aufs: add files
[pandora-kernel.git] / fs / aufs / iinfo.c
diff --git a/fs/aufs/iinfo.c b/fs/aufs/iinfo.c
new file mode 100644 (file)
index 0000000..cd1086e
--- /dev/null
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2005-2011 Junjiro R. Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+ * inode private data
+ */
+
+#include "aufs.h"
+
+struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex)
+{
+       struct inode *h_inode;
+
+       IiMustAnyLock(inode);
+
+       h_inode = au_ii(inode)->ii_hinode[0 + bindex].hi_inode;
+       AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
+       return h_inode;
+}
+
+/* todo: hard/soft set? */
+void au_hiput(struct au_hinode *hinode)
+{
+       au_hn_free(hinode);
+       dput(hinode->hi_whdentry);
+       iput(hinode->hi_inode);
+}
+
+unsigned int au_hi_flags(struct inode *inode, int isdir)
+{
+       unsigned int flags;
+       const unsigned int mnt_flags = au_mntflags(inode->i_sb);
+
+       flags = 0;
+       if (au_opt_test(mnt_flags, XINO))
+               au_fset_hi(flags, XINO);
+       if (isdir && au_opt_test(mnt_flags, UDBA_HNOTIFY))
+               au_fset_hi(flags, HNOTIFY);
+       return flags;
+}
+
+void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
+                  struct inode *h_inode, unsigned int flags)
+{
+       struct au_hinode *hinode;
+       struct inode *hi;
+       struct au_iinfo *iinfo = au_ii(inode);
+
+       IiMustWriteLock(inode);
+
+       hinode = iinfo->ii_hinode + bindex;
+       hi = hinode->hi_inode;
+       AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
+
+       if (hi)
+               au_hiput(hinode);
+       hinode->hi_inode = h_inode;
+       if (h_inode) {
+               int err;
+               struct super_block *sb = inode->i_sb;
+               struct au_branch *br;
+
+               AuDebugOn(inode->i_mode
+                         && (h_inode->i_mode & S_IFMT)
+                         != (inode->i_mode & S_IFMT));
+               if (bindex == iinfo->ii_bstart)
+                       au_cpup_igen(inode, h_inode);
+               br = au_sbr(sb, bindex);
+               hinode->hi_id = br->br_id;
+               if (au_ftest_hi(flags, XINO)) {
+                       err = au_xino_write(sb, bindex, h_inode->i_ino,
+                                           inode->i_ino);
+                       if (unlikely(err))
+                               AuIOErr1("failed au_xino_write() %d\n", err);
+               }
+
+               if (au_ftest_hi(flags, HNOTIFY)
+                   && au_br_hnotifyable(br->br_perm)) {
+                       err = au_hn_alloc(hinode, inode);
+                       if (unlikely(err))
+                               AuIOErr1("au_hn_alloc() %d\n", err);
+               }
+       }
+}
+
+void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
+                 struct dentry *h_wh)
+{
+       struct au_hinode *hinode;
+
+       IiMustWriteLock(inode);
+
+       hinode = au_ii(inode)->ii_hinode + bindex;
+       AuDebugOn(hinode->hi_whdentry);
+       hinode->hi_whdentry = h_wh;
+}
+
+void au_update_iigen(struct inode *inode)
+{
+       atomic_set(&au_ii(inode)->ii_generation, au_sigen(inode->i_sb));
+       /* smp_mb(); */ /* atomic_set */
+}
+
+/* it may be called at remount time, too */
+void au_update_ibrange(struct inode *inode, int do_put_zero)
+{
+       struct au_iinfo *iinfo;
+       aufs_bindex_t bindex, bend;
+
+       iinfo = au_ii(inode);
+       if (!iinfo)
+               return;
+
+       IiMustWriteLock(inode);
+
+       if (do_put_zero && iinfo->ii_bstart >= 0) {
+               for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
+                    bindex++) {
+                       struct inode *h_i;
+
+                       h_i = iinfo->ii_hinode[0 + bindex].hi_inode;
