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-rw-r--r--fs/aufs/vdir.c888
1 files changed, 888 insertions, 0 deletions
diff --git a/fs/aufs/vdir.c b/fs/aufs/vdir.c
new file mode 100644
index 000000000..0929d393a
--- /dev/null
+++ b/fs/aufs/vdir.c
@@ -0,0 +1,888 @@
+/*
+ * Copyright (C) 2005-2015 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * virtual or vertical directory
+ */
+
+#include "aufs.h"
+
+static unsigned int calc_size(int nlen)
+{
+ return ALIGN(sizeof(struct au_vdir_de) + nlen, sizeof(ino_t));
+}
+
+static int set_deblk_end(union au_vdir_deblk_p *p,
+ union au_vdir_deblk_p *deblk_end)
+{
+ if (calc_size(0) <= deblk_end->deblk - p->deblk) {
+ p->de->de_str.len = 0;
+ /* smp_mb(); */
+ return 0;
+ }
+ return -1; /* error */
+}
+
+/* returns true or false */
+static int is_deblk_end(union au_vdir_deblk_p *p,
+ union au_vdir_deblk_p *deblk_end)
+{
+ if (calc_size(0) <= deblk_end->deblk - p->deblk)
+ return !p->de->de_str.len;
+ return 1;
+}
+
+static unsigned char *last_deblk(struct au_vdir *vdir)
+{
+ return vdir->vd_deblk[vdir->vd_nblk - 1];
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* estimate the apropriate size for name hash table */
+unsigned int au_rdhash_est(loff_t sz)
+{
+ unsigned int n;
+
+ n = UINT_MAX;
+ sz >>= 10;
+ if (sz < n)
+ n = sz;
+ if (sz < AUFS_RDHASH_DEF)
+ n = AUFS_RDHASH_DEF;
+ /* pr_info("n %u\n", n); */
+ return n;
+}
+
+/*
+ * the allocated memory has to be freed by
+ * au_nhash_wh_free() or au_nhash_de_free().
+ */
+int au_nhash_alloc(struct au_nhash *nhash, unsigned int num_hash, gfp_t gfp)
+{
+ struct hlist_head *head;
+ unsigned int u;
+ size_t sz;
+
+ sz = sizeof(*nhash->nh_head) * num_hash;
+ head = kmalloc(sz, gfp);
+ if (head) {
+ nhash->nh_num = num_hash;
+ nhash->nh_head = head;
+ for (u = 0; u < num_hash; u++)
+ INIT_HLIST_HEAD(head++);
+ return 0; /* success */
+ }
+
+ return -ENOMEM;
+}
+
+static void nhash_count(struct hlist_head *head)
+{
+#if 0
+ unsigned long n;
+ struct hlist_node *pos;
+
+ n = 0;
+ hlist_for_each(pos, head)
+ n++;
+ pr_info("%lu\n", n);
+#endif
+}
+
+static void au_nhash_wh_do_free(struct hlist_head *head)
+{
+ struct au_vdir_wh *pos;
+ struct hlist_node *node;
+
+ hlist_for_each_entry_safe(pos, node, head, wh_hash)
+ kfree(pos);
+}
+
+static void au_nhash_de_do_free(struct hlist_head *head)
+{
+ struct au_vdir_dehstr *pos;
+ struct hlist_node *node;
+
+ hlist_for_each_entry_safe(pos, node, head, hash)
+ au_cache_free_vdir_dehstr(pos);
+}
+
+static void au_nhash_do_free(struct au_nhash *nhash,
+ void (*free)(struct hlist_head *head))
+{
+ unsigned int n;
+ struct hlist_head *head;
+
+ n = nhash->nh_num;
+ if (!n)
+ return;
+
+ head = nhash->nh_head;
+ while (n-- > 0) {
+ nhash_count(head);
+ free(head++);
+ }
