gfs2: gfs2_iomap_begin cleanup
Following commit d0a22a4b03b8 ("gfs2: Fix iomap write page reclaim deadlock"),
gfs2_iomap_begin and gfs2_iomap_begin_write can be further cleaned up and the
split between those two functions can be improved.
With suggestions from Christoph Hellwig.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 4f8b5fd..907b794 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1065,54 +1065,38 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos,
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
- unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
- bool unstuff, alloc_required;
+ bool unstuff;
int ret;
- ret = gfs2_write_lock(inode);
- if (ret)
- return ret;
-
unstuff = gfs2_is_stuffed(ip) &&
pos + length > gfs2_max_stuffed_size(ip);
- ret = gfs2_iomap_get(inode, pos, length, flags, iomap, mp);
- if (ret)
- goto out_unlock;
+ if (unstuff || iomap->type == IOMAP_HOLE) {
+ unsigned int data_blocks, ind_blocks;
+ struct gfs2_alloc_parms ap = {};
+ unsigned int rblocks;
+ struct gfs2_trans *tr;
- alloc_required = unstuff || iomap->type == IOMAP_HOLE;
-
- if (alloc_required || gfs2_is_jdata(ip))
gfs2_write_calc_reserv(ip, iomap->length, &data_blocks,
&ind_blocks);
-
- if (alloc_required) {
- struct gfs2_alloc_parms ap = {
- .target = data_blocks + ind_blocks
- };
-
+ ap.target = data_blocks + ind_blocks;
ret = gfs2_quota_lock_check(ip, &ap);
if (ret)
- goto out_unlock;
+ return ret;
ret = gfs2_inplace_reserve(ip, &ap);
if (ret)
goto out_qunlock;
- }
- rblocks = RES_DINODE + ind_blocks;
- if (gfs2_is_jdata(ip))
- rblocks += data_blocks;
- if (ind_blocks || data_blocks)
- rblocks += RES_STATFS + RES_QUOTA;
- if (inode == sdp->sd_rindex)
- rblocks += 2 * RES_STATFS;
- if (alloc_required)
+ rblocks = RES_DINODE + ind_blocks;
+ if (gfs2_is_jdata(ip))
+ rblocks += data_blocks;
+ if (ind_blocks || data_blocks)
+ rblocks += RES_STATFS + RES_QUOTA;
+ if (inode == sdp->sd_rindex)
+ rblocks += 2 * RES_STATFS;
rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
- if (unstuff || iomap->type == IOMAP_HOLE) {
- struct gfs2_trans *tr;
-
ret = gfs2_trans_begin(sdp, rblocks,
iomap->length >> inode->i_blkbits);
if (ret)
@@ -1153,16 +1137,17 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos,
out_trans_end:
gfs2_trans_end(sdp);
out_trans_fail:
- if (alloc_required)
- gfs2_inplace_release(ip);
+ gfs2_inplace_release(ip);
out_qunlock:
- if (alloc_required)
- gfs2_quota_unlock(ip);
-out_unlock:
- gfs2_write_unlock(inode);
+ gfs2_quota_unlock(ip);
return ret;
}
+static inline bool gfs2_iomap_need_write_lock(unsigned flags)
+{
+ return (flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT);
+}
+
static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -1173,20 +1158,39 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
iomap->flags |= IOMAP_F_BUFFER_HEAD;
trace_gfs2_iomap_start(ip, pos, length, flags);
- if ((flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT)) {
- ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp);
- } else {
- ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
-
- /*
- * Silently fall back to buffered I/O for stuffed files or if
- * we've hot a hole (see gfs2_file_direct_write).
- */
- if ((flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT) &&
- iomap->type != IOMAP_MAPPED)
- ret = -ENOTBLK;
+ if (gfs2_iomap_need_write_lock(flags)) {
+ ret = gfs2_write_lock(inode);
+ if (ret)
+ goto out;
}
+
+ ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
+ if (ret)
+ goto out_unlock;
+
+ switch(flags & IOMAP_WRITE) {
+ case IOMAP_WRITE:
+ if (flags & IOMAP_DIRECT) {
+ /*
+ * Silently fall back to buffered I/O for stuffed files
+ * or if we've got a hole (see gfs2_file_direct_write).
+ */
+ if (iomap->type != IOMAP_MAPPED)
+ ret = -ENOTBLK;
+ goto out_unlock;
+ }
+ break;
+ default:
+ goto out_unlock;
+ }
+
+ ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp);
+
+out_unlock:
+ if (ret && gfs2_iomap_need_write_lock(flags))
+ gfs2_write_unlock(inode);
release_metapath(&mp);
+out:
trace_gfs2_iomap_end(ip, iomap, ret);
return ret;
}
@@ -1197,8 +1201,14 @@ static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
- if ((flags & (IOMAP_WRITE | IOMAP_DIRECT)) != IOMAP_WRITE)
- goto out;
+ switch (flags & IOMAP_WRITE) {
+ case IOMAP_WRITE:
+ if (flags & IOMAP_DIRECT)
+ return 0;
+ break;
+ default:
+ return 0;
+ }
if (!gfs2_is_stuffed(ip))
gfs2_ordered_add_inode(ip);
@@ -1231,8 +1241,8 @@ static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
out_unlock:
- gfs2_write_unlock(inode);
-out:
+ if (gfs2_iomap_need_write_lock(flags))
+ gfs2_write_unlock(inode);
return 0;
}