[Aufs 06/25] aufs xino

J. R. Okajima
2009-03-09T03:39:21Z

external inode number translation table and bitmap

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
fs/aufs/xino.c | 1181 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1181 insertions(+), 0 deletions(-)
create mode 100644 fs/aufs/xino.c

diff --git a/fs/aufs/xino.c b/fs/aufs/xino.c
new file mode 100644
index 0000000..bc19b86
--- /dev/null
+++ b/fs/aufs/xino.c
@@ -0,0 +1,1181 @@
+/*
+ * Copyright (C) 2005-2009 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.
+ */
+
+/*
+ * external inode number translation table and bitmap
+ */
+
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include "aufs.h"
+
+ssize_t xino_fread(au_readf_t func, struct file *file, void *buf, size_t size,
+ loff_t *pos)
+{
+ ssize_t err;
+ mm_segment_t oldfs;
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ do {
+ /* todo: signal_pending? */
+ err = func(file, (char __user *)buf, size, pos);
+ } while (err == -EAGAIN || err == -EINTR);
+ set_fs(oldfs);
+
+#if 0 /* reserved for future use */
+ if (err > 0)
+ fsnotify_access(file->f_dentry);
+#endif
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static ssize_t do_xino_fwrite(au_writef_t func, struct file *file, void *buf,
+ size_t size, loff_t *pos)
+{
+ ssize_t err;
+ mm_segment_t oldfs;
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ lockdep_off();
+ do {
+ /* todo: signal_pending? */
+ err = func(file, (const char __user *)buf, size, pos);
+ } while (err == -EAGAIN || err == -EINTR);
+ lockdep_on();
+ set_fs(oldfs);
+
+#if 0 /* reserved for future use */
+ if (err > 0)
+ fsnotify_modify(file->f_dentry);
+#endif
+
+ return err;
+}
+
+struct do_xino_fwrite_args {
+ ssize_t *errp;
+ au_writef_t func;
+ struct file *file;
+ void *buf;
+ size_t size;
+ loff_t *pos;
+};
+
+static void call_do_xino_fwrite(void *args)
+{
+ struct do_xino_fwrite_args *a = args;
+ *a->errp = do_xino_fwrite(a->func, a->file, a->buf, a->size, a->pos);
+}
+
+ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
+ loff_t *pos)
+{
+ ssize_t err;
+
+ /* todo: signal block and no wkq? */
+ /* todo: new credential scheme */
+ /*
+ * it breaks RLIMIT_FSIZE and normal user's limit,
+ * users should care about quota and real 'filesystem full.'
+ */
+ if (!au_test_wkq(current)) {
+ int wkq_err;
+ struct do_xino_fwrite_args args = {
+ .errp = &err,
+ .func = func,
+ .file = file,
+ .buf = buf,
+ .size = size,
+ .pos = pos
+ };
+
+ wkq_err = au_wkq_wait(call_do_xino_fwrite, &args);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+ } else
+ err = do_xino_fwrite(func, file, buf, size, pos);
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * create a new xinofile at the same place/path as @base_file.
+ */
+static struct file *au_xino_create2(struct file *base_file,
+ struct file *copy_src)
+{
+ struct file *file;
+ struct dentry *base, *dentry, *parent;
+ struct inode *dir;
+ struct qstr *name;
+ int err;
+
+ base = base_file->f_dentry;
+ parent = base->d_parent; /* dir inode is locked */
+ dir = parent->d_inode;
+ IMustLock(dir);
+
+ file = ERR_PTR(-EINVAL);
+ name = &base->d_name;
+ dentry = vfsub_lookup_one_len(name->name, parent, name->len);
+ if (IS_ERR(dentry)) {
+ file = (void *)dentry;
+ AuErr("%.*s lookup err %ld\n", AuLNPair(name), PTR_ERR(dentry));
