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Commit 1cea312a authored by Boaz Harrosh's avatar Boaz Harrosh
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exofs: Write sbi->s_nextid as part of the Create command 



Before when creating a new inode, we'd set the sb->s_dirt flag,
and sometime later the system would write out s_nextid as part
of the sb_info. Also on inode sync we would force the sb sync
as well.

Define the s_nextid as a new partition attribute and set it
every time we create a new object.
At mount we read it from it's new place.

We now never set sb->s_dirt anywhere in exofs. write_super
is actually never called. The call to exofs_write_super from
exofs_put_super is also removed because the VFS always calls
->sync_fs before calling ->put_super twice.

To stay backward-and-forward compatible we also write the old
s_nextid in the super_block object at unmount, and support zero
length attribute on mount.

This also fixes a BUG where in layouts when group_width was not
a divisor of EXOFS_SUPER_ID (0x10000) the s_nextid was not read
from the device it was written to. Because of the sliding window
layout trick, and because the read was always done from the 0
device but the write was done via the raid engine that might slide
the device view. Now we read and write through the raid engine.

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
parent 9ed96484

fs/exofs/common.h

+16 −2
Original line number Diff line number Diff line
@@ -53,10 +53,14 @@ 
#define EXOFS_ROOT_ID	0x10002	/* object ID for root directory */



/* exofs Application specific page/attribute */

/* Inode attrs */

# define EXOFS_APAGE_FS_DATA	(OSD_APAGE_APP_DEFINED_FIRST + 3)

# define EXOFS_ATTR_INODE_DATA	1

# define EXOFS_ATTR_INODE_FILE_LAYOUT	2

# define EXOFS_ATTR_INODE_DIR_LAYOUT	3

/* Partition attrs */

# define EXOFS_APAGE_SB_DATA	(0xF0000000U + 3)

# define EXOFS_ATTR_SB_STATS	1



/*

 * The maximum number of files we can have is limited by the size of the
@@ -86,8 +90,8 @@ enum { 
 */

enum {EXOFS_FSCB_VER = 1, EXOFS_DT_VER = 1};

struct exofs_fscb {

	__le64  s_nextid;	/* Highest object ID used */

	__le64  s_numfiles;	/* Number of files on fs */

	__le64  s_nextid;	/* Only used after mkfs */

	__le64  s_numfiles;	/* Only used after mkfs */

	__le32	s_version;	/* == EXOFS_FSCB_VER */

	__le16  s_magic;	/* Magic signature */

	__le16  s_newfs;	/* Non-zero if this is a new fs */
@@ -97,6 +101,16 @@ struct exofs_fscb { 
	__le64	s_dev_table_count; /* == 0 means no dev_table */

} __packed;



/*

 * This struct is set on the FS partition's attributes.

 * [EXOFS_APAGE_SB_DATA, EXOFS_ATTR_SB_STATS] and is written together

 * with the create command, to atomically persist the sb writeable information.

 */

struct exofs_sb_stats {

	__le64  s_nextid;	/* Highest object ID used */

	__le64  s_numfiles;	/* Number of files on fs */

} __packed;



/*

 * Describes the raid used in the FS. It is part of the device table.

 * This here is taken from the pNFS-objects definition. In exofs we

fs/exofs/exofs.h

+2 −2
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ struct exofs_layout { 
 * our extension to the in-memory superblock

 */

struct exofs_sb_info {

	struct exofs_fscb s_fscb;		/* Written often, pre-allocate*/

	struct exofs_sb_stats s_ess;		/* Written often, pre-allocate*/

	int		s_timeout;		/* timeout for OSD operations */

	uint64_t	s_nextid;		/* highest object ID used     */

	uint32_t	s_numfiles;		/* number of files on fs      */
@@ -281,7 +281,7 @@ int exofs_set_link(struct inode *, struct exofs_dir_entry *, struct page *, 
		    struct inode *);



/* super.c               */

int exofs_sync_fs(struct super_block *sb, int wait);

int exofs_sbi_write_stats(struct exofs_sb_info *sbi);



