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-rw-r--r--fs/overlayfs/copy_up.c16
-rw-r--r--fs/overlayfs/dir.c31
-rw-r--r--fs/overlayfs/export.c40
-rw-r--r--fs/overlayfs/inode.c99
-rw-r--r--fs/overlayfs/namei.c5
-rw-r--r--fs/overlayfs/overlayfs.h25
-rw-r--r--fs/overlayfs/ovl_entry.h2
-rw-r--r--fs/overlayfs/readdir.c25
-rw-r--r--fs/overlayfs/super.c258
-rw-r--r--fs/overlayfs/util.c40
10 files changed, 380 insertions, 161 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 9fc47c2e078d..9709cf22cab3 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -36,6 +36,13 @@ static int ovl_ccup_get(char *buf, const struct kernel_param *param)
module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644);
MODULE_PARM_DESC(check_copy_up, "Obsolete; does nothing");
+static bool ovl_must_copy_xattr(const char *name)
+{
+ return !strcmp(name, XATTR_POSIX_ACL_ACCESS) ||
+ !strcmp(name, XATTR_POSIX_ACL_DEFAULT) ||
+ !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN);
+}
+
int ovl_copy_xattr(struct dentry *old, struct dentry *new)
{
ssize_t list_size, size, value_size = 0;
@@ -107,8 +114,13 @@ retry:
continue; /* Discard */
}
error = vfs_setxattr(new, name, value, size, 0);
- if (error)
- break;
+ if (error) {
+ if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name))
+ break;
+
+ /* Ignore failure to copy unknown xattrs */
+ error = 0;
+ }
}
kfree(value);
out:
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 8e57d5372b8f..279009dee366 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -42,7 +42,7 @@ int ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
return err;
}
-static struct dentry *ovl_lookup_temp(struct dentry *workdir)
+struct dentry *ovl_lookup_temp(struct dentry *workdir)
{
struct dentry *temp;
char name[20];
@@ -243,6 +243,9 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
ovl_dir_modified(dentry->d_parent, false);
ovl_dentry_set_upper_alias(dentry);
+ ovl_dentry_update_reval(dentry, newdentry,
+ DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+
if (!hardlink) {
/*
* ovl_obtain_alias() can be called after ovl_create_real()
@@ -819,6 +822,28 @@ static bool ovl_pure_upper(struct dentry *dentry)
!ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry));
}
+static void ovl_drop_nlink(struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ struct dentry *alias;
+
+ /* Try to find another, hashed alias */
+ spin_lock(&inode->i_lock);
+ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
+ if (alias != dentry && !d_unhashed(alias))
+ break;
+ }
+ spin_unlock(&inode->i_lock);
+
+ /*
+ * Changes to underlying layers may cause i_nlink to lose sync with
+ * reality. In this case prevent the link count from going to zero
+ * prematurely.
