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-rw-r--r--fs/aufs/branch.c1414
1 files changed, 1414 insertions, 0 deletions
diff --git a/fs/aufs/branch.c b/fs/aufs/branch.c
new file mode 100644
index 000000000..2ec496438
--- /dev/null
+++ b/fs/aufs/branch.c
@@ -0,0 +1,1414 @@
+/*
+ * 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/>.
+ */
+
+/*
+ * branch management
+ */
+
+#include <linux/compat.h>
+#include <linux/statfs.h>
+#include "aufs.h"
+
+/*
+ * free a single branch
+ */
+static void au_br_do_free(struct au_branch *br)
+{
+ int i;
+ struct au_wbr *wbr;
+ struct au_dykey **key;
+
+ au_hnotify_fin_br(br);
+
+ if (br->br_xino.xi_file)
+ fput(br->br_xino.xi_file);
+ mutex_destroy(&br->br_xino.xi_nondir_mtx);
+
+ AuDebugOn(atomic_read(&br->br_count));
+
+ wbr = br->br_wbr;
+ if (wbr) {
+ for (i = 0; i < AuBrWh_Last; i++)
+ dput(wbr->wbr_wh[i]);
+ AuDebugOn(atomic_read(&wbr->wbr_wh_running));
+ AuRwDestroy(&wbr->wbr_wh_rwsem);
+ }
+
+ if (br->br_fhsm) {
+ au_br_fhsm_fin(br->br_fhsm);
+ kfree(br->br_fhsm);
+ }
+
+ key = br->br_dykey;
+ for (i = 0; i < AuBrDynOp; i++, key++)
+ if (*key)
+ au_dy_put(*key);
+ else
+ break;
+
+ /* recursive lock, s_umount of branch's */
+ lockdep_off();
+ path_put(&br->br_path);
+ lockdep_on();
+ kfree(wbr);
+ kfree(br);
+}
+
+/*
+ * frees all branches
+ */
+void au_br_free(struct au_sbinfo *sbinfo)
+{
+ aufs_bindex_t bmax;
+ struct au_branch **br;
+
+ AuRwMustWriteLock(&sbinfo->si_rwsem);
+
+ bmax = sbinfo->si_bend + 1;
+ br = sbinfo->si_branch;
+ while (bmax--)
+ au_br_do_free(*br++);
+}
+
+/*
+ * find the index of a branch which is specified by @br_id.
+ */
+int au_br_index(struct super_block *sb, aufs_bindex_t br_id)
+{
+ aufs_bindex_t bindex, bend;
+
+ bend = au_sbend(sb);
+ for (bindex = 0; bindex <= bend; bindex++)
+ if (au_sbr_id(sb, bindex) == br_id)
+ return bindex;
+ return -1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * add a branch
+ */
+
+static int test_overlap(struct super_block *sb, struct dentry *h_adding,
+ struct dentry *h_root)
+{
+ if (unlikely(h_adding == h_root
+ || au_test_loopback_overlap(sb, h_adding)))
+ return 1;
+ if (h_adding->d_sb != h_root->d_sb)
+ return 0;
+ return au_test_subdir(h_adding, h_root)
+ || au_test_subdir(h_root, h_adding);
+}
+
+/*
+ * returns a newly allocated branch. @new_nbranch is a number of branches
+ * after adding a branch.
+ */
+static struct au_branch *au_br_alloc(struct super_block *sb, int new_nbranch,
+ int perm)
+{
+ struct au_branch *add_branch;
+ struct dentry *root;
+ struct inode *inode;
+ int err;
+
+ err = -ENOMEM;
+ root = sb->s_root;
+ add_branch = kmalloc(sizeof(*add_branch), GFP_NOFS);
+ if (unlikely(!add_branch))
+ goto out;
+
+ err = au_hnotify_init_br(add_branch, perm);
+ if (unlikely(err))
+ goto out_br;
+
+ add_branch->br_wbr = NULL;
+ if (au_br_writable(perm)) {
+ /* may be freed separately at changing the branch permission */
+ add_branch->br_wbr = kmalloc(sizeof(*add_branch->br_wbr),
+ GFP_NOFS);
+ if (unlikely(!add_branch->br_wbr))
+ goto out_hnotify;
+ }
+
+ add_branch->br_fhsm = NULL;
+ if (au_br_fhsm(perm)) {
+ err = au_fhsm_br_alloc(add_branch);
+ if (unlikely(err))
+ goto out_wbr;
+ }
+
+ err = au_sbr_realloc(au_sbi(sb), new_nbranch);
+ if (!err)
+ err = au_di_realloc(au_di(root), new_nbranch);
+ if (!err) {
+ inode = d_inode(root);
+ err = au_ii_realloc(au_ii(inode), new_nbranch);
+ }
+ if (!err)
+ return add_branch; /* success */
+
+out_wbr:
+ kfree(add_branch->br_wbr);
+out_hnotify:
+ au_hnotify_fin_br(add_branch);
+out_br:
+ kfree(add_branch);
+out:
+ return ERR_PTR(err);
+}
+
+/*
+ * test if the branch permission is legal or not.
