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gfs2: Only use struct gfs2_rbm for bitmap manipulations

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GFS2 uses struct gfs2_rbm to represent a filesystem block number as a
bit position within a resource group.  This representation is used in
the bitmap manipulation code to prevent excessive conversions between
block numbers and bit positions, but also in struct gfs2_blkreserv which
is part of struct gfs2_inode, to mark the start of a reservation.  In
the inode, the bit position representation makes less sense: first, the
start position is used as a block number about as often as a bit
position; second, the bit position representation makes the code
unnecessarily complicated and difficult to read.

Therefore, change struct gfs2_blkreserv to represent the start of a
reservation as a block number instead of a bit position.  (This requires
keeping track of the resource group in gfs2_blkreserv separately.) With
that change, various things can be slightly simplified, and struct
gfs2_rbm can be moved to rgrp.c.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2018-10-11 18:56:40 +02:00
parent 0eacdd16ad
commit c65b76b893
5 changed files with 101 additions and 97 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/gfs2/bmap.c
View File

@ -1544,7 +1544,7 @@ more_rgrps:
/* Must be done with the rgrp glock held: */
if (gfs2_rs_active(&ip->i_res) &&
rgd == ip->i_res.rs_rbm.rgd)
rgd == ip->i_res.rs_rgd)
gfs2_rs_deltree(&ip->i_res);
}

30
fs/gfs2/incore.h
View File

@ -125,31 +125,6 @@ struct gfs2_rgrpd {
struct rb_root rd_rstree; /* multi-block reservation tree */
};
struct gfs2_rbm {
struct gfs2_rgrpd *rgd;
u32 offset; /* The offset is bitmap relative */
int bii; /* Bitmap index */
};
static inline struct gfs2_bitmap *rbm_bi(const struct gfs2_rbm *rbm)
{
return rbm->rgd->rd_bits + rbm->bii;
}
static inline u64 gfs2_rbm_to_block(const struct gfs2_rbm *rbm)
{
BUG_ON(rbm->offset >= rbm->rgd->rd_data);
return rbm->rgd->rd_data0 + (rbm_bi(rbm)->bi_start * GFS2_NBBY) +
rbm->offset;
}
static inline bool gfs2_rbm_eq(const struct gfs2_rbm *rbm1,
const struct gfs2_rbm *rbm2)
{
return (rbm1->rgd == rbm2->rgd) && (rbm1->bii == rbm2->bii) &&
(rbm1->offset == rbm2->offset);
}
enum gfs2_state_bits {
BH_Pinned = BH_PrivateStart,
BH_Escaped = BH_PrivateStart + 1,
@ -313,8 +288,9 @@ struct gfs2_qadata { /* quota allocation data */
*/
struct gfs2_blkreserv {
struct rb_node rs_node; /* link to other block reservations */
struct gfs2_rbm rs_rbm; /* Start of reservation */
struct rb_node rs_node; /* node within rd_rstree */
struct gfs2_rgrpd *rs_rgd;
u64 rs_start; /* start of reservation */
u32 rs_free; /* how many blocks are still free */
};

