diff options
Diffstat (limited to 'fs/aufs/dentry.c')
| -rw-r--r-- | fs/aufs/dentry.c | 1154 |
1 files changed, 1154 insertions, 0 deletions
diff --git a/fs/aufs/dentry.c b/fs/aufs/dentry.c new file mode 100644 index 000000000000..50aaaa21d089 --- /dev/null +++ b/fs/aufs/dentry.c @@ -0,0 +1,1154 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2005-2020 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/>. + */ + +/* + * lookup and dentry operations + */ + +#include <linux/iversion.h> +#include <linux/namei.h> +#include "aufs.h" + +/* + * returns positive/negative dentry, NULL or an error. + * NULL means whiteout-ed or not-found. + */ +static struct dentry* +au_do_lookup(struct dentry *h_parent, struct dentry *dentry, + aufs_bindex_t bindex, struct au_do_lookup_args *args) +{ + struct dentry *h_dentry; + struct inode *h_inode; + struct au_branch *br; + int wh_found, opq; + unsigned char wh_able; + const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG); + const unsigned char ignore_perm = !!au_ftest_lkup(args->flags, + IGNORE_PERM); + + wh_found = 0; + br = au_sbr(dentry->d_sb, bindex); + wh_able = !!au_br_whable(br->br_perm); + if (wh_able) + wh_found = au_wh_test(h_parent, &args->whname, ignore_perm); + h_dentry = ERR_PTR(wh_found); + if (!wh_found) + goto real_lookup; + if (unlikely(wh_found < 0)) + goto out; + + /* We found a whiteout */ + /* au_set_dbbot(dentry, bindex); */ + au_set_dbwh(dentry, bindex); + if (!allow_neg) + return NULL; /* success */ + +real_lookup: + if (!ignore_perm) + h_dentry = vfsub_lkup_one(args->name, h_parent); + else + h_dentry = au_sio_lkup_one(args->name, h_parent); + if (IS_ERR(h_dentry)) { + if (PTR_ERR(h_dentry) == -ENAMETOOLONG + && !allow_neg) + h_dentry = NULL; + goto out; + } + + h_inode = d_inode(h_dentry); + if (d_is_negative(h_dentry)) { + if (!allow_neg) + goto out_neg; + } else if (wh_found + || (args->type && args->type != (h_inode->i_mode & S_IFMT))) + goto out_neg; + else if (au_ftest_lkup(args->flags, DIRREN) + /* && h_inode */ + && !au_dr_lkup_h_ino(args, bindex, h_inode->i_ino)) { + AuDbg("b%d %pd ignored hi%llu\n", bindex, h_dentry, + (unsigned long long)h_inode->i_ino); + goto out_neg; + } + + if (au_dbbot(dentry) <= bindex) + au_set_dbbot(dentry, bindex); + if (au_dbtop(dentry) < 0 || bindex < au_dbtop(dentry)) + au_set_dbtop(dentry, bindex); + au_set_h_dptr(dentry, bindex, h_dentry); + + if (!d_is_dir(h_dentry) + || !wh_able + || (d_really_is_positive(dentry) && !d_is_dir(dentry))) + goto out; /* success */ + + inode_lock_shared_nested(h_inode, AuLsc_I_CHILD); + opq = au_diropq_test(h_dentry); + inode_unlock_shared(h_inode); + if (opq > 0) + au_set_dbdiropq(dentry, bindex); + else if (unlikely(opq < 0)) { + au_set_h_dptr(dentry, bindex, NULL); + h_dentry = ERR_PTR(opq); + } + goto out; + +out_neg: + dput(h_dentry); + h_dentry = NULL; +out: + return h_dentry; +} + +static int au_test_shwh(struct super_block *sb, const struct qstr *name) +{ + if (unlikely(!au_opt_test(au_mntflags(sb), SHWH) + && !strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))) + return -EPERM; + return 0; +} + +/* + * returns the number of lower positive dentries, + * otherwise an error. + * can be called at unlinking with @type is zero. + */ +int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t btop, + unsigned int flags) +{ + int npositive, err; + aufs_bindex_t bindex, btail, bdiropq; + unsigned