[GFS2] Readpages support
This adds readpages support (and also corrects a small bug in
the readpage error path at the same time). Hopefully this will
improve performance by allowing GFS to submit larger lumps of
I/O at a time.
In order to simplify the setting of BH_Boundary, it currently gets
set when we hit the end of a indirect pointer block. There is
always a boundary at this point with the current allocation code.
It doesn't get all the boundaries right though, so there is still
room for improvement in this.
See comments in fs/gfs2/ops_address.c for further information about
readpages with GFS2.
Signed-off-by: Steven Whitehouse
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index cfe1a42..474b9a1 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -314,13 +314,17 @@
* metadata tree.
*/
-static inline uint64_t *metapointer(struct buffer_head *bh,
- unsigned int height, struct metapath *mp)
+static inline u64 *metapointer(struct buffer_head *bh, int *boundary,
+ unsigned int height, const struct metapath *mp)
{
unsigned int head_size = (height > 0) ?
sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode);
-
- return ((uint64_t *)(bh->b_data + head_size)) + mp->mp_list[height];
+ u64 *ptr;
+ *boundary = 0;
+ ptr = ((u64 *)(bh->b_data + head_size)) + mp->mp_list[height];
+ if (ptr + 1 == (u64*)(bh->b_data + bh->b_size))
+ *boundary = 1;
+ return ptr;
}
/**
@@ -339,24 +343,24 @@
*
*/
-static void lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
- unsigned int height, struct metapath *mp, int create,
- int *new, uint64_t *block)
+static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
+ unsigned int height, struct metapath *mp, int create,
+ int *new, uint64_t *block)
{
- uint64_t *ptr = metapointer(bh, height, mp);
+ int boundary;
+ uint64_t *ptr = metapointer(bh, &boundary, height, mp);
if (*ptr) {
*block = be64_to_cpu(*ptr);
- return;
+ return boundary;
}
*block = 0;
if (!create)
- return;
+ return 0;
- if (height == ip->i_di.di_height - 1 &&
- !gfs2_is_dir(ip))
+ if (height == ip->i_di.di_height - 1 && !gfs2_is_dir(ip))
*block = gfs2_alloc_data(ip);
else
*block = gfs2_alloc_meta(ip);
@@ -367,15 +371,16 @@
ip->i_di.di_blocks++;
*new = 1;
+ return 0;
}
/**
- * gfs2_block_map - Map a block from an inode to a disk block
- * @ip: The GFS2 inode
+ * gfs2_block_pointers - Map a block from an inode to a disk block
+ * @inode: The inode
* @lblock: The logical block number
* @new: Value/Result argument (1 = may create/did create new blocks)
- * @dblock: the disk block number of the start of an extent
- * @extlen: the size of the extent
+ * @boundary: gets set if we've hit a block boundary
+ * @mp: metapath to use
*
* Find the block number on the current device which corresponds to an
* inode's block. If the block had to be created, "new" will be set.
