v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
new file mode 100644
index 0000000..4e3171a
--- /dev/null
+++ b/fs/xfs/xfs_buf.h
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#ifndef __XFS_BUF_H__
+#define __XFS_BUF_H__
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/dax.h>
+#include <linux/uio.h>
+#include <linux/list_lru.h>
+
+/*
+ * Base types
+ */
+
+#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
+
+typedef enum {
+ XBRW_READ = 1, /* transfer into target memory */
+ XBRW_WRITE = 2, /* transfer from target memory */
+ XBRW_ZERO = 3, /* Zero target memory */
+} xfs_buf_rw_t;
+
+#define XBF_READ (1 << 0) /* buffer intended for reading from device */
+#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
+#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
+#define XBF_NO_IOACCT (1 << 3) /* bypass I/O accounting (non-LRU bufs) */
+#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
+#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
+#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
+#define XBF_WRITE_FAIL (1 << 24)/* async writes have failed on this buffer */
+
+/* I/O hints for the BIO layer */
+#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
+#define XBF_FUA (1 << 11)/* force cache write through mode */
+#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
+
+/* flags used only as arguments to access routines */
+#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
+#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
+
+/* flags used only internally */
+#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
+#define _XBF_KMEM (1 << 21)/* backed by heap memory */
+#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
+#define _XBF_COMPOUND (1 << 23)/* compound buffer */
+
+typedef unsigned int xfs_buf_flags_t;
+
+#define XFS_BUF_FLAGS \
+ { XBF_READ, "READ" }, \
+ { XBF_WRITE, "WRITE" }, \
+ { XBF_READ_AHEAD, "READ_AHEAD" }, \
+ { XBF_NO_IOACCT, "NO_IOACCT" }, \
+ { XBF_ASYNC, "ASYNC" }, \
+ { XBF_DONE, "DONE" }, \
+ { XBF_STALE, "STALE" }, \
+ { XBF_WRITE_FAIL, "WRITE_FAIL" }, \
+ { XBF_SYNCIO, "SYNCIO" }, \
+ { XBF_FUA, "FUA" }, \
+ { XBF_FLUSH, "FLUSH" }, \
+ { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
+ { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
+ { _XBF_PAGES, "PAGES" }, \
+ { _XBF_KMEM, "KMEM" }, \
+ { _XBF_DELWRI_Q, "DELWRI_Q" }, \
+ { _XBF_COMPOUND, "COMPOUND" }
+
+
+/*
+ * Internal state flags.
+ */
+#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
+#define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */
+
+/*
+ * The xfs_buftarg contains 2 notions of "sector size" -
+ *
+ * 1) The metadata sector size, which is the minimum unit and
+ * alignment of IO which will be performed by metadata operations.
+ * 2) The device logical sector size
+ *
+ * The first is specified at mkfs time, and is stored on-disk in the
+ * superblock's sb_sectsize.
+ *
+ * The latter is derived from the underlying device, and controls direct IO
+ * alignment constraints.
+ */
+typedef struct xfs_buftarg {
+ dev_t bt_dev;
+ struct block_device *bt_bdev;
+ struct dax_device *bt_daxdev;
+ struct xfs_mount *bt_mount;
+ unsigned int bt_meta_sectorsize;
+ size_t bt_meta_sectormask;
+ size_t bt_logical_sectorsize;
+ size_t bt_logical_sectormask;
+
+ /* LRU control structures */
+ struct shrinker bt_shrinker;
+ struct list_lru bt_lru;
+
+ struct percpu_counter bt_io_count;
+} xfs_buftarg_t;
+
+struct xfs_buf;
+typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
+
+
+#define XB_PAGES 2
+
+struct xfs_buf_map {
+ xfs_daddr_t bm_bn; /* block number for I/O */
+ int bm_len; /* size of I/O */
+};
+
+#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
+ struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
+
+struct xfs_buf_ops {
+ char *name;
+ void (*verify_read)(struct xfs_buf *);
+ void (*verify_write)(struct xfs_buf *);
+ xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp);
+};
+
+typedef struct xfs_buf {
+ /*
+ * first cacheline holds all the fields needed for an uncontended cache
+ * hit to be fully processed. The semaphore straddles the cacheline
+ * boundary, but the counter and lock sits on the first cacheline,
+ * which is the only bit that is touched if we hit the semaphore
+ * fast-path on locking.