char isdir, dirperm1, dirren; + struct au_do_lookup_args args = { + .flags = flags, + .name = &dentry->d_name + }; + struct dentry *parent; + struct super_block *sb; + + sb = dentry->d_sb; + err = au_test_shwh(sb, args.name); + if (unlikely(err)) + goto out; + + err = au_wh_name_alloc(&args.whname, args.name); + if (unlikely(err)) + goto out; + + isdir = !!d_is_dir(dentry); + dirperm1 = !!au_opt_test(au_mntflags(sb), DIRPERM1); + dirren = !!au_opt_test(au_mntflags(sb), DIRREN); + if (dirren) + au_fset_lkup(args.flags, DIRREN); + + npositive = 0; + parent = dget_parent(dentry); + btail = au_dbtaildir(parent); + for (bindex = btop; bindex <= btail; bindex++) { + struct dentry *h_parent, *h_dentry; + struct inode *h_inode, *h_dir; + struct au_branch *br; + + h_dentry = au_h_dptr(dentry, bindex); + if (h_dentry) { + if (d_is_positive(h_dentry)) + npositive++; + break; + } + h_parent = au_h_dptr(parent, bindex); + if (!h_parent || !d_is_dir(h_parent)) + continue; + + if (dirren) { + /* if the inum matches, then use the prepared name */ + err = au_dr_lkup_name(&args, bindex); + if (unlikely(err)) + goto out_parent; + } + + h_dir = d_inode(h_parent); + inode_lock_shared_nested(h_dir, AuLsc_I_PARENT); + h_dentry = au_do_lookup(h_parent, dentry, bindex, &args); + inode_unlock_shared(h_dir); + err = PTR_ERR(h_dentry); + if (IS_ERR(h_dentry)) + goto out_parent; + if (h_dentry) + au_fclr_lkup(args.flags, ALLOW_NEG); + if (dirperm1) + au_fset_lkup(args.flags, IGNORE_PERM); + + if (au_dbwh(dentry) == bindex) + break; + if (!h_dentry) + continue; + if (d_is_negative(h_dentry)) + continue; + h_inode = d_inode(h_dentry); + npositive++; + if (!args.type) + args.type = h_inode->i_mode & S_IFMT; + if (args.type != S_IFDIR) + break; + else if (isdir) { + /* the type of lower may be different */ + bdiropq = au_dbdiropq(dentry); + if (bdiropq >= 0 && bdiropq <= bindex) + break; + } + br = au_sbr(sb, bindex); + if (dirren + && au_dr_hino_test_add(&br->br_dirren, h_inode->i_ino, + /*add_ent*/NULL)) { + /* prepare next name to lookup */ + err = au_dr_lkup(&args, dentry, bindex); + if (unlikely(err)) + goto out_parent; + } + } + + if (npositive) { + AuLabel(positive); + au_update_dbtop(dentry); + } + err = npositive; + if (unlikely(!au_opt_test(au_mntflags(sb), UDBA_NONE) + && au_dbtop(dentry) < 0)) { + err = -EIO; + AuIOErr("both of real entry and whiteout found, %pd, err %d\n", + dentry, err); + } + +out_parent: + dput(parent); + au_kfree_try_rcu(args.whname.name); + if (dirren) + au_dr_lkup_fin(&args); +out: + return err; +} + +struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent) +{ + struct dentry *dentry; + int wkq_err; + + if (!au_test_h_perm_sio(d_inode(parent), MAY_EXEC)) + dentry = vfsub_lkup_one(name, parent); + else { + struct vfsub_lkup_one_args args = { + .errp = &dentry, + .name = name, + .parent = parent + }; + + wkq_err = au_wkq_wait(vfsub_call_lkup_one, &args); + if (unlikely(wkq_err)) + dentry = ERR_PTR(wkq_err); + } + + return dentry; +} + +/* + * lookup @dentry on @bindex which should be negative. + */ +int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex, int wh) +{ + int err; + struct dentry *parent, *h_parent, *h_dentry; + struct au_branch *br; + + parent = dget_parent(dentry); + h_parent = au_h_dptr(parent, bindex); + br = au_sbr(dentry->d_sb, bindex); + if (wh) + h_dentry = au_whtmp_lkup(h_parent, br, &dentry->d_name); + else + h_dentry = au_sio_lkup_one(&dentry->d_name, h_parent); + err = PTR_ERR(h_dentry); + if (IS_ERR(h_dentry)) + goto out; + if (unlikely(d_is_positive(h_dentry))) { + err = -EIO; + AuIOErr("%pd should be negative on b%d.