+ */
+static int test_br(struct inode *inode, int brperm, char *path)
+{
+ int err;
+
+ err = (au_br_writable(brperm) && IS_RDONLY(inode));
+ if (!err)
+ goto out;
+
+ err = -EINVAL;
+ pr_err("write permission for readonly mount or inode, %s\n", path);
+
+out:
+ return err;
+}
+
+/*
+ * returns:
+ * 0: success, the caller will add it
+ * plus: success, it is already unified, the caller should ignore it
+ * minus: error
+ */
+static int test_add(struct super_block *sb, struct au_opt_add *add, int remount)
+{
+ int err;
+ aufs_bindex_t bend, bindex;
+ struct dentry *root, *h_dentry;
+ struct inode *inode, *h_inode;
+
+ root = sb->s_root;
+ bend = au_sbend(sb);
+ if (unlikely(bend >= 0
+ && au_find_dbindex(root, add->path.dentry) >= 0)) {
+ err = 1;
+ if (!remount) {
+ err = -EINVAL;
+ pr_err("%s duplicated\n", add->pathname);
+ }
+ goto out;
+ }
+
+ err = -ENOSPC; /* -E2BIG; */
+ if (unlikely(AUFS_BRANCH_MAX <= add->bindex
+ || AUFS_BRANCH_MAX - 1 <= bend)) {
+ pr_err("number of branches exceeded %s\n", add->pathname);
+ goto out;
+ }
+
+ err = -EDOM;
+ if (unlikely(add->bindex < 0 || bend + 1 < add->bindex)) {
+ pr_err("bad index %d\n", add->bindex);
+ goto out;
+ }
+
+ inode = d_inode(add->path.dentry);
+ err = -ENOENT;
+ if (unlikely(!inode->i_nlink)) {
+ pr_err("no existence %s\n", add->pathname);
+ goto out;
+ }
+
+ err = -EINVAL;
+ if (unlikely(inode->i_sb == sb)) {
+ pr_err("%s must be outside\n", add->pathname);
+ goto out;
+ }
+
+ if (unlikely(au_test_fs_unsuppoted(inode->i_sb))) {
+ pr_err("unsupported filesystem, %s (%s)\n",
+ add->pathname, au_sbtype(inode->i_sb));
+ goto out;
+ }
+
+ if (unlikely(inode->i_sb->s_stack_depth)) {
+ pr_err("already stacked, %s (%s)\n",
+ add->pathname, au_sbtype(inode->i_sb));
+ goto out;
+ }
+
+ err = test_br(d_inode(add->path.dentry), add->perm, add->pathname);
+ if (unlikely(err))
+ goto out;
+
+ if (bend < 0)
+ return 0; /* success */
+
+ err = -EINVAL;
+ for (bindex = 0; bindex <= bend; bindex++)
+ if (unlikely(test_overlap(sb, add->path.dentry,
+ au_h_dptr(root, bindex)))) {
+ pr_err("%s is overlapped\n", add->pathname);
+ goto out;
+ }
+
+ err = 0;
+ if (au_opt_test(au_mntflags(sb), WARN_PERM)) {
+ h_dentry = au_h_dptr(root, 0);
+ h_inode = d_inode(h_dentry);
+ if ((h_inode->i_mode & S_IALLUGO) != (inode->i_mode & S_IALLUGO)
+ || !uid_eq(h_inode->i_uid, inode->i_uid)
+ || !gid_eq(h_inode->i_gid, inode->i_gid))
+ pr_warn("uid/gid/perm %s %u/%u/0%o, %u/%u/0%o\n",
+ add->pathname,
+ i_uid_read(inode), i_gid_read(inode),
+ (inode->i_mode & S_IALLUGO),
+ i_uid_read(h_inode), i_gid_read(h_inode),
+ (h_inode->i_mode & S_IALLUGO));
+ }
+
+out:
+ return err;
+}
+
+/*
+ * initialize or clean the whiteouts for an adding branch
+ */
+static int au_br_init_wh(struct super_block *sb, struct au_branch *br,
+ int new_perm)
+{
+ int err, old_perm;
+ aufs_bindex_t bindex;
+ struct mutex *h_mtx;
+ struct au_wbr *wbr;
+ struct au_hinode *hdir;
+ struct dentry *h_dentry;
+
+ err = vfsub_mnt_want_write(au_br_mnt(br));
+ if (unlikely(err))
+ goto out;
+
+ wbr = br->br_wbr;
+ old_perm = br->br_perm;
+ br->br_perm = new_perm;
+ hdir = NULL;
+ h_mtx = NULL;
+ bindex = au_br_index(sb, br->br_id);
+ if (0 <= bindex) {
+ hdir = au_hi(d_inode(sb->s_root), bindex);
+ au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
+ } else {
+ h_dentry = au_br_dentry(br);
+ h_mtx = &d_inode(h_dentry)->i_mutex;
+ mutex_lock_nested(h_mtx, AuLsc_I_PARENT);
+ }
+ if (!wbr)
+ err = au_wh_init(br, sb);
+ else {
+ wbr_wh_write_lock(wbr);
+ err = au_wh_init(br, sb);
+ wbr_wh_write_unlock(wbr);
+ }
+ if (hdir)
+ au_hn_imtx_unlock(hdir);
+ else
+ mutex_unlock(h_mtx);
+ vfsub_mnt_drop_write(au_br_mnt(br));
+ br->br_perm = old_perm;
+
+ if (!err && wbr && !au_br_writable(new_perm)) {
+ kfree(wbr);
+ br->br_wbr = NULL;
+ }
+
+out:
+ return err;
+}
+
+static int au_wbr_init(struct au_branch *br, struct super_block *sb,
+ int perm)
+{
+ int err;
+ struct kstatfs kst;
+ struct au_wbr *wbr;
+
+ wbr = br->br_wbr;
+ au_rw_init(&wbr->wbr_wh_rwsem);
+ memset(wbr->wbr_wh, 0, sizeof(wbr->wbr_wh));
+ atomic_set(&wbr->wbr_wh_running, 0);
+ wbr->wbr_bytes = 0;
+
+ /*
+ * a limit for rmdir/rename a dir
+ * cf. AUFS_MAX_NAMELEN in include/uapi/linux/aufs_type.h
+ */
+ err = vfs_statfs(&br->br_path, &kst);
+ if (unlikely(err))
+ goto out;
+ err = -EINVAL;
+ if (kst.f_namelen >= NAME_MAX)
+ err = au_br_init_wh(sb, br, perm);