154
fs/gfs2/rgrp.c
View File

@ -36,6 +36,24 @@
#define BFITNOENT ((u32)~0)
#define NO_BLOCK ((u64)~0)
struct gfs2_rbm {
struct gfs2_rgrpd *rgd;
u32 offset; /* The offset is bitmap relative */
int bii; /* Bitmap index */
};
static inline struct gfs2_bitmap *rbm_bi(const struct gfs2_rbm *rbm)
{
return rbm->rgd->rd_bits + rbm->bii;
}
static inline u64 gfs2_rbm_to_block(const struct gfs2_rbm *rbm)
{
BUG_ON(rbm->offset >= rbm->rgd->rd_data);
return rbm->rgd->rd_data0 + (rbm_bi(rbm)->bi_start * GFS2_NBBY) +
rbm->offset;
}
/*
* These routines are used by the resource group routines (rgrp.c)
* to keep track of block allocation. Each block is represented by two
@ -175,7 +193,7 @@ static inline u64 gfs2_bit_search(const __le64 *ptr, u64 mask, u8 state)
/**
* rs_cmp - multi-block reservation range compare
* @blk: absolute file system block number of the new reservation
* @start: start of the new reservation
* @len: number of blocks in the new reservation
* @rs: existing reservation to compare against
*
@ -183,13 +201,11 @@ static inline u64 gfs2_bit_search(const __le64 *ptr, u64 mask, u8 state)
* -1 if the block range is before the start of the reservation
* 0 if the block range overlaps with the reservation
*/
static inline int rs_cmp(u64 blk, u32 len, struct gfs2_blkreserv *rs)
static inline int rs_cmp(u64 start, u32 len, struct gfs2_blkreserv *rs)
{
u64 startblk = gfs2_rbm_to_block(&rs->rs_rbm);
if (blk >= startblk + rs->rs_free)
if (start >= rs->rs_start + rs->rs_free)
return 1;
if (blk + len - 1 < startblk)
if (rs->rs_start >= start + len)
return -1;
return 0;
}
@ -311,13 +327,28 @@ static bool gfs2_rbm_add(struct gfs2_rbm *rbm, u32 blocks)
}
}
static struct gfs2_bitmap *gfs2_block_to_bitmap(struct gfs2_rgrpd *rgd,
u64 block)
{
unsigned int delta = (sizeof(struct gfs2_rgrp) -
sizeof(struct gfs2_meta_header)) * GFS2_NBBY;
unsigned int rblock, bii;
if (!rgrp_contains_block(rgd, block))
return NULL;
rblock = block - rgd->rd_data0;
bii = (rblock + delta) / rgd->rd_sbd->sd_blocks_per_bitmap;
return rgd->rd_bits + bii;
}
/**
* gfs2_unaligned_extlen - Look for free blocks which are not byte aligned
* @rbm: Position to search (value/result)
* @n_unaligned: Number of unaligned blocks to check
* @len: Decremented for each block found (terminate on zero)
*
* Returns: true if a non-free block is encountered
* Returns: true if a non-free block is encountered or the end of the resource
* group is reached.
*/
static bool gfs2_unaligned_extlen(struct gfs2_rbm *rbm, u32 n_unaligned, u32 *len)
@ -604,10 +635,11 @@ static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs,
{
struct gfs2_inode *ip = container_of(rs, struct gfs2_inode, i_res);
gfs2_print_dbg(seq, "%s B: n:%llu s:%llu b:%u f:%u\n", fs_id_buf,
gfs2_print_dbg(seq, "%s B: n:%llu s:%llu f:%u\n",
fs_id_buf,
(unsigned long long)ip->i_no_addr,
(unsigned long long)gfs2_rbm_to_block(&rs->rs_rbm),
rs->rs_rbm.offset, rs->rs_free);
(unsigned long long)rs->rs_start,
rs->rs_free);
}
/**
@ -622,30 +654,28 @@ static void __rs_deltree(struct gfs2_blkreserv *rs)
if (!gfs2_rs_active(rs))
return;
rgd = rs->rs_rbm.rgd;
rgd = rs->rs_rgd;
trace_gfs2_rs(rs, TRACE_RS_TREEDEL);
rb_erase(&rs->rs_node, &rgd->rd_rstree);
RB_CLEAR_NODE(&rs->rs_node);
if (rs->rs_free) {
u64 last_block = gfs2_rbm_to_block(&rs->rs_rbm) +
rs->rs_free - 1;
struct gfs2_rbm last_rbm = { .rgd = rs->rs_rbm.rgd, };
u64 last_block = rs->rs_start + rs->rs_free - 1;
struct gfs2_bitmap *start, *last;
/* return reserved blocks to the rgrp */
BUG_ON(rs->rs_rbm.rgd->rd_reserved < rs->rs_free);
rs->rs_rbm.rgd->rd_reserved -= rs->rs_free;
BUG_ON(rs->rs_rgd->rd_reserved < rs->rs_free);
rs->rs_rgd->rd_reserved -= rs->rs_free;