+ goto out;
+ }
+
+ /* no need to mnt_want_write() since we call dentry_open() later */
+ err = vfs_create(dir, dentry, S_IRUGO | S_IWUGO, NULL);
+ if (unlikely(err)) {
+ file = ERR_PTR(err);
+ AuErr("%.*s create err %d\n", AuLNPair(name), err);
+ goto out_dput;
+ }
+
+ file = dentry_open(dget(dentry), mntget(base_file->f_vfsmnt),
+ O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE,
+ current_cred());
+ if (IS_ERR(file)) {
+ AuErr("%.*s open err %ld\n", AuLNPair(name), PTR_ERR(file));
+ goto out_dput;
+ }
+
+ err = vfsub_unlink(dir, &file->f_path, /*force*/0);
+ if (unlikely(err)) {
+ AuErr("%.*s unlink err %d\n", AuLNPair(name), err);
+ goto out_fput;
+ }
+
+ if (copy_src) {
+ /* no one can touch copy_src xino */
+ err = au_copy_file(file, copy_src,
+ i_size_read(copy_src->f_dentry->d_inode));
+ if (unlikely(err)) {
+ AuErr("%.*s copy err %d\n", AuLNPair(name), err);
+ goto out_fput;
+ }
+ }
+ goto out_dput; /* success */
+
+ out_fput:
+ fput(file);
+ file = ERR_PTR(err);
+ out_dput:
+ dput(dentry);
+ out:
+ return file;
+}
+
+struct au_xino_lock_dir {
+ struct au_hinode *hdir;
+ struct dentry *parent;
+ struct mutex *mtx;
+};
+
+static void au_xino_lock_dir(struct super_block *sb, struct file *xino,
+ struct au_xino_lock_dir *ldir)
+{
+ aufs_bindex_t brid, bindex;
+
+ ldir->hdir = NULL;
+ bindex = -1;
+ brid = au_xino_brid(sb);
+ if (brid >= 0)
+ bindex = au_br_index(sb, brid);
+ if (bindex >= 0) {
+ ldir->hdir = au_hi(sb->s_root->d_inode, bindex);
+ au_hin_imtx_lock_nested(ldir->hdir, AuLsc_I_PARENT);
+ } else {
+ ldir->parent = dget_parent(xino->f_dentry);
+ ldir->mtx = &ldir->parent->d_inode->i_mutex;
+ mutex_lock_nested(ldir->mtx, AuLsc_I_PARENT);
+ }
+}
+
+static void au_xino_unlock_dir(struct au_xino_lock_dir *ldir)
+{
+ if (ldir->hdir)
+ au_hin_imtx_unlock(ldir->hdir);
+ else {
+ mutex_unlock(ldir->mtx);
+ dput(ldir->parent);
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* trucate xino files asynchronously */
+
+int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex)
+{
+ int err;
+ aufs_bindex_t bi, bend;
+ struct au_branch *br;
+ struct file *new_xino, *file;
+ struct super_block *h_sb;
+ struct au_xino_lock_dir ldir;
+
+ err = -EINVAL;
+ bend = au_sbend(sb);
+ if (unlikely(bindex < 0 || bend < bindex))
+ goto out;
+ br = au_sbr(sb, bindex);
+ file = br->br_xino.xi_file;
+ if (!file)
+ goto out;
+
+ au_xino_lock_dir(sb, file, &ldir);
+ /* mnt_want_write() is unnecessary here */
+ new_xino = au_xino_create2(file, file);
+ au_xino_unlock_dir(&ldir);
+ err = PTR_ERR(new_xino);
+ if (IS_ERR(new_xino))
+ goto out;
+ err = 0;
+ fput(file);
+ br->br_xino.xi_file = new_xino;
+
+ h_sb = br->br_mnt->mnt_sb;
+ for (bi = 0; bi <= bend; bi++) {
+ if (unlikely(bi == bindex))
+ continue;
+ br = au_sbr(sb, bi);
+ if (br->br_mnt->mnt_sb != h_sb)
+ continue;
+
+ fput(br->br_xino.xi_file);
+ br->br_xino.xi_file = new_xino;
+ get_file(new_xino);
+ }
+
+ out:
+ return err;
+}
+
+struct xino_do_trunc_args {
+ struct super_block *sb;
+ struct au_branch *br;
+};
+
+static void xino_do_trunc(void *_args)
+{
+ struct xino_do_trunc_args *args = _args;
+ struct super_block *sb;
+ struct au_branch *br;
+ struct inode *dir;
+ int err;
+ aufs_bindex_t bindex;
+
+ err = 0;
+ sb = args->sb;
+ dir = sb->s_root->d_inode;