+ */
+ struct rhash_head b_rhash_head; /* pag buffer hash node */
+ xfs_daddr_t b_bn; /* block number of buffer */
+ int b_length; /* size of buffer in BBs */
+ atomic_t b_hold; /* reference count */
+ atomic_t b_lru_ref; /* lru reclaim ref count */
+ xfs_buf_flags_t b_flags; /* status flags */
+ struct semaphore b_sema; /* semaphore for lockables */
+
+ /*
+ * concurrent access to b_lru and b_lru_flags are protected by
+ * bt_lru_lock and not by b_sema
+ */
+ struct list_head b_lru; /* lru list */
+ spinlock_t b_lock; /* internal state lock */
+ unsigned int b_state; /* internal state flags */
+ int b_io_error; /* internal IO error state */
+ wait_queue_head_t b_waiters; /* unpin waiters */
+ struct list_head b_list;
+ struct xfs_perag *b_pag; /* contains rbtree root */
+ xfs_buftarg_t *b_target; /* buffer target (device) */
+ void *b_addr; /* virtual address of buffer */
+ struct work_struct b_ioend_work;
+ struct workqueue_struct *b_ioend_wq; /* I/O completion wq */
+ xfs_buf_iodone_t b_iodone; /* I/O completion function */
+ struct completion b_iowait; /* queue for I/O waiters */
+ void *b_log_item;
+ struct list_head b_li_list; /* Log items list head */
+ struct xfs_trans *b_transp;
+ struct page **b_pages; /* array of page pointers */
+ struct page *b_page_array[XB_PAGES]; /* inline pages */
+ struct xfs_buf_map *b_maps; /* compound buffer map */
+ struct xfs_buf_map __b_map; /* inline compound buffer map */
+ int b_map_count;
+ int b_io_length; /* IO size in BBs */
+ atomic_t b_pin_count; /* pin count */
+ atomic_t b_io_remaining; /* #outstanding I/O requests */
+ unsigned int b_page_count; /* size of page array */
+ unsigned int b_offset; /* page offset in first page */
+ int b_error; /* error code on I/O */
+
+ /*
+ * async write failure retry count. Initialised to zero on the first
+ * failure, then when it exceeds the maximum configured without a
+ * success the write is considered to be failed permanently and the
+ * iodone handler will take appropriate action.
+ *
+ * For retry timeouts, we record the jiffie of the first failure. This
+ * means that we can change the retry timeout for buffers already under
+ * I/O and thus avoid getting stuck in a retry loop with a long timeout.
+ *
+ * last_error is used to ensure that we are getting repeated errors, not
+ * different errors. e.g. a block device might change ENOSPC to EIO when
+ * a failure timeout occurs, so we want to re-initialise the error
+ * retry behaviour appropriately when that happens.
