exofs: ios: Move to a per inode components & device-table

Exofs raid engine was saving on memory space by having a single layout-info,
single pid, and a single device-table, global to the filesystem. Then passing
a credential and object_id info at the io_state level, private for each
inode. It would also devise this contraption of rotating the device table
view for each inode->ino to spread out the device usage.

This is not compatible with the pnfs-objects standard, demanding that
each inode can have it's own layout-info, device-table, and each object
component it's own pid, oid and creds.

So: Bring exofs raid engine to be usable for generic pnfs-objects use by:

* Define an exofs_comp structure that holds obj_id and credential info.

* Break up exofs_layout struct to an exofs_components structure that holds a
  possible array of exofs_comp and the array of devices + the size of the
  arrays.

* Add a "comps" parameter to get_io_state() that specifies the ids creds
  and device array to use for each IO.

  This enables to keep the layout global, but the device-table view, creds
  and IDs at the inode level. It only adds two 64bit to each inode, since
  some of these members already existed in another form.

* ios raid engine now access layout-info and comps-info through the passed
  pointers. Everything is pre-prepared by caller for generic access of
  these structures and arrays.

At the exofs Level:

* Super block holds an exofs_components struct that holds the device
  array, previously in layout. The devices there are in device-table
  order. The device-array is twice bigger and repeats the device-table
  twice so now each inode's device array can point to a random device
  and have a round-robin view of the table, making it compatible to
  previous exofs versions.

* Each inode has an exofs_components struct that is initialized at
  load time, with it's own view of the device table IDs and creds.
  When doing IO this gets passed to the io_state together with the
  layout.

While preforming this change. Bugs where found where credentials with the
wrong IDs where used to access the different SB objects (super.c). As well
as some dead code. It was never noticed because the target we use does not
check the credentials.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

1 files changed, 27 insertions, 32 deletions

diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
index abcdac9..3cc24f2 100644
--- a/fs/exofs/inode.c
+++ b/fs/exofs/inode.c
@@ -270,7 +270,7 @@ static int read_exec(struct page_collect *pcol)
 		return 0;
 
 	if (!pcol->ios) {
-		int ret = exofs_get_rw_state(&pcol->sbi->layout, true,
+		int ret = exofs_get_rw_state(&pcol->sbi->layout, &oi->comps, true,
 					     pcol->pg_first << PAGE_CACHE_SHIFT,
 					     pcol->length, &pcol->ios);
 
@@ -283,7 +283,7 @@ static int read_exec(struct page_collect *pcol)
 	ios->nr_pages = pcol->nr_pages;
 
 	if (pcol->read_4_write) {
-		exofs_oi_read(oi, pcol->ios);
+		exofs_sbi_read(pcol->ios);
 		return __readpages_done(pcol);
 	}
 
@@ -296,14 +296,14 @@ static int read_exec(struct page_collect *pcol)
 	*pcol_copy = *pcol;
 	ios->done = readpages_done;
 	ios->private = pcol_copy;
-	ret = exofs_oi_read(oi, ios);
+	ret = exofs_sbi_read(ios);
 	if (unlikely(ret))
 		goto err;
 
 	atomic_inc(&pcol->sbi->s_curr_pending);
 
 	EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
-		  ios->obj.id, _LLU(ios->offset), pcol->length);
+		  oi->one_comp.obj.id, _LLU(ios->offset), pcol->length);
 
 	/* pages ownership was passed to pcol_copy */
 	_pcol_reset(pcol);
@@ -516,7 +516,7 @@ static int write_exec(struct page_collect *pcol)
 		return 0;
 
 	BUG_ON(pcol->ios);
-	ret = exofs_get_rw_state(&pcol->sbi->layout, false,
+	ret = exofs_get_rw_state(&pcol->sbi->layout, &oi->comps, false,
 				 pcol->pg_first << PAGE_CACHE_SHIFT,
 				 pcol->length, &pcol->ios);
 
@@ -538,9 +538,9 @@ static int write_exec(struct page_collect *pcol)
 	ios->done = writepages_done;
 	ios->private = pcol_copy;
 
-	ret = exofs_oi_write(oi, ios);
+	ret = exofs_sbi_write(ios);
 	if (unlikely(ret)) {
-		EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
+		EXOFS_ERR("write_exec: exofs_sbi_write() Failed\n");
 		goto err;
 	}
 
@@ -855,11 +855,12 @@ static inline int exofs_inode_is_fast_symlink(struct inode *inode)
 static int _do_truncate(struct inode *inode, loff_t newsize)
 {
 	struct exofs_i_info *oi = exofs_i(inode);
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
 	int ret;
 
 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 
-	ret = exofs_oi_truncate(oi, (u64)newsize);
+	ret = exofs_truncate(&sbi->layout, &oi->comps, (u64)newsize);
 	if (likely(!ret))
 		truncate_setsize(inode, newsize);
 
@@ -926,18 +927,14 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
 	struct exofs_on_disk_inode_layout *layout;
 	int ret;
 
