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 fallocate_chunk, zero-initialize struct iomap.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/gfs2/bmap.c | 203 ++++++++++++++++++++++++++++--------------------
fs/gfs2/bmap.h | 6 +-
fs/gfs2/file.c | 6 +-
fs/gfs2/inode.c | 4 -
4 files changed, 125 insertions(+), 94 deletions(-)
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 5226c3bfbcf7..8ea65aea34da 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -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;
+
+ down_read(&ip->i_rw_mutex);
- ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
+ 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);
+ 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, flags = 0;
+ 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 @@ static int trunc_start(struct inode *inode, u64 newsize)
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
diff --git a/fs/gfs2/bmap.h b/fs/gfs2/bmap.h
index c3402fe00653..6b18fb323f0a 100644
--- a/fs/gfs2/bmap.h
+++ b/fs/gfs2/bmap.h
@@ -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);
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 4b71f021a9e2..378ff1a1e9ae 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -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 = { 0 };
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;
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 8700eb815638..feda55f67050 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -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)
{
--
2.17.0
