84d6961910
To gracefully handle the situation where a CoW operation turns a single refcount extent into a lot of tiny ones and then run out of space when a tree split has to happen, use the per-AG reserved block pool to pre-allocate all the space we'll ever need for a maximal btree. For a 4K block size, this only costs an overhead of 0.3% of available disk space. When reflink is enabled, we have an unfortunate problem with rmap -- since we can share a block billions of times, this means that the reverse mapping btree can expand basically infinitely. When an AG is so full that there are no free blocks with which to expand the rmapbt, the filesystem will shut down hard. This is rather annoying to the user, so use the AG reservation code to reserve a "reasonable" amount of space for rmap. We'll prevent reflinks and CoW operations if we think we're getting close to exhausting an AG's free space rather than shutting down, but this permanent reservation should be enough for "most" users. Hopefully. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch@lst.de: ensure that we invalidate the freed btree buffer] Signed-off-by: Christoph Hellwig <hch@lst.de>
32 lines
1.3 KiB
C
32 lines
1.3 KiB
C
/*
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* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef __XFS_FSOPS_H__
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#define __XFS_FSOPS_H__
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extern int xfs_fs_geometry(xfs_mount_t *mp, xfs_fsop_geom_t *geo, int nversion);
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extern int xfs_growfs_data(xfs_mount_t *mp, xfs_growfs_data_t *in);
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extern int xfs_growfs_log(xfs_mount_t *mp, xfs_growfs_log_t *in);
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extern int xfs_fs_counts(xfs_mount_t *mp, xfs_fsop_counts_t *cnt);
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extern int xfs_reserve_blocks(xfs_mount_t *mp, __uint64_t *inval,
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xfs_fsop_resblks_t *outval);
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extern int xfs_fs_goingdown(xfs_mount_t *mp, __uint32_t inflags);
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extern int xfs_fs_reserve_ag_blocks(struct xfs_mount *mp);
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extern int xfs_fs_unreserve_ag_blocks(struct xfs_mount *mp);
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#endif /* __XFS_FSOPS_H__ */
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