+ else
+ pr_err("%pd(%s), unsupported namelen %ld\n",
+ au_br_dentry(br),
+ au_sbtype(au_br_dentry(br)->d_sb), kst.f_namelen);
+
+out:
+ return err;
+}
+
+/* initialize a new branch */
+static int au_br_init(struct au_branch *br, struct super_block *sb,
+ struct au_opt_add *add)
+{
+ int err;
+ struct inode *h_inode;
+
+ err = 0;
+ memset(&br->br_xino, 0, sizeof(br->br_xino));
+ mutex_init(&br->br_xino.xi_nondir_mtx);
+ br->br_perm = add->perm;
+ br->br_path = add->path; /* set first, path_get() later */
+ spin_lock_init(&br->br_dykey_lock);
+ memset(br->br_dykey, 0, sizeof(br->br_dykey));
+ atomic_set(&br->br_count, 0);
+ atomic_set(&br->br_xino_running, 0);
+ br->br_id = au_new_br_id(sb);
+ AuDebugOn(br->br_id < 0);
+
+ if (au_br_writable(add->perm)) {
+ err = au_wbr_init(br, sb, add->perm);
+ if (unlikely(err))
+ goto out_err;
+ }
+
+ if (au_opt_test(au_mntflags(sb), XINO)) {
+ h_inode = d_inode(add->path.dentry);
+ err = au_xino_br(sb, br, h_inode->i_ino,
+ au_sbr(sb, 0)->br_xino.xi_file, /*do_test*/1);
+ if (unlikely(err)) {
+ AuDebugOn(br->br_xino.xi_file);
+ goto out_err;
+ }
+ }
+
+ sysaufs_br_init(br);
+ path_get(&br->br_path);
+ goto out; /* success */
+
+out_err:
+ memset(&br->br_path, 0, sizeof(br->br_path));
+out:
+ return err;
+}
+
+static void au_br_do_add_brp(struct au_sbinfo *sbinfo, aufs_bindex_t bindex,
+ struct au_branch *br, aufs_bindex_t bend,
+ aufs_bindex_t amount)
+{
+ struct au_branch **brp;
+
+ AuRwMustWriteLock(&sbinfo->si_rwsem);
+
+ brp = sbinfo->si_branch + bindex;
+ memmove(brp + 1, brp, sizeof(*brp) * amount);
+ *brp = br;
+ sbinfo->si_bend++;
+ if (unlikely(bend < 0))
+ sbinfo->si_bend = 0;
+}
+
+static void au_br_do_add_hdp(struct au_dinfo *dinfo, aufs_bindex_t bindex,
+ aufs_bindex_t bend, aufs_bindex_t amount)
+{
+ struct au_hdentry *hdp;
+
+ AuRwMustWriteLock(&dinfo->di_rwsem);
+
+ hdp = dinfo->di_hdentry + bindex;
+ memmove(hdp + 1, hdp, sizeof(*hdp) * amount);
+ au_h_dentry_init(hdp);
+ dinfo->di_bend++;
+ if (unlikely(bend < 0))
+ dinfo->di_bstart = 0;
+}
+
+static void au_br_do_add_hip(struct au_iinfo *iinfo, aufs_bindex_t bindex,
+ aufs_bindex_t bend, aufs_bindex_t amount)
+{
+ struct au_hinode *hip;
+
+ AuRwMustWriteLock(&iinfo->ii_rwsem);
+
+ hip = iinfo->ii_hinode + bindex;
+ memmove(hip + 1, hip, sizeof(*hip) * amount);
+ hip->hi_inode = NULL;
+ au_hn_init(hip);
+ iinfo->ii_bend++;
+ if (unlikely(bend < 0))
+ iinfo->ii_bstart = 0;
+}
+
+static void au_br_do_add(struct super_block *sb, struct au_branch *br,
+ aufs_bindex_t bindex)
+{
+ struct dentry *root, *h_dentry;
+ struct inode *root_inode, *h_inode;
+ aufs_bindex_t bend, amount;
+
+ root = sb->s_root;
+ root_inode = d_inode(root);
+ bend = au_sbend(sb);
+ amount = bend + 1 - bindex;
+ h_dentry = au_br_dentry(br);
+ au_sbilist_lock();
+ au_br_do_add_brp(au_sbi(sb), bindex, br, bend, amount);
+ au_br_do_add_hdp(au_di(root), bindex, bend, amount);
+ au_br_do_add_hip(au_ii(root_inode), bindex, bend, amount);
+ au_set_h_dptr(root, bindex, dget(h_dentry));
+ h_inode = d_inode(h_dentry);
+ au_set_h_iptr(root_inode, bindex, au_igrab(h_inode), /*flags*/0);
+ au_sbilist_unlock();
+}
+
+int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount)
+{
+ int err;
+ aufs_bindex_t bend, add_bindex;
+ struct dentry *root, *h_dentry;
+ struct inode *root_inode;
+ struct au_branch *add_branch;
+
+ root = sb->s_root;
+ root_inode = d_inode(root);
+ IMustLock(root_inode);
+ err = test_add(sb, add, remount);
+ if (unlikely(err < 0))
+ goto out;
+ if (err) {
+ err = 0;
+ goto out; /* success */
+ }
+
+ bend = au_sbend(sb);
+ add_branch = au_br_alloc(sb, bend + 2, add->perm);
+ err = PTR_ERR(add_branch);
+ if (IS_ERR(add_branch))
+ goto out;
+
+ err = au_br_init(add_branch, sb, add);
+ if (unlikely(err)) {
+ au_br_do_free(add_branch);
+ goto out;
+ }
+
+ add_bindex = add->bindex;
+ if (!remount)
+ au_br_do_add(sb, add_branch, add_bindex);
+ else {
+ sysaufs_brs_del(sb, add_bindex);
+ au_br_do_add(sb, add_branch, add_bindex);
+ sysaufs_brs_add(sb, add_bindex);
+ }
+
+ h_dentry = add->path.dentry;
+ if (!add_bindex) {
+ au_cpup_attr_all(root_inode, /*force*/1);
+ sb->s_maxbytes = h_dentry->d_sb->s_maxbytes;
+ } else
+ au_add_nlink(root_inode, d_inode(h_dentry));
+
+ /*
+ * this test/set prevents aufs from handling unnecesary notify events
+ * of xino files, in case of re-adding a writable branch which was
+ * once detached from aufs.
