diff options
Diffstat (limited to 'fs/aufs/dirren.c')
| -rw-r--r-- | fs/aufs/dirren.c | 1316 |
1 files changed, 1316 insertions, 0 deletions
diff --git a/fs/aufs/dirren.c b/fs/aufs/dirren.c new file mode 100644 index 000000000000..0bd412ab68c9 --- /dev/null +++ b/fs/aufs/dirren.c @@ -0,0 +1,1316 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017-2019 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/>. + */ + +/* + * special handling in renaming a directory + * in order to support looking-up the before-renamed name on the lower readonly + * branches + */ + +#include <linux/byteorder/generic.h> +#include "aufs.h" + +static void au_dr_hino_del(struct au_dr_br *dr, struct au_dr_hino *ent) +{ + int idx; + + idx = au_dr_ihash(ent->dr_h_ino); + au_hbl_del(&ent->dr_hnode, dr->dr_h_ino + idx); +} + +static int au_dr_hino_test_empty(struct au_dr_br *dr) +{ + int ret, i; + struct hlist_bl_head *hbl; + + ret = 1; + for (i = 0; ret && i < AuDirren_NHASH; i++) { + hbl = dr->dr_h_ino + i; + hlist_bl_lock(hbl); + ret &= hlist_bl_empty(hbl); + hlist_bl_unlock(hbl); + } + + return ret; +} + +static struct au_dr_hino *au_dr_hino_find(struct au_dr_br *dr, ino_t ino) +{ + struct au_dr_hino *found, *ent; + struct hlist_bl_head *hbl; + struct hlist_bl_node *pos; + int idx; + + found = NULL; + idx = au_dr_ihash(ino); + hbl = dr->dr_h_ino + idx; + hlist_bl_lock(hbl); + hlist_bl_for_each_entry(ent, pos, hbl, dr_hnode) + if (ent->dr_h_ino == ino) { + found = ent; + break; + } + hlist_bl_unlock(hbl); + + return found; +} + +int au_dr_hino_test_add(struct au_dr_br *dr, ino_t ino, + struct au_dr_hino *add_ent) +{ + int found, idx; + struct hlist_bl_head *hbl; + struct hlist_bl_node *pos; + struct au_dr_hino *ent; + + found = 0; + idx = au_dr_ihash(ino); + hbl = dr->dr_h_ino + idx; +#if 0 + { + struct hlist_bl_node *tmp; + + hlist_bl_for_each_entry_safe(ent, pos, tmp, hbl, dr_hnode) + AuDbg("hi%llu\n", (unsigned long long)ent->dr_h_ino); + } +#endif + hlist_bl_lock(hbl); + hlist_bl_for_each_entry(ent, pos, hbl, dr_hnode) + if (ent->dr_h_ino == ino) { + found = 1; + break; + } + if (!found && add_ent) + hlist_bl_add_head(&add_ent->dr_hnode, hbl); + hlist_bl_unlock(hbl); + + if (!found && add_ent) + AuDbg("i%llu added\n", (unsigned long long)add_ent->dr_h_ino); + + return found; +} + +void au_dr_hino_free(struct au_dr_br *dr) +{ + int i; + struct hlist_bl_head *hbl; + struct hlist_bl_node *pos, *tmp; + struct au_dr_hino *ent; + + /* SiMustWriteLock(sb); */ + + for (i = 0; i < AuDirren_NHASH; i++) { + hbl = dr->dr_h_ino + i; + /* no spinlock since sbinfo must be write-locked */ + hlist_bl_for_each_entry_safe(ent, pos, tmp, hbl, dr_hnode) + au_kfree_rcu(ent); + INIT_HLIST_BL_HEAD(hbl); + } +} + +/* returns the number of inodes or an error */ +static int au_dr_hino_store(struct super_block *sb, struct au_branch *br, + struct file *hinofile) +{ + int err, i; + ssize_t ssz; + loff_t pos, oldsize; + __be64 u64; + struct inode *hinoinode; + struct hlist_bl_head *hbl; + struct hlist_bl_node *n1, *n2; + struct au_dr_hino *ent; + + SiMustWriteLock(sb); + AuDebugOn(!au_br_writable(br->br_perm)); + + hinoinode = file_inode(hinofile); + oldsize = i_size_read(hinoinode); + + err = 0; + pos = 0; + hbl = br->br_dirren.dr_h_ino; + for (i = 0; !err && i < AuDirren_NHASH; i++, hbl++) { + /* no bit-lock since sbinfo must be write-locked */ + hlist_bl_for_each_entry_safe(ent, n1, n2, hbl, dr_hnode) { + AuDbg("hi%llu, %pD2\n", + (unsigned long long)ent->dr_h_ino, hinofile); + u64 = cpu_to_be64(ent->dr_h_ino); + ssz = vfsub_write_k(hinofile, &u64, sizeof(u64), &pos); + if (ssz == sizeof(u64)) + continue; + + /* write error */ + pr_err("ssz %zd, %pD2\n", ssz, hinofile); + err = -ENOSPC; + if (ssz < 0) + err = ssz; + break; + } + } + /* regardless the error */ + if (pos < oldsize) { + err = vfsub_trunc(&hinofile->f_path, pos, /*attr*/0, hinofile); + AuTraceErr(err); + } + + AuTraceErr(err); + return err; +} + +static int au_dr_hino_load(struct au_dr_br *dr, struct file *hinofile) +{ + int err, hidx; + ssize_t ssz; + size_t sz, n; + loff_t pos; + uint64_t u64; + struct au_dr_hino *ent; + struct inode *hinoinode; + struct hlist_bl_head *hbl; + + err = 0; + pos = 0; + hbl = dr->dr_h_ino; + hinoinode = file_inode(hinofile); + sz = i_size_read(hinoinode); + AuDebugOn(sz % sizeof(u64)); + n = sz / sizeof(u64); + while (n--) { + ssz = vfsub_read_k(hinofile, &u64, sizeof(u64), &pos); + if (unlikely(ssz != sizeof(u64))) { + pr_err("ssz %zd, %pD2\n", ssz, hinofile); + err = -EINVAL; + if (ssz < 0) + err = ssz; + goto out_free; + } + + ent = kmalloc(sizeof(*ent), GFP_NOFS); + if (!ent) { + err = -ENOMEM; + AuTraceErr(err); + goto out_free; + } + ent->dr_h_ino = be64_to_cpu((__force __be64)u64); + AuDbg("hi%llu, %pD2\n", + (unsigned long long)ent->dr_h_ino, hinofile); + hidx = au_dr_ihash(ent->dr_h_ino); + au_hbl_add(&ent->dr_hnode, hbl + hidx); + } + goto out; /* success */ + +out_free: + au_dr_hino_free(dr); +out: + AuTraceErr(err); + return err; +} + +/* + * @bindex/@br is a switch to distinguish whether suspending hnotify or not. + * @path is a switch to distinguish load and store. + */ +static int au_dr_hino(struct super_block *sb, aufs_bindex_t bindex, + struct au_branch *br, const struct path *path) +{ + int err, flags; + unsigned char load, suspend; + struct file *hinofile; + struct au_hinode *hdir; + struct inode *dir, *delegated; + struct path hinopath; + struct qstr hinoname = QSTR_INIT(AUFS_WH_DR_BRHINO, + sizeof(AUFS_WH_DR_BRHINO) - 1); + + AuDebugOn(bindex < 0 && !br); + AuDebugOn(bindex >= 0 && br); + + err = -EINVAL; + suspend = !br; + if (suspend) + br = au_sbr(sb, bindex); + load = !!path; + if (!load) { + path = &br->br_path; + AuDebugOn(!au_br_writable(br->br_perm)); + if (unlikely(!au_br_writable(br->br_perm))) + goto out; + } + + hdir = NULL; + if (suspend) { + dir = d_inode(sb->s_root); + hdir = au_hinode(au_ii(dir), bindex); + dir = hdir->hi_inode; + au_hn_inode_lock_nested(hdir, AuLsc_I_CHILD); + } else { + dir = d_inode(path->dentry); + inode_lock_nested(dir, AuLsc_I_CHILD); + } + hinopath.dentry = vfsub_lkup_one(&hinoname, path->dentry); + err = PTR_ERR(hinopath.dentry); + if (IS_ERR(hinopath.dentry)) + goto out_unlock; + + err = 0; + flags = O_RDONLY; + if (load) { + if (d_is_negative(hinopath.dentry)) + goto out_dput; /* success */ + } else { + if (au_dr_hino_test_empty(&br->br_dirren)) { + if (d_is_positive(hinopath.dentry)) { + delegated = NULL; + err = vfsub_unlink(dir, &hinopath, &delegated, + /*force*/0); + AuTraceErr(err); + if (unlikely(err)) + pr_err("ignored err %d, %pd2\n", + err, hinopath.dentry); + if (unlikely(err == -EWOULDBLOCK)) + iput(delegated); + err = 0; + } + goto out_dput; + } else if (!d_is_positive(hinopath.dentry)) { + err = vfsub_create(dir, &hinopath, 0600, + /*want_excl*/false); + AuTraceErr(err); + if (unlikely(err)) + goto out_dput; + } + flags = O_WRONLY; + } + hinopath.mnt = path->mnt; + hinofile = vfsub_dentry_open(&hinopath, flags); + if (suspend) + au_hn_inode_unlock(hdir); + else + inode_unlock(dir); + dput(hinopath.dentry); + AuTraceErrPtr(hinofile); + if (IS_ERR(hinofile)) { + err = PTR_ERR(hinofile); + goto out; + } + + if (load) + err = au_dr_hino_load(&br->br_dirren, hinofile); + else + err = au_dr_hino_store(sb, br, hinofile); + fput(hinofile); + goto out; + +out_dput: + dput(hinopath.dentry); +out_unlock: + if (suspend) + au_hn_inode_unlock(hdir); + else + inode_unlock(dir); +out: + AuTraceErr(err); + return err; +} + +/* ---------------------------------------------------------------------- */ + +static int au_dr_brid_init(struct au_dr_brid *brid, const struct path *path) +{ + int err; + struct kstatfs kstfs; + dev_t dev; + struct dentry *dentry; + struct super_block *sb; + + err = vfs_statfs((void *)path, &kstfs); + AuTraceErr(err); + if (unlikely(err)) + goto out; + + /* todo: support for UUID */ + + if (kstfs.f_fsid.val[0] || kstfs.f_fsid.val[1]) { + brid->type = AuBrid_FSID; + brid->fsid = kstfs.f_fsid; + } else { + dentry = path->dentry; + sb = dentry->d_sb; + dev = sb->s_dev; + if (dev) { + brid->type = AuBrid_DEV; + brid->dev = dev; + } + } + +out: + return err; +} + +int au_dr_br_init(struct super_block *sb, struct au_branch *br, + const struct path *path) +{ + int err, i; + struct au_dr_br *dr; + struct hlist_bl_head *hbl; + + dr = &br->br_dirren; + hbl = dr->dr_h_ino; + for (i = 0; i < AuDirren_NHASH; i++, hbl++) + INIT_HLIST_BL_HEAD(hbl); + + err = au_dr_brid_init(&dr->dr_brid, path); + if (unlikely(err)) + goto out; + + if (au_opt_test(au_mntflags(sb), DIRREN)) + err = au_dr_hino(sb, /*bindex*/-1, br, path); + +out: + AuTraceErr(err); + return err; +} + +int au_dr_br_fin(struct super_block *sb, struct au_branch *br) +{ + int err; + + err = 0; + if (au_br_writable(br->br_perm)) + err = au_dr_hino(sb, /*bindex*/-1, br, /*path*/NULL); + if (!err) + au_dr_hino_free(&br->br_dirren); + + return err; +} + +/* ---------------------------------------------------------------------- */ + +static int au_brid_str(struct au_dr_brid *brid, struct inode *h_inode, + char *buf, size_t sz) +{ + int err; + unsigned int major, minor; + char *p; + + p = buf; + err = snprintf(p, sz, "%d_", brid->type); + AuDebugOn(err > sz); + p += err; + sz -= err; + switch (brid->type) { + case AuBrid_Unset: + return -EINVAL; + case AuBrid_UUID: + err = snprintf(p, sz, "%pU", brid->uuid.b); + break; + case AuBrid_FSID: + err = snprintf(p, sz, "%08x-%08x", + brid->fsid.val[0], brid->fsid.val[1]); + break; + case AuBrid_DEV: + major = MAJOR(brid->dev); + minor = MINOR(brid->dev); + if (major <= 0xff && minor <= 0xff) + err = snprintf(p, sz, "%02x%02x", major, minor); + else + err = snprintf(p, sz, "%03x:%05x", major, minor); + break; + } + AuDebugOn(err > sz); + p += err; + sz -= err; + err = snprintf(p, sz, "_%llu", (unsigned long long)h_inode->i_ino); + AuDebugOn(err > sz); + p += err; + sz -= err; + + return p - buf; +} + +static int au_drinfo_name(struct au_branch *br, char *name, int len) +{ + int rlen; + struct dentry *br_dentry; + struct inode *br_inode; + + br_dentry = au_br_dentry(br); + br_inode = d_inode(br_dentry); + rlen = au_brid_str(&br->br_dirren.dr_brid, br_inode, name, len); + AuDebugOn(rlen >= AUFS_DIRREN_ENV_VAL_SZ); + AuDebugOn(rlen > len); + + return rlen; +} + +/* ---------------------------------------------------------------------- */ + +/* + * from the given @h_dentry, construct drinfo at @*fdata. + * when the size of @*fdata is not enough, reallocate and return new @fdata and + * @allocated. + */ +static int au_drinfo_construct(struct au_drinfo_fdata **fdata, + struct dentry *h_dentry, + unsigned char *allocated) +{ + int err, v; + struct au_drinfo_fdata *f, *p; + struct au_drinfo *drinfo; + struct inode *h_inode; + struct qstr *qname; + + err = 0; + f = *fdata; + h_inode = d_inode(h_dentry); + qname = &h_dentry->d_name; + drinfo = &f->drinfo; + drinfo->ino = (__force uint64_t)cpu_to_be64(h_inode->i_ino); + drinfo->oldnamelen = qname->len; + if (*allocated < sizeof(*f) + qname->len) { + v = roundup_pow_of_two(*allocated + qname->len); + p = au_krealloc(f, v, GFP_NOFS, /*may_shrink*/0); + if (unlikely(!p)) { + err = -ENOMEM; + AuTraceErr(err); + goto out; + } + f = p; + *fdata = f; + *allocated = v; + drinfo = &f->drinfo; + } + memcpy(drinfo->oldname, qname->name, qname->len); + AuDbg("i%llu, %.