/* The rgrp extent failure point is likely not to increase;
it will only do so if the freed blocks are somehow
contiguous with a span of free blocks that follows. Still,
it will force the number to be recalculated later. */
rgd->rd_extfail_pt += rs->rs_free;
rs->rs_free = 0;
if (gfs2_rbm_from_block(&last_rbm, last_block))
start = gfs2_block_to_bitmap(rgd, rs->rs_start);
last = gfs2_block_to_bitmap(rgd, last_block);
if (!start || !last)
return;
start = rbm_bi(&rs->rs_rbm);
last = rbm_bi(&last_rbm);
do
clear_bit(GBF_FULL, &start->bi_flags);
while (start++ != last);
@ -661,7 +691,7 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs)
{
struct gfs2_rgrpd *rgd;
rgd = rs->rs_rbm.rgd;
rgd = rs->rs_rgd;
if (rgd) {
spin_lock(&rgd->rd_rsspin);
__rs_deltree(rs);
@ -1467,8 +1497,7 @@ static void rs_insert(struct gfs2_inode *ip)
struct rb_node **newn, *parent = NULL;
int rc;
struct gfs2_blkreserv *rs = &ip->i_res;
struct gfs2_rgrpd *rgd = rs->rs_rbm.rgd;
u64 fsblock = gfs2_rbm_to_block(&rs->rs_rbm);
struct gfs2_rgrpd *rgd = rs->rs_rgd;
BUG_ON(gfs2_rs_active(rs));
@ -1479,7 +1508,7 @@ static void rs_insert(struct gfs2_inode *ip)
rb_entry(*newn, struct gfs2_blkreserv, rs_node);
parent = *newn;
rc = rs_cmp(fsblock, rs->rs_free, cur);
rc = rs_cmp(rs->rs_start, rs->rs_free, cur);
if (rc > 0)
newn = &((*newn)->rb_right);
else if (rc < 0)
@ -1567,7 +1596,7 @@ static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
ret = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, &extlen, ip, true);
if (ret == 0) {
rs->rs_rbm = rbm;
rs->rs_start = gfs2_rbm_to_block(&rbm);
rs->rs_free = extlen;
rs_insert(ip);
} else {
@ -1612,7 +1641,7 @@ static u64 gfs2_next_unreserved_block(struct gfs2_rgrpd *rgd, u64 block,
if (n) {
while ((rs_cmp(block, length, rs) == 0) && (&ip->i_res != rs)) {
block = gfs2_rbm_to_block(&rs->rs_rbm) + rs->rs_free;
block = rs->rs_start + rs->rs_free;
n = n->rb_right;
if (n == NULL)
break;
@ -1949,7 +1978,7 @@ static bool gfs2_rgrp_used_recently(const struct gfs2_blkreserv *rs,
u64 tdiff;
tdiff = ktime_to_ns(ktime_sub(ktime_get_real(),
rs->rs_rbm.rgd->rd_gl->gl_dstamp));
rs->rs_rgd->rd_gl->gl_dstamp));
return tdiff > (msecs * 1000 * 1000);
}
@ -2027,45 +2056,45 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
if (gfs2_assert_warn(sdp, ap->target))
return -EINVAL;
if (gfs2_rs_active(rs)) {
begin = rs->rs_rbm.rgd;
} else if (rs->rs_rbm.rgd &&
rgrp_contains_block(rs->rs_rbm.rgd, ip->i_goal)) {
begin = rs->rs_rbm.rgd;
begin = rs->rs_rgd;
} else if (rs->rs_rgd &&
rgrp_contains_block(rs->rs_rgd, ip->i_goal)) {
begin = rs->rs_rgd;
} else {
check_and_update_goal(ip);
rs->rs_rbm.rgd = begin = gfs2_blk2rgrpd(sdp, ip->i_goal, 1);
rs->rs_rgd = begin = gfs2_blk2rgrpd(sdp, ip->i_goal, 1);
}
if (S_ISDIR(ip->i_inode.i_mode) && (ap->aflags & GFS2_AF_ORLOV))
skip = gfs2_orlov_skip(ip);
if (rs->rs_rbm.rgd == NULL)
if (rs->rs_rgd == NULL)
return -EBADSLT;
while (loops < 3) {
rg_locked = 1;
if (!gfs2_glock_is_locked_by_me(rs->rs_rbm.rgd->rd_gl)) {
if (!gfs2_glock_is_locked_by_me(rs->rs_rgd->rd_gl)) {
rg_locked = 0;
if (skip && skip--)
goto next_rgrp;
if (!gfs2_rs_active(rs)) {
if (loops == 0 &&
!fast_to_acquire(rs->rs_rbm.rgd))
!fast_to_acquire(rs->rs_rgd))
goto next_rgrp;
if ((loops < 2) &&
gfs2_rgrp_used_recently(rs, 1000) &&
gfs2_rgrp_congested(rs->rs_rbm.rgd, loops))
gfs2_rgrp_congested(rs->rs_rgd, loops))
goto next_rgrp;
}
error = gfs2_glock_nq_init(rs->rs_rbm.rgd->rd_gl,
error = gfs2_glock_nq_init(rs->rs_rgd->rd_gl,
LM_ST_EXCLUSIVE, flags,
&ip->i_rgd_gh);
if (unlikely(error))
return error;
if (!gfs2_rs_active(rs) && (loops < 2) &&
gfs2_rgrp_congested(rs->rs_rbm.rgd, loops))
gfs2_rgrp_congested(rs->rs_rgd, loops))
goto skip_rgrp;