/*********************

 * operation vectors *

fs/exofs/file.c

+1 −10
Original line number Diff line number Diff line
@@ -45,17 +45,8 @@ static int exofs_release_file(struct inode *inode, struct file *filp) 
static int exofs_file_fsync(struct file *filp, int datasync)

{

	int ret;

	struct inode *inode = filp->f_mapping->host;

	struct super_block *sb;



	ret = sync_inode_metadata(inode, 1);



	/* This is a good place to write the sb */

	/* TODO: Sechedule an sb-sync on create */

	sb = inode->i_sb;

	if (sb->s_dirt)

		exofs_sync_fs(sb, 1);



	ret = sync_inode_metadata(filp->f_mapping->host, 1);

	return ret;

}

fs/exofs/inode.c

+3 −1
Original line number Diff line number Diff line
@@ -1102,6 +1102,7 @@ int __exofs_wait_obj_created(struct exofs_i_info *oi) 
	}

	return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;

}



/*

 * Callback function from exofs_new_inode().  The important thing is that we

 * set the obj_created flag so that other methods know that the object exists on
@@ -1160,7 +1161,6 @@ struct inode *exofs_new_inode(struct inode *dir, int mode) 
	sbi = sb->s_fs_info;



	inode->i_mapping->backing_dev_info = sb->s_bdi;

	sb->s_dirt = 1;

	inode_init_owner(inode, dir, mode);

	inode->i_ino = sbi->s_nextid++;

	inode->i_blkbits = EXOFS_BLKSHIFT;
@@ -1171,6 +1171,8 @@ struct inode *exofs_new_inode(struct inode *dir, int mode) 
	spin_unlock(&sbi->s_next_gen_lock);

	insert_inode_hash(inode);



	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);

fs/exofs/super.c

+119 −16
Original line number Diff line number Diff line
@@ -213,6 +213,101 @@ static void destroy_inodecache(void) 
static const struct super_operations exofs_sops;

static const struct export_operations exofs_export_ops;



static const struct osd_attr g_attr_sb_stats = ATTR_DEF(

	EXOFS_APAGE_SB_DATA,

	EXOFS_ATTR_SB_STATS,

	sizeof(struct exofs_sb_stats));



static int __sbi_read_stats(struct exofs_sb_info *sbi)

{

	struct osd_attr attrs[] = {

		[0] = g_attr_sb_stats,

	};

	struct exofs_io_state *ios;

	int ret;



	ret = exofs_get_io_state(&sbi->layout, &ios);

	if (unlikely(ret)) {

		EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);

		return ret;

	}



	ios->cred = sbi->s_cred;



	ios->in_attr = attrs;

	ios->in_attr_len = ARRAY_SIZE(attrs);



	ret = exofs_sbi_read(ios);

	if (unlikely(ret)) {

		EXOFS_ERR("Error reading super_block stats => %d\n", ret);

		goto out;

	}



	ret = extract_attr_from_ios(ios, &attrs[0]);

	if (ret) {

		EXOFS_ERR("%s: extract_attr of sb_stats failed\n", __func__);

		goto out;

	}

	if (attrs[0].len) {

		struct exofs_sb_stats *ess;



		if (unlikely(attrs[0].len != sizeof(*ess))) {

			EXOFS_ERR("%s: Wrong version of exofs_sb_stats "

				  "size(%d) != expected(%zd)\n",

				  __func__, attrs[0].len, sizeof(*ess));

			goto out;

		}



		ess = attrs[0].val_ptr;

		sbi->s_nextid = le64_to_cpu(ess->s_nextid);

		sbi->s_numfiles = le32_to_cpu(ess->s_numfiles);

	}



out:

	exofs_put_io_state(ios);

	return ret;

}



static void stats_done(struct exofs_io_state *ios, void *p)

{

	exofs_put_io_state(ios);

	/* Good thanks nothing to do anymore */

}



/* Asynchronously write the stats attribute */

int exofs_sbi_write_stats(struct exofs_sb_info *sbi)

{

	struct osd_attr attrs[] = {

		[0] = g_attr_sb_stats,

	};

	struct exofs_io_state *ios;

	int ret;



	ret = exofs_get_io_state(&sbi->layout, &ios);

	if (unlikely(ret)) {

		EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);

		return ret;