*s\n", + be64_to_cpu((__force __be64)drinfo->ino), drinfo->oldnamelen, + drinfo->oldname); + +out: + AuTraceErr(err); + return err; +} + +/* callers have to free the return value */ +static struct au_drinfo *au_drinfo_read_k(struct file *file, ino_t h_ino) +{ + struct au_drinfo *ret, *drinfo; + struct au_drinfo_fdata fdata; + int len; + loff_t pos; + ssize_t ssz; + + ret = ERR_PTR(-EIO); + pos = 0; + ssz = vfsub_read_k(file, &fdata, sizeof(fdata), &pos); + if (unlikely(ssz != sizeof(fdata))) { + AuIOErr("ssz %zd, %u, %pD2\n", + ssz, (unsigned int)sizeof(fdata), file); + goto out; + } + + fdata.magic = ntohl((__force __be32)fdata.magic); + switch (fdata.magic) { + case AUFS_DRINFO_MAGIC_V1: + break; + default: + AuIOErr("magic-num 0x%x, 0x%x, %pD2\n", + fdata.magic, AUFS_DRINFO_MAGIC_V1, file); + goto out; + } + + drinfo = &fdata.drinfo; + len = drinfo->oldnamelen; + if (!len) { + AuIOErr("broken drinfo %pD2\n", file); + goto out; + } + + ret = NULL; + drinfo->ino = be64_to_cpu((__force __be64)drinfo->ino); + if (unlikely(h_ino && drinfo->ino != h_ino)) { + AuDbg("ignored i%llu, i%llu, %pD2\n", + (unsigned long long)drinfo->ino, + (unsigned long long)h_ino, file); + goto out; /* success */ + } + + ret = kmalloc(sizeof(*ret) + len, GFP_NOFS); + if (unlikely(!ret)) { + ret = ERR_PTR(-ENOMEM); + AuTraceErrPtr(ret); + goto out; + } + + *ret = *drinfo; + ssz = vfsub_read_k(file, (void *)ret->oldname, len, &pos); + if (unlikely(ssz != len)) { + au_kfree_rcu(ret); + ret = ERR_PTR(-EIO); + AuIOErr("ssz %zd, %u, %pD2\n", ssz, len, file); + goto out; + } + + AuDbg("oldname %.*s\n", ret->oldnamelen, ret->oldname); + +out: + return ret; +} + +/* ---------------------------------------------------------------------- */ + +/* in order to be revertible */ +struct au_drinfo_rev_elm { + int created; + struct dentry *info_dentry; + struct au_drinfo *info_last; +}; + +struct au_drinfo_rev { + unsigned char already; + aufs_bindex_t nelm; + struct au_drinfo_rev_elm elm[0]; +}; + +/* todo: isn't it too large? */ +struct au_drinfo_store { + struct path h_ppath; + struct dentry *h_dentry; + struct au_drinfo_fdata *fdata; + char *infoname; /* inside of whname, just after PFX */ + char whname[sizeof(AUFS_WH_DR_INFO_PFX) + AUFS_DIRREN_ENV_VAL_SZ]; + aufs_bindex_t btgt, btail; + unsigned char no_sio, + allocated, /* current size of *fdata */ + infonamelen, /* room size for p */ + whnamelen, /* length of the generated name */ + renameback; /* renamed back */ +}; + +/* on rename(2) error, the caller should revert it using @elm */ +static int au_drinfo_do_store(struct au_drinfo_store *w, + struct au_drinfo_rev_elm *elm) +{ + int err, len; + ssize_t ssz; + loff_t pos; + struct path infopath = { + .mnt = w->h_ppath.mnt + }; + struct inode *h_dir, *h_inode, *delegated; + struct file *infofile; + struct qstr *qname; + + AuDebugOn(elm + && memcmp(elm, page_address(ZERO_PAGE(0)), sizeof(*elm))); + + infopath.dentry = vfsub_lookup_one_len(w->whname, w->h_ppath.dentry, + w->whnamelen); + AuTraceErrPtr(infopath.dentry); + if (IS_ERR(infopath.dentry)) { + err = PTR_ERR(infopath.dentry); + goto out; + } + + err = 0; + h_dir = d_inode(w->h_ppath.dentry); + if (elm && d_is_negative(infopath.dentry)) { + err = vfsub_create(h_dir, &infopath, 0600, /*want_excl*/true); + AuTraceErr(err); + if (unlikely(err)) + goto out_dput; + elm->created = 1; + elm->info_dentry = dget(infopath.dentry); + } + + infofile = vfsub_dentry_open(&infopath, O_RDWR); + AuTraceErrPtr(infofile); + if (IS_ERR(infofile)) { + err = PTR_ERR(infofile); + goto out_dput; + } + + h_inode = d_inode(infopath.dentry); + if (elm && i_size_read(h_inode)) { + h_inode = d_inode(w->h_dentry); + elm->info_last = au_drinfo_read_k(infofile, h_inode->i_ino); + AuTraceErrPtr(elm->info_last); + if (IS_ERR(elm->info_last)) { + err = PTR_ERR(elm->info_last); + elm->info_last = NULL; + AuDebugOn(elm->info_dentry); + goto out_fput; + } + } + + if (elm && w->renameback) { + delegated = NULL; + err = vfsub_unlink(h_dir, &infopath, &delegated, /*force*/0); + AuTraceErr(err); + if (unlikely(err == -EWOULDBLOCK)) + iput(delegated); + goto out_fput; + } + + pos = 0; + qname = &w->h_dentry->d_name; + len = sizeof(*w->fdata) + qname->len; + if (!elm) + len = sizeof(*w->fdata) + w->fdata->drinfo.oldnamelen; + ssz = vfsub_write_k(infofile, w->fdata, len, &pos); + if (ssz == len) { + AuDbg("hi%llu, %.