+ br = args->br;
+
+ si_noflush_write_lock(sb);
+ ii_read_lock_parent(dir);
+ bindex = au_br_index(sb, br->br_id);
+ err = au_xino_trunc(sb, bindex);
+ if (unlikely(err))
+ goto out;
+
+ if (br->br_xino.xi_file->f_dentry->d_inode->i_blocks
+ >= br->br_xino_upper)
+ br->br_xino_upper += AUFS_XINO_TRUNC_STEP;
+
+ out:
+ ii_read_unlock(dir);
+ if (unlikely(err))
+ AuWarn("err b%d, (%d)\n", bindex, err);
+ atomic_dec(&br->br_xino_running);
+ atomic_dec(&br->br_count);
+ au_nwt_done(&au_sbi(sb)->si_nowait);
+ si_write_unlock(sb);
+ kfree(args);
+}
+
+static void xino_try_trunc(struct super_block *sb, struct au_branch *br)
+{
+ struct xino_do_trunc_args *args;
+ int wkq_err;
+
+ if (br->br_xino.xi_file->f_dentry->d_inode->i_blocks
+ < br->br_xino_upper)
+ return;
+
+ if (atomic_inc_return(&br->br_xino_running) > 1)
+ goto out;
+
+ /* lock and kfree() will be called in trunc_xino() */
+ args = kmalloc(sizeof(*args), GFP_NOFS);
+ if (unlikely(!args)) {
+ AuErr1("no memory\n");
+ goto out_args;
+ }
+
+ atomic_inc(&br->br_count);
+ args->sb = sb;
+ args->br = br;
+ wkq_err = au_wkq_nowait(xino_do_trunc, args, sb);
+ if (!wkq_err)
+ return; /* success */
+
+ AuErr("wkq %d\n", wkq_err);
+ atomic_dec(&br->br_count);
+
+ out_args:
+ kfree(args);
+ out:
+ atomic_dec(&br->br_xino_running);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static const loff_t au_loff_max = LLONG_MAX;
+
+static int au_xino_do_write(au_writef_t write, struct file *file,
+ ino_t h_ino, ino_t ino)
+{
+ loff_t pos;
+ ssize_t sz;
+
+ pos = h_ino;
+ if (unlikely(au_loff_max / sizeof(ino) - 1 < pos)) {
+ AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
+ return -EFBIG;
+ }
+ pos *= sizeof(ino);
+ sz = xino_fwrite(write, file, &ino, sizeof(ino), &pos);
+ if (sz == sizeof(ino))
+ return 0; /* success */
+
+ AuIOErr("write failed (%zd)\n", sz);
+ return -EIO;
+}
+
+/*
+ * write @ino to the xinofile for the specified branch{@sb, @bindex}
+ * at the position of @h_ino.
+ * even if @ino is zero, it is written to the xinofile and means no entry.
+ * if the size of the xino file on a specific filesystem exceeds the watermark,
+ * try truncating it.
+ */
+int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
+ ino_t ino)
+{
+ int err;
+ unsigned int mnt_flags;
+ struct au_branch *br;
+
+ BUILD_BUG_ON(sizeof(long long) != sizeof(au_loff_max)
+ || ((loff_t)-1) > 0);
+
+ mnt_flags = au_mntflags(sb);
+ if (!au_opt_test(mnt_flags, XINO))
+ return 0;
+
+ br = au_sbr(sb, bindex);
+ err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
+ h_ino, ino);
+ if (!err) {
+ if (au_opt_test(mnt_flags, TRUNC_XINO)
+ && au_test_fs_trunc_xino(br->br_mnt->mnt_sb))
+ xino_try_trunc(sb, br);
+ return 0; /* success */
+ }
+
+ AuIOErr("write failed (%d)\n", err);
+ return -EIO;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* aufs inode number bitmap */
+
+static const int page_bits = (int)PAGE_SIZE * BITS_PER_BYTE;
+static ino_t xib_calc_ino(unsigned long pindex, int bit)
+{
+ ino_t ino;
+
+ AuDebugOn(bit < 0 || page_bits <= bit);
+ ino = AUFS_FIRST_INO + pindex * page_bits + bit;
+ return ino;
+}
+
+static void xib_calc_bit(ino_t ino, unsigned long *pindex, int *bit)
+{
+ AuDebugOn(ino < AUFS_FIRST_INO);
+ ino -= AUFS_FIRST_INO;
+ *pindex = ino / page_bits;
+ *bit = ino % page_bits;