\n", h_dentry, bindex); + dput(h_dentry); + goto out; + } + + err = 0; + if (bindex < au_dbtop(dentry)) + au_set_dbtop(dentry, bindex); + if (au_dbbot(dentry) < bindex) + au_set_dbbot(dentry, bindex); + au_set_h_dptr(dentry, bindex, h_dentry); + +out: + dput(parent); + return err; +} + +/* ---------------------------------------------------------------------- */ + +/* subset of struct inode */ +struct au_iattr { + unsigned long i_ino; + /* unsigned int i_nlink; */ + kuid_t i_uid; + kgid_t i_gid; + u64 i_version; +/* + loff_t i_size; + blkcnt_t i_blocks; +*/ + umode_t i_mode; +}; + +static void au_iattr_save(struct au_iattr *ia, struct inode *h_inode) +{ + ia->i_ino = h_inode->i_ino; + /* ia->i_nlink = h_inode->i_nlink; */ + ia->i_uid = h_inode->i_uid; + ia->i_gid = h_inode->i_gid; + ia->i_version = inode_query_iversion(h_inode); +/* + ia->i_size = h_inode->i_size; + ia->i_blocks = h_inode->i_blocks; +*/ + ia->i_mode = (h_inode->i_mode & S_IFMT); +} + +static int au_iattr_test(struct au_iattr *ia, struct inode *h_inode) +{ + return ia->i_ino != h_inode->i_ino + /* || ia->i_nlink != h_inode->i_nlink */ + || !uid_eq(ia->i_uid, h_inode->i_uid) + || !gid_eq(ia->i_gid, h_inode->i_gid) + || !inode_eq_iversion(h_inode, ia->i_version) +/* + || ia->i_size != h_inode->i_size + || ia->i_blocks != h_inode->i_blocks +*/ + || ia->i_mode != (h_inode->i_mode & S_IFMT); +} + +static int au_h_verify_dentry(struct dentry *h_dentry, struct dentry *h_parent, + struct au_branch *br) +{ + int err; + struct au_iattr ia; + struct inode *h_inode; + struct dentry *h_d; + struct super_block *h_sb; + + err = 0; + memset(&ia, -1, sizeof(ia)); + h_sb = h_dentry->d_sb; + h_inode = NULL; + if (d_is_positive(h_dentry)) { + h_inode = d_inode(h_dentry); + au_iattr_save(&ia, h_inode); + } else if (au_test_nfs(h_sb) || au_test_fuse(h_sb)) + /* nfs d_revalidate may return 0 for negative dentry */ + /* fuse d_revalidate always return 0 for negative dentry */ + goto out; + + /* main purpose is namei.c:cached_lookup() and d_revalidate */ + h_d = vfsub_lkup_one(&h_dentry->d_name, h_parent); + err = PTR_ERR(h_d); + if (IS_ERR(h_d)) + goto out; + + err = 0; + if (unlikely(h_d != h_dentry + || d_inode(h_d) != h_inode + || (h_inode && au_iattr_test(&ia, h_inode)))) + err = au_busy_or_stale(); + dput(h_d); + +out: + AuTraceErr(err); + return err; +} + +int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir, + struct dentry *h_parent, struct au_branch *br) +{ + int err; + + err = 0; + if (udba == AuOpt_UDBA_REVAL + && !au_test_fs_remote(h_dentry->d_sb)) { + IMustLock(h_dir); + err = (d_inode(h_dentry->d_parent) != h_dir); + } else if (udba != AuOpt_UDBA_NONE) + err = au_h_verify_dentry(h_dentry, h_parent, br); + + return err; +} + +/* ---------------------------------------------------------------------- */ + +static int au_do_refresh_hdentry(struct dentry *dentry, struct dentry *parent) +{ + int err; + aufs_bindex_t new_bindex, bindex, bbot, bwh, bdiropq; + struct au_hdentry tmp, *p, *q; + struct au_dinfo *dinfo; + struct super_block *sb; + + DiMustWriteLock(dentry); + + sb = dentry->d_sb; + dinfo = au_di(dentry); + bbot = dinfo->di_bbot; + bwh = dinfo->di_bwh; + bdiropq = dinfo->di_bdiropq; + bindex = dinfo->di_btop; + p = au_hdentry(dinfo, bindex); + for (; bindex <= bbot; bindex++, p++) { + if (!p->hd_dentry) + continue; + + new_bindex = au_br_index(sb, p->hd_id); + if (new_bindex == bindex) + continue; + + if (dinfo->di_bwh == bindex) + bwh = new_bindex; + if (dinfo->di_bdiropq == bindex) + bdiropq = new_bindex; + if (new_bindex < 0) { + au_hdput(p); + p->hd_dentry = NULL; + continue; + } + + /* swap two lower dentries, and loop again */ + q = au_hdentry(dinfo, new_bindex); + tmp = *q; + *q = *p; + *p = tmp; + if (tmp.hd_dentry) { + bindex--; + p--; + } + } + + dinfo->di_bwh = -1; + if (bwh >= 0 && bwh <= au_sbbot(sb) && au_sbr_whable(sb, bwh)) + dinfo->di_bwh = bwh; + + dinfo->di_bdiropq = -1; + if (bdiropq >= 0 + && bdiropq <= au_sbbot(sb) + && au_sbr_whable(sb, bdiropq)) + dinfo->di_bdiropq = bdiropq; + + err = -EIO; + dinfo->di_btop = -1; + dinfo->di_bbot = -1; + bbot = au_dbbot(parent); + bindex = 0; + p = au_hdentry(dinfo, bindex); + for (; bindex <= bbot; bindex++, p++) + if (p->hd_dentry) { + dinfo->di_btop = bindex; + break; + } + + if (dinfo->di_btop >= 0) { + bindex = bbot; + p = au_hdentry(dinfo, bindex); + for (; bindex >= 0; bindex--, p--) + if (p->hd_dentry) { + dinfo->di_bbot = bindex; + err = 0; + break; + } + } + + return err; +} + +static void au_do_hide(struct dentry *dentry) +{ + struct inode *inode; + + if (d_really_is_positive(dentry)) { + inode = d_inode(dentry); + if (!d_is_dir(dentry)) { + if (inode->i_nlink && !d_unhashed(dentry)) + drop_nlink(inode); + } else { + clear_nlink(inode); + /* stop next lookup */ + inode->i_flags |= S_DEAD; + } + smp_mb(); /* necessary? */ + } + d_drop(dentry); +} + +static int au_hide_children(struct dentry *parent) +{ + int err, i, j, ndentry; + struct au_dcsub_pages dpages; + struct au_dpage *dpage; + struct dentry *dentry; + + err = au_dpages_init(&dpages, GFP_NOFS); + if (unlikely(err)) + goto out; + err = au_dcsub_pages(&dpages, parent, NULL, NULL); + if (unlikely(err)) + goto out_dpages; + + /* in reverse order */ + for (i = dpages.ndpage - 1; i >= 0; i--) { + dpage = dpages.dpages + i; + ndentry = dpage->ndentry; + for (j = ndentry - 1; j >= 0; j--) { + dentry = dpage->dentries[j]; + if (dentry != parent) + au_do_hide(dentry); + } + } + +out_dpages: + au_dpages_free(&dpages); +out: + return err; +} + +static void au_hide(struct dentry *dentry) +{ + int err; + + AuDbgDentry(dentry); + if (d_is_dir(dentry)) { + /* shrink_dcache_parent(dentry); */ + err = au_hide_children(dentry); + if (unlikely(err)) + AuIOErr("%pd, failed hiding children, ignored %d\n", + dentry, err); + } + au_do_hide(dentry); +} + +/* + * By adding a dirty branch, a cached dentry may be affected in various ways. + * + * a dirty branch is added + * - on the top of layers + * - in the middle of layers + * - to the bottom of layers + * + * on the added branch there exists + * - a whiteout + * - a diropq + * - a same named entry + * + exist + * * negative --> positive + * * positive --> positive + * - type is unchanged + * - type is changed + * + doesn't exist + * * negative --> negative + * * positive --> negative (rejected by au_br_del() for non-dir case) + * - none + */ +static int au_refresh_by_dinfo(struct dentry *dentry, struct au_dinfo *dinfo, + struct au_dinfo *tmp) +{ + int err; + aufs_bindex_t bindex, bbot; + struct { + struct dentry *dentry; + struct inode *inode; + mode_t