+ */
+ if (au_xino_brid(sb) < 0
+ && au_br_writable(add_branch->br_perm)
+ && !au_test_fs_bad_xino(h_dentry->d_sb)
+ && add_branch->br_xino.xi_file
+ && add_branch->br_xino.xi_file->f_path.dentry->d_parent == h_dentry)
+ au_xino_brid_set(sb, add_branch->br_id);
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static unsigned long long au_farray_cb(void *a,
+ unsigned long long max __maybe_unused,
+ void *arg)
+{
+ unsigned long long n;
+ struct file **p, *f;
+ struct au_sphlhead *files;
+ struct au_finfo *finfo;
+ struct super_block *sb = arg;
+
+ n = 0;
+ p = a;
+ files = &au_sbi(sb)->si_files;
+ spin_lock(&files->spin);
+ hlist_for_each_entry(finfo, &files->head, fi_hlist) {
+ f = finfo->fi_file;
+ if (file_count(f)
+ && !special_file(file_inode(f)->i_mode)) {
+ get_file(f);
+ *p++ = f;
+ n++;
+ AuDebugOn(n > max);
+ }
+ }
+ spin_unlock(&files->spin);
+
+ return n;
+}
+
+static struct file **au_farray_alloc(struct super_block *sb,
+ unsigned long long *max)
+{
+ *max = atomic_long_read(&au_sbi(sb)->si_nfiles);
+ return au_array_alloc(max, au_farray_cb, sb);
+}
+
+static void au_farray_free(struct file **a, unsigned long long max)
+{
+ unsigned long long ull;
+
+ for (ull = 0; ull < max; ull++)
+ if (a[ull])
+ fput(a[ull]);
+ au_array_free(a);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * delete a branch
+ */
+
+/* to show the line number, do not make it inlined function */
+#define AuVerbose(do_info, fmt, ...) do { \
+ if (do_info) \
+ pr_info(fmt, ##__VA_ARGS__); \
+} while (0)
+
+static int au_test_ibusy(struct inode *inode, aufs_bindex_t bstart,
+ aufs_bindex_t bend)
+{
+ return (inode && !S_ISDIR(inode->i_mode)) || bstart == bend;
+}
+
+static int au_test_dbusy(struct dentry *dentry, aufs_bindex_t bstart,
+ aufs_bindex_t bend)
+{
+ return au_test_ibusy(d_inode(dentry), bstart, bend);
+}
+
+/*
+ * test if the branch is deletable or not.
+ */
+static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
+ unsigned int sigen, const unsigned int verbose)
+{
+ int err, i, j, ndentry;
+ aufs_bindex_t bstart, bend;
+ struct au_dcsub_pages dpages;
+ struct au_dpage *dpage;
+ struct dentry *d;
+
+ err = au_dpages_init(&dpages, GFP_NOFS);
+ if (unlikely(err))
+ goto out;
+ err = au_dcsub_pages(&dpages, root, NULL, NULL);
+ if (unlikely(err))
+ goto out_dpages;
+
+ for (i = 0; !err && i < dpages.ndpage; i++) {
+ dpage = dpages.dpages + i;
+ ndentry = dpage->ndentry;
+ for (j = 0; !err && j < ndentry; j++) {
+ d = dpage->dentries[j];
+ AuDebugOn(au_dcount(d) <= 0);
+ if (!au_digen_test(d, sigen)) {
+ di_read_lock_child(d, AuLock_IR);
+ if (unlikely(au_dbrange_test(d))) {
+ di_read_unlock(d, AuLock_IR);
+ continue;
+ }
+ } else {
+ di_write_lock_child(d);
+ if (unlikely(au_dbrange_test(d))) {
+ di_write_unlock(d);
+ continue;
+ }
+ err = au_reval_dpath(d, sigen);
+ if (!err)
+ di_downgrade_lock(d, AuLock_IR);
+ else {
+ di_write_unlock(d);
+ break;
+ }
+ }
+
+ /* AuDbgDentry(d); */
+ bstart = au_dbstart(d);
+ bend = au_dbend(d);
+ if (bstart <= bindex
+ && bindex <= bend
+ && au_h_dptr(d, bindex)
+ && au_test_dbusy(d, bstart, bend)) {
+ err = -EBUSY;
+ AuVerbose(verbose, "busy %pd\n", d);
+ AuDbgDentry(d);
+ }
+ di_read_unlock(d, AuLock_IR);
+ }
+ }
+
+out_dpages:
+ au_dpages_free(&dpages);
+out:
+ return err;
+}
+
+static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
+ unsigned int sigen, const unsigned int verbose)
+{
+ int err;
+ unsigned long long max, ull;
+ struct inode *i, **array;
+ aufs_bindex_t bstart, bend;
+
+ array = au_iarray_alloc(sb, &max);
+ err = PTR_ERR(array);
+ if (IS_ERR(array))
+ goto out;
+
+ err = 0;
+ AuDbg("b%d\n", bindex);
+ for (ull = 0; !err && ull < max; ull++) {
+ i = array[ull];
+ if (unlikely(!i))
+ break;
+ if (i->i_ino == AUFS_ROOT_INO)
+ continue;
+
+ /* AuDbgInode(i); */
+ if (au_iigen(i, NULL) == sigen)
+ ii_read_lock_child(i);
+ else {