+ */
+ if (inode->i_nlink > !!alias)
+ drop_nlink(inode);
+}
+
static int ovl_do_remove(struct dentry *dentry, bool is_dir)
{
int err;
@@ -856,7 +881,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
if (is_dir)
clear_nlink(dentry->d_inode);
else
- drop_nlink(dentry->d_inode);
+ ovl_drop_nlink(dentry);
}
ovl_nlink_end(dentry);
@@ -1201,7 +1226,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
if (new_is_dir)
clear_nlink(d_inode(new));
else
- drop_nlink(d_inode(new));
+ ovl_drop_nlink(new);
}
ovl_dir_modified(old->d_parent, ovl_type_origin(old) ||
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 6f54d70cef27..475c61f53f0f 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -308,29 +308,35 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb,
ovl_set_flag(OVL_UPPERDATA, inode);
dentry = d_find_any_alias(inode);
- if (!dentry) {
- dentry = d_alloc_anon(inode->i_sb);
- if (!dentry)
- goto nomem;
- oe = ovl_alloc_entry(lower ? 1 : 0);
- if (!oe)
- goto nomem;
-
- if (lower) {
- oe->lowerstack->dentry = dget(lower);
- oe->lowerstack->layer = lowerpath->layer;
- }
- dentry->d_fsdata = oe;
- if (upper_alias)
- ovl_dentry_set_upper_alias(dentry);
+ if (dentry)
+ goto out_iput;
+
+ dentry = d_alloc_anon(inode->i_sb);
+ if (unlikely(!dentry))
+ goto nomem;
+ oe = ovl_alloc_entry(lower ? 1 : 0);
+ if (!oe)
+ goto nomem;
+
+ if (lower) {
+ oe->lowerstack->dentry = dget(lower);
+ oe->lowerstack->layer = lowerpath->layer;
}
+ dentry->d_fsdata = oe;
+ if (upper_alias)
+ ovl_dentry_set_upper_alias(dentry);
+
+ ovl_dentry_update_reval(dentry, upper,
+ DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
return d_instantiate_anon(dentry, inode);
nomem:
- iput(inode);
dput(dentry);
- return ERR_PTR(-ENOMEM);
+ dentry = ERR_PTR(-ENOMEM);
+out_iput:
+ iput(inode);
+ return dentry;
}
/* Get the upper or lower dentry in stach whose on layer @idx */
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 79e8994e3bc1..b0d42ece4d7c 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -79,6 +79,7 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
{
bool samefs = ovl_same_fs(dentry->d_sb);
unsigned int xinobits = ovl_xino_bits(dentry->d_sb);
+ unsigned int xinoshift = 64 - xinobits;
if (samefs) {
/*
@@ -89,22 +90,22 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
stat->dev = dentry->d_sb->s_dev;
return 0;
} else if (xinobits) {
- unsigned int shift = 64 - xinobits;
/*
* All inode numbers of underlying fs should not be using the
* high xinobits, so we use high xinobits to partition the
* overlay st_ino address space. The high bits holds the fsid
- * (upper fsid is 0). This way overlay inode numbers are unique
- * and all inodes use overlay st_dev. Inode numbers are also
- * persistent for a given layer configuration.
+ * (upper fsid is 0). The lowest xinobit is reserved for mapping
+ * the non-peresistent inode numbers range in case of overflow.
+ * This way all overlay inode numbers are unique and use the
+ * overlay st_dev.
*/
- if (stat->ino >> shift) {
- pr_warn_ratelimited("inode number too big (%pd2, ino=%llu, xinobits=%d)\n",
- dentry, stat->ino, xinobits);
- } else {
- stat->ino |= ((u64)fsid) << shift;
+ if (likely(!(stat->ino >> xinoshift))) {
+ stat->ino |= ((u64)fsid) << (xinoshift + 1);
stat->dev = dentry->d_sb->s_dev;
return 0;
+ } else if (ovl_xino_warn(dentry->d_sb)) {
+ pr_warn_ratelimited("inode number too big (%pd2, ino=%llu, xinobits=%d)\n",
+ dentry, stat->ino, xinobits);
}
}
@@ -504,7 +505,7 @@ static const struct address_space_operations ovl_aops = {
/*
* It is possible to stack overlayfs instance on top of another
- * overlayfs instance as lower layer. We need to annonate the
+ * overlayfs instance as lower layer. We need to annotate the
* stackable i_mutex locks according to stack level of the super
* block instance. An overlayfs instance can never be in stack
* depth 0 (there is always a real fs below it). An overlayfs
@@ -561,27 +562,73 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode)
#endif
}
-static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
- unsigned long ino, int fsid)
+static void ovl_next_ino(struct inode *inode)
+{
+ struct ovl_fs *ofs = inode->i_sb->s_fs_info;
+
+ inode->i_ino = atomic_long_inc_return(&ofs->last_ino);
+ if (unlikely(!inode->i_ino))
+ inode->i_ino = atomic_long_inc_return(&ofs->last_ino);
+}
+
+static void ovl_map_ino(struct inode *inode, unsigned long ino, int fsid)
{
int xinobits = ovl_xino_bits(inode->i_sb);
+ unsigned int xinoshift = 64 - xinobits;
/*
* When d_ino is consistent with st_ino (samefs or i_ino has enough
* bits to encode layer), set the same value used for st_ino to i_ino,
* so inode number exposed via /proc/locks and a like will be
* consistent with d_ino and st_ino values. An i_ino value inconsistent
- * with d_ino also causes nfsd readdirplus to fail. When called from
- * ovl_new_inode(), ino arg is 0, so i_ino will be updated to real
- * upper inode i_ino on ovl_inode_init() or ovl_inode_update().
