gfs2: Iomap cleanups and improvements

Clean up gfs2_iomap_alloc and gfs2_iomap_get.  Document how
gfs2_iomap_alloc works: it now needs to be called separately after
gfs2_iomap_get where necessary; this will be used later by iomap write.
Move gfs2_iomap_ops into bmap.c.

Introduce a new gfs2_iomap_get_alloc helper and use it in
fallocate_chunk: gfs2_iomap_begin will become unsuitable for fallocate
with proper iomap write support.

In gfs2_block_map and fallocate_chunk, zero-initialize struct iomap.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2018-06-04 07:56:51 -05:00 committed by Bob Peterson
parent 845802b112
commit 628e366df1
4 changed files with 126 additions and 95 deletions

View File

@ -572,22 +572,6 @@ static int gfs2_hole_size(struct inode *inode, sector_t lblock, u64 len,
return ret;
}
static inline void bmap_lock(struct gfs2_inode *ip, int create)
{
if (create)
down_write(&ip->i_rw_mutex);
else
down_read(&ip->i_rw_mutex);
}
static inline void bmap_unlock(struct gfs2_inode *ip, int create)
{
if (create)
up_write(&ip->i_rw_mutex);
else
up_read(&ip->i_rw_mutex);
}
static inline __be64 *gfs2_indirect_init(struct metapath *mp,
struct gfs2_glock *gl, unsigned int i,
unsigned offset, u64 bn)
@ -614,15 +598,11 @@ enum alloc_state {
};
/**
* gfs2_bmap_alloc - Build a metadata tree of the requested height
* gfs2_iomap_alloc - Build a metadata tree of the requested height
* @inode: The GFS2 inode
* @lblock: The logical starting block of the extent
* @bh_map: This is used to return the mapping details
* @zero_new: True if newly allocated blocks should be zeroed
* @iomap: The iomap structure
* @flags: iomap flags
* @mp: The metapath, with proper height information calculated
* @maxlen: The max number of data blocks to alloc
* @dblock: Pointer to return the resulting new block
* @dblks: Pointer to return the number of blocks allocated
*
* In this routine we may have to alloc:
* i) Indirect blocks to grow the metadata tree height
@ -635,6 +615,13 @@ enum alloc_state {
* blocks are available, there will only be one request per bmap call)
* and uses the state machine to initialise the blocks in order.
*
* Right now, this function will allocate at most one indirect block
* worth of data -- with a default block size of 4K, that's slightly
* less than 2M. If this limitation is ever removed to allow huge
* allocations, we would probably still want to limit the iomap size we
* return to avoid stalling other tasks during huge writes; the next
* iomap iteration would then find the blocks already allocated.
*
* Returns: errno on error
*/
@ -649,6 +636,7 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
unsigned dblks = 0;
unsigned ptrs_per_blk;
const unsigned end_of_metadata = mp->mp_fheight - 1;
int ret;
enum alloc_state state;
__be64 *ptr;
__be64 zero_bn = 0;
@ -659,6 +647,8 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
gfs2_trans_add_meta(ip->i_gl, dibh);
down_write(&ip->i_rw_mutex);
if (mp->mp_fheight == mp->mp_aheight) {
struct buffer_head *bh;
int eob;
@ -694,11 +684,10 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
blks = dblks + iblks;
i = mp->mp_aheight;
do {
int error;
n = blks - alloced;
error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
if (error)
return error;
ret = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
if (ret)
goto out;
alloced += n;
if (state != ALLOC_DATA || gfs2_is_jdata(ip))
gfs2_trans_add_unrevoke(sdp, bn, n);
@ -754,7 +743,7 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
dblks = n;
ptr = metapointer(end_of_metadata, mp);
iomap->addr = bn << inode->i_blkbits;
iomap->flags |= IOMAP_F_NEW;
iomap->flags |= IOMAP_F_MERGED | IOMAP_F_NEW;
while (n-- > 0)
*ptr++ = cpu_to_be64(bn++);
break;
@ -764,8 +753,10 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
iomap->length = (u64)dblks << inode->i_blkbits;
ip->i_height = mp->mp_fheight;
gfs2_add_inode_blocks(&ip->i_inode, alloced);
gfs2_dinode_out(ip, mp->mp_bh[0]->b_data);
return 0;
gfs2_dinode_out(ip, dibh->b_data);
out:
up_write(&ip->i_rw_mutex);
return ret;
}
static void gfs2_stuffed_iomap(struct inode *inode, struct iomap *iomap)
@ -781,110 +772,130 @@ static void gfs2_stuffed_iomap(struct inode *inode, struct iomap *iomap)
}
/**
* gfs2_iomap_begin - Map blocks from an inode to disk blocks
* gfs2_iomap_get - Map blocks from an inode to disk blocks
* @inode: The inode
* @pos: Starting position in bytes
* @length: Length to map, in bytes
* @flags: iomap flags
* @iomap: The iomap structure
* @mp: The metapath
*
* Returns: errno
*/
int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap)
static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap,
struct metapath *mp)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct metapath mp = { .mp_aheight = 1, };
__be64 *ptr;
sector_t lblock;
sector_t lend;
int ret = 0;
sector_t lblock_stop;
int ret;
int eob;
unsigned int len;
u64 len;
struct buffer_head *bh;
u8 height;
trace_gfs2_iomap_start(ip, pos, length, flags);
if (!length) {
ret = -EINVAL;
goto out;
}
if (!length)
return -EINVAL;
if (gfs2_is_stuffed(ip)) {