+ kfree(nhash->nh_head);
+}
+
+void au_nhash_wh_free(struct au_nhash *whlist)
+{
+ au_nhash_do_free(whlist, au_nhash_wh_do_free);
+}
+
+static void au_nhash_de_free(struct au_nhash *delist)
+{
+ au_nhash_do_free(delist, au_nhash_de_do_free);
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
+ int limit)
+{
+ int num;
+ unsigned int u, n;
+ struct hlist_head *head;
+ struct au_vdir_wh *pos;
+
+ num = 0;
+ n = whlist->nh_num;
+ head = whlist->nh_head;
+ for (u = 0; u < n; u++, head++)
+ hlist_for_each_entry(pos, head, wh_hash)
+ if (pos->wh_bindex == btgt && ++num > limit)
+ return 1;
+ return 0;
+}
+
+static struct hlist_head *au_name_hash(struct au_nhash *nhash,
+ unsigned char *name,
+ unsigned int len)
+{
+ unsigned int v;
+ /* const unsigned int magic_bit = 12; */
+
+ AuDebugOn(!nhash->nh_num || !nhash->nh_head);
+
+ v = 0;
+ while (len--)
+ v += *name++;
+ /* v = hash_long(v, magic_bit); */
+ v %= nhash->nh_num;
+ return nhash->nh_head + v;
+}
+
+static int au_nhash_test_name(struct au_vdir_destr *str, const char *name,
+ int nlen)
+{
+ return str->len == nlen && !memcmp(str->name, name, nlen);
+}
+
+/* returns found or not */
+int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int nlen)
+{
+ struct hlist_head *head;
+ struct au_vdir_wh *pos;
+ struct au_vdir_destr *str;
+
+ head = au_name_hash(whlist, name, nlen);
+ hlist_for_each_entry(pos, head, wh_hash) {
+ str = &pos->wh_str;
+ AuDbg("%.*s\n", str->len, str->name);
+ if (au_nhash_test_name(str, name, nlen))
+ return 1;
+ }
+ return 0;
+}
+
+/* returns found(true) or not */
+static int test_known(struct au_nhash *delist, char *name, int nlen)
+{
+ struct hlist_head *head;
+ struct au_vdir_dehstr *pos;
+ struct au_vdir_destr *str;
+
+ head = au_name_hash(delist, name, nlen);
+ hlist_for_each_entry(pos, head, hash) {
+ str = pos->str;
+ AuDbg("%.*s\n", str->len, str->name);
+ if (au_nhash_test_name(str, name, nlen))
+ return 1;
+ }
+ return 0;
+}
+
+static void au_shwh_init_wh(struct au_vdir_wh *wh, ino_t ino,
+ unsigned char d_type)
+{
+#ifdef CONFIG_AUFS_SHWH
+ wh->wh_ino = ino;
+ wh->wh_type = d_type;
+#endif
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_nhash_append_wh(struct au_nhash *whlist, char *name, int nlen, ino_t ino,
+ unsigned int d_type, aufs_bindex_t bindex,
+ unsigned char shwh)
+{
+ int err;
+ struct au_vdir_destr *str;
+ struct au_vdir_wh *wh;
+
+ AuDbg("%.*s\n", nlen, name);
+ AuDebugOn(!whlist->nh_num || !whlist->nh_head);
+
+ err = -ENOMEM;
+ wh = kmalloc(sizeof(*wh) + nlen, GFP_NOFS);
+ if (unlikely(!wh))
+ goto out;
+
+ err = 0;
+ wh->wh_bindex = bindex;
+ if (shwh)
+ au_shwh_init_wh(wh, ino, d_type);
+ str = &wh->wh_str;
+ str->len = nlen;
+ memcpy(str->name, name, nlen);
+ hlist_add_head(&wh->wh_hash, au_name_hash(whlist, name, nlen));