+ * with d_ino also causes nfsd readdirplus to fail.
*/
- if (ovl_same_dev(inode->i_sb)) {
- inode->i_ino = ino;
- if (xinobits && fsid && !(ino >> (64 - xinobits)))
- inode->i_ino |= (unsigned long)fsid << (64 - xinobits);
- } else {
- inode->i_ino = get_next_ino();
+ inode->i_ino = ino;
+ if (ovl_same_fs(inode->i_sb)) {
+ return;
+ } else if (xinobits && likely(!(ino >> xinoshift))) {
+ inode->i_ino |= (unsigned long)fsid << (xinoshift + 1);
+ return;
+ }
+
+ /*
+ * For directory inodes on non-samefs with xino disabled or xino
+ * overflow, we allocate a non-persistent inode number, to be used for
+ * resolving st_ino collisions in ovl_map_dev_ino().
+ *
+ * To avoid ino collision with legitimate xino values from upper
+ * layer (fsid 0), use the lowest xinobit to map the non
+ * persistent inode numbers to the unified st_ino address space.
+ */
+ if (S_ISDIR(inode->i_mode)) {
+ ovl_next_ino(inode);
+ if (xinobits) {
+ inode->i_ino &= ~0UL >> xinobits;
+ inode->i_ino |= 1UL << xinoshift;
+ }
}
+}
+
+void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
+ unsigned long ino, int fsid)
+{
+ struct inode *realinode;
+
+ if (oip->upperdentry)
+ OVL_I(inode)->__upperdentry = oip->upperdentry;
+ if (oip->lowerpath && oip->lowerpath->dentry)
+ OVL_I(inode)->lower = igrab(d_inode(oip->lowerpath->dentry));
+ if (oip->lowerdata)
+ OVL_I(inode)->lowerdata = igrab(d_inode(oip->lowerdata));
+
+ realinode = ovl_inode_real(inode);
+ ovl_copyattr(realinode, inode);
+ ovl_copyflags(realinode, inode);
+ ovl_map_ino(inode, ino, fsid);
+}
+
+static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev)
+{
inode->i_mode = mode;
inode->i_flags |= S_NOCMTIME;
#ifdef CONFIG_FS_POSIX_ACL
@@ -719,7 +766,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev)
inode = new_inode(sb);
if (inode)
- ovl_fill_inode(inode, mode, rdev, 0, 0);
+ ovl_fill_inode(inode, mode, rdev);
return inode;
}
@@ -891,7 +938,7 @@ struct inode *ovl_get_inode(struct super_block *sb,
struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry,
oip->index);
- int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
+ int fsid = bylower ? lowerpath->layer->fsid : 0;
bool is_dir, metacopy = false;
unsigned long ino = 0;
int err = oip->newinode ? -EEXIST : -ENOMEM;
@@ -941,9 +988,11 @@ struct inode *ovl_get_inode(struct super_block *sb,
err = -ENOMEM;
goto out_err;
}
+ ino = realinode->i_ino;
+ fsid = lowerpath->layer->fsid;
}
- ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
- ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);
+ ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);
+ ovl_inode_init(inode, oip, ino, fsid);
if (upperdentry && ovl_is_impuredir(upperdentry))
ovl_set_flag(OVL_IMPURE, inode);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index ed9e129fae04..0db23baf98e7 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -845,7 +845,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (err)
goto out;
- if (upperdentry && unlikely(ovl_dentry_remote(upperdentry))) {
+ if (upperdentry && upperdentry->d_flags & DCACHE_OP_REAL) {
dput(upperdentry);
err = -EREMOTE;
goto out;
@@ -1076,6 +1076,9 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
goto out_free_oe;
}
+ ovl_dentry_update_reval(dentry, upperdentry,
+ DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+
revert_creds(old_cred);
if (origin_path) {
dput(origin_path->dentry);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 3d3f2b8bdae5..e6f3670146ed 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -48,6 +48,12 @@ enum ovl_entry_flag {
OVL_E_CONNECTED,
};
+enum {
+ OVL_XINO_OFF,
+ OVL_XINO_AUTO,
+ OVL_XINO_ON,
+};
+
/*
* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
* where:
@@ -87,7 +93,7 @@ struct ovl_fb {
