xfs_buf_read_uncached( @@ -875,7 +877,7 @@ xfs_buf_read_uncached( /* set up the buffer for a read IO */ ASSERT(bp->b_map_count == 1); - bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ + bp->b_rhash_key = XFS_BUF_DADDR_NULL; bp->b_maps[0].bm_bn = daddr; bp->b_flags |= XBF_READ; bp->b_ops = ops; @@ -1513,7 +1515,7 @@ _xfs_buf_ioapply( SHUTDOWN_CORRUPT_INCORE); return; } - } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { + } else if (bp->b_rhash_key != XFS_BUF_DADDR_NULL) { struct xfs_mount *mp = bp->b_mount; /* @@ -1523,7 +1525,8 @@ _xfs_buf_ioapply( if (xfs_has_crc(mp)) { xfs_warn(mp, "%s: no buf ops on daddr 0x%llx len %d", - __func__, bp->b_bn, bp->b_length); + __func__, xfs_buf_daddr(bp), + bp->b_length); xfs_hex_dump(bp->b_addr, XFS_CORRUPTION_DUMP_LEN); dump_stack(); @@ -1793,7 +1796,7 @@ xfs_buftarg_drain( xfs_buf_alert_ratelimited(bp, "XFS: Corruption Alert", "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", - (long long)bp->b_bn); + (long long)xfs_buf_daddr(bp)); } xfs_buf_rele(bp); } diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index 6db2fba44b46..6b0200b8007d 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -134,11 +134,7 @@ struct xfs_buf { */ struct rhash_head b_rhash_head; /* pag buffer hash node */ - /* - * b_bn is the cache index. Do not use directly, use b_maps[0].bm_bn - * for the buffer disk address instead. - */ - xfs_daddr_t b_bn; + xfs_daddr_t b_rhash_key; /* buffer cache index */ int b_length; /* size of buffer in BBs */ atomic_t b_hold; /* reference count */ atomic_t b_lru_ref; /* lru reclaim ref count */ @@ -301,18 +297,6 @@ extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); extern int xfs_buf_init(void); extern void xfs_buf_terminate(void); -/* - * These macros use the IO block map rather than b_bn. b_bn is now really - * just for the buffer cache index for cached buffers. As IO does not use b_bn - * anymore, uncached buffers do not use b_bn at all and hence must modify the IO - * map directly. Uncached buffers are not allowed to be discontiguous, so this - * is safe to do. - * - * In future, uncached buffers will pass the block number directly to the io - * request function and hence these macros will go away at that point. - */ -#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) - static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) { return bp->b_maps[0].bm_bn;