if (sdp->sd_args.ar_rgrplvb) {
error = update_rgrp_lvb(rs->rs_rbm.rgd);
error = update_rgrp_lvb(rs->rs_rgd);
if (unlikely(error)) {
gfs2_glock_dq_uninit(&ip->i_rgd_gh);
return error;
@ -2074,24 +2103,24 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
}
/* Skip unusable resource groups */
if ((rs->rs_rbm.rgd->rd_flags & (GFS2_RGF_NOALLOC |
if ((rs->rs_rgd->rd_flags & (GFS2_RGF_NOALLOC |
GFS2_RDF_ERROR)) ||
(loops == 0 && ap->target > rs->rs_rbm.rgd->rd_extfail_pt))
(loops == 0 && ap->target > rs->rs_rgd->rd_extfail_pt))
goto skip_rgrp;
if (sdp->sd_args.ar_rgrplvb)
gfs2_rgrp_bh_get(rs->rs_rbm.rgd);
gfs2_rgrp_bh_get(rs->rs_rgd);
/* Get a reservation if we don't already have one */
if (!gfs2_rs_active(rs))
rg_mblk_search(rs->rs_rbm.rgd, ip, ap);
rg_mblk_search(rs->rs_rgd, ip, ap);
/* Skip rgrps when we can't get a reservation on first pass */
if (!gfs2_rs_active(rs) && (loops < 1))
goto check_rgrp;
/* If rgrp has enough free space, use it */
free_blocks = rgd_free(rs->rs_rbm.rgd, rs);
free_blocks = rgd_free(rs->rs_rgd, rs);
if (free_blocks >= ap->target ||
(loops == 2 && ap->min_target &&
free_blocks >= ap->min_target)) {
@ -2100,8 +2129,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
}
check_rgrp:
/* Check for unlinked inodes which can be reclaimed */
if (rs->rs_rbm.rgd->rd_flags & GFS2_RDF_CHECK)
try_rgrp_unlink(rs->rs_rbm.rgd, &last_unlinked,
if (rs->rs_rgd->rd_flags & GFS2_RDF_CHECK)
try_rgrp_unlink(rs->rs_rgd, &last_unlinked,
ip->i_no_addr);
skip_rgrp:
/* Drop reservation, if we couldn't use reserved rgrp */
@ -2113,7 +2142,7 @@ skip_rgrp:
gfs2_glock_dq_uninit(&ip->i_rgd_gh);
next_rgrp:
/* Find the next rgrp, and continue looking */
if (gfs2_select_rgrp(&rs->rs_rbm.rgd, begin))
if (gfs2_select_rgrp(&rs->rs_rgd, begin))
continue;
if (skip)
continue;
@ -2284,20 +2313,21 @@ static void gfs2_adjust_reservation(struct gfs2_inode *ip,
{
struct gfs2_blkreserv *rs = &ip->i_res;
struct gfs2_rgrpd *rgd = rbm->rgd;
unsigned rlen;
u64 block;
int ret;
spin_lock(&rgd->rd_rsspin);
if (gfs2_rs_active(rs)) {
if (gfs2_rbm_eq(&rs->rs_rbm, rbm)) {
block = gfs2_rbm_to_block(rbm);
ret = gfs2_rbm_from_block(&rs->rs_rbm, block + len);
u64 start = gfs2_rbm_to_block(rbm);
if (rs->rs_start == start) {
unsigned int rlen;
rs->rs_start += len;
rlen = min(rs->rs_free, len);
rs->rs_free -= rlen;
rgd->rd_reserved -= rlen;
trace_gfs2_rs(rs, TRACE_RS_CLAIM);
if (rs->rs_free && !ret)
if (rs->rs_start < rgd->rd_data0 + rgd->rd_data &&
rs->rs_free)
goto out;
/* We used up our block reservation, so we should
reserve more blocks next time. */
@ -2326,15 +2356,13 @@ static void gfs2_set_alloc_start(struct gfs2_rbm *rbm,
u64 goal;
if (gfs2_rs_active(&ip->i_res)) {
*rbm = ip->i_res.rs_rbm;
return;
goal = ip->i_res.rs_start;
} else {
if (!dinode && rgrp_contains_block(rbm->rgd, ip->i_goal))
goal = ip->i_goal;
else
goal = rbm->rgd->rd_last_alloc + rbm->rgd->rd_data0;
}
if (!dinode && rgrp_contains_block(rbm->rgd, ip->i_goal))
goal = ip->i_goal;
else
goal = rbm->rgd->rd_last_alloc + rbm->rgd->rd_data0;
if (WARN_ON_ONCE(gfs2_rbm_from_block(rbm, goal))) {
rbm->bii = 0;
rbm->offset = 0;
@ -2357,7 +2385,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct buffer_head *dibh;
struct gfs2_rbm rbm = { .rgd = ip->i_res.rs_rbm.rgd, };
struct gfs2_rbm rbm = { .rgd = ip->i_res.rs_rgd, };
unsigned int ndata;
u64 block; /* block, within the file system scope */
int error;
@ -2589,7 +2617,7 @@ void gfs2_rlist_add(struct gfs2_inode *ip, struct gfs2_rgrp_list *rlist,
return;
rgd = gfs2_blk2rgrpd(sdp, block, 1);
} else {
rgd = ip->i_res.rs_rbm.rgd;
rgd = ip->i_res.rs_rgd;
if (!rgd || !rgrp_contains_block(rgd, block))
rgd = gfs2_blk2rgrpd(sdp, block, 1);
}