u8 flags; /* OVL_FH_FLAG_* */
u8 type; /* fid_type of fid */
uuid_t uuid; /* uuid of filesystem */
- u32 fid[0]; /* file identifier should be 32bit aligned in-memory */
+ u32 fid[]; /* file identifier should be 32bit aligned in-memory */
} __packed;
/* In-memory and on-wire format for overlay file handle */
@@ -230,6 +236,8 @@ bool ovl_index_all(struct super_block *sb);
bool ovl_verify_lower(struct super_block *sb);
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
bool ovl_dentry_remote(struct dentry *dentry);
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask);
bool ovl_dentry_weird(struct dentry *dentry);
enum ovl_path_type ovl_path_type(struct dentry *dentry);
void ovl_path_upper(struct dentry *dentry, struct path *path);
@@ -264,8 +272,6 @@ void ovl_set_upperdata(struct inode *inode);
bool ovl_redirect_dir(struct super_block *sb);
const char *ovl_dentry_get_redirect(struct dentry *dentry);
void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
-void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
- struct dentry *lowerdentry, struct dentry *lowerdata);
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
void ovl_dir_modified(struct dentry *dentry, bool impurity);
u64 ovl_dentry_version_get(struct dentry *dentry);
@@ -301,6 +307,16 @@ static inline bool ovl_is_impuredir(struct dentry *dentry)
return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
}
+/*
+ * With xino=auto, we do best effort to keep all inodes on same st_dev and
+ * d_ino consistent with st_ino.
+ * With xino=on, we do the same effort but we warn if we failed.
+ */
+static inline bool ovl_xino_warn(struct super_block *sb)
+{
+ return OVL_FS(sb)->config.xino == OVL_XINO_ON;
+}
+
/* All layers on same fs? */
static inline bool ovl_same_fs(struct super_block *sb)
{
@@ -410,6 +426,8 @@ struct ovl_inode_params {
char *redirect;
struct dentry *lowerdata;
};
+void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
+ unsigned long ino, int fsid);
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
bool is_upper);
@@ -451,6 +469,7 @@ struct ovl_cattr {
struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
struct ovl_cattr *attr);
int ovl_cleanup(struct inode *dir, struct dentry *dentry);
+struct dentry *ovl_lookup_temp(struct dentry *workdir);
struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
/* file.c */
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 89015ea822e7..5762d802fe01 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -75,6 +75,8 @@ struct ovl_fs {
struct inode *indexdir_trap;
/* -1: disabled, 0: same fs, 1..32: number of unused ino bits */
int xino_mode;
+ /* For allocation of non-persistent inode numbers */
+ atomic_long_t last_ino;
};
static inline struct ovl_fs *OVL_FS(struct super_block *sb)
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 40ac9ce2465a..e452ff7d583d 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -438,15 +438,23 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
/* Map inode number to lower fs unique range */
static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid,
- const char *name, int namelen)
+ const char *name, int namelen, bool warn)
{
- if (ino >> (64 - xinobits)) {
- pr_warn_ratelimited("d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
- namelen, name, ino, xinobits);
+ unsigned int xinoshift = 64 - xinobits;
+
+ if (unlikely(ino >> xinoshift)) {
+ if (warn) {
+ pr_warn_ratelimited("d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
+ namelen, name, ino, xinobits);
+ }
return ino;
}
- return ino | ((u64)fsid) << (64 - xinobits);
+ /*
+ * The lowest xinobit is reserved for mapping the non-peresistent inode
+ * numbers range, but this range is only exposed via st_ino, not here.