	}



	sbi->s_ess.s_nextid   = cpu_to_le64(sbi->s_nextid);

	sbi->s_ess.s_numfiles = cpu_to_le64(sbi->s_numfiles);

	attrs[0].val_ptr = &sbi->s_ess;



	ios->cred = sbi->s_cred;

	ios->done = stats_done;

	ios->private = sbi;

	ios->out_attr = attrs;

	ios->out_attr_len = ARRAY_SIZE(attrs);



	ret = exofs_sbi_write(ios);

	if (unlikely(ret)) {

		EXOFS_ERR("%s: exofs_sbi_write failed.\n", __func__);

		exofs_put_io_state(ios);

	}



	return ret;

}



/*

 * Write the superblock to the OSD

 */
@@ -223,18 +318,25 @@ int exofs_sync_fs(struct super_block *sb, int wait) 
	struct exofs_io_state *ios;

	int ret = -ENOMEM;



	lock_super(sb);

	fscb = kmalloc(sizeof(*fscb), GFP_KERNEL);

	if (unlikely(!fscb))

		return -ENOMEM;



	sbi = sb->s_fs_info;

	fscb = &sbi->s_fscb;



	/* NOTE: We no longer dirty the super_block anywhere in exofs. The

	 * reason we write the fscb here on unmount is so we can stay backwards

	 * compatible with fscb->s_version == 1. (What we are not compatible

	 * with is if a new version FS crashed and then we try to mount an old

	 * version). Otherwise the exofs_fscb is read-only from mkfs time. All

	 * the writeable info is set in exofs_sbi_write_stats() above.

	 */

	ret = exofs_get_io_state(&sbi->layout, &ios);

	if (ret)

	if (unlikely(ret))

		goto out;



	/* Note: We only write the changing part of the fscb. .i.e upto the

	 *       the fscb->s_dev_table_oid member. There is no read-modify-write

	 *       here.

	 */

	lock_super(sb);



	ios->length = offsetof(struct exofs_fscb, s_dev_table_oid);

	memset(fscb, 0, ios->length);

	fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
@@ -249,16 +351,17 @@ int exofs_sync_fs(struct super_block *sb, int wait) 
	ios->cred = sbi->s_cred;



	ret = exofs_sbi_write(ios);

	if (unlikely(ret)) {

	if (unlikely(ret))

		EXOFS_ERR("%s: exofs_sbi_write failed.\n", __func__);

		goto out;

	}

	else

		sb->s_dirt = 0;





	unlock_super(sb);

out:

	EXOFS_DBGMSG("s_nextid=0x%llx ret=%d\n", _LLU(sbi->s_nextid), ret);

	exofs_put_io_state(ios);

	unlock_super(sb);

	kfree(fscb);

	return ret;

}
@@ -302,9 +405,6 @@ static void exofs_put_super(struct super_block *sb) 
	int num_pend;

	struct exofs_sb_info *sbi = sb->s_fs_info;



	if (sb->s_dirt)

		exofs_write_super(sb);



	/* make sure there are no pending commands */

	for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;

	     num_pend = atomic_read(&sbi->s_curr_pending)) {
@@ -629,6 +729,7 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent) 
		goto free_sbi;



	sb->s_magic = le16_to_cpu(fscb.s_magic);

	/* NOTE: we read below to be backward compatible with old versions */

	sbi->s_nextid = le64_to_cpu(fscb.s_nextid);

	sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
@@ -639,7 +740,7 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent) 
		ret = -EINVAL;

		goto free_sbi;

	}

	if (le32_to_cpu(fscb.s_version) != EXOFS_FSCB_VER) {

	if (le32_to_cpu(fscb.s_version) > EXOFS_FSCB_VER) {

		EXOFS_ERR("ERROR: Bad FSCB version expected-%d got-%d\n",

			  EXOFS_FSCB_VER, le32_to_cpu(fscb.s_version));

		ret = -EINVAL;
@@ -657,6 +758,8 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent) 
			goto free_sbi;

	}



	__sbi_read_stats(sbi);



	/* set up operation vectors */

	sbi->bdi.ra_pages = __ra_pages(&sbi->layout);

	sb->s_bdi = &sbi->bdi;