*s\n", w->fdata->drinfo.ino, + w->fdata->drinfo.oldnamelen, w->fdata->drinfo.oldname); + goto out_fput; /* success */ + } else { + err = -EIO; + if (ssz < 0) + err = ssz; + /* the caller should revert it using @elm */ + } + +out_fput: + fput(infofile); +out_dput: + dput(infopath.dentry); +out: + AuTraceErr(err); + return err; +} + +struct au_call_drinfo_do_store_args { + int *errp; + struct au_drinfo_store *w; + struct au_drinfo_rev_elm *elm; +}; + +static void au_call_drinfo_do_store(void *args) +{ + struct au_call_drinfo_do_store_args *a = args; + + *a->errp = au_drinfo_do_store(a->w, a->elm); +} + +static int au_drinfo_store_sio(struct au_drinfo_store *w, + struct au_drinfo_rev_elm *elm) +{ + int err, wkq_err; + + if (w->no_sio) + err = au_drinfo_do_store(w, elm); + else { + struct au_call_drinfo_do_store_args a = { + .errp = &err, + .w = w, + .elm = elm + }; + wkq_err = au_wkq_wait(au_call_drinfo_do_store, &a); + if (unlikely(wkq_err)) + err = wkq_err; + } + AuTraceErr(err); + + return err; +} + +static int au_drinfo_store_work_init(struct au_drinfo_store *w, + aufs_bindex_t btgt) +{ + int err; + + memset(w, 0, sizeof(*w)); + w->allocated = roundup_pow_of_two(sizeof(*w->fdata) + 40); + strcpy(w->whname, AUFS_WH_DR_INFO_PFX); + w->infoname = w->whname + sizeof(AUFS_WH_DR_INFO_PFX) - 1; + w->infonamelen = sizeof(w->whname) - sizeof(AUFS_WH_DR_INFO_PFX); + w->btgt = btgt; + w->no_sio = !!uid_eq(current_fsuid(), GLOBAL_ROOT_UID); + + err = -ENOMEM; + w->fdata = kcalloc(1, w->allocated, GFP_NOFS); + if (unlikely(!w->fdata)) { + AuTraceErr(err); + goto out; + } + w->fdata->magic = (__force uint32_t)htonl(AUFS_DRINFO_MAGIC_V1); + err = 0; + +out: + return err; +} + +static void au_drinfo_store_work_fin(struct au_drinfo_store *w) +{ + au_kfree_rcu(w->fdata); +} + +static void au_drinfo_store_rev(struct au_drinfo_rev *rev, + struct au_drinfo_store *w) +{ + struct au_drinfo_rev_elm *elm; + struct inode *h_dir, *delegated; + int err, nelm; + struct path infopath = { + .mnt = w->h_ppath.mnt + }; + + h_dir = d_inode(w->h_ppath.dentry); + IMustLock(h_dir); + + err = 0; + elm = rev->elm; + for (nelm = rev->nelm; nelm > 0; nelm--, elm++) { + AuDebugOn(elm->created && elm->info_last); + if (elm->created) { + AuDbg("here\n"); + delegated = NULL; + infopath.dentry = elm->info_dentry; + err = vfsub_unlink(h_dir, &infopath, &delegated, + !w->no_sio); + AuTraceErr(err); + if (unlikely(err == -EWOULDBLOCK)) + iput(delegated); + dput(elm->info_dentry); + } else if (elm->info_last) { + AuDbg("here\n"); + w->fdata->drinfo = *elm->info_last; + memcpy(w->fdata->drinfo.oldname, + elm->info_last->oldname, + elm->info_last->oldnamelen); + err = au_drinfo_store_sio(w, /*elm*/NULL); + au_kfree_rcu(elm->info_last); + } + if (unlikely(err)) + AuIOErr("%d, %s\n", err, w->whname); + /* go on even if err */ + } +} + +/* caller has to call au_dr_rename_fin() later */ +static int au_drinfo_store(struct dentry *dentry, aufs_bindex_t btgt, + struct qstr *dst_name, void *_rev) +{ + int err, sz, nelm; + aufs_bindex_t bindex, btail; + struct au_drinfo_store work; + struct au_drinfo_rev *rev, **p; + struct au_drinfo_rev_elm *elm; + struct super_block *sb; + struct au_branch *br; + struct au_hinode *hdir; + + err = au_drinfo_store_work_init(&work, btgt); + AuTraceErr(err); + if (unlikely(err)) + goto out; + + err = -ENOMEM; + btail = au_dbtaildir(dentry); + nelm = btail - btgt; + sz = sizeof(*rev) + sizeof(*elm) * nelm; + rev = kcalloc(1, sz, GFP_NOFS); + if (unlikely(!rev)) { + AuTraceErr(err); + goto out_args; + } + rev->nelm = nelm; + elm = rev->elm; + p = _rev; + *p = rev; + + err = 0; + sb = dentry->d_sb; + work.h_ppath.dentry = au_h_dptr(dentry, btgt); + work.h_ppath.mnt = au_sbr_mnt(sb, btgt); + hdir = au_hi(d_inode(dentry), btgt); + au_hn_inode_lock_nested(hdir, AuLsc_I_CHILD); + for (bindex = btgt + 1; bindex <= btail; bindex++, elm++) { + work.h_dentry = au_h_dptr(dentry, bindex); + if (!work.h_dentry) + continue; + + err = au_drinfo_construct(&work.fdata, work.h_dentry, + &work.allocated); + AuTraceErr(err); + if (unlikely(err)) + break; + + work.renameback = au_qstreq(&work.h_dentry->d_name, dst_name); + br = au_sbr(sb, bindex); + work.whnamelen = sizeof(AUFS_WH_DR_INFO_PFX) - 1; + work.whnamelen += au_drinfo_name(br, work.infoname, + work.infonamelen); + AuDbg("whname %.*s, i%llu, %.*s\n", + work.whnamelen, work.whname, + be64_to_cpu((__force __be64)work.fdata->drinfo.ino), + work.fdata->drinfo.oldnamelen, + work.fdata->drinfo.oldname); + + err = au_drinfo_store_sio(&work, elm); + AuTraceErr(err); + if (unlikely(err)) + break; + } + if (unlikely(err)) { + /* revert all drinfo */ + au_drinfo_store_rev(rev, &work); + au_kfree_try_rcu(rev); + *p = NULL; + } + au_hn_inode_unlock(hdir); + +out_args: + au_drinfo_store_work_fin(&work); +out: + return err; +} + +/* ---------------------------------------------------------------------- */ + +int au_dr_rename(struct dentry *src, aufs_bindex_t bindex, + struct qstr *dst_name, void *_rev) +{ + int err, already; + ino_t ino; + struct super_block *sb; + struct au_branch *br; + struct au_dr_br *dr; + struct dentry *h_dentry; + struct inode *h_inode; + struct au_dr_hino *ent; + struct au_drinfo_rev *rev, **p; + + AuDbg("bindex %d\n", bindex); + + err = -ENOMEM; + ent = kmalloc(sizeof(*ent), GFP_NOFS); + if (unlikely(!ent)) + goto out; + + sb = src->d_sb; + br = au_sbr(sb, bindex); + dr = &br->br_dirren; + h_dentry = au_h_dptr(src, bindex); + h_inode = d_inode(h_dentry); + ino = h_inode->i_ino; + ent->dr_h_ino = ino; + already = au_dr_hino_test_add(dr, ino, ent); + AuDbg("b%d, hi%llu, already %d\n", + bindex, (unsigned long long)ino, already); + + err = au_drinfo_store(src, bindex, dst_name, _rev); + AuTraceErr(err); + if (!err) { + p = _rev; + rev = *p; + rev->already = already; + goto out; /* success */ + } + + /* revert */ + if (!already) + au_dr_hino_del(dr, ent); + au_kfree_rcu(ent); + +out: + AuTraceErr(err); + return err; +} + +void au_dr_rename_fin(struct dentry *src, aufs_bindex_t btgt, void *_rev) +{ + struct au_drinfo_rev *rev; + struct au_drinfo_rev_elm *elm; + int nelm; + + rev = _rev; + elm = rev->elm; + for (nelm = rev->nelm; nelm > 0; nelm--, elm++) { + dput(elm->info_dentry); + au_kfree_rcu(elm->info_last); + } + au_kfree_try_rcu(rev); +} + +void au_dr_rename_rev(struct dentry *src, aufs_bindex_t btgt, void *_rev) +{ + int err; + struct au_drinfo_store work; + struct au_drinfo_rev *rev = _rev; + struct super_block *sb; + struct au_branch *br; + struct inode *h_inode; + struct au_dr_br *dr; + struct au_dr_hino *ent; + + err = au_drinfo_store_work_init(&work, btgt); + if (unlikely(err)) + goto out; + + sb = src->d_sb; + br = au_sbr(sb, btgt); + work.h_ppath.dentry = au_h_dptr(src, btgt); + work.h_ppath.mnt = au_br_mnt(br); + au_drinfo_store_rev(rev, &work); + au_drinfo_store_work_fin(&work); + if (rev->already) + goto out; + + dr = &br->br_dirren; + h_inode = d_inode(work.h_ppath.dentry); + ent = au_dr_hino_find(dr, h_inode->i_ino); + BUG_ON(!ent); + au_dr_hino_del(dr, ent); + au_kfree_rcu(ent); + +out: + au_kfree_try_rcu(rev); + if (unlikely(err)) + pr_err("failed to remove dirren info\n"); +} + +/* ---------------------------------------------------------------------- */ + +static struct au_drinfo *au_drinfo_do_load(struct path *h_ppath, + char *whname, int whnamelen, + struct dentry **info_dentry) +{ + struct au_drinfo *drinfo; + struct file *f; + struct inode *h_dir; + struct path infopath; + int unlocked; + + AuDbg("%pd/%.