redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity
alistair23-linux/fs/xfs/libxfs/xfs_shared.h
Brian Foster f74681ba20 xfs: preserve rmapbt swapext block reservation from freed blocks 
The rmapbt extent swap algorithm remaps individual extents between
the source inode and the target to trigger reverse mapping metadata
updates. If either inode straddles a format or other bmap allocation
boundary, the individual unmap and map cycles can trigger repeated
bmap block allocations and frees as the extent count bounces back
and forth across the boundary. While net block usage is bound across
the swap operation, this behavior can prematurely exhaust the
transaction block reservation because it continuously drains as the
transaction rolls. Each allocation accounts against the reservation
and each free returns to global free space on transaction roll.

The previous workaround to this problem attempted to detect this
boundary condition and provide surplus block reservation to
acommodate it. This is insufficient because more remaps can occur
than implied by the extent counts; if start offset boundaries are
not aligned between the two inodes, for example.

To address this problem more generically and dynamically, add a
transaction accounting mode that returns freed blocks to the
transaction reservation instead of the superblock counters on
transaction roll and use it when the rmapbt based algorithm is
active. This allows the chain of remap transactions to preserve the
block reservation based own its own frees and prevent premature
exhaustion regardless of the remap pattern. Note that this is only
safe for superblocks with lazy sb accounting, but the latter is
required for v5 supers and the rmap feature depends on v5.

Fixes: b3fed43482 ("xfs: account format bouncing into rmapbt swapext tx reservation")
Root-caused-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-06 10:46:56 -07:00