if (flags & IOMAP_REPORT) {
if (pos >= i_size_read(inode))
return -ENOENT;
gfs2_stuffed_iomap(inode, iomap);
if (pos >= iomap->length)
ret = -ENOENT;
goto out;
return 0;
}
BUG_ON(!(flags & IOMAP_WRITE));
}
lblock = pos >> inode->i_blkbits;
lend = (pos + length + sdp->sd_sb.sb_bsize - 1) >> inode->i_blkbits;
len = lend - lblock;
iomap->offset = lblock << inode->i_blkbits;
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_HOLE;
iomap->length = (u64)(lend - lblock) << inode->i_blkbits;
iomap->flags = IOMAP_F_MERGED;
bmap_lock(ip, flags & IOMAP_WRITE);
lblock_stop = (pos + length - 1) >> inode->i_blkbits;
len = lblock_stop - lblock + 1;
ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
down_read(&ip->i_rw_mutex);
ret = gfs2_meta_inode_buffer(ip, &mp->mp_bh[0]);
if (ret)
goto out_release;
goto unlock;
height = ip->i_height;
while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])
height++;
find_metapath(sdp, lblock, &mp, height);
find_metapath(sdp, lblock, mp, height);
if (height > ip->i_height || gfs2_is_stuffed(ip))
goto do_alloc;
ret = lookup_metapath(ip, &mp);
ret = lookup_metapath(ip, mp);
if (ret)
goto out_release;
goto unlock;
if (mp.mp_aheight != ip->i_height)
if (mp->mp_aheight != ip->i_height)
goto do_alloc;
ptr = metapointer(ip->i_height - 1, &mp);
ptr = metapointer(ip->i_height - 1, mp);
if (*ptr == 0)
goto do_alloc;
iomap->type = IOMAP_MAPPED;
iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
bh = mp->mp_bh[ip->i_height - 1];
len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, len, &eob);
bh = mp.mp_bh[ip->i_height - 1];
len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, lend - lblock, &eob);
iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
iomap->length = len << inode->i_blkbits;
iomap->type = IOMAP_MAPPED;
iomap->flags = IOMAP_F_MERGED;
if (eob)
iomap->flags |= IOMAP_F_BOUNDARY;
iomap->length = (u64)len << inode->i_blkbits;
out_release:
release_metapath(&mp);
bmap_unlock(ip, flags & IOMAP_WRITE);
out:
trace_gfs2_iomap_end(ip, iomap, ret);
iomap->bdev = inode->i_sb->s_bdev;
unlock:
up_read(&ip->i_rw_mutex);
return ret;
do_alloc:
if (flags & IOMAP_WRITE) {
ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);
} else if (flags & IOMAP_REPORT) {
iomap->addr = IOMAP_NULL_ADDR;
iomap->length = len << inode->i_blkbits;
iomap->type = IOMAP_HOLE;
iomap->flags = 0;
if (flags & IOMAP_REPORT) {
loff_t size = i_size_read(inode);
if (pos >= size)
ret = -ENOENT;
else if (height <= ip->i_height)
ret = gfs2_hole_size(inode, lblock, len, &mp, iomap);
else if (height == ip->i_height)
ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
else
iomap->length = size - pos;
}
goto out_release;
goto out;
}
static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct metapath mp = { .mp_aheight = 1, };
int ret;
trace_gfs2_iomap_start(ip, pos, length, flags);
if (flags & IOMAP_WRITE) {
ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
if (!ret && iomap->type == IOMAP_HOLE)
ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);
release_metapath(&mp);
} else {
ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
release_metapath(&mp);
}
trace_gfs2_iomap_end(ip, iomap, ret);
return ret;
}
const struct iomap_ops gfs2_iomap_ops = {
.iomap_begin = gfs2_iomap_begin,
};
/**
* gfs2_block_map - Map one or more blocks of an inode to a disk block
* @inode: The inode
@ -910,25 +921,34 @@ int gfs2_block_map(struct inode *inode, sector_t lblock,
struct buffer_head *bh_map, int create)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct iomap iomap;
int ret, flags = 0;
loff_t pos = (loff_t)lblock << inode->i_blkbits;
loff_t length = bh_map->b_size;
struct metapath mp = { .mp_aheight = 1, };
struct iomap iomap = { };
int ret;
clear_buffer_mapped(bh_map);
clear_buffer_new(bh_map);
clear_buffer_boundary(bh_map);
trace_gfs2_bmap(ip, bh_map, lblock, create, 1);
if (create)
flags |= IOMAP_WRITE;
ret = gfs2_iomap_begin(inode, (loff_t)lblock << inode->i_blkbits,
bh_map->b_size, flags, &iomap);
if (ret) {
if (!create && ret == -ENOENT) {
/* Return unmapped buffer beyond the end of file. */
if (create) {
ret = gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, &iomap, &mp);
if (!ret && iomap.type == IOMAP_HOLE)
ret = gfs2_iomap_alloc(inode, &iomap, IOMAP_WRITE, &mp);
release_metapath(&mp);
} else {
ret = gfs2_iomap_get(inode, pos, length, 0, &iomap, &mp);
release_metapath(&mp);
/* Return unmapped buffer beyond the end of file. */
if (ret == -ENOENT) {
ret = 0;
goto out;
}
goto out;
}
if (ret)
goto out;
if (iomap.length > bh_map->b_size) {
iomap.length = bh_map->b_size;
@ -1143,6 +1163,19 @@ out:
return error;
}
int gfs2_iomap_get_alloc(struct inode *inode, loff_t pos, loff_t length,
struct iomap *iomap)
{
struct metapath mp = { .mp_aheight = 1, };
int ret;
ret = gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, iomap, &mp);
if (!ret && iomap->type == IOMAP_HOLE)
ret = gfs2_iomap_alloc(inode, iomap, IOMAP_WRITE, &mp);
release_metapath(&mp);
return ret;
}
/**
* sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein
* @ip: inode

