JFS: Don't save agno in the inode

Resizing the file system can result in an in-memory inode being remapped
to a different aggregate group (AG). A cached AG number can cause
problems when trying to free or allocate inodes. Instead, save the IAG's
agstart address and calculate the agno when we need it.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

3 files changed, 9 insertions, 9 deletions

diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index c5ce6c1d1ff4..2f3f531f3606 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -66,9 +66,9 @@ static int jfs_open(struct inode *inode, struct file *file)
                 struct jfs_inode_info *ji = JFS_IP(inode);
                 spin_lock_irq(&ji->ag_lock);
                 if (ji->active_ag == -1) {
-                        ji->active_ag = ji->agno;
-                        atomic_inc(
-                            &JFS_SBI(inode->i_sb)->bmap->db_active[ji->agno]);
+                        struct jfs_sb_info *jfs_sb = JFS_SBI(inode->i_sb);
+                        ji->active_ag = BLKTOAG(addressPXD(&ji->ixpxd), jfs_sb);
+                        atomic_inc( &jfs_sb->bmap->db_active[ji->active_ag]);
                 }
                 spin_unlock_irq(&ji->ag_lock);
         }
diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index 0533e8f3d19e..b78b2f978f04 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -397,7 +397,7 @@ int diRead(struct inode *ip)
         release_metapage(mp);
 
         /* set the ag for the inode */
-        JFS_IP(ip)->agno = BLKTOAG(agstart, sbi);
+        JFS_IP(ip)->agstart = agstart;
         JFS_IP(ip)->active_ag = -1;
 
         return (rc);
@@ -901,7 +901,7 @@ int diFree(struct inode *ip)
 
         /* get the allocation group for this ino.
          */
-        agno = JFS_IP(ip)->agno;
+        agno = BLKTOAG(JFS_IP(ip)->agstart, JFS_SBI(ip->i_sb));
 
         /* Lock the AG specific inode map information
          */
@@ -1315,12 +1315,11 @@ int diFree(struct inode *ip)
 static inline void
 diInitInode(struct inode *ip, int iagno, int ino, int extno, struct iag * iagp)
 {
-        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
         struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 
         ip->i_ino = (iagno << L2INOSPERIAG) + ino;
         jfs_ip->ixpxd = iagp->inoext[extno];
-        jfs_ip->agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
+        jfs_ip->agstart = le64_to_cpu(iagp->agstart);
         jfs_ip->active_ag = -1;
 }
 
@@ -1379,7 +1378,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
          */
 
         /* get the ag number of this iag */
-        agno = JFS_IP(pip)->agno;
+        agno = BLKTOAG(JFS_IP(pip)->agstart, JFS_SBI(pip->i_sb));
 
         if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
                 /*
diff --git a/fs/jfs/jfs_incore.h b/fs/jfs/jfs_incore.h
index 1439f119ec83..5097839b7709 100644
--- a/fs/jfs/jfs_incore.h
+++ b/fs/jfs/jfs_incore.h
@@ -50,8 +50,9 @@ struct jfs_inode_info {
         short   btindex;        /* btpage entry index*/
         struct inode *ipimap;   /* inode map                    */
         unsigned long cflag;    /* commit flags         */
+        long    agstart;        /* agstart of the containing IAG */
         u16     bxflag;         /* xflag of pseudo buffer?      */
-        unchar  agno;           /* ag number                    */
+        unchar  pad;
         signed char active_ag;  /* ag currently allocating from */
         lid_t   blid;           /* lid of pseudo buffer?        */
         lid_t   atlhead;        /* anonymous tlock list head    */