mode; + } orig_h, tmp_h = { + .dentry = NULL + }; + struct au_hdentry *hd; + struct inode *inode, *h_inode; + struct dentry *h_dentry; + + err = 0; + AuDebugOn(dinfo->di_btop < 0); + orig_h.mode = 0; + orig_h.dentry = au_hdentry(dinfo, dinfo->di_btop)->hd_dentry; + orig_h.inode = NULL; + if (d_is_positive(orig_h.dentry)) { + orig_h.inode = d_inode(orig_h.dentry); + orig_h.mode = orig_h.inode->i_mode & S_IFMT; + } + if (tmp->di_btop >= 0) { + tmp_h.dentry = au_hdentry(tmp, tmp->di_btop)->hd_dentry; + if (d_is_positive(tmp_h.dentry)) { + tmp_h.inode = d_inode(tmp_h.dentry); + tmp_h.mode = tmp_h.inode->i_mode & S_IFMT; + } + } + + inode = NULL; + if (d_really_is_positive(dentry)) + inode = d_inode(dentry); + if (!orig_h.inode) { + AuDbg("negative originally\n"); + if (inode) { + au_hide(dentry); + goto out; + } + AuDebugOn(inode); + AuDebugOn(dinfo->di_btop != dinfo->di_bbot); + AuDebugOn(dinfo->di_bdiropq != -1); + + if (!tmp_h.inode) { + AuDbg("negative --> negative\n"); + /* should have only one negative lower */ + if (tmp->di_btop >= 0 + && tmp->di_btop < dinfo->di_btop) { + AuDebugOn(tmp->di_btop != tmp->di_bbot); + AuDebugOn(dinfo->di_btop != dinfo->di_bbot); + au_set_h_dptr(dentry, dinfo->di_btop, NULL); + au_di_cp(dinfo, tmp); + hd = au_hdentry(tmp, tmp->di_btop); + au_set_h_dptr(dentry, tmp->di_btop, + dget(hd->hd_dentry)); + } + au_dbg_verify_dinode(dentry); + } else { + AuDbg("negative --> positive\n"); + /* + * similar to the behaviour of creating with bypassing + * aufs. + * unhash it in order to force an error in the + * succeeding create operation. + * we should not set S_DEAD here. + */ + d_drop(dentry); + /* au_di_swap(tmp, dinfo); */ + au_dbg_verify_dinode(dentry); + } + } else { + AuDbg("positive originally\n"); + /* inode may be NULL */ + AuDebugOn(inode && (inode->i_mode & S_IFMT) != orig_h.mode); + if (!tmp_h.inode) { + AuDbg("positive --> negative\n"); + /* or bypassing aufs */ + au_hide(dentry); + if (tmp->di_bwh >= 0 && tmp->di_bwh <= dinfo->di_btop) + dinfo->di_bwh = tmp->di_bwh; + if (inode) + err = au_refresh_hinode_self(inode); + au_dbg_verify_dinode(dentry); + } else if (orig_h.mode == tmp_h.mode) { + AuDbg("positive --> positive, same type\n"); + if (!S_ISDIR(orig_h.mode) + && dinfo->di_btop > tmp->di_btop) { + /* + * similar to the behaviour of removing and + * creating. + */ + au_hide(dentry); + if (inode) + err = au_refresh_hinode_self(inode); + au_dbg_verify_dinode(dentry); + } else { + /* fill empty slots */ + if (dinfo->di_btop > tmp->di_btop) + dinfo->di_btop = tmp->di_btop; + if (dinfo->di_bbot < tmp->di_bbot) + dinfo->di_bbot = tmp->di_bbot; + dinfo->di_bwh = tmp->di_bwh; + dinfo->di_bdiropq = tmp->di_bdiropq; + bbot = dinfo->di_bbot; + bindex = tmp->di_btop; + hd = au_hdentry(tmp, bindex); + for (; bindex <= bbot; bindex++, hd++) { + if (au_h_dptr(dentry, bindex)) + continue; + h_dentry = hd->hd_dentry; + if (!h_dentry) + continue; + AuDebugOn(d_is_negative(h_dentry)); + h_inode = d_inode(h_dentry); + AuDebugOn(orig_h.mode + != (h_inode->i_mode + & S_IFMT)); + au_set_h_dptr(dentry, bindex, + dget(h_dentry)); + } + if (inode) + err = au_refresh_hinode(inode, dentry); + au_dbg_verify_dinode(dentry); + } + } else { + AuDbg("positive --> positive, different type\n"); + /* similar to the behaviour of removing and creating */ + au_hide(dentry); + if (inode) + err = au_refresh_hinode_self(inode); + au_dbg_verify_dinode(dentry); + } + } + +out: + return err; +} + +void au_refresh_dop(struct dentry *dentry, int force_reval) +{ + const struct dentry_operations *dop + = force_reval ? &aufs_dop : dentry->d_sb->s_d_op; + static const unsigned int mask + = DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE; + + BUILD_BUG_ON(sizeof(mask) != sizeof(dentry->d_flags)); + + if (dentry->d_op == dop) + return; + + AuDbg("%pd\n", dentry); + spin_lock(&dentry->d_lock); + if (dop == &aufs_dop) + dentry->d_flags |= mask; + else + dentry->d_flags &= ~mask; + dentry->d_op = dop; + spin_unlock(&dentry->d_lock); +} + +int au_refresh_dentry(struct dentry *dentry, struct dentry *parent) +{ + int err, ebrange, nbr; + unsigned int sigen; + struct au_dinfo *dinfo, *tmp; + struct super_block *sb; + struct inode *inode; + + DiMustWriteLock(dentry); + AuDebugOn(IS_ROOT(dentry)); + AuDebugOn(d_really_is_negative(parent)); + + sb = dentry->d_sb; + sigen = au_sigen(sb); + err = au_digen_test(parent, sigen); + if (unlikely(err)) + goto out; + + nbr = au_sbbot(sb) + 1; + dinfo = au_di(dentry); + err = au_di_realloc(dinfo, nbr, /*may_shrink*/0); + if (unlikely(err)) + goto out; + ebrange = au_dbrange_test(dentry); + if (!ebrange) + ebrange = au_do_refresh_hdentry(dentry, parent); + + if (d_unhashed(dentry) || ebrange /* || dinfo->di_tmpfile */) { + AuDebugOn(au_dbtop(dentry) < 0 && au_dbbot(dentry) >= 0); + if (d_really_is_positive(dentry)) { + inode = d_inode(dentry); + err = au_refresh_hinode_self(inode); + } + au_dbg_verify_dinode(dentry); + if (!err) + goto out_dgen; /* success */ + goto out; + } + + /* temporary dinfo */ + AuDbgDentry(dentry); + err = -ENOMEM; + tmp = au_di_alloc(sb, AuLsc_DI_TMP); + if (unlikely(!tmp)) + goto out; + au_di_swap(tmp, dinfo); + /* returns the number of positive dentries */ + /* + * if current working dir is removed, it returns an error. + * but the dentry is legal. + */ + err = au_lkup_dentry(dentry, /*btop*/0, AuLkup_ALLOW_NEG); + AuDbgDentry(dentry); + au_di_swap(tmp, dinfo); + if (err == -ENOENT) + err = 0; + if (err >= 0) { + /* compare/refresh by dinfo */ + AuDbgDentry(dentry); + err = au_refresh_by_dinfo(dentry, dinfo, tmp); + au_dbg_verify_dinode(dentry); + AuTraceErr(err); + } + au_di_realloc(dinfo, nbr, /*may_shrink*/1); /* harmless if err */ + au_rw_write_unlock(&tmp->di_rwsem); + au_di_free(tmp); + if (unlikely(err)) + goto out; + +out_dgen: + au_update_digen(dentry); +out: + if (unlikely(err && !(dentry->d_flags & DCACHE_NFSFS_RENAMED))) { + AuIOErr("failed refreshing %pd, %d\n", dentry, err); + AuDbgDentry(dentry); + } + AuTraceErr(err); + return err; +} + +static int au_do_h_d_reval(struct dentry *h_dentry, unsigned int flags, + struct dentry *dentry, aufs_bindex_t bindex) +{ + int err, valid; + + err = 0; + if (!(h_dentry->d_flags & DCACHE_OP_REVALIDATE)) + goto out; + + AuDbg("b%d\n", bindex); + /* + * gave up supporting LOOKUP_CREATE/OPEN for lower fs, + * due to whiteout and branch permission. + */ + flags &= ~(/*LOOKUP_PARENT |*/ LOOKUP_OPEN | LOOKUP_CREATE + | LOOKUP_FOLLOW | LOOKUP_EXCL); + /* it may return tri-state */ + valid = h_dentry->d_op->d_revalidate(h_dentry, flags); + + if (unlikely(valid < 0)) + err = valid; + else if (!valid) + err = -EINVAL; + +out: + AuTraceErr(err); + return err; +} + +/* todo: remove this */ +static int h_d_revalidate(struct dentry *dentry, struct inode *inode, + unsigned int flags, int do_udba, int