View File

@ -46,11 +46,13 @@ static inline void gfs2_write_calc_reserv(const struct gfs2_inode *ip,
}
}
extern const struct iomap_ops gfs2_iomap_ops;
extern int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page);
extern int gfs2_block_map(struct inode *inode, sector_t lblock,
struct buffer_head *bh, int create);
extern int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap);
extern int gfs2_iomap_get_alloc(struct inode *inode, loff_t pos, loff_t length,
struct iomap *iomap);
extern int gfs2_extent_map(struct inode *inode, u64 lblock, int *new,
u64 *dblock, unsigned *extlen);
extern int gfs2_setattr_size(struct inode *inode, u64 size);

View File

@ -733,7 +733,7 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
struct gfs2_inode *ip = GFS2_I(inode);
loff_t end = offset + len;
struct buffer_head *dibh;
struct iomap iomap;
struct iomap iomap = { };
int error;
error = gfs2_meta_inode_buffer(ip, &dibh);
@ -749,8 +749,8 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
}
while (offset < end) {
error = gfs2_iomap_begin(inode, offset, end - offset,
IOMAP_WRITE, &iomap);
error = gfs2_iomap_get_alloc(inode, offset, end - offset,
&iomap);
if (error)
goto out;
offset = iomap.offset + iomap.length;

View File

@ -2006,10 +2006,6 @@ static int gfs2_getattr(const struct path *path, struct kstat *stat,
return 0;
}
const struct iomap_ops gfs2_iomap_ops = {
.iomap_begin = gfs2_iomap_begin,
};
static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{