+}
+
+static int xib_pindex(struct super_block *sb, unsigned long pindex)
+{
+ int err;
+ loff_t pos;
+ ssize_t sz;
+ struct au_sbinfo *sbinfo;
+ struct file *xib;
+ unsigned long *p;
+
+ sbinfo = au_sbi(sb);
+ MtxMustLock(&sbinfo->si_xib_mtx);
+ AuDebugOn(pindex > ULONG_MAX / PAGE_SIZE
+ || !au_opt_test(sbinfo->si_mntflags, XINO));
+
+ if (pindex == sbinfo->si_xib_last_pindex)
+ return 0;
+
+ xib = sbinfo->si_xib;
+ p = sbinfo->si_xib_buf;
+ pos = sbinfo->si_xib_last_pindex;
+ pos *= PAGE_SIZE;
+ sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
+ if (unlikely(sz != PAGE_SIZE))
+ goto out;
+
+ pos = pindex;
+ pos *= PAGE_SIZE;
+ if (i_size_read(xib->f_dentry->d_inode) >= pos + PAGE_SIZE)
+ sz = xino_fread(sbinfo->si_xread, xib, p, PAGE_SIZE, &pos);
+ else {
+ memset(p, 0, PAGE_SIZE);
+ sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
+ }
+ if (sz == PAGE_SIZE) {
+ sbinfo->si_xib_last_pindex = pindex;
+ return 0; /* success */
+ }
+
+ out:
+ AuIOErr1("write failed (%zd)\n", sz);
+ err = sz;
+ if (sz >= 0)
+ err = -EIO;
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
+ ino_t ino)
+{
+ int err, bit;
+ unsigned long pindex;
+ struct au_sbinfo *sbinfo;
+
+ if (!au_opt_test(au_mntflags(sb), XINO))
+ return 0;
+
+ err = 0;
+ if (ino) {
+ sbinfo = au_sbi(sb);
+ xib_calc_bit(ino, &pindex, &bit);
+ AuDebugOn(page_bits <= bit);
+ mutex_lock(&sbinfo->si_xib_mtx);
+ err = xib_pindex(sb, pindex);
+ if (!err) {
+ clear_bit(bit, sbinfo->si_xib_buf);
+ sbinfo->si_xib_next_bit = bit;
+ }
+ mutex_unlock(&sbinfo->si_xib_mtx);
+ }
+
+ if (!err)
+ err = au_xino_write(sb, bindex, h_ino, 0);
+ return err;
+}
+
+/* get an unused inode number from bitmap */
+ino_t au_xino_new_ino(struct super_block *sb)
+{
+ ino_t ino;
+ unsigned long *p, pindex, ul, pend;
+ struct au_sbinfo *sbinfo;
+ struct file *file;
+ int free_bit, err;
+
+ if (!au_opt_test(au_mntflags(sb), XINO))
+ return iunique(sb, AUFS_FIRST_INO);
+
+ sbinfo = au_sbi(sb);
+ mutex_lock(&sbinfo->si_xib_mtx);
+ p = sbinfo->si_xib_buf;
+ free_bit = sbinfo->si_xib_next_bit;
+ if (free_bit < page_bits && !test_bit(free_bit, p))
+ goto out; /* success */
+ free_bit = find_first_zero_bit(p, page_bits);
+ if (free_bit < page_bits)
+ goto out; /* success */
+
+ pindex = sbinfo->si_xib_last_pindex;
+ for (ul = pindex - 1; ul < ULONG_MAX; ul--) {
+ err = xib_pindex(sb, ul);
+ if (unlikely(err))
+ goto out_err;
+ free_bit = find_first_zero_bit(p, page_bits);
+ if (free_bit < page_bits)
+ goto out; /* success */
+ }
+
+ file = sbinfo->si_xib;
+ pend = i_size_read(file->f_dentry->d_inode) / PAGE_SIZE;
+ for (ul = pindex + 1; ul <= pend; ul++) {
+ err = xib_pindex(sb, ul);
+ if (unlikely(err))
+ goto out_err;
+ free_bit = find_first_zero_bit(p, page_bits);
+ if (free_bit < page_bits)
+ goto out; /* success */
+ }
+ BUG();
+
+ out:
+ set_bit(free_bit, p);
+ sbinfo->si_xib_next_bit++;
+ pindex = sbinfo->si_xib_last_pindex;
+ mutex_unlock(&sbinfo->si_xib_mtx);
+ ino = xib_calc_ino(pindex, free_bit);
+ AuDbg("i%lu\n", (unsigned long)ino);
+ return ino;
+ out_err:
+ mutex_unlock(&sbinfo->si_xib_mtx);
+ AuDbg("i0\n");
+ return 0;
+}
+
+/*
+ * read @ino from xinofile for the specified branch{@sb, @bindex}
+ * at the position of @h_ino.
+ * if @ino does not exist and @do_new is true, get new one.
