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linux/fs/xfs/libxfs/xfs_refcount.h

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xfs: add refcount btree operations Implement the generic btree operations required to manipulate refcount btree blocks. The implementation is similar to the bmapbt, though it will only allocate and free blocks from the AG. Since the refcount root and level fields are separate from the existing roots and levels array, they need a separate logging flag. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: fix logging of AGF refcount btree fields] Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:19 +08:00
/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __XFS_REFCOUNT_H__
#define __XFS_REFCOUNT_H__
extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
xfs_agblock_t bno, int *stat);
extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
xfs_agblock_t bno, int *stat);
extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
struct xfs_refcount_irec *irec, int *stat);
xfs: log refcount intent items Provide a mechanism for higher levels to create CUI/CUD items, submit them to the log, and a stub function to deal with recovered CUI items. These parts will be connected to the refcountbt in a later patch. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:21 +08:00
enum xfs_refcount_intent_type {
XFS_REFCOUNT_INCREASE = 1,
XFS_REFCOUNT_DECREASE,
XFS_REFCOUNT_ALLOC_COW,
XFS_REFCOUNT_FREE_COW,
};
struct xfs_refcount_intent {
struct list_head ri_list;
enum xfs_refcount_intent_type ri_type;
xfs_fsblock_t ri_startblock;
xfs_extlen_t ri_blockcount;
};
xfs: connect refcount adjust functions to upper layers Plumb in the upper level interface to schedule and finish deferred refcount operations via the deferred ops mechanism. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:22 +08:00
extern int xfs_refcount_increase_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
extern int xfs_refcount_decrease_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
struct xfs_btree_cur *rcur, int error);
extern int xfs_refcount_finish_one(struct xfs_trans *tp,
struct xfs_defer_ops *dfops, enum xfs_refcount_intent_type type,
xfs_fsblock_t startblock, xfs_extlen_t blockcount,
xfs_fsblock_t *new_fsb, xfs_extlen_t *new_len,
struct xfs_btree_cur **pcur);
xfs: introduce reflink utility functions These functions will be used by the other reflink functions to find the maximum length of a range of shared blocks. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:25 +08:00
extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
xfs_extlen_t *flen, bool find_end_of_shared);
xfs: store in-progress CoW allocations in the refcount btree Due to the way the CoW algorithm in XFS works, there's an interval during which blocks allocated to handle a CoW can be lost -- if the FS goes down after the blocks are allocated but before the block remapping takes place. This is exacerbated by the cowextsz hint -- allocated reservations can sit around for a while, waiting to get used. Since the refcount btree doesn't normally store records with refcount of 1, we can use it to record these in-progress extents. In-progress blocks cannot be shared because they're not user-visible, so there shouldn't be any conflicts with other programs. This is a better solution than holding EFIs during writeback because (a) EFIs can't be relogged currently, (b) even if they could, EFIs are bound by available log space, which puts an unnecessary upper bound on how much CoW we can have in flight, and (c) we already have a mechanism to track blocks. At mount time, read the refcount records and free anything we find with a refcount of 1 because those were in-progress when the FS went down. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:39 +08:00
extern int xfs_refcount_alloc_cow_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
xfs_extlen_t len);
extern int xfs_refcount_free_cow_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
xfs_extlen_t len);
extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
xfs_agnumber_t agno);
xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent In a pathological scenario where we are trying to bunmapi a single extent in which every other block is shared, it's possible that trying to unmap the entire large extent in a single transaction can generate so many EFIs that we overflow the transaction reservation. Therefore, use a heuristic to guess at the number of blocks we can safely unmap from a reflink file's data fork in an single transaction. This should prevent problems such as the log head slamming into the tail and ASSERTs that trigger because we've exceeded the transaction reservation. Note that since bunmapi can fail to unmap the entire range, we must also teach the deferred unmap code to roll into a new transaction whenever we get low on reservation. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: random edits, all bugs are my fault] Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-15 12:25:57 +08:00
/*
* While we're adjusting the refcounts records of an extent, we have
* to keep an eye on the number of extents we're dirtying -- run too
* many in a single transaction and we'll exceed the transaction's
* reservation and crash the fs. Each record adds 12 bytes to the
* log (plus any key updates) so we'll conservatively assume 32 bytes
* per record. We must also leave space for btree splits on both ends
* of the range and space for the CUD and a new CUI.
*/
#define XFS_REFCOUNT_ITEM_OVERHEAD 32
static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
{
return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
}
xfs: add scrub cross-referencing helpers for the refcount btrees Add a couple of functions to the refcount btrees that will be used to cross-reference metadata against the refcountbt. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-01-17 10:52:14 +08:00
extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
xfs: add refcount btree operations Implement the generic btree operations required to manipulate refcount btree blocks. The implementation is similar to the bmapbt, though it will only allocate and free blocks from the AG. Since the refcount root and level fields are separate from the existing roots and levels array, they need a separate logging flag. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: fix logging of AGF refcount btree fields] Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-04 00:11:19 +08:00
#endif /* __XFS_REFCOUNT_H__ */