+ */
+ return ino | ((u64)fsid) << (xinoshift + 1);
}
/*
@@ -515,7 +523,8 @@ get:
} else if (xinobits && !OVL_TYPE_UPPER(type)) {
ino = ovl_remap_lower_ino(ino, xinobits,
ovl_layer_lower(this)->fsid,
- p->name, p->len);
+ p->name, p->len,
+ ovl_xino_warn(dir->d_sb));
}
out:
@@ -645,6 +654,7 @@ struct ovl_readdir_translate {
u64 parent_ino;
int fsid;
int xinobits;
+ bool xinowarn;
};
static int ovl_fill_real(struct dir_context *ctx, const char *name,
@@ -665,7 +675,7 @@ static int ovl_fill_real(struct dir_context *ctx, const char *name,
ino = p->ino;
} else if (rdt->xinobits) {
ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid,
- name, namelen);
+ name, namelen, rdt->xinowarn);
}
return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
@@ -696,6 +706,7 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
.ctx.actor = ovl_fill_real,
.orig_ctx = ctx,
.xinobits = ovl_xino_bits(dir->d_sb),
+ .xinowarn = ovl_xino_warn(dir->d_sb),
};
if (rdt.xinobits && lower_layer)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index ac967f1cb6e5..732ad5495c92 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -113,53 +113,54 @@ bug:
return dentry;
}
-static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags)
+static int ovl_revalidate_real(struct dentry *d, unsigned int flags, bool weak)
{
- struct ovl_entry *oe = dentry->d_fsdata;
- unsigned int i;
int ret = 1;
- for (i = 0; i < oe->numlower; i++) {
- struct dentry *d = oe->lowerstack[i].dentry;
-
- if (d->d_flags & DCACHE_OP_REVALIDATE) {
- ret = d->d_op->d_revalidate(d, flags);
- if (ret < 0)
- return ret;
- if (!ret) {
- if (!(flags & LOOKUP_RCU))
- d_invalidate(d);
- return -ESTALE;
- }
+ if (weak) {
+ if (d->d_flags & DCACHE_OP_WEAK_REVALIDATE)
+ ret = d->d_op->d_weak_revalidate(d, flags);
+ } else if (d->d_flags & DCACHE_OP_REVALIDATE) {
+ ret = d->d_op->d_revalidate(d, flags);
+ if (!ret) {
+ if (!(flags & LOOKUP_RCU))
+ d_invalidate(d);
+ ret = -ESTALE;
}
}
- return 1;
+ return ret;
}
-static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
+static int ovl_dentry_revalidate_common(struct dentry *dentry,
+ unsigned int flags, bool weak)
{
struct ovl_entry *oe = dentry->d_fsdata;
+ struct dentry *upper;
unsigned int i;
int ret = 1;
- for (i = 0; i < oe->numlower; i++) {
- struct dentry *d = oe->lowerstack[i].dentry;
+ upper = ovl_dentry_upper(dentry);
+ if (upper)
+ ret = ovl_revalidate_real(upper, flags, weak);
- if (d->d_flags & DCACHE_OP_WEAK_REVALIDATE) {
- ret = d->d_op->d_weak_revalidate(d, flags);
- if (ret <= 0)
- break;
- }
+ for (i = 0; ret > 0 && i < oe->numlower; i++) {
+ ret = ovl_revalidate_real(oe->lowerstack[i].dentry, flags,
+ weak);
}
return ret;
}
-static const struct dentry_operations ovl_dentry_operations = {
- .d_release = ovl_dentry_release,
- .d_real = ovl_d_real,
-};
+static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ return ovl_dentry_revalidate_common(dentry, flags, false);
+}
+
+static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ return ovl_dentry_revalidate_common(dentry, flags, true);
+}
-static const struct dentry_operations ovl_reval_dentry_operations = {
+static const struct dentry_operations ovl_dentry_operations = {
.d_release = ovl_dentry_release,