+ */
+int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
+ ino_t *ino)
+{
+ int err;
+ ssize_t sz;
+ loff_t pos;
+ struct file *file;
+ struct au_sbinfo *sbinfo;
+
+ *ino = 0;
+ if (!au_opt_test(au_mntflags(sb), XINO))
+ return 0; /* no xino */
+
+ err = 0;
+ sbinfo = au_sbi(sb);
+ pos = h_ino;
+ if (unlikely(au_loff_max / sizeof(*ino) - 1 < pos)) {
+ AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
+ return -EFBIG;
+ }
+ pos *= sizeof(*ino);
+
+ file = au_sbr(sb, bindex)->br_xino.xi_file;
+ if (i_size_read(file->f_dentry->d_inode) < pos + sizeof(*ino))
+ return 0; /* no ino */
+
+ sz = xino_fread(sbinfo->si_xread, file, ino, sizeof(*ino), &pos);
+ if (sz == sizeof(*ino))
+ return 0; /* success */
+
+ err = sz;
+ if (unlikely(sz >= 0)) {
+ err = -EIO;
+ AuIOErr("xino read error (%zd)\n", sz);
+ }
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* create and set a new xino file */
+
+struct file *au_xino_create(struct super_block *sb, char *fname, int silent)
+{
+ struct file *file;
+ struct dentry *h_parent, *d;
+ struct inode *h_dir;
+ int err;
+
+ /*
+ * at mount-time, and the xino file is the default path,
+ * hinotify is disabled so we have no inotify events to ignore.
+ * when a user specified the xino, we cannot get au_hdir to be ignored.
+ */
+ file = vfsub_filp_open(fname, O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE,
+ S_IRUGO | S_IWUGO);
+ if (IS_ERR(file)) {
+ if (!silent)
+ AuErr("open %s(%ld)\n", fname, PTR_ERR(file));
+ return file;
+ }
+
+ /* keep file count */
+ h_parent = dget_parent(file->f_dentry);
+ h_dir = h_parent->d_inode;
+ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
+ /* mnt_want_write() is unnecessary here */
+ err = vfsub_unlink(h_dir, &file->f_path, /*force*/0);
+ mutex_unlock(&h_dir->i_mutex);
+ dput(h_parent);
+ if (unlikely(err)) {
+ if (!silent)
+ AuErr("unlink %s(%d)\n", fname, err);
+ goto out;
+ }
+
+ err = -EINVAL;
+ d = file->f_dentry;
+ if (unlikely(sb == d->d_sb)) {
+ if (!silent)
+ AuErr("%s must be outside\n", fname);
+ goto out;
+ }
+ if (unlikely(au_test_fs_bad_xino(d->d_sb))) {
+ if (!silent)
+ AuErr("xino doesn't support %s(%s)\n",
+ fname, au_sbtype(d->d_sb));
+ goto out;
+ }
+ return file; /* success */
+
+ out:
+ fput(file);
+ file = ERR_PTR(err);
+ return file;
+}
+
+/*
+ * find another branch who is on the same filesystem of the specified
+ * branch{@btgt}. search until @bend.
+ */
+static int is_sb_shared(struct super_block *sb, aufs_bindex_t btgt,
+ aufs_bindex_t bend)
+{
+ aufs_bindex_t bindex;
+ struct super_block *tgt_sb = au_sbr_sb(sb, btgt);
+
+ for (bindex = 0; bindex < btgt; bindex++)
+ if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
+ return bindex;
+ for (bindex++; bindex <= bend; bindex++)
+ if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
+ return bindex;
+ return -1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * initialize the xinofile for the specified branch @br
+ * at the place/path where @base_file indicates.
+ * test whether another branch is on the same filesystem or not,
+ * if @do_test is true.