*s\n", h_ppath->dentry, whnamelen, whname); + + *info_dentry = NULL; + drinfo = NULL; + unlocked = 0; + h_dir = d_inode(h_ppath->dentry); + inode_lock_shared_nested(h_dir, AuLsc_I_PARENT); + infopath.dentry = vfsub_lookup_one_len(whname, h_ppath->dentry, + whnamelen); + if (IS_ERR(infopath.dentry)) { + drinfo = (void *)infopath.dentry; + goto out; + } + + if (d_is_negative(infopath.dentry)) + goto out_dput; /* success */ + + infopath.mnt = h_ppath->mnt; + f = vfsub_dentry_open(&infopath, O_RDONLY); + inode_unlock_shared(h_dir); + unlocked = 1; + if (IS_ERR(f)) { + drinfo = (void *)f; + goto out_dput; + } + + drinfo = au_drinfo_read_k(f, /*h_ino*/0); + if (IS_ERR_OR_NULL(drinfo)) + goto out_fput; + + AuDbg("oldname %.*s\n", drinfo->oldnamelen, drinfo->oldname); + *info_dentry = dget(infopath.dentry); /* keep it alive */ + +out_fput: + fput(f); +out_dput: + dput(infopath.dentry); +out: + if (!unlocked) + inode_unlock_shared(h_dir); + AuTraceErrPtr(drinfo); + return drinfo; +} + +struct au_drinfo_do_load_args { + struct au_drinfo **drinfop; + struct path *h_ppath; + char *whname; + int whnamelen; + struct dentry **info_dentry; +}; + +static void au_call_drinfo_do_load(void *args) +{ + struct au_drinfo_do_load_args *a = args; + + *a->drinfop = au_drinfo_do_load(a->h_ppath, a->whname, a->whnamelen, + a->info_dentry); +} + +struct au_drinfo_load { + struct path h_ppath; + struct qstr *qname; + unsigned char no_sio; + + aufs_bindex_t ninfo; + struct au_drinfo **drinfo; +}; + +static int au_drinfo_load(struct au_drinfo_load *w, aufs_bindex_t bindex, + struct au_branch *br) +{ + int err, wkq_err, whnamelen, e; + char whname[sizeof(AUFS_WH_DR_INFO_PFX) + AUFS_DIRREN_ENV_VAL_SZ] + = AUFS_WH_DR_INFO_PFX; + struct au_drinfo *drinfo; + struct qstr oldname; + struct inode *h_dir, *delegated; + struct dentry *info_dentry; + struct path infopath; + + whnamelen = sizeof(AUFS_WH_DR_INFO_PFX) - 1; + whnamelen += au_drinfo_name(br, whname + whnamelen, + sizeof(whname) - whnamelen); + if (w->no_sio) + drinfo = au_drinfo_do_load(&w->h_ppath, whname, whnamelen, + &info_dentry); + else { + struct au_drinfo_do_load_args args = { + .drinfop = &drinfo, + .h_ppath = &w->h_ppath, + .whname = whname, + .whnamelen = whnamelen, + .info_dentry = &info_dentry + }; + wkq_err = au_wkq_wait(au_call_drinfo_do_load, &args); + if (unlikely(wkq_err)) + drinfo = ERR_PTR(wkq_err); + } + err = PTR_ERR(drinfo); + if (IS_ERR_OR_NULL(drinfo)) + goto out; + + err = 0; + oldname.len = drinfo->oldnamelen; + oldname.name = drinfo->oldname; + if (au_qstreq(w->qname, &oldname)) { + /* the name is renamed back */ + au_kfree_rcu(drinfo); + drinfo = NULL; + + infopath.dentry = info_dentry; + infopath.mnt = w->h_ppath.mnt; + h_dir = d_inode(w->h_ppath.dentry); + delegated = NULL; + inode_lock_nested(h_dir, AuLsc_I_PARENT); + e = vfsub_unlink(h_dir, &infopath, &delegated, !w->no_sio); + inode_unlock(h_dir); + if (unlikely(e)) + AuIOErr("ignored %d, %pd2\n", e, &infopath.dentry); + if (unlikely(e == -EWOULDBLOCK)) + iput(delegated); + } + au_kfree_rcu(w->drinfo[bindex]); + w->drinfo[bindex] = drinfo; + dput(info_dentry); + +out: + AuTraceErr(err); + return err; +} + +/* ---------------------------------------------------------------------- */ + +static void au_dr_lkup_free(struct au_drinfo **drinfo, int n) +{ + struct au_drinfo **p = drinfo; + + while (n-- > 0) + au_kfree_rcu(*drinfo++); + au_kfree_try_rcu(p); +} + +int au_dr_lkup(struct au_do_lookup_args *lkup, struct dentry *dentry, + aufs_bindex_t btgt) +{ + int err, ninfo; + struct au_drinfo_load w; + aufs_bindex_t bindex, bbot; + struct au_branch *br; + struct inode *h_dir; + struct au_dr_hino *ent; + struct super_block *sb; + + AuDbg("%.