.d_real = ovl_d_real,
.d_revalidate = ovl_dentry_revalidate,
@@ -316,12 +317,6 @@ static const char *ovl_redirect_mode_def(void)
return ovl_redirect_dir_def ? "on" : "off";
}
-enum {
- OVL_XINO_OFF,
- OVL_XINO_AUTO,
- OVL_XINO_ON,
-};
-
static const char * const ovl_xino_str[] = {
"off",
"auto",
@@ -751,13 +746,12 @@ static int ovl_mount_dir(const char *name, struct path *path)
ovl_unescape(tmp);
err = ovl_mount_dir_noesc(tmp, path);
- if (!err)
- if (ovl_dentry_remote(path->dentry)) {
- pr_err("filesystem on '%s' not supported as upperdir\n",
- tmp);
- path_put_init(path);
- err = -EINVAL;
- }
+ if (!err && path->dentry->d_flags & DCACHE_OP_REAL) {
+ pr_err("filesystem on '%s' not supported as upperdir\n",
+ tmp);
+ path_put_init(path);
+ err = -EINVAL;
+ }
kfree(tmp);
}
return err;
@@ -778,7 +772,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
}
static int ovl_lower_dir(const char *name, struct path *path,
- struct ovl_fs *ofs, int *stack_depth, bool *remote)
+ struct ovl_fs *ofs, int *stack_depth)
{
int fh_type;
int err;
@@ -793,9 +787,6 @@ static int ovl_lower_dir(const char *name, struct path *path,
*stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth);
- if (ovl_dentry_remote(path->dentry))
- *remote = true;
-
/*
* The inodes index feature and NFS export need to encode and decode
* file handles, so they require that all layers support them.
@@ -1074,11 +1065,73 @@ out:
return err;
}
+/*
+ * Returns 1 if RENAME_WHITEOUT is supported, 0 if not supported and
+ * negative values if error is encountered.
+ */
+static int ovl_check_rename_whiteout(struct dentry *workdir)
+{
+ struct inode *dir = d_inode(workdir);
+ struct dentry *temp;
+ struct dentry *dest;
+ struct dentry *whiteout;
+ struct name_snapshot name;
+ int err;
+
+ inode_lock_nested(dir, I_MUTEX_PARENT);
+
+ temp = ovl_create_temp(workdir, OVL_CATTR(S_IFREG | 0));
+ err = PTR_ERR(temp);
+ if (IS_ERR(temp))
+ goto out_unlock;
+
+ dest = ovl_lookup_temp(workdir);
+ err = PTR_ERR(dest);
+ if (IS_ERR(dest)) {
+ dput(temp);
+ goto out_unlock;
+ }
+
+ /* Name is inline and stable - using snapshot as a copy helper */
+ take_dentry_name_snapshot(&name, temp);
+ err = ovl_do_rename(dir, temp, dir, dest, RENAME_WHITEOUT);
+ if (err) {
+ if (err == -EINVAL)
+ err = 0;
+ goto cleanup_temp;
+ }
+
+ whiteout = lookup_one_len(name.name.name, workdir, name.name.len);
+ err = PTR_ERR(whiteout);
+ if (IS_ERR(whiteout))
+ goto cleanup_temp;
+
+ err = ovl_is_whiteout(whiteout);
+
+ /* Best effort cleanup of whiteout and temp file */
+ if (err)
+ ovl_cleanup(dir, whiteout);
+ dput(whiteout);
+
+cleanup_temp:
+ ovl_cleanup(dir, temp);
+ release_dentry_name_snapshot(&name);
+ dput(temp);
+ dput(dest);
+
+out_unlock:
+ inode_unlock(dir);
+
+ return err;
+}
+
static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
struct path *workpath)
{
struct vfsmount *mnt = ofs->upper_mnt;
struct dentry *temp;
+ bool rename_whiteout;
+ bool d_type;
int fh_type;
int err;
@@ -1104,11 +1157,8 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
if (err < 0)
goto out;
- /*
- * We allowed this configuration and don't want to break users over
- * kernel upgrade. So warn instead of erroring out.