+ */
+int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t h_ino,
+ struct file *base_file, int do_test)
+{
+ int err;
+ ino_t ino;
+ aufs_bindex_t bend, bindex;
+ struct au_branch *shared_br, *b;
+ struct file *file;
+ struct super_block *tgt_sb;
+
+ shared_br = NULL;
+ bend = au_sbend(sb);
+ if (do_test) {
+ tgt_sb = br->br_mnt->mnt_sb;
+ for (bindex = 0; bindex <= bend; bindex++) {
+ b = au_sbr(sb, bindex);
+ if (tgt_sb == b->br_mnt->mnt_sb) {
+ shared_br = b;
+ break;
+ }
+ }
+ }
+
+ if (!shared_br || !shared_br->br_xino.xi_file) {
+ struct au_xino_lock_dir ldir;
+
+ au_xino_lock_dir(sb, base_file, &ldir);
+ /* mnt_want_write() is unnecessary here */
+ file = au_xino_create2(base_file, NULL);
+ au_xino_unlock_dir(&ldir);
+ err = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out;
+ br->br_xino.xi_file = file;
+ } else {
+ br->br_xino.xi_file = shared_br->br_xino.xi_file;
+ get_file(br->br_xino.xi_file);
+ }
+
+ ino = AUFS_ROOT_INO;
+ err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
+ h_ino, ino);
+ if (!err)
+ return 0; /* success */
+
+
+ out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* trucate a xino bitmap file */
+
+/* todo: slow */
+static int do_xib_restore(struct super_block *sb, struct file *file, void *page)
+{
+ int err, bit;
+ ssize_t sz;
+ unsigned long pindex;
+ loff_t pos, pend;
+ struct au_sbinfo *sbinfo;
+ au_readf_t func;
+ ino_t *ino;
+ unsigned long *p;
+
+ err = 0;
+ sbinfo = au_sbi(sb);
+ p = sbinfo->si_xib_buf;
+ func = sbinfo->si_xread;
+ pend = i_size_read(file->f_dentry->d_inode);
+ pos = 0;
+ while (pos < pend) {
+ sz = xino_fread(func, file, page, PAGE_SIZE, &pos);
+ err = sz;
+ if (unlikely(sz <= 0))
+ goto out;
+
+ err = 0;
+ for (ino = page; sz > 0; ino++, sz -= sizeof(ino)) {
+ if (unlikely(*ino < AUFS_FIRST_INO))
+ continue;
+
+ xib_calc_bit(*ino, &pindex, &bit);
+ AuDebugOn(page_bits <= bit);
+ err = xib_pindex(sb, pindex);
+ if (!err)
+ set_bit(bit, p);
+ else
+ goto out;
+ }
+ }
+
+ out:
+ return err;
+}
+
+static int xib_restore(struct super_block *sb)
+{
+ int err;
+ aufs_bindex_t bindex, bend;
+ void *page;
+
+ err = -ENOMEM;
+ page = (void *)__get_free_page(GFP_NOFS);
+ if (unlikely(!page))
+ goto out;
+
+ err = 0;
+ bend = au_sbend(sb);
+ for (bindex = 0; !err && bindex <= bend; bindex++)
+ if (!bindex || is_sb_shared(sb, bindex, bindex - 1) < 0)
+ err = do_xib_restore
+ (sb, au_sbr(sb, bindex)->br_xino.xi_file, page);
+ else
+ AuDbg("b%d\n", bindex);
+ free_page((unsigned long)page);
+
+ out:
+ return err;
+}
+
+int au_xib_trunc(struct super_block *sb)
+{
+ int err;
+ ssize_t sz;
+ loff_t pos;
+ struct au_xino_lock_dir ldir;
+ struct au_sbinfo *sbinfo;
+ unsigned long *p;
+ struct file *file;
+
+ err = 0;
+ sbinfo = au_sbi(sb);
+ if (!au_opt_test(sbinfo->si_mntflags, XINO))
+ goto out;
+
+ file = sbinfo->si_xib;
+ if (i_size_read(file->f_dentry->d_inode) <= PAGE_SIZE)
+ goto out;
+
+ au_xino_lock_dir(sb, file, &ldir);
+ /* mnt_want_write() is unnecessary here */
+ file = au_xino_create2(sbinfo->si_xib, NULL);
+ au_xino_unlock_dir(&ldir);
+ err = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out;
+ fput(sbinfo->si_xib);
+ sbinfo->si_xib = file;
+
+ p = sbinfo->si_xib_buf;
+ memset(p, 0, PAGE_SIZE);
+ pos = 0;
+ sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xib, p, PAGE_SIZE, &pos);
+ if (unlikely(sz != PAGE_SIZE)) {
+ err = sz;
+ AuIOErr("err %d\n", err);
+ if (sz >= 0)
+ err = -EIO;
+ goto out;
+ }
+
+ mutex_lock(&sbinfo->si_xib_mtx);