+ ii_write_lock_child(i);
+ err = au_refresh_hinode_self(i);
+ au_iigen_dec(i);
+ if (!err)
+ ii_downgrade_lock(i);
+ else {
+ ii_write_unlock(i);
+ break;
+ }
+ }
+
+ bstart = au_ibstart(i);
+ bend = au_ibend(i);
+ if (bstart <= bindex
+ && bindex <= bend
+ && au_h_iptr(i, bindex)
+ && au_test_ibusy(i, bstart, bend)) {
+ err = -EBUSY;
+ AuVerbose(verbose, "busy i%lu\n", i->i_ino);
+ AuDbgInode(i);
+ }
+ ii_read_unlock(i);
+ }
+ au_iarray_free(array, max);
+
+out:
+ return err;
+}
+
+static int test_children_busy(struct dentry *root, aufs_bindex_t bindex,
+ const unsigned int verbose)
+{
+ int err;
+ unsigned int sigen;
+
+ sigen = au_sigen(root->d_sb);
+ DiMustNoWaiters(root);
+ IiMustNoWaiters(d_inode(root));
+ di_write_unlock(root);
+ err = test_dentry_busy(root, bindex, sigen, verbose);
+ if (!err)
+ err = test_inode_busy(root->d_sb, bindex, sigen, verbose);
+ di_write_lock_child(root); /* aufs_write_lock() calls ..._child() */
+
+ return err;
+}
+
+static int test_dir_busy(struct file *file, aufs_bindex_t br_id,
+ struct file **to_free, int *idx)
+{
+ int err;
+ unsigned char matched, root;
+ aufs_bindex_t bindex, bend;
+ struct au_fidir *fidir;
+ struct au_hfile *hfile;
+
+ err = 0;
+ root = IS_ROOT(file->f_path.dentry);
+ if (root) {
+ get_file(file);
+ to_free[*idx] = file;
+ (*idx)++;
+ goto out;
+ }
+
+ matched = 0;
+ fidir = au_fi(file)->fi_hdir;
+ AuDebugOn(!fidir);
+ bend = au_fbend_dir(file);
+ for (bindex = au_fbstart(file); bindex <= bend; bindex++) {
+ hfile = fidir->fd_hfile + bindex;
+ if (!hfile->hf_file)
+ continue;
+
+ if (hfile->hf_br->br_id == br_id) {
+ matched = 1;
+ break;
+ }
+ }
+ if (matched)
+ err = -EBUSY;
+
+out:
+ return err;
+}
+
+static int test_file_busy(struct super_block *sb, aufs_bindex_t br_id,
+ struct file **to_free, int opened)
+{
+ int err, idx;
+ unsigned long long ull, max;
+ aufs_bindex_t bstart;
+ struct file *file, **array;
+ struct dentry *root;
+ struct au_hfile *hfile;
+
+ array = au_farray_alloc(sb, &max);
+ err = PTR_ERR(array);
+ if (IS_ERR(array))
+ goto out;
+
+ err = 0;
+ idx = 0;
+ root = sb->s_root;
+ di_write_unlock(root);
+ for (ull = 0; ull < max; ull++) {
+ file = array[ull];
+ if (unlikely(!file))
+ break;
+
+ /* AuDbg("%pD\n", file); */
+ fi_read_lock(file);
+ bstart = au_fbstart(file);
+ if (!d_is_dir(file->f_path.dentry)) {
+ hfile = &au_fi(file)->fi_htop;
+ if (hfile->hf_br->br_id == br_id)
+ err = -EBUSY;
+ } else
+ err = test_dir_busy(file, br_id, to_free, &idx);
+ fi_read_unlock(file);
+ if (unlikely(err))
+ break;
+ }
+ di_write_lock_child(root);
+ au_farray_free(array, max);
+ AuDebugOn(idx > opened);
+
+out:
+ return err;
+}
+
+static void br_del_file(struct file **to_free, unsigned long long opened,
+ aufs_bindex_t br_id)
+{
+ unsigned long long ull;
+ aufs_bindex_t bindex, bstart, bend, bfound;
+ struct file *file;
+ struct au_fidir *fidir;
+ struct au_hfile *hfile;
+
+ for (ull = 0; ull < opened; ull++) {
+ file = to_free[ull];
+ if (unlikely(!file))
+ break;
+
+ /* AuDbg("%pD\n", file); */
+ AuDebugOn(!d_is_dir(file->f_path.dentry));
+ bfound = -1;
+ fidir = au_fi(file)->fi_hdir;
+ AuDebugOn(!fidir);
+ fi_write_lock(file);
+ bstart = au_fbstart(file);
+ bend = au_fbend_dir(file);
+ for (bindex = bstart; bindex <= bend; bindex++) {
+ hfile = fidir->fd_hfile + bindex;
+ if (!hfile->hf_file)
+ continue;
+
+ if (hfile->hf_br->br_id == br_id) {
+ bfound = bindex;
+ break;
+ }
+ }
+ AuDebugOn(bfound < 0);
+ au_set_h_fptr(file, bfound, NULL);
+ if (bfound == bstart) {
+ for (bstart++; bstart <= bend; bstart++)
+ if (au_hf_dir(file, bstart)) {
+ au_set_fbstart(file, bstart);
+ break;
+ }
+ }
+ fi_write_unlock(file);
+ }
+}
+
+static void au_br_do_del_brp(struct au_sbinfo *sbinfo,
+ const aufs_bindex_t bindex,
+ const aufs_bindex_t bend)
+{
+ struct au_branch **brp, **p;
+
+ AuRwMustWriteLock(&sbinfo->si_rwsem);
+
+ brp = sbinfo->si_branch + bindex;