@@ -383,12 +388,14 @@
* Returns: errno
*/
-int gfs2_block_map(struct gfs2_inode *ip, uint64_t lblock, int *new,
- uint64_t *dblock, uint32_t *extlen)
+static struct buffer_head *gfs2_block_pointers(struct inode *inode, u64 lblock,
+ int *new, u64 *dblock,
+ int *boundary,
+ struct metapath *mp)
{
+ struct gfs2_inode *ip = inode->u.generic_ip;
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
- struct metapath mp;
int create = *new;
unsigned int bsize;
unsigned int height;
@@ -398,13 +405,6 @@
*new = 0;
*dblock = 0;
- if (extlen)
- *extlen = 0;
-
- if (create)
- down_write(&ip->i_rw_mutex);
- else
- down_read(&ip->i_rw_mutex);
if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
goto out;
@@ -421,7 +421,7 @@
goto out;
}
- find_metapath(ip, lblock, &mp);
+ find_metapath(ip, lblock, mp);
end_of_metadata = ip->i_di.di_height - 1;
error = gfs2_meta_inode_buffer(ip, &bh);
@@ -429,7 +429,7 @@
goto out;
for (x = 0; x < end_of_metadata; x++) {
- lookup_block(ip, bh, x, &mp, create, new, dblock);
+ lookup_block(ip, bh, x, mp, create, new, dblock);
brelse(bh);
if (!*dblock)
goto out;
@@ -439,49 +439,95 @@
goto out;
}
- lookup_block(ip, bh, end_of_metadata, &mp, create, new, dblock);
-
- if (extlen && *dblock) {
- *extlen = 1;
-
- if (!*new) {
- uint64_t tmp_dblock;
- int tmp_new;
- unsigned int nptrs;
-
- nptrs = (end_of_metadata) ? sdp->sd_inptrs :
- sdp->sd_diptrs;
-
- while (++mp.mp_list[end_of_metadata] < nptrs) {
- lookup_block(ip, bh, end_of_metadata, &mp,
- 0, &tmp_new, &tmp_dblock);
-
- if (*dblock + *extlen != tmp_dblock)
- break;
-
- (*extlen)++;
- }
- }
- }
-
- brelse(bh);
-
+ *boundary = lookup_block(ip, bh, end_of_metadata, mp, create, new, dblock);
if (*new) {
- error = gfs2_meta_inode_buffer(ip, &bh);
+ struct buffer_head *dibh;
+ error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
- gfs2_trans_add_bh(ip->i_gl, bh, 1);
- gfs2_dinode_out(&ip->i_di, bh->b_data);
- brelse(bh);
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+ gfs2_dinode_out(&ip->i_di, dibh->b_data);
+ brelse(dibh);
}
}
+ return bh;
+out:
+ return ERR_PTR(error);
+}
- out:
+
+static inline void bmap_lock(struct inode *inode, int create)
+{
+ struct gfs2_inode *ip = inode->u.generic_ip;
+ if (create)
+ down_write(&ip->i_rw_mutex);
+ else
+ down_read(&ip->i_rw_mutex);
+}
+
+static inline void bmap_unlock(struct inode *inode, int create)
+{
+ struct gfs2_inode *ip = inode->u.generic_ip;
if (create)
up_write(&ip->i_rw_mutex);
else
up_read(&ip->i_rw_mutex);
+}
- return error;
+int gfs2_block_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, int *boundary)
+{
+ struct metapath mp;
+ struct buffer_head *bh;
+ int create = *new;
+
+ bmap_lock(inode, create);
+ bh = gfs2_block_pointers(inode, lblock, new, dblock, boundary, &mp);
+ bmap_unlock(inode, create);
+ if (!bh)
+ return 0;
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ brelse(bh);
+ return 0;
+}
+
+int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
+{
+ struct gfs2_inode *ip = inode->u.generic_ip;
+ struct gfs2_sbd *sdp = ip->i_sbd;
+ struct metapath mp;
+ struct buffer_head *bh;
+ int boundary;
+ int create = *new;
+
+ BUG_ON(!extlen);
+ BUG_ON(!dblock);
+ BUG_ON(!new);
+
+ bmap_lock(inode, create);
+ bh = gfs2_block_pointers(inode, lblock, new, dblock, &boundary, &mp);
+ *extlen = 1;
+
+ if (bh && !IS_ERR(bh) && *dblock && !*new) {
+ u64 tmp_dblock;
+ int tmp_new;
+ unsigned int nptrs;
+ unsigned end_of_metadata = ip->i_di.di_height - 1;
+
+ nptrs = (end_of_metadata) ? sdp->sd_inptrs : sdp->sd_diptrs;
+ while (++mp.mp_list[end_of_metadata] < nptrs) {
+ lookup_block(ip, bh, end_of_metadata, &mp, 0, &tmp_new, &tmp_dblock);
+ if (*dblock + *extlen != tmp_dblock)
+ break;
+ (*extlen)++;
+ }
+ }
+ bmap_unlock(inode, create);
+ if (!bh)
+ return 0;
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ brelse(bh);
+ return 0;
}
/**
@@ -1053,7 +1099,7 @@
}
for (; lblock < lblock_stop; lblock += extlen) {
- error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+ error = gfs2_extent_map(ip->i_vnode, lblock, &new, &dblock, &extlen);
if (error)
return error;