+                       if (h_i && !h_i->i_nlink)
+                               au_set_h_iptr(inode, bindex, NULL, 0);
+               }
+       }
+
+       iinfo->ii_bstart = -1;
+       iinfo->ii_bend = -1;
+       bend = au_sbend(inode->i_sb);
+       for (bindex = 0; bindex <= bend; bindex++)
+               if (iinfo->ii_hinode[0 + bindex].hi_inode) {
+                       iinfo->ii_bstart = bindex;
+                       break;
+               }
+       if (iinfo->ii_bstart >= 0)
+               for (bindex = bend; bindex >= iinfo->ii_bstart; bindex--)
+                       if (iinfo->ii_hinode[0 + bindex].hi_inode) {
+                               iinfo->ii_bend = bindex;
+                               break;
+                       }
+       AuDebugOn(iinfo->ii_bstart > iinfo->ii_bend);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void au_icntnr_init_once(void *_c)
+{
+       struct au_icntnr *c = _c;
+       struct au_iinfo *iinfo = &c->iinfo;
+       static struct lock_class_key aufs_ii;
+
+       au_rw_init(&iinfo->ii_rwsem);
+       au_rw_class(&iinfo->ii_rwsem, &aufs_ii);
+       inode_init_once(&c->vfs_inode);
+}
+
+int au_iinfo_init(struct inode *inode)
+{
+       struct au_iinfo *iinfo;
+       struct super_block *sb;
+       int nbr, i;
+
+       sb = inode->i_sb;
+       iinfo = &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
+       nbr = au_sbend(sb) + 1;
+       if (unlikely(nbr <= 0))
+               nbr = 1;
+       iinfo->ii_hinode = kcalloc(nbr, sizeof(*iinfo->ii_hinode), GFP_NOFS);
+       if (iinfo->ii_hinode) {
+               au_ninodes_inc(sb);
+               for (i = 0; i < nbr; i++)
+                       iinfo->ii_hinode[i].hi_id = -1;
+
+               atomic_set(&iinfo->ii_generation, au_sigen(sb));
+               /* smp_mb(); */ /* atomic_set */
+               iinfo->ii_bstart = -1;
+               iinfo->ii_bend = -1;
+               iinfo->ii_vdir = NULL;
+               return 0;
+       }
+       return -ENOMEM;
+}
+
+int au_ii_realloc(struct au_iinfo *iinfo, int nbr)
+{
+       int err, sz;
+       struct au_hinode *hip;
+
+       AuRwMustWriteLock(&iinfo->ii_rwsem);
+
+       err = -ENOMEM;
+       sz = sizeof(*hip) * (iinfo->ii_bend + 1);
+       if (!sz)
+               sz = sizeof(*hip);
+       hip = au_kzrealloc(iinfo->ii_hinode, sz, sizeof(*hip) * nbr, GFP_NOFS);
+       if (hip) {
+               iinfo->ii_hinode = hip;
+               err = 0;
+       }
+
+       return err;
+}
+
+void au_iinfo_fin(struct inode *inode)
+{
+       struct au_iinfo *iinfo;
+       struct au_hinode *hi;
+       struct super_block *sb;
+       aufs_bindex_t bindex, bend;
+       const unsigned char unlinked = !inode->i_nlink;
+
+       iinfo = au_ii(inode);
+       /* bad_inode case */
+       if (!iinfo)
+               return;
+
+       sb = inode->i_sb;
+       au_ninodes_dec(sb);
+       if (si_pid_test(sb))
+               au_xino_delete_inode(inode, unlinked);
+       else {
+               /*
+                * it is safe to hide the dependency between sbinfo and
+                * sb->s_umount.
+                */
+               lockdep_off();
+               si_noflush_read_lock(sb);
+               au_xino_delete_inode(inode, unlinked);
+               si_read_unlock(sb);
+               lockdep_on();
+       }
+
+       if (iinfo->ii_vdir)
+               au_vdir_free(iinfo->ii_vdir);
+
+       bindex = iinfo->ii_bstart;
+       if (bindex >= 0) {
+               hi = iinfo->ii_hinode + bindex;
+               bend = iinfo->ii_bend;
+               while (bindex++ <= bend) {
+                       if (hi->hi_inode)
+                               au_hiput(hi);
+                       hi++;
+               }
+       }
+       kfree(iinfo->ii_hinode);
+       iinfo->ii_hinode = NULL;
+       AuRwDestroy(&iinfo->ii_rwsem);
+}