10
fs/gfs2/trace_gfs2.h
View File

@ -603,13 +603,13 @@ TRACE_EVENT(gfs2_rs,
),
TP_fast_assign(
__entry->dev = rs->rs_rbm.rgd->rd_sbd->sd_vfs->s_dev;
__entry->rd_addr = rs->rs_rbm.rgd->rd_addr;
__entry->rd_free_clone = rs->rs_rbm.rgd->rd_free_clone;
__entry->rd_reserved = rs->rs_rbm.rgd->rd_reserved;
__entry->dev = rs->rs_rgd->rd_sbd->sd_vfs->s_dev;
__entry->rd_addr = rs->rs_rgd->rd_addr;
__entry->rd_free_clone = rs->rs_rgd->rd_free_clone;
__entry->rd_reserved = rs->rs_rgd->rd_reserved;
__entry->inum = container_of(rs, struct gfs2_inode,
i_res)->i_no_addr;
__entry->start = gfs2_rbm_to_block(&rs->rs_rbm);
__entry->start = rs->rs_start;
__entry->free = rs->rs_free;
__entry->func = func;
),

2
fs/gfs2/trans.h
View File

@ -27,7 +27,7 @@ struct gfs2_glock;
* block, or all of the blocks in the rg, whichever is smaller */
static inline unsigned int gfs2_rg_blocks(const struct gfs2_inode *ip, unsigned requested)
{
struct gfs2_rgrpd *rgd = ip->i_res.rs_rbm.rgd;
struct gfs2_rgrpd *rgd = ip->i_res.rs_rgd;
if (requested < rgd->rd_length)
return requested + 1;