*s, name %.*s, whname %.*s, b%d\n", + AuLNPair(&dentry->d_name), AuLNPair(&lkup->dirren.dr_name), + AuLNPair(&lkup->whname), btgt); + + sb = dentry->d_sb; + bbot = au_sbbot(sb); + w.ninfo = bbot + 1; + if (!lkup->dirren.drinfo) { + lkup->dirren.drinfo = kcalloc(w.ninfo, + sizeof(*lkup->dirren.drinfo), + GFP_NOFS); + if (unlikely(!lkup->dirren.drinfo)) { + err = -ENOMEM; + goto out; + } + lkup->dirren.ninfo = w.ninfo; + } + w.drinfo = lkup->dirren.drinfo; + w.no_sio = !!uid_eq(current_fsuid(), GLOBAL_ROOT_UID); + w.h_ppath.dentry = au_h_dptr(dentry, btgt); + AuDebugOn(!w.h_ppath.dentry); + w.h_ppath.mnt = au_sbr_mnt(sb, btgt); + w.qname = &dentry->d_name; + + ninfo = 0; + for (bindex = btgt + 1; bindex <= bbot; bindex++) { + br = au_sbr(sb, bindex); + err = au_drinfo_load(&w, bindex, br); + if (unlikely(err)) + goto out_free; + if (w.drinfo[bindex]) + ninfo++; + } + if (!ninfo) { + br = au_sbr(sb, btgt); + h_dir = d_inode(w.h_ppath.dentry); + ent = au_dr_hino_find(&br->br_dirren, h_dir->i_ino); + AuDebugOn(!ent); + au_dr_hino_del(&br->br_dirren, ent); + au_kfree_rcu(ent); + } + goto out; /* success */ + +out_free: + au_dr_lkup_free(lkup->dirren.drinfo, lkup->dirren.ninfo); + lkup->dirren.ninfo = 0; + lkup->dirren.drinfo = NULL; +out: + AuTraceErr(err); + return err; +} + +void au_dr_lkup_fin(struct au_do_lookup_args *lkup) +{ + au_dr_lkup_free(lkup->dirren.drinfo, lkup->dirren.ninfo); +} + +int au_dr_lkup_name(struct au_do_lookup_args *lkup, aufs_bindex_t btgt) +{ + int err; + struct au_drinfo *drinfo; + + err = 0; + if (!lkup->dirren.drinfo) + goto out; + AuDebugOn(lkup->dirren.ninfo < btgt + 1); + drinfo = lkup->dirren.drinfo[btgt + 1]; + if (!drinfo) + goto out; + + au_kfree_try_rcu(lkup->whname.name); + lkup->whname.name = NULL; + lkup->dirren.dr_name.len = drinfo->oldnamelen; + lkup->dirren.dr_name.name = drinfo->oldname; + lkup->name = &lkup->dirren.dr_name; + err = au_wh_name_alloc(&lkup->whname, lkup->name); + if (!err) + AuDbg("name %.*s, whname %.*s, b%d\n", + AuLNPair(lkup->name), AuLNPair(&lkup->whname), + btgt); + +out: + AuTraceErr(err); + return err; +} + +int au_dr_lkup_h_ino(struct au_do_lookup_args *lkup, aufs_bindex_t bindex, + ino_t h_ino) +{ + int match; + struct au_drinfo *drinfo; + + match = 1; + if (!lkup->dirren.drinfo) + goto out; + AuDebugOn(lkup->dirren.ninfo < bindex + 1); + drinfo = lkup->dirren.drinfo[bindex + 1]; + if (!drinfo) + goto out; + + match = (drinfo->ino == h_ino); + AuDbg("match %d\n", match); + +out: + return match; +} + +/* ---------------------------------------------------------------------- */ + +int au_dr_opt_set(struct super_block *sb) +{ + int err; + aufs_bindex_t bindex, bbot; + struct au_branch *br; + + err = 0; + bbot = au_sbbot(sb); + for (bindex = 0; !err && bindex <= bbot; bindex++) { + br = au_sbr(sb, bindex); + err = au_dr_hino(sb, bindex, /*br*/NULL, &br->br_path); + } + + return err; +} + +int au_dr_opt_flush(struct super_block *sb) +{ + int err; + aufs_bindex_t bindex, bbot; + struct au_branch *br; + + err = 0; + bbot = au_sbbot(sb); + for (bindex = 0; !err && bindex <= bbot; bindex++) { + br = au_sbr(sb, bindex); + if (au_br_writable(br->br_perm)) + err = au_dr_hino(sb, bindex, /*br*/NULL, /*path*/NULL); + } + + return err; +} + +int au_dr_opt_clr(struct super_block *sb, int no_flush) +{ + int err; + aufs_bindex_t bindex, bbot; + struct au_branch *br; + + err = 0; + if (!no_flush) { + err = au_dr_opt_flush(sb); + if (unlikely(err)) + goto out; + } + + bbot = au_sbbot(sb); + for (bindex = 0; bindex <= bbot; bindex++) { + br = au_sbr(sb, bindex); + au_dr_hino_free(&br->br_dirren); + } + +out: + return err; +} |