+ /* mnt_want_write() is unnecessary here */
+ err = xib_restore(sb);
+ mutex_unlock(&sbinfo->si_xib_mtx);
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * xino mount option handlers
+ */
+static au_readf_t find_readf(struct file *h_file)
+{
+ const struct file_operations *fop = h_file->f_op;
+
+ if (fop) {
+ if (fop->read)
+ return fop->read;
+ if (fop->aio_read)
+ return do_sync_read;
+ }
+ return ERR_PTR(-ENOSYS);
+}
+
+static au_writef_t find_writef(struct file *h_file)
+{
+ const struct file_operations *fop = h_file->f_op;
+
+ if (fop) {
+ if (fop->write)
+ return fop->write;
+ if (fop->aio_write)
+ return do_sync_write;
+ }
+ return ERR_PTR(-ENOSYS);
+}
+
+/* xino bitmap */
+static void xino_clear_xib(struct super_block *sb)
+{
+ struct au_sbinfo *sbinfo;
+
+ sbinfo = au_sbi(sb);
+ sbinfo->si_xread = NULL;
+ sbinfo->si_xwrite = NULL;
+ if (sbinfo->si_xib)
+ fput(sbinfo->si_xib);
+ sbinfo->si_xib = NULL;
+ free_page((unsigned long)sbinfo->si_xib_buf);
+ sbinfo->si_xib_buf = NULL;
+}
+
+static int au_xino_set_xib(struct super_block *sb, struct file *base)
+{
+ int err;
+ loff_t pos;
+ struct au_sbinfo *sbinfo;
+ struct file *file;
+
+ sbinfo = au_sbi(sb);
+ file = au_xino_create2(base, sbinfo->si_xib);
+ err = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out;
+ if (sbinfo->si_xib)
+ fput(sbinfo->si_xib);
+ sbinfo->si_xib = file;
+ sbinfo->si_xread = find_readf(file);
+ sbinfo->si_xwrite = find_writef(file);
+
+ err = -ENOMEM;
+ if (!sbinfo->si_xib_buf)
+ sbinfo->si_xib_buf = (void *)get_zeroed_page(GFP_NOFS);
+ if (unlikely(!sbinfo->si_xib_buf))
+ goto out_unset;
+
+ sbinfo->si_xib_last_pindex = 0;
+ sbinfo->si_xib_next_bit = 0;
+ if (i_size_read(file->f_dentry->d_inode) < PAGE_SIZE) {
+ pos = 0;
+ err = xino_fwrite(sbinfo->si_xwrite, file, sbinfo->si_xib_buf,
+ PAGE_SIZE, &pos);
+ if (unlikely(err != PAGE_SIZE))
+ goto out_free;
+ }
+ err = 0;
+ goto out; /* success */
+
+ out_free:
+ free_page((unsigned long)sbinfo->si_xib_buf);
+ sbinfo->si_xib_buf = NULL;
+ if (err >= 0)
+ err = -EIO;
+ out_unset:
+ fput(sbinfo->si_xib);
+ sbinfo->si_xib = NULL;
+ sbinfo->si_xread = NULL;
+ sbinfo->si_xwrite = NULL;
+ out:
+ return err;
+}
+
+/* xino for each branch */
+static void xino_clear_br(struct super_block *sb)
+{
+ aufs_bindex_t bindex, bend;
+ struct au_branch *br;
+
+ bend = au_sbend(sb);
+ for (bindex = 0; bindex <= bend; bindex++) {
+ br = au_sbr(sb, bindex);
+ if (!br || !br->br_xino.xi_file)
+ continue;
+
+ fput(br->br_xino.xi_file);
+ br->br_xino.xi_file = NULL;
+ }
+}
+
+static int au_xino_set_br(struct super_block *sb, struct file *base)
+{
+ int err;
+ ino_t ino;
+ aufs_bindex_t bindex, bend, bshared;
+ struct {
+ struct file *old, *new;
+ } *fpair, *p;
+ struct au_branch *br;
+ struct inode *inode;
+ au_writef_t writef;
+
+ err = -ENOMEM;
+ bend = au_sbend(sb);
+ fpair = kcalloc(bend + 1, sizeof(*fpair), GFP_NOFS);
+ if (unlikely(!fpair))
+ goto out;
+
+ inode = sb->s_root->d_inode;
+ ino = AUFS_ROOT_INO;
+ writef = au_sbi(sb)->si_xwrite;
+ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
+ br = au_sbr(sb, bindex);
+ bshared = is_sb_shared(sb, bindex, bindex - 1);
+ if (bshared >= 0) {
+ /* shared xino */
+ *p = fpair[bshared];
+ get_file(p->new);
+ }
+
+ if (!p->new) {
+ /* new xino */
+ p->old = br->br_xino.xi_file;
+ p->new = au_xino_create2(base, br->br_xino.xi_file);
+ err = PTR_ERR(p->new);
+ if (IS_ERR(p->new)) {
+ p->new = NULL;
+ goto out_pair;
+ }
+ }
+
+ err = au_xino_do_write(writef, p->new,
+ au_h_iptr(inode, bindex)->i_ino, ino);