+ /* smp_mb(); */
+
+out:
+ return err;
+}
+
+static int append_deblk(struct au_vdir *vdir)
+{
+ int err;
+ unsigned long ul;
+ const unsigned int deblk_sz = vdir->vd_deblk_sz;
+ union au_vdir_deblk_p p, deblk_end;
+ unsigned char **o;
+
+ err = -ENOMEM;
+ o = krealloc(vdir->vd_deblk, sizeof(*o) * (vdir->vd_nblk + 1),
+ GFP_NOFS);
+ if (unlikely(!o))
+ goto out;
+
+ vdir->vd_deblk = o;
+ p.deblk = kmalloc(deblk_sz, GFP_NOFS);
+ if (p.deblk) {
+ ul = vdir->vd_nblk++;
+ vdir->vd_deblk[ul] = p.deblk;
+ vdir->vd_last.ul = ul;
+ vdir->vd_last.p.deblk = p.deblk;
+ deblk_end.deblk = p.deblk + deblk_sz;
+ err = set_deblk_end(&p, &deblk_end);
+ }
+
+out:
+ return err;
+}
+
+static int append_de(struct au_vdir *vdir, char *name, int nlen, ino_t ino,
+ unsigned int d_type, struct au_nhash *delist)
+{
+ int err;
+ unsigned int sz;
+ const unsigned int deblk_sz = vdir->vd_deblk_sz;
+ union au_vdir_deblk_p p, *room, deblk_end;
+ struct au_vdir_dehstr *dehstr;
+
+ p.deblk = last_deblk(vdir);
+ deblk_end.deblk = p.deblk + deblk_sz;
+ room = &vdir->vd_last.p;
+ AuDebugOn(room->deblk < p.deblk || deblk_end.deblk <= room->deblk
+ || !is_deblk_end(room, &deblk_end));
+
+ sz = calc_size(nlen);
+ if (unlikely(sz > deblk_end.deblk - room->deblk)) {
+ err = append_deblk(vdir);
+ if (unlikely(err))
+ goto out;
+
+ p.deblk = last_deblk(vdir);
+ deblk_end.deblk = p.deblk + deblk_sz;
+ /* smp_mb(); */
+ AuDebugOn(room->deblk != p.deblk);
+ }
+
+ err = -ENOMEM;
+ dehstr = au_cache_alloc_vdir_dehstr();
+ if (unlikely(!dehstr))
+ goto out;
+
+ dehstr->str = &room->de->de_str;
+ hlist_add_head(&dehstr->hash, au_name_hash(delist, name, nlen));
+ room->de->de_ino = ino;
+ room->de->de_type = d_type;
+ room->de->de_str.len = nlen;
+ memcpy(room->de->de_str.name, name, nlen);
+
+ err = 0;
+ room->deblk += sz;
+ if (unlikely(set_deblk_end(room, &deblk_end)))
+ err = append_deblk(vdir);
+ /* smp_mb(); */
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void au_vdir_free(struct au_vdir *vdir)
+{
+ unsigned char **deblk;
+
+ deblk = vdir->vd_deblk;
+ while (vdir->vd_nblk--)
+ kfree(*deblk++);
+ kfree(vdir->vd_deblk);
+ au_cache_free_vdir(vdir);
+}
+
+static struct au_vdir *alloc_vdir(struct file *file)
+{
+ struct au_vdir *vdir;
+ struct super_block *sb;
+ int err;
+
+ sb = file->f_path.dentry->d_sb;
+ SiMustAnyLock(sb);
+
+ err = -ENOMEM;
+ vdir = au_cache_alloc_vdir();
+ if (unlikely(!vdir))
+ goto out;
+
+ vdir->vd_deblk = kzalloc(sizeof(*vdir->vd_deblk), GFP_NOFS);
+ if (unlikely(!vdir->vd_deblk))
+ goto out_free;
+
+ vdir->vd_deblk_sz = au_sbi(sb)->si_rdblk;
+ if (!vdir->vd_deblk_sz) {
+ /* estimate the apropriate size for deblk */
+ vdir->vd_deblk_sz = au_dir_size(file, /*dentry*/NULL);
+ /* pr_info("vd_deblk_sz %u\n", vdir->vd_deblk_sz); */