182 lines
6.5 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_SHARED_H__
#define __XFS_SHARED_H__
/*
* Definitions shared between kernel and userspace that don't fit into any other
* header file that is shared with userspace.
*/
struct xfs_ifork;
struct xfs_buf;
struct xfs_buf_ops;
struct xfs_mount;
struct xfs_trans;
struct xfs_inode;
/*
* Buffer verifier operations are widely used, including userspace tools
*/
extern const struct xfs_buf_ops xfs_agf_buf_ops;
extern const struct xfs_buf_ops xfs_agi_buf_ops;
extern const struct xfs_buf_ops xfs_agf_buf_ops;
extern const struct xfs_buf_ops xfs_agfl_buf_ops;
extern const struct xfs_buf_ops xfs_bnobt_buf_ops;
extern const struct xfs_buf_ops xfs_cntbt_buf_ops;
extern const struct xfs_buf_ops xfs_rmapbt_buf_ops;
extern const struct xfs_buf_ops xfs_refcountbt_buf_ops;
extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops;
extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops;
extern const struct xfs_buf_ops xfs_bmbt_buf_ops;
extern const struct xfs_buf_ops xfs_da3_node_buf_ops;
extern const struct xfs_buf_ops xfs_dquot_buf_ops;
extern const struct xfs_buf_ops xfs_symlink_buf_ops;
extern const struct xfs_buf_ops xfs_agi_buf_ops;
extern const struct xfs_buf_ops xfs_inobt_buf_ops;
extern const struct xfs_buf_ops xfs_finobt_buf_ops;
extern const struct xfs_buf_ops xfs_inode_buf_ops;
extern const struct xfs_buf_ops xfs_inode_buf_ra_ops;
extern const struct xfs_buf_ops xfs_dquot_buf_ops;
extern const struct xfs_buf_ops xfs_dquot_buf_ra_ops;
extern const struct xfs_buf_ops xfs_sb_buf_ops;
extern const struct xfs_buf_ops xfs_sb_quiet_buf_ops;
extern const struct xfs_buf_ops xfs_symlink_buf_ops;
extern const struct xfs_buf_ops xfs_rtbuf_ops;
/* log size calculation functions */
int xfs_log_calc_unit_res(struct xfs_mount *mp, int unit_bytes);
int xfs_log_calc_minimum_size(struct xfs_mount *);
struct xfs_trans_res;
void xfs_log_get_max_trans_res(struct xfs_mount *mp,
struct xfs_trans_res *max_resp);
/*
* Values for t_flags.
*/
#define XFS_TRANS_DIRTY 0x01 /* something needs to be logged */
#define XFS_TRANS_SB_DIRTY 0x02 /* superblock is modified */
#define XFS_TRANS_PERM_LOG_RES 0x04 /* xact took a permanent log res */
#define XFS_TRANS_SYNC 0x08 /* make commit synchronous */
#define XFS_TRANS_DQ_DIRTY 0x10 /* at least one dquot in trx dirty */
#define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */
#define XFS_TRANS_NO_WRITECOUNT 0x40 /* do not elevate SB writecount */
#define XFS_TRANS_RES_FDBLKS 0x80 /* reserve newly freed blocks */
/*
* LOWMODE is used by the allocator to activate the lowspace algorithm - when
* free space is running low the extent allocator may choose to allocate an
* extent from an AG without leaving sufficient space for a btree split when
* inserting the new extent. In this case the allocator will enable the
* lowspace algorithm which is supposed to allow further allocations (such as
* btree splits and newroots) to allocate from sequential AGs. In order to
* avoid locking AGs out of order the lowspace algorithm will start searching
* for free space from AG 0. If the correct transaction reservations have been
* made then this algorithm will eventually find all the space it needs.
*/
#define XFS_TRANS_LOWMODE 0x100 /* allocate in low space mode */
/*
* Field values for xfs_trans_mod_sb.
*/
#define XFS_TRANS_SB_ICOUNT 0x00000001
#define XFS_TRANS_SB_IFREE 0x00000002
#define XFS_TRANS_SB_FDBLOCKS 0x00000004
#define XFS_TRANS_SB_RES_FDBLOCKS 0x00000008
#define XFS_TRANS_SB_FREXTENTS 0x00000010
#define XFS_TRANS_SB_RES_FREXTENTS 0x00000020
#define XFS_TRANS_SB_DBLOCKS 0x00000040
#define XFS_TRANS_SB_AGCOUNT 0x00000080
#define XFS_TRANS_SB_IMAXPCT 0x00000100
#define XFS_TRANS_SB_REXTSIZE 0x00000200
#define XFS_TRANS_SB_RBMBLOCKS 0x00000400
#define XFS_TRANS_SB_RBLOCKS 0x00000800
#define XFS_TRANS_SB_REXTENTS 0x00001000
#define XFS_TRANS_SB_REXTSLOG 0x00002000
/*
* Here we centralize the specification of XFS meta-data buffer reference count
* values. This determines how hard the buffer cache tries to hold onto the
* buffer.
*/
#define XFS_AGF_REF 4
#define XFS_AGI_REF 4
#define XFS_AGFL_REF 3
#define XFS_INO_BTREE_REF 3
#define XFS_ALLOC_BTREE_REF 2
#define XFS_BMAP_BTREE_REF 2
#define XFS_RMAP_BTREE_REF 2
#define XFS_DIR_BTREE_REF 2
#define XFS_INO_REF 2
#define XFS_ATTR_BTREE_REF 1
#define XFS_DQUOT_REF 1
#define XFS_REFC_BTREE_REF 1
#define XFS_SSB_REF 0
/*
* Flags for xfs_trans_ichgtime().
*/
#define XFS_ICHGTIME_MOD 0x1 /* data fork modification timestamp */
#define XFS_ICHGTIME_CHG 0x2 /* inode field change timestamp */
#define XFS_ICHGTIME_CREATE 0x4 /* inode create timestamp */
/*
* Symlink decoding/encoding functions
*/
int xfs_symlink_blocks(struct xfs_mount *mp, int pathlen);
int xfs_symlink_hdr_set(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
uint32_t size, struct xfs_buf *bp);
bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset,
uint32_t size, struct xfs_buf *bp);
void xfs_symlink_local_to_remote(struct xfs_trans *tp, struct xfs_buf *bp,
struct xfs_inode *ip, struct xfs_ifork *ifp);
xfs_failaddr_t xfs_symlink_shortform_verify(struct xfs_inode *ip);
/* Computed inode geometry for the filesystem. */
struct xfs_ino_geometry {
/* Maximum inode count in this filesystem. */
uint64_t maxicount;
/* Actual inode cluster buffer size, in bytes. */
unsigned int inode_cluster_size;
/*
* Desired inode cluster buffer size, in bytes. This value is not
* rounded up to at least one filesystem block, which is necessary for
* the sole purpose of validating sb_spino_align. Runtime code must
* only ever use inode_cluster_size.
*/
unsigned int inode_cluster_size_raw;
/* Inode cluster sizes, adjusted to be at least 1 fsb. */
unsigned int inodes_per_cluster;
unsigned int blocks_per_cluster;
/* Inode cluster alignment. */
unsigned int cluster_align;
unsigned int cluster_align_inodes;
unsigned int inoalign_mask; /* mask sb_inoalignmt if used */
unsigned int inobt_mxr[2]; /* max inobt btree records */
unsigned int inobt_mnr[2]; /* min inobt btree records */
unsigned int inobt_maxlevels; /* max inobt btree levels. */
/* Size of inode allocations under normal operation. */
unsigned int ialloc_inos;
unsigned int ialloc_blks;
/* Minimum inode blocks for a sparse allocation. */
unsigned int ialloc_min_blks;
/* stripe unit inode alignment */
unsigned int ialloc_align;
unsigned int agino_log; /* #bits for agino in inum */
};
#endif /* __XFS_SHARED_H__ */
View git blame Copy permalink