+ if (bindex < bend)
+ memmove(brp, brp + 1, sizeof(*brp) * (bend - bindex));
+ sbinfo->si_branch[0 + bend] = NULL;
+ sbinfo->si_bend--;
+
+ p = krealloc(sbinfo->si_branch, sizeof(*p) * bend, AuGFP_SBILIST);
+ if (p)
+ sbinfo->si_branch = p;
+ /* harmless error */
+}
+
+static void au_br_do_del_hdp(struct au_dinfo *dinfo, const aufs_bindex_t bindex,
+ const aufs_bindex_t bend)
+{
+ struct au_hdentry *hdp, *p;
+
+ AuRwMustWriteLock(&dinfo->di_rwsem);
+
+ hdp = dinfo->di_hdentry;
+ if (bindex < bend)
+ memmove(hdp + bindex, hdp + bindex + 1,
+ sizeof(*hdp) * (bend - bindex));
+ hdp[0 + bend].hd_dentry = NULL;
+ dinfo->di_bend--;
+
+ p = krealloc(hdp, sizeof(*p) * bend, AuGFP_SBILIST);
+ if (p)
+ dinfo->di_hdentry = p;
+ /* harmless error */
+}
+
+static void au_br_do_del_hip(struct au_iinfo *iinfo, const aufs_bindex_t bindex,
+ const aufs_bindex_t bend)
+{
+ struct au_hinode *hip, *p;
+
+ AuRwMustWriteLock(&iinfo->ii_rwsem);
+
+ hip = iinfo->ii_hinode + bindex;
+ if (bindex < bend)
+ memmove(hip, hip + 1, sizeof(*hip) * (bend - bindex));
+ iinfo->ii_hinode[0 + bend].hi_inode = NULL;
+ au_hn_init(iinfo->ii_hinode + bend);
+ iinfo->ii_bend--;
+
+ p = krealloc(iinfo->ii_hinode, sizeof(*p) * bend, AuGFP_SBILIST);
+ if (p)
+ iinfo->ii_hinode = p;
+ /* harmless error */
+}
+
+static void au_br_do_del(struct super_block *sb, aufs_bindex_t bindex,
+ struct au_branch *br)
+{
+ aufs_bindex_t bend;
+ struct au_sbinfo *sbinfo;
+ struct dentry *root, *h_root;
+ struct inode *inode, *h_inode;
+ struct au_hinode *hinode;
+
+ SiMustWriteLock(sb);
+
+ root = sb->s_root;
+ inode = d_inode(root);
+ sbinfo = au_sbi(sb);
+ bend = sbinfo->si_bend;
+
+ h_root = au_h_dptr(root, bindex);
+ hinode = au_hi(inode, bindex);
+ h_inode = au_igrab(hinode->hi_inode);
+ au_hiput(hinode);
+
+ au_sbilist_lock();
+ au_br_do_del_brp(sbinfo, bindex, bend);
+ au_br_do_del_hdp(au_di(root), bindex, bend);
+ au_br_do_del_hip(au_ii(inode), bindex, bend);
+ au_sbilist_unlock();
+
+ dput(h_root);
+ iput(h_inode);
+ au_br_do_free(br);
+}
+
+static unsigned long long empty_cb(void *array, unsigned long long max,
+ void *arg)
+{
+ return max;
+}
+
+int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount)
+{
+ int err, rerr, i;
+ unsigned long long opened;
+ unsigned int mnt_flags;
+ aufs_bindex_t bindex, bend, br_id;
+ unsigned char do_wh, verbose;
+ struct au_branch *br;
+ struct au_wbr *wbr;
+ struct dentry *root;
+ struct file **to_free;
+
+ err = 0;
+ opened = 0;
+ to_free = NULL;
+ root = sb->s_root;
+ bindex = au_find_dbindex(root, del->h_path.dentry);
+ if (bindex < 0) {
+ if (remount)
+ goto out; /* success */
+ err = -ENOENT;
+ pr_err("%s no such branch\n", del->pathname);
+ goto out;
+ }
+ AuDbg("bindex b%d\n", bindex);
+
+ err = -EBUSY;
+ mnt_flags = au_mntflags(sb);
+ verbose = !!au_opt_test(mnt_flags, VERBOSE);
+ bend = au_sbend(sb);
+ if (unlikely(!bend)) {
+ AuVerbose(verbose, "no more branches left\n");
+ goto out;
+ }
+ br = au_sbr(sb, bindex);
+ AuDebugOn(!path_equal(&br->br_path, &del->h_path));
+
+ br_id = br->br_id;
+ opened = atomic_read(&br->br_count);
+ if (unlikely(opened)) {
+ to_free = au_array_alloc(&opened, empty_cb, NULL);
+ err = PTR_ERR(to_free);
+ if (IS_ERR(to_free))
+ goto out;
+
+ err = test_file_busy(sb, br_id, to_free, opened);
+ if (unlikely(err)) {
+ AuVerbose(verbose, "%llu file(s) opened\n", opened);
+ goto out;
+ }
+ }
+
+ wbr = br->br_wbr;
+ do_wh = wbr && (wbr->wbr_whbase || wbr->wbr_plink || wbr->wbr_orph);
+ if (do_wh) {
+ /* instead of WbrWhMustWriteLock(wbr) */
+ SiMustWriteLock(sb);
+ for (i = 0; i < AuBrWh_Last; i++) {
+ dput(wbr->wbr_wh[i]);
+ wbr->wbr_wh[i] = NULL;
+ }
+ }
+
+ err = test_children_busy(root, bindex, verbose);
+ if (unlikely(err)) {
+ if (do_wh)
+ goto out_wh;
+ goto out;
+ }
+
+ err = 0;
+ if (to_free) {
+ /*
+ * now we confirmed the branch is deletable.