+ }
+ vdir->vd_nblk = 0;
+ vdir->vd_version = 0;
+ vdir->vd_jiffy = 0;
+ err = append_deblk(vdir);
+ if (!err)
+ return vdir; /* success */
+
+ kfree(vdir->vd_deblk);
+
+out_free:
+ au_cache_free_vdir(vdir);
+out:
+ vdir = ERR_PTR(err);
+ return vdir;
+}
+
+static int reinit_vdir(struct au_vdir *vdir)
+{
+ int err;
+ union au_vdir_deblk_p p, deblk_end;
+
+ while (vdir->vd_nblk > 1) {
+ kfree(vdir->vd_deblk[vdir->vd_nblk - 1]);
+ /* vdir->vd_deblk[vdir->vd_nblk - 1] = NULL; */
+ vdir->vd_nblk--;
+ }
+ p.deblk = vdir->vd_deblk[0];
+ deblk_end.deblk = p.deblk + vdir->vd_deblk_sz;
+ err = set_deblk_end(&p, &deblk_end);
+ /* keep vd_dblk_sz */
+ vdir->vd_last.ul = 0;
+ vdir->vd_last.p.deblk = vdir->vd_deblk[0];
+ vdir->vd_version = 0;
+ vdir->vd_jiffy = 0;
+ /* smp_mb(); */
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#define AuFillVdir_CALLED 1
+#define AuFillVdir_WHABLE (1 << 1)
+#define AuFillVdir_SHWH (1 << 2)
+#define au_ftest_fillvdir(flags, name) ((flags) & AuFillVdir_##name)
+#define au_fset_fillvdir(flags, name) \
+ do { (flags) |= AuFillVdir_##name; } while (0)
+#define au_fclr_fillvdir(flags, name) \
+ do { (flags) &= ~AuFillVdir_##name; } while (0)
+
+#ifndef CONFIG_AUFS_SHWH
+#undef AuFillVdir_SHWH
+#define AuFillVdir_SHWH 0
+#endif
+
+struct fillvdir_arg {
+ struct dir_context ctx;
+ struct file *file;
+ struct au_vdir *vdir;
+ struct au_nhash delist;
+ struct au_nhash whlist;
+ aufs_bindex_t bindex;
+ unsigned int flags;
+ int err;
+};
+
+static int fillvdir(struct dir_context *ctx, const char *__name, int nlen,
+ loff_t offset __maybe_unused, u64 h_ino,
+ unsigned int d_type)
+{
+ struct fillvdir_arg *arg = container_of(ctx, struct fillvdir_arg, ctx);
+ char *name = (void *)__name;
+ struct super_block *sb;
+ ino_t ino;
+ const unsigned char shwh = !!au_ftest_fillvdir(arg->flags, SHWH);
+
+ arg->err = 0;
+ sb = arg->file->f_path.dentry->d_sb;
+ au_fset_fillvdir(arg->flags, CALLED);
+ /* smp_mb(); */
+ if (nlen <= AUFS_WH_PFX_LEN
+ || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
+ if (test_known(&arg->delist, name, nlen)
+ || au_nhash_test_known_wh(&arg->whlist, name, nlen))
+ goto out; /* already exists or whiteouted */
+
+ arg->err = au_ino(sb, arg->bindex, h_ino, d_type, &ino);
+ if (!arg->err) {
+ if (unlikely(nlen > AUFS_MAX_NAMELEN))
+ d_type = DT_UNKNOWN;
+ arg->err = append_de(arg->vdir, name, nlen, ino,
+ d_type, &arg->delist);
+ }
+ } else if (au_ftest_fillvdir(arg->flags, WHABLE)) {
+ name += AUFS_WH_PFX_LEN;
+ nlen -= AUFS_WH_PFX_LEN;
+ if (au_nhash_test_known_wh(&arg->whlist, name, nlen))
+ goto out; /* already whiteouted */
+
+ if (shwh)
+ arg->err = au_wh_ino(sb, arg->bindex, h_ino, d_type,
+ &ino);
+ if (!arg->err) {
+ if (nlen <= AUFS_MAX_NAMELEN + AUFS_WH_PFX_LEN)