dirren) +{ + int err; + umode_t mode, h_mode; + aufs_bindex_t bindex, btail, btop, ibs, ibe; + unsigned char plus, unhashed, is_root, h_plus, h_nfs, tmpfile; + struct inode *h_inode, *h_cached_inode; + struct dentry *h_dentry; + struct qstr *name, *h_name; + + err = 0; + plus = 0; + mode = 0; + ibs = -1; + ibe = -1; + unhashed = !!d_unhashed(dentry); + is_root = !!IS_ROOT(dentry); + name = &dentry->d_name; + tmpfile = au_di(dentry)->di_tmpfile; + + /* + * Theoretically, REVAL test should be unnecessary in case of + * {FS,I}NOTIFY. + * But {fs,i}notify doesn't fire some necessary events, + * IN_ATTRIB for atime/nlink/pageio + * Let's do REVAL test too. + */ + if (do_udba && inode) { + mode = (inode->i_mode & S_IFMT); + plus = (inode->i_nlink > 0); + ibs = au_ibtop(inode); + ibe = au_ibbot(inode); + } + + btop = au_dbtop(dentry); + btail = btop; + if (inode && S_ISDIR(inode->i_mode)) + btail = au_dbtaildir(dentry); + for (bindex = btop; bindex <= btail; bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + + AuDbg("b%d, %pd\n", bindex, h_dentry); + h_nfs = !!au_test_nfs(h_dentry->d_sb); + spin_lock(&h_dentry->d_lock); + h_name = &h_dentry->d_name; + if (unlikely(do_udba + && !is_root + && ((!h_nfs + && (unhashed != !!d_unhashed(h_dentry) + || (!tmpfile && !dirren + && !au_qstreq(name, h_name)) + )) + || (h_nfs + && !(flags & LOOKUP_OPEN) + && (h_dentry->d_flags + & DCACHE_NFSFS_RENAMED))) + )) { + int h_unhashed; + + h_unhashed = d_unhashed(h_dentry); + spin_unlock(&h_dentry->d_lock); + AuDbg("unhash 0x%x 0x%x, %pd %pd\n", + unhashed, h_unhashed, dentry, h_dentry); + goto err; + } + spin_unlock(&h_dentry->d_lock); + + err = au_do_h_d_reval(h_dentry, flags, dentry, bindex); + if (unlikely(err)) + /* do not goto err, to keep the errno */ + break; + + /* todo: plink too? */ + if (!do_udba) + continue; + + /* UDBA tests */ + if (unlikely(!!inode != d_is_positive(h_dentry))) + goto err; + + h_inode = NULL; + if (d_is_positive(h_dentry)) + h_inode = d_inode(h_dentry); + h_plus = plus; + h_mode = mode; + h_cached_inode = h_inode; + if (h_inode) { + h_mode = (h_inode->i_mode & S_IFMT); + h_plus = (h_inode->i_nlink > 0); + } + if (inode && ibs <= bindex && bindex <= ibe) + h_cached_inode = au_h_iptr(inode, bindex); + + if (!h_nfs) { + if (unlikely(plus != h_plus && !tmpfile)) + goto err; + } else { + if (unlikely(!(h_dentry->d_flags & DCACHE_NFSFS_RENAMED) + && !is_root + && !IS_ROOT(h_dentry) + && unhashed != d_unhashed(h_dentry))) + goto err; + } + if (unlikely(mode != h_mode + || h_cached_inode != h_inode)) + goto err; + continue; + +err: + err = -EINVAL; + break; + } + + AuTraceErr(err); + return err; +} + +/* todo: consolidate with do_refresh() and au_reval_for_attr() */ +static int simple_reval_dpath(struct dentry *dentry, unsigned int sigen) +{ + int err; + struct dentry *parent; + + if (!au_digen_test(dentry, sigen)) + return 0; + + parent = dget_parent(dentry); + di_read_lock_parent(parent, AuLock_IR); + AuDebugOn(au_digen_test(parent, sigen)); + au_dbg_verify_gen(parent, sigen); + err = au_refresh_dentry(dentry, parent); + di_read_unlock(parent, AuLock_IR); + dput(parent); + AuTraceErr(err); + return err; +} + +int au_reval_dpath(struct dentry *dentry, unsigned int sigen) +{ + int err; + struct dentry *d, *parent; + + if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIR)) + return simple_reval_dpath(dentry, sigen); + + /* slow loop, keep