+ * let's free the remaining opened dirs on the branch.
+ */
+ di_write_unlock(root);
+ br_del_file(to_free, opened, br_id);
+ di_write_lock_child(root);
+ }
+
+ if (!remount)
+ au_br_do_del(sb, bindex, br);
+ else {
+ sysaufs_brs_del(sb, bindex);
+ au_br_do_del(sb, bindex, br);
+ sysaufs_brs_add(sb, bindex);
+ }
+
+ if (!bindex) {
+ au_cpup_attr_all(d_inode(root), /*force*/1);
+ sb->s_maxbytes = au_sbr_sb(sb, 0)->s_maxbytes;
+ } else
+ au_sub_nlink(d_inode(root), d_inode(del->h_path.dentry));
+ if (au_opt_test(mnt_flags, PLINK))
+ au_plink_half_refresh(sb, br_id);
+
+ if (au_xino_brid(sb) == br_id)
+ au_xino_brid_set(sb, -1);
+ goto out; /* success */
+
+out_wh:
+ /* revert */
+ rerr = au_br_init_wh(sb, br, br->br_perm);
+ if (rerr)
+ pr_warn("failed re-creating base whiteout, %s. (%d)\n",
+ del->pathname, rerr);
+out:
+ if (to_free)
+ au_farray_free(to_free, opened);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int au_ibusy(struct super_block *sb, struct aufs_ibusy __user *arg)
+{
+ int err;
+ aufs_bindex_t bstart, bend;
+ struct aufs_ibusy ibusy;
+ struct inode *inode, *h_inode;
+
+ err = -EPERM;
+ if (unlikely(!capable(CAP_SYS_ADMIN)))
+ goto out;
+
+ err = copy_from_user(&ibusy, arg, sizeof(ibusy));
+ if (!err)
+ err = !access_ok(VERIFY_WRITE, &arg->h_ino, sizeof(arg->h_ino));
+ if (unlikely(err)) {
+ err = -EFAULT;
+ AuTraceErr(err);
+ goto out;
+ }
+
+ err = -EINVAL;
+ si_read_lock(sb, AuLock_FLUSH);
+ if (unlikely(ibusy.bindex < 0 || ibusy.bindex > au_sbend(sb)))
+ goto out_unlock;
+
+ err = 0;
+ ibusy.h_ino = 0; /* invalid */
+ inode = ilookup(sb, ibusy.ino);
+ if (!inode
+ || inode->i_ino == AUFS_ROOT_INO
+ || is_bad_inode(inode))
+ goto out_unlock;
+
+ ii_read_lock_child(inode);
+ bstart = au_ibstart(inode);
+ bend = au_ibend(inode);
+ if (bstart <= ibusy.bindex && ibusy.bindex <= bend) {
+ h_inode = au_h_iptr(inode, ibusy.bindex);
+ if (h_inode && au_test_ibusy(inode, bstart, bend))
+ ibusy.h_ino = h_inode->i_ino;
+ }
+ ii_read_unlock(inode);
+ iput(inode);
+
+out_unlock:
+ si_read_unlock(sb);
+ if (!err) {
+ err = __put_user(ibusy.h_ino, &arg->h_ino);
+ if (unlikely(err)) {
+ err = -EFAULT;
+ AuTraceErr(err);
+ }
+ }
+out:
+ return err;
+}
+
+long au_ibusy_ioctl(struct file *file, unsigned long arg)
+{
+ return au_ibusy(file->f_path.dentry->d_sb, (void __user *)arg);
+}
+
+#ifdef CONFIG_COMPAT
+long au_ibusy_compat_ioctl(struct file *file, unsigned long arg)
+{
+ return au_ibusy(file->f_path.dentry->d_sb, compat_ptr(arg));
+}
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * change a branch permission
+ */
+
+static void au_warn_ima(void)
+{
+#ifdef CONFIG_IMA
+ /* since it doesn't support mark_files_ro() */
+ AuWarn1("RW -> RO makes IMA to produce wrong message\n");
+#endif
+}
+
+static int do_need_sigen_inc(int a, int b)
+{
+ return au_br_whable(a) && !au_br_whable(b);
+}
+
+static int need_sigen_inc(int old, int new)
+{
+ return do_need_sigen_inc(old, new)
+ || do_need_sigen_inc(new, old);
+}
+
+static int au_br_mod_files_ro(struct super_block *sb, aufs_bindex_t bindex)
+{
+ int err, do_warn;
+ unsigned int mnt_flags;
+ unsigned long long ull, max;
+ aufs_bindex_t br_id;
+ unsigned char verbose, writer;
+ struct file *file, *hf, **array;
+ struct au_hfile *hfile;
+
+ mnt_flags = au_mntflags(sb);
+ verbose = !!au_opt_test(mnt_flags, VERBOSE);
+
+ array = au_farray_alloc(sb, &max);
+ err = PTR_ERR(array);
+ if (IS_ERR(array))
+ goto out;
+
+ do_warn = 0;
+ br_id = au_sbr_id(sb, bindex);
+ for (ull = 0; ull < max; ull++) {
+ file = array[ull];
+ if (unlikely(!file))
+ break;
+
+ /* AuDbg("%pD\n", file); */
+ fi_read_lock(file);
+ if (unlikely(au_test_mmapped(file))) {
+ err = -EBUSY;
+ AuVerbose(verbose, "mmapped %pD\n", file);
+ AuDbgFile(file);
+ FiMustNoWaiters(file);
+ fi_read_unlock(file);
+ goto out_array;
+ }
+
+ hfile = &au_fi(file)->fi_htop;
+ hf = hfile->hf_file;
+ if (!d_is_reg(file->f_path.dentry)
+ || !(file->f_mode & FMODE_WRITE)
+ || hfile->hf_br->br_id != br_id
+ || !(hf->f_mode & FMODE_WRITE))
+ array[ull] = NULL;
+ else {
+ do_warn = 1;
+ get_file(file);
+ }
+
+ FiMustNoWaiters(file);
+ fi_read_unlock(file);
+ fput(file);
+ }
+
+ err = 0;
+ if (do_warn)
+ au_warn_ima();
+
+ for (ull = 0; ull < max; ull++) {
+ file = array[ull];
+ if (!file)
+ continue;
+
+ /* todo: already flushed? */
+ /*
+ * fs/super.c:mark_files_ro() is gone, but aufs keeps its
+ * approach which resets f_mode and calls mnt_drop_write() and
+ * file_release_write() for each file, because the branch
+ * attribute in aufs world is totally different from the native
+ * fs rw/ro mode.