+ d_type = DT_UNKNOWN;
+ arg->err = au_nhash_append_wh
+ (&arg->whlist, name, nlen, ino, d_type,
+ arg->bindex, shwh);
+ }
+ }
+
+out:
+ if (!arg->err)
+ arg->vdir->vd_jiffy = jiffies;
+ /* smp_mb(); */
+ AuTraceErr(arg->err);
+ return arg->err;
+}
+
+static int au_handle_shwh(struct super_block *sb, struct au_vdir *vdir,
+ struct au_nhash *whlist, struct au_nhash *delist)
+{
+#ifdef CONFIG_AUFS_SHWH
+ int err;
+ unsigned int nh, u;
+ struct hlist_head *head;
+ struct au_vdir_wh *pos;
+ struct hlist_node *n;
+ char *p, *o;
+ struct au_vdir_destr *destr;
+
+ AuDebugOn(!au_opt_test(au_mntflags(sb), SHWH));
+
+ err = -ENOMEM;
+ o = p = (void *)__get_free_page(GFP_NOFS);
+ if (unlikely(!p))
+ goto out;
+
+ err = 0;
+ nh = whlist->nh_num;
+ memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
+ p += AUFS_WH_PFX_LEN;
+ for (u = 0; u < nh; u++) {
+ head = whlist->nh_head + u;
+ hlist_for_each_entry_safe(pos, n, head, wh_hash) {
+ destr = &pos->wh_str;
+ memcpy(p, destr->name, destr->len);
+ err = append_de(vdir, o, destr->len + AUFS_WH_PFX_LEN,
+ pos->wh_ino, pos->wh_type, delist);
+ if (unlikely(err))
+ break;
+ }
+ }
+
+ free_page((unsigned long)o);
+
+out:
+ AuTraceErr(err);
+ return err;
+#else
+ return 0;
+#endif
+}
+
+static int au_do_read_vdir(struct fillvdir_arg *arg)
+{
+ int err;
+ unsigned int rdhash;
+ loff_t offset;
+ aufs_bindex_t bend, bindex, bstart;
+ unsigned char shwh;
+ struct file *hf, *file;
+ struct super_block *sb;
+
+ file = arg->file;
+ sb = file->f_path.dentry->d_sb;
+ SiMustAnyLock(sb);
+
+ rdhash = au_sbi(sb)->si_rdhash;
+ if (!rdhash)
+ rdhash = au_rdhash_est(au_dir_size(file, /*dentry*/NULL));
+ err = au_nhash_alloc(&arg->delist, rdhash, GFP_NOFS);
+ if (unlikely(err))
+ goto out;
+ err = au_nhash_alloc(&arg->whlist, rdhash, GFP_NOFS);
+ if (unlikely(err))
+ goto out_delist;
+
+ err = 0;
+ arg->flags = 0;
+ shwh = 0;
+ if (au_opt_test(au_mntflags(sb), SHWH)) {
+ shwh = 1;
+ au_fset_fillvdir(arg->flags, SHWH);
+ }
+ bstart = au_fbstart(file);
+ bend = au_fbend_dir(file);
+ for (bindex = bstart; !err && bindex <= bend; bindex++) {
+ hf = au_hf_dir(file, bindex);
+ if (!hf)
+ continue;
+
+ offset = vfsub_llseek(hf, 0, SEEK_SET);
+ err = offset;
+ if (unlikely(offset))
+ break;
+
+ arg->bindex = bindex;
+ au_fclr_fillvdir(arg->flags, WHABLE);
+ if (shwh
+ || (bindex != bend
+ && au_br_whable(au_sbr_perm(sb, bindex))))
+ au_fset_fillvdir(arg->flags, WHABLE);
+ do {
+ arg->err = 0;
+ au_fclr_fillvdir(arg->flags, CALLED);
+ /* smp_mb(); */
+ err = vfsub_iterate_dir(hf, &arg->ctx);
+ if (err >= 0)
+ err = arg->err;
+ } while (!err && au_ftest_fillvdir(arg->flags, CALLED));
+
+ /*
+ * dir_relax() may be good for concurrency, but aufs should not
+ * use it since it will cause a lockdep problem.