+ if (unlikely(err))
+ goto out_pair;
+ }
+
+ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
+ br = au_sbr(sb, bindex);
+ if (br->br_xino.xi_file)
+ fput(br->br_xino.xi_file);
+ get_file(p->new);
+ br->br_xino.xi_file = p->new;
+ }
+
+ out_pair:
+ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++)
+ if (p->new)
+ fput(p->new);
+ else
+ break;
+ kfree(fpair);
+ out:
+ return err;
+}
+
+void au_xino_clr(struct super_block *sb)
+{
+ struct au_sbinfo *sbinfo;
+
+ xino_clear_xib(sb);
+ xino_clear_br(sb);
+ sbinfo = au_sbi(sb);
+ /* lvalue, do not call au_mntflags() */
+ au_opt_clr(sbinfo->si_mntflags, XINO);
+}
+
+int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount)
+{
+ int err, skip;
+ struct dentry *parent, *cur_parent;
+ struct qstr *dname, *cur_name;
+ struct file *cur_xino;
+ struct inode *dir;
+ struct au_sbinfo *sbinfo;
+
+ err = 0;
+ sbinfo = au_sbi(sb);
+ parent = dget_parent(xino->file->f_dentry);
+ if (remount) {
+ skip = 0;
+ dname = &xino->file->f_dentry->d_name;
+ cur_xino = sbinfo->si_xib;
+ if (cur_xino) {
+ cur_parent = dget_parent(cur_xino->f_dentry);
+ cur_name = &cur_xino->f_dentry->d_name;
+ skip = (cur_parent == parent
+ && dname->len == cur_name->len
+ && !memcmp(dname->name, cur_name->name,
+ dname->len));
+ dput(cur_parent);
+ }
+ if (skip)
+ goto out;
+ }
+
+ au_opt_set(sbinfo->si_mntflags, XINO);
+ dir = parent->d_inode;
+ mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
+ /* mnt_want_write() is unnecessary here */
+ err = au_xino_set_xib(sb, xino->file);
+ if (!err)
+ err = au_xino_set_br(sb, xino->file);
+ mutex_unlock(&dir->i_mutex);
+ if (!err)
+ goto out; /* success */
+
+ /* reset all */
+ AuIOErr("failed creating xino(%d).\n", err);
+
+ out:
+ dput(parent);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * create a xinofile at the default place/path.
+ */
+struct file *au_xino_def(struct super_block *sb)
+{
+ struct file *file;
+ char *page, *p;
+ struct au_branch *br;
+ struct super_block *h_sb;
+ struct path path;
+ aufs_bindex_t bend, bindex, bwr;
+
+ br = NULL;
+ bend = au_sbend(sb);
+ bwr = -1;
+ for (bindex = 0; bindex <= bend; bindex++) {
+ br = au_sbr(sb, bindex);
+ if (au_br_writable(br->br_perm)
+ && !au_test_fs_bad_xino(br->br_mnt->mnt_sb)) {
+ bwr = bindex;
+ break;
+ }
+ }
+
+ if (bwr >= 0) {
+ file = ERR_PTR(-ENOMEM);
+ page = __getname();
+ if (unlikely(!page))
+ goto out;
+ path.mnt = br->br_mnt;
+ path.dentry = au_h_dptr(sb->s_root, bwr);
+ p = d_path(&path, page, PATH_MAX - sizeof(AUFS_XINO_FNAME));
+ file = (void *)p;
+ if (!IS_ERR(p)) {
+ strcat(p, "/" AUFS_XINO_FNAME);
+ AuDbg("%s\n", p);
+ file = au_xino_create(sb, p, /*silent*/0);
+ if (!IS_ERR(file))
+ au_xino_brid_set(sb, br->br_id);
+ }
+ __putname(page);
+ } else {
+ file = au_xino_create(sb, AUFS_XINO_DEFPATH, /*silent*/0);
+ if (IS_ERR(file))
+ goto out;
+ h_sb = file->f_dentry->d_sb;
+ if (unlikely(au_test_fs_bad_xino(h_sb))) {
+ AuErr("xino doesn't support %s(%s)\n",
+ AUFS_XINO_DEFPATH, au_sbtype(h_sb));
+ fput(file);
+ file = ERR_PTR(-EINVAL);
+ }
+ if (!IS_ERR(file))
+ au_xino_brid_set(sb, -1);
+ }
+
+ out:
+ return file;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_xino_path(struct seq_file *seq, struct file *file)
+{
+ int err;
+
+ err = au_seq_path(seq, &file->f_path);
+ if (unlikely(err < 0))
+ goto out;
+
+ err = 0;
+#define Deleted "\\040(deleted)"
+ seq->count -= sizeof(Deleted) - 1;
+ AuDebugOn(memcmp(seq->buf + seq->count, Deleted,
+ sizeof(Deleted) - 1));
+#undef Deleted