+ */
+ /* fi_read_lock(file); */
+ hfile = &au_fi(file)->fi_htop;
+ hf = hfile->hf_file;
+ /* fi_read_unlock(file); */
+ spin_lock(&hf->f_lock);
+ writer = !!(hf->f_mode & FMODE_WRITER);
+ hf->f_mode &= ~(FMODE_WRITE | FMODE_WRITER);
+ spin_unlock(&hf->f_lock);
+ if (writer) {
+ put_write_access(file_inode(hf));
+ __mnt_drop_write(hf->f_path.mnt);
+ }
+ }
+
+out_array:
+ au_farray_free(array, max);
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
+ int *do_refresh)
+{
+ int err, rerr;
+ aufs_bindex_t bindex;
+ struct dentry *root;
+ struct au_branch *br;
+ struct au_br_fhsm *bf;
+
+ root = sb->s_root;
+ bindex = au_find_dbindex(root, mod->h_root);
+ if (bindex < 0) {
+ if (remount)
+ return 0; /* success */
+ err = -ENOENT;
+ pr_err("%s no such branch\n", mod->path);
+ goto out;
+ }
+ AuDbg("bindex b%d\n", bindex);
+
+ err = test_br(d_inode(mod->h_root), mod->perm, mod->path);
+ if (unlikely(err))
+ goto out;
+
+ br = au_sbr(sb, bindex);
+ AuDebugOn(mod->h_root != au_br_dentry(br));
+ if (br->br_perm == mod->perm)
+ return 0; /* success */
+
+ /* pre-allocate for non-fhsm --> fhsm */
+ bf = NULL;
+ if (!au_br_fhsm(br->br_perm) && au_br_fhsm(mod->perm)) {
+ err = au_fhsm_br_alloc(br);
+ if (unlikely(err))
+ goto out;
+ bf = br->br_fhsm;
+ br->br_fhsm = NULL;
+ }
+
+ if (au_br_writable(br->br_perm)) {
+ /* remove whiteout base */
+ err = au_br_init_wh(sb, br, mod->perm);
+ if (unlikely(err))
+ goto out_bf;
+
+ if (!au_br_writable(mod->perm)) {
+ /* rw --> ro, file might be mmapped */
+ DiMustNoWaiters(root);
+ IiMustNoWaiters(d_inode(root));
+ di_write_unlock(root);
+ err = au_br_mod_files_ro(sb, bindex);
+ /* aufs_write_lock() calls ..._child() */
+ di_write_lock_child(root);
+
+ if (unlikely(err)) {
+ rerr = -ENOMEM;
+ br->br_wbr = kmalloc(sizeof(*br->br_wbr),
+ GFP_NOFS);
+ if (br->br_wbr)
+ rerr = au_wbr_init(br, sb, br->br_perm);
+ if (unlikely(rerr)) {
+ AuIOErr("nested error %d (%d)\n",
+ rerr, err);
+ br->br_perm = mod->perm;
+ }
+ }
+ }
+ } else if (au_br_writable(mod->perm)) {
+ /* ro --> rw */
+ err = -ENOMEM;
+ br->br_wbr = kmalloc(sizeof(*br->br_wbr), GFP_NOFS);
+ if (br->br_wbr) {
+ err = au_wbr_init(br, sb, mod->perm);
+ if (unlikely(err)) {
+ kfree(br->br_wbr);
+ br->br_wbr = NULL;
+ }
+ }
+ }
+ if (unlikely(err))
+ goto out_bf;
+
+ if (au_br_fhsm(br->br_perm)) {
+ if (!au_br_fhsm(mod->perm)) {
+ /* fhsm --> non-fhsm */
+ au_br_fhsm_fin(br->br_fhsm);
+ kfree(br->br_fhsm);
+ br->br_fhsm = NULL;
+ }
+ } else if (au_br_fhsm(mod->perm))
+ /* non-fhsm --> fhsm */
+ br->br_fhsm = bf;
+
+ *do_refresh |= need_sigen_inc(br->br_perm, mod->perm);
+ br->br_perm = mod->perm;
+ goto out; /* success */
+
+out_bf:
+ kfree(bf);
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_br_stfs(struct au_branch *br, struct aufs_stfs *stfs)
+{
+ int err;
+ struct kstatfs kstfs;
+
+ err = vfs_statfs(&br->br_path, &kstfs);
+ if (!err) {
+ stfs->f_blocks = kstfs.f_blocks;
+ stfs->f_bavail = kstfs.f_bavail;
+ stfs->f_files = kstfs.f_files;
+ stfs->f_ffree = kstfs.f_ffree;
+ }
+
+ return err;
+}