+ */
+ }
+
+ if (!err && shwh)
+ err = au_handle_shwh(sb, arg->vdir, &arg->whlist, &arg->delist);
+
+ au_nhash_wh_free(&arg->whlist);
+
+out_delist:
+ au_nhash_de_free(&arg->delist);
+out:
+ return err;
+}
+
+static int read_vdir(struct file *file, int may_read)
+{
+ int err;
+ unsigned long expire;
+ unsigned char do_read;
+ struct fillvdir_arg arg = {
+ .ctx = {
+ .actor = fillvdir
+ }
+ };
+ struct inode *inode;
+ struct au_vdir *vdir, *allocated;
+
+ err = 0;
+ inode = file_inode(file);
+ IMustLock(inode);
+ SiMustAnyLock(inode->i_sb);
+
+ allocated = NULL;
+ do_read = 0;
+ expire = au_sbi(inode->i_sb)->si_rdcache;
+ vdir = au_ivdir(inode);
+ if (!vdir) {
+ do_read = 1;
+ vdir = alloc_vdir(file);
+ err = PTR_ERR(vdir);
+ if (IS_ERR(vdir))
+ goto out;
+ err = 0;
+ allocated = vdir;
+ } else if (may_read
+ && (inode->i_version != vdir->vd_version
+ || time_after(jiffies, vdir->vd_jiffy + expire))) {
+ do_read = 1;
+ err = reinit_vdir(vdir);
+ if (unlikely(err))
+ goto out;
+ }
+
+ if (!do_read)
+ return 0; /* success */
+
+ arg.file = file;
+ arg.vdir = vdir;
+ err = au_do_read_vdir(&arg);
+ if (!err) {
+ /* file->f_pos = 0; */ /* todo: ctx->pos? */
+ vdir->vd_version = inode->i_version;
+ vdir->vd_last.ul = 0;
+ vdir->vd_last.p.deblk = vdir->vd_deblk[0];
+ if (allocated)
+ au_set_ivdir(inode, allocated);
+ } else if (allocated)
+ au_vdir_free(allocated);
+
+out:
+ return err;
+}
+
+static int copy_vdir(struct au_vdir *tgt, struct au_vdir *src)
+{
+ int err, rerr;
+ unsigned long ul, n;
+ const unsigned int deblk_sz = src->vd_deblk_sz;
+
+ AuDebugOn(tgt->vd_nblk != 1);
+
+ err = -ENOMEM;
+ if (tgt->vd_nblk < src->vd_nblk) {
+ unsigned char **p;
+
+ p = krealloc(tgt->vd_deblk, sizeof(*p) * src->vd_nblk,
+ GFP_NOFS);
+ if (unlikely(!p))
+ goto out;
+ tgt->vd_deblk = p;
+ }
+
+ if (tgt->vd_deblk_sz != deblk_sz) {
+ unsigned char *p;
+
+ tgt->vd_deblk_sz = deblk_sz;
+ p = krealloc(tgt->vd_deblk[0], deblk_sz, GFP_NOFS);
+ if (unlikely(!p))
+ goto out;
+ tgt->vd_deblk[0] = p;
+ }
+ memcpy(tgt->vd_deblk[0], src->vd_deblk[0], deblk_sz);
+ tgt->vd_version = src->vd_version;
+ tgt->vd_jiffy = src->vd_jiffy;
+
+ n = src->vd_nblk;
+ for (ul = 1; ul < n; ul++) {
+ tgt->vd_deblk[ul] = kmemdup(src->vd_deblk[ul], deblk_sz,
+ GFP_NOFS);
+ if (unlikely(!tgt->vd_deblk[ul]))
+ goto out;
+ tgt->vd_nblk++;
+ }
+ tgt->vd_nblk = n;
+ tgt->vd_last.ul = tgt->vd_last.ul;
+ tgt->vd_last.p.deblk = tgt->vd_deblk[tgt->vd_last.ul];
+ tgt->vd_last.p.deblk += src->vd_last.p.deblk
+ - src->vd_deblk[src->vd_last.ul];
+ /* smp_mb(); */
+ return 0; /* success */
+
+out:
+ rerr = reinit_vdir(tgt);
+ BUG_ON(rerr);
+ return err;
+}
+
+int au_vdir_init(struct file *file)
+{
+ int err;
+ struct inode *inode;
+ struct au_vdir *vdir_cache, *allocated;
+
+ /* test file->f_pos here instead of ctx->pos */
+ err = read_vdir(file, !file->f_pos);
+ if (unlikely(err))
+ goto out;
+
+ allocated = NULL;
+ vdir_cache = au_fvdir_cache(file);
+ if (!vdir_cache) {
+ vdir_cache = alloc_vdir(file);
+ err = PTR_ERR(vdir_cache);
+ if (IS_ERR(vdir_cache))
+ goto out;
+ allocated = vdir_cache;