-	ret = exofs_get_io_state(&sbi->layout, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &oi->comps, &ios);
 	if (unlikely(ret)) {
 		EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
 		return ret;
 	}
 
-	ios->obj.id = exofs_oi_objno(oi);
-	exofs_make_credential(oi->i_cred, &ios->obj);
-	ios->cred = oi->i_cred;
-
-	attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
-	attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
+	attrs[1].len = exofs_on_disk_inode_layout_size(sbi->comps.numdevs);
+	attrs[2].len = exofs_on_disk_inode_layout_size(sbi->comps.numdevs);
 
 	ios->in_attr = attrs;
 	ios->in_attr_len = ARRAY_SIZE(attrs);
@@ -945,7 +942,7 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
 	ret = exofs_sbi_read(ios);
 	if (unlikely(ret)) {
 		EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
-			  _LLU(ios->obj.id), ret);
+			  _LLU(oi->one_comp.obj.id), ret);
 		memset(inode, 0, sizeof(*inode));
 		inode->i_mode = 0040000 | (0777 & ~022);
 		/* If object is lost on target we might as well enable it's
@@ -1021,6 +1018,8 @@ struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
 		return inode;
 	oi = exofs_i(inode);
 	__oi_init(oi);
+	exofs_init_comps(&oi->comps, &oi->one_comp, sb->s_fs_info,
+			 exofs_oi_objno(oi));
 
 	/* read the inode from the osd */
 	ret = exofs_get_inode(sb, oi, &fcb);
@@ -1126,7 +1125,8 @@ static void create_done(struct exofs_io_state *ios, void *p)
 
 	if (unlikely(ret)) {
 		EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
-			  _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
+			  _LLU(exofs_oi_objno(oi)),
+			  _LLU(oi->one_comp.obj.partition));
 		/*TODO: When FS is corrupted creation can fail, object already
 		 * exist. Get rid of this asynchronous creation, if exist
 		 * increment the obj counter and try the next object. Until we
@@ -1145,14 +1145,13 @@ static void create_done(struct exofs_io_state *ios, void *p)
  */
 struct inode *exofs_new_inode(struct inode *dir, int mode)
 {
-	struct super_block *sb;
+	struct super_block *sb = dir->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
 	struct inode *inode;
 	struct exofs_i_info *oi;
-	struct exofs_sb_info *sbi;
 	struct exofs_io_state *ios;
 	int ret;
 
-	sb = dir->i_sb;
 	inode = new_inode(sb);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);
@@ -1162,8 +1161,6 @@ struct inode *exofs_new_inode(struct inode *dir, int mode)
 
 	set_obj_2bcreated(oi);
 
-	sbi = sb->s_fs_info;
-
 	inode->i_mapping->backing_dev_info = sb->s_bdi;
 	inode_init_owner(inode, dir, mode);
 	inode->i_ino = sbi->s_nextid++;
@@ -1175,22 +1172,21 @@ struct inode *exofs_new_inode(struct inode *dir, int mode)
 	spin_unlock(&sbi->s_next_gen_lock);
 	insert_inode_hash(inode);
 
+	exofs_init_comps(&oi->comps, &oi->one_comp, sb->s_fs_info,
+			 exofs_oi_objno(oi));
 	exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
 
 	mark_inode_dirty(inode);
 
-	ret = exofs_get_io_state(&sbi->layout, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &oi->comps, &ios);
 	if (unlikely(ret)) {
 		EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
 		return ERR_PTR(ret);
 	}
 
-	ios->obj.id = exofs_oi_objno(oi);
-	exofs_make_credential(oi->i_cred, &ios->obj);
-
 	ios->done = create_done;
 	ios->private = inode;
-	ios->cred = oi->i_cred;
+
 	ret = exofs_sbi_create(ios);
 	if (ret) {
 		exofs_put_io_state(ios);
@@ -1271,7 +1267,7 @@ static int exofs_update_inode(struct inode *inode, int do_sync)
 	} else
 		memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
 
-	ret = exofs_get_io_state(&sbi->layout, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &oi->comps, &ios);
 	if (unlikely(ret)) {
 		EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
 		goto free_args;
@@ -1290,7 +1286,7 @@ static int exofs_update_inode(struct inode *inode, int do_sync)
 		ios->private = args;
 	}
 
-	ret = exofs_oi_write(oi, ios);
+	ret = exofs_sbi_write(ios);
 	if (!do_sync && !ret) {
 		atomic_inc(&sbi->s_curr_pending);
 		goto out; /* deallocation in updatei_done */
@@ -1354,16 +1350,15 @@ void exofs_evict_inode(struct inode *inode)
 	/* ignore the error, attempt a remove anyway */
 
 	/* Now Remove the OSD objects */
-	ret = exofs_get_io_state(&sbi->layout, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &oi->comps, &ios);
 	if (unlikely(ret)) {
 		EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
 		return;
 	}
 
-	ios->obj.id = exofs_oi_objno(oi);
 	ios->done = delete_done;
 	ios->private = sbi;
-	ios->cred = oi->i_cred;
+
 	ret = exofs_sbi_remove(ios);
 	if (ret) {
 		EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);