+ */
+ int b_retries;
+ unsigned long b_first_retry_time; /* in jiffies */
+ int b_last_error;
+
+ const struct xfs_buf_ops *b_ops;
+} xfs_buf_t;
+
+/* Finding and Reading Buffers */
+struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target,
+ xfs_daddr_t blkno, size_t numblks,
+ xfs_buf_flags_t flags);
+
+struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags);
+
+static inline struct xfs_buf *
+xfs_buf_alloc(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return _xfs_buf_alloc(target, &map, 1, flags);
+}
+
+struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags);
+struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ xfs_buf_flags_t flags,
+ const struct xfs_buf_ops *ops);
+void xfs_buf_readahead_map(struct xfs_buftarg *target,
+ struct xfs_buf_map *map, int nmaps,
+ const struct xfs_buf_ops *ops);
+
+static inline struct xfs_buf *
+xfs_buf_get(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_get_map(target, &map, 1, flags);
+}
+
+static inline struct xfs_buf *
+xfs_buf_read(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ xfs_buf_flags_t flags,
+ const struct xfs_buf_ops *ops)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_read_map(target, &map, 1, flags, ops);
+}
+
+static inline void
+xfs_buf_readahead(
+ struct xfs_buftarg *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
+ const struct xfs_buf_ops *ops)
+{
+ DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+ return xfs_buf_readahead_map(target, &map, 1, ops);
+}
+
+void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks);
+int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
+
+struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
+ int flags);
+int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
+ size_t numblks, int flags, struct xfs_buf **bpp,
+ const struct xfs_buf_ops *ops);
+void xfs_buf_hold(struct xfs_buf *bp);
+
+/* Releasing Buffers */
+extern void xfs_buf_free(xfs_buf_t *);
+extern void xfs_buf_rele(xfs_buf_t *);
+
+/* Locking and Unlocking Buffers */
+extern int xfs_buf_trylock(xfs_buf_t *);
+extern void xfs_buf_lock(xfs_buf_t *);
+extern void xfs_buf_unlock(xfs_buf_t *);
+#define xfs_buf_islocked(bp) \
+ ((bp)->b_sema.count <= 0)
+
+/* Buffer Read and Write Routines */
+extern int xfs_bwrite(struct xfs_buf *bp);
+extern void xfs_buf_ioend(struct xfs_buf *bp);
+extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
+ xfs_failaddr_t failaddr);
+#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
+extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
+
+extern int __xfs_buf_submit(struct xfs_buf *bp, bool);
+static inline int xfs_buf_submit(struct xfs_buf *bp)
+{
+ bool wait = bp->b_flags & XBF_ASYNC ? false : true;
+ return __xfs_buf_submit(bp, wait);
+}
+
+extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
+ xfs_buf_rw_t);
+#define xfs_buf_zero(bp, off, len) \
+ xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
+
+/* Buffer Utility Routines */
+extern void *xfs_buf_offset(struct xfs_buf *, size_t);
+extern void xfs_buf_stale(struct xfs_buf *bp);
+
+/* Delayed Write Buffer Routines */
+extern void xfs_buf_delwri_cancel(struct list_head *);
+extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
+extern int xfs_buf_delwri_submit(struct list_head *);
+extern int xfs_buf_delwri_submit_nowait(struct list_head *);
+extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *);
+
+/* Buffer Daemon Setup Routines */
+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_ADDR(bp) ((bp)->b_maps[0].bm_bn)
+#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
+
+void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
+
+/*
+ * If the buffer is already on the LRU, do nothing. Otherwise set the buffer
+ * up with a reference count of 0 so it will be tossed from the cache when
+ * released.
+ */
+static inline void xfs_buf_oneshot(struct xfs_buf *bp)
+{
+ if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1)
+ return;
+ atomic_set(&bp->b_lru_ref, 0);
+}
+
+static inline int xfs_buf_ispinned(struct xfs_buf *bp)
+{
+ return atomic_read(&bp->b_pin_count);
+}
+
+static inline void xfs_buf_relse(xfs_buf_t *bp)
+{
+ xfs_buf_unlock(bp);
+ xfs_buf_rele(bp);
+}
+
+static inline int
+xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
+{
+ return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+ cksum_offset);
+}
+
+static inline void
+xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
+{
+ xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+ cksum_offset);
+}
+
+/*
+ * Handling of buftargs.
+ */
+extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
+ struct block_device *, struct dax_device *);
+extern void xfs_free_buftarg(struct xfs_buftarg *);
+extern void xfs_wait_buftarg(xfs_buftarg_t *);
+extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int);
+
+#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
+#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
+
+#endif /* __XFS_BUF_H__ */