+ } else if (!file->f_pos && vdir_cache->vd_version != file->f_version) {
+ /* test file->f_pos here instead of ctx->pos */
+ err = reinit_vdir(vdir_cache);
+ if (unlikely(err))
+ goto out;
+ } else
+ return 0; /* success */
+
+ inode = file_inode(file);
+ err = copy_vdir(vdir_cache, au_ivdir(inode));
+ if (!err) {
+ file->f_version = inode->i_version;
+ if (allocated)
+ au_set_fvdir_cache(file, allocated);
+ } else if (allocated)
+ au_vdir_free(allocated);
+
+out:
+ return err;
+}
+
+static loff_t calc_offset(struct au_vdir *vdir)
+{
+ loff_t offset;
+ union au_vdir_deblk_p p;
+
+ p.deblk = vdir->vd_deblk[vdir->vd_last.ul];
+ offset = vdir->vd_last.p.deblk - p.deblk;
+ offset += vdir->vd_deblk_sz * vdir->vd_last.ul;
+ return offset;
+}
+
+/* returns true or false */
+static int seek_vdir(struct file *file, struct dir_context *ctx)
+{
+ int valid;
+ unsigned int deblk_sz;
+ unsigned long ul, n;
+ loff_t offset;
+ union au_vdir_deblk_p p, deblk_end;
+ struct au_vdir *vdir_cache;
+
+ valid = 1;
+ vdir_cache = au_fvdir_cache(file);
+ offset = calc_offset(vdir_cache);
+ AuDbg("offset %lld\n", offset);
+ if (ctx->pos == offset)
+ goto out;
+
+ vdir_cache->vd_last.ul = 0;
+ vdir_cache->vd_last.p.deblk = vdir_cache->vd_deblk[0];
+ if (!ctx->pos)
+ goto out;
+
+ valid = 0;
+ deblk_sz = vdir_cache->vd_deblk_sz;
+ ul = div64_u64(ctx->pos, deblk_sz);
+ AuDbg("ul %lu\n", ul);
+ if (ul >= vdir_cache->vd_nblk)
+ goto out;
+
+ n = vdir_cache->vd_nblk;
+ for (; ul < n; ul++) {
+ p.deblk = vdir_cache->vd_deblk[ul];
+ deblk_end.deblk = p.deblk + deblk_sz;
+ offset = ul;
+ offset *= deblk_sz;
+ while (!is_deblk_end(&p, &deblk_end) && offset < ctx->pos) {
+ unsigned int l;
+
+ l = calc_size(p.de->de_str.len);
+ offset += l;
+ p.deblk += l;
+ }
+ if (!is_deblk_end(&p, &deblk_end)) {
+ valid = 1;
+ vdir_cache->vd_last.ul = ul;
+ vdir_cache->vd_last.p = p;
+ break;
+ }
+ }
+
+out:
+ /* smp_mb(); */
+ AuTraceErr(!valid);
+ return valid;
+}
+
+int au_vdir_fill_de(struct file *file, struct dir_context *ctx)
+{
+ unsigned int l, deblk_sz;
+ union au_vdir_deblk_p deblk_end;
+ struct au_vdir *vdir_cache;
+ struct au_vdir_de *de;
+
+ vdir_cache = au_fvdir_cache(file);
+ if (!seek_vdir(file, ctx))
+ return 0;
+
+ deblk_sz = vdir_cache->vd_deblk_sz;
+ while (1) {
+ deblk_end.deblk = vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
+ deblk_end.deblk += deblk_sz;
+ while (!is_deblk_end(&vdir_cache->vd_last.p, &deblk_end)) {
+ de = vdir_cache->vd_last.p.de;
+ AuDbg("%.*s, off%lld, i%lu, dt%d\n",
+ de->de_str.len, de->de_str.name, ctx->pos,
+ (unsigned long)de->de_ino, de->de_type);
+ if (unlikely(!dir_emit(ctx, de->de_str.name,
+ de->de_str.len, de->de_ino,
+ de->de_type))) {
+ /* todo: ignore the error caused by udba? */
+ /* return err; */
+ return 0;
+ }
+
+ l = calc_size(de->de_str.len);
+ vdir_cache->vd_last.p.deblk += l;
+ ctx->pos += l;
+ }
+ if (vdir_cache->vd_last.ul < vdir_cache->vd_nblk - 1) {
+ vdir_cache->vd_last.ul++;
+ vdir_cache->vd_last.p.deblk
+ = vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
+ ctx->pos = deblk_sz * vdir_cache->vd_last.ul;
+ continue;
+ }
+ break;
+ }
+
+ /* smp_mb(); */
+ return 0;
+}