it simple and stupid */ + /* cf: au_cpup_dirs() */ + err = 0; + parent = NULL; + while (au_digen_test(dentry, sigen)) { + d = dentry; + while (1) { + dput(parent); + parent = dget_parent(d); + if (!au_digen_test(parent, sigen)) + break; + d = parent; + } + + if (d != dentry) + di_write_lock_child2(d); + + /* someone might update our dentry while we were sleeping */ + if (au_digen_test(d, sigen)) { + /* + * todo: consolidate with simple_reval_dpath(), + * do_refresh() and au_reval_for_attr(). + */ + di_read_lock_parent(parent, AuLock_IR); + err = au_refresh_dentry(d, parent); + di_read_unlock(parent, AuLock_IR); + } + + if (d != dentry) + di_write_unlock(d); + dput(parent); + if (unlikely(err)) + break; + } + + return err; +} + +/* + * if valid returns 1, otherwise 0. + */ +static int aufs_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + int valid, err; + unsigned int sigen; + unsigned char do_udba, dirren; + struct super_block *sb; + struct inode *inode; + + /* todo: support rcu-walk? */ + if (flags & LOOKUP_RCU) + return -ECHILD; + + valid = 0; + if (unlikely(!au_di(dentry))) + goto out; + + valid = 1; + sb = dentry->d_sb; + /* + * todo: very ugly + * i_mutex of parent dir may be held, + * but we should not return 'invalid' due to busy. + */ + err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM); + if (unlikely(err)) { + valid = err; + AuTraceErr(err); + goto out; + } + inode = NULL; + if (d_really_is_positive(dentry)) + inode = d_inode(dentry); + if (unlikely(inode && au_is_bad_inode(inode))) { + err = -EINVAL; + AuTraceErr(err); + goto out_dgrade; + } + if (unlikely(au_dbrange_test(dentry))) { + err = -EINVAL; + AuTraceErr(err); + goto out_dgrade; + } + + sigen = au_sigen(sb); + if (au_digen_test(dentry, sigen)) { + AuDebugOn(IS_ROOT(dentry)); + err = au_reval_dpath(dentry, sigen); + if (unlikely(err)) { + AuTraceErr(err); + goto out_dgrade; + } + } + di_downgrade_lock(dentry, AuLock_IR); + + err = -EINVAL; + if (!(flags & (LOOKUP_OPEN | LOOKUP_EMPTY)) + && inode + && !(inode->i_state && I_LINKABLE) + && (IS_DEADDIR(inode) || !inode->i_nlink)) { + AuTraceErr(err); + goto out_inval; + } + + do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE); + if (do_udba && inode) { + aufs_bindex_t btop = au_ibtop(inode); + struct inode *h_inode; + + if (btop >= 0) { + h_inode = au_h_iptr(inode, btop); + if (h_inode && au_test_higen(inode, h_inode)) { + AuTraceErr(err); + goto out_inval; + } + } + } + + dirren = !!au_opt_test(au_mntflags(sb), DIRREN); + err = h_d_revalidate(dentry, inode, flags, do_udba, dirren); + if (unlikely(!err && do_udba && au_dbtop(dentry) < 0)) { + err = -EIO; + AuDbg("both of real entry and whiteout found, %p, err %d\n", + dentry, err); + } + goto out_inval; + +out_dgrade: + di_downgrade_lock(dentry, AuLock_IR); +out_inval: + aufs_read_unlock(dentry, AuLock_IR); + AuTraceErr(err); + valid = !err; +out: + if (!valid) { + AuDbg("%pd invalid, %d\n", dentry, valid); + d_drop(dentry); + } + return valid; +} + +static void aufs_d_release(struct dentry *dentry) +{ + if (au_di(dentry)) { + au_di_fin(dentry); + au_hn_di_reinit(dentry); + } +} + +const struct dentry_operations aufs_dop = { + .d_revalidate = aufs_d_revalidate, + .d_weak_revalidate = aufs_d_revalidate, + .d_release = aufs_d_release +}; + +/* aufs_dop without d_revalidate */ +const struct dentry_operations aufs_dop_noreval = { + .d_release = aufs_d_release +}; |