- */
- if (!err)
+ d_type = err;
+ if (!d_type)
pr_warn("upper fs needs to support d_type.\n");
/* Check if upper/work fs supports O_TMPFILE */
@@ -1119,6 +1169,16 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
else
pr_warn("upper fs does not support tmpfile.\n");
+
+ /* Check if upper/work fs supports RENAME_WHITEOUT */
+ err = ovl_check_rename_whiteout(ofs->workdir);
+ if (err < 0)
+ goto out;
+
+ rename_whiteout = err;
+ if (!rename_whiteout)
+ pr_warn("upper fs does not support RENAME_WHITEOUT.\n");
+
/*
* Check if upper/work fs supports trusted.overlay.* xattr
*/
@@ -1133,6 +1193,18 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
}
+ /*
+ * We allowed sub-optimal upper fs configuration and don't want to break
+ * users over kernel upgrade, but we never allowed remote upper fs, so
+ * we can enforce strict requirements for remote upper fs.
+ */
+ if (ovl_dentry_remote(ofs->workdir) &&
+ (!d_type || !rename_whiteout || ofs->noxattr)) {
+ pr_err("upper fs missing required features.\n");
+ err = -EINVAL;
+ goto out;
+ }
+
/* Check if upper/work fs supports file handles */
fh_type = ovl_can_decode_fh(ofs->workdir->d_sb);
if (ofs->config.index && !fh_type) {
@@ -1401,11 +1473,12 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
/*
* When all layers on same fs, overlay can use real inode numbers.
- * With mount option "xino=on", mounter declares that there are enough
- * free high bits in underlying fs to hold the unique fsid.
+ * With mount option "xino=<on|auto>", mounter declares that there are
+ * enough free high bits in underlying fs to hold the unique fsid.
* If overlayfs does encounter underlying inodes using the high xino
* bits reserved for fsid, it emits a warning and uses the original
- * inode number.
+ * inode number or a non persistent inode number allocated from a
+ * dedicated range.
*/
if (ofs->numfs - !ofs->upper_mnt == 1) {
if (ofs->config.xino == OVL_XINO_ON)
@@ -1413,14 +1486,16 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
ofs->xino_mode = 0;
} else if (ofs->config.xino == OVL_XINO_OFF) {
ofs->xino_mode = -1;
- } else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) {
+ } else if (ofs->xino_mode < 0) {
/*
* This is a roundup of number of bits needed for encoding
- * fsid, where fsid 0 is reserved for upper fs even with
- * lower only overlay.
+ * fsid, where fsid 0 is reserved for upper fs (even with
+ * lower only overlay) +1 extra bit is reserved for the non
+ * persistent inode number range that is used for resolving
+ * xino lower bits overflow.
*/
- BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31);
- ofs->xino_mode = ilog2(ofs->numfs - 1) + 1;
+ BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 30);
+ ofs->xino_mode = ilog2(ofs->numfs - 1) + 2;
}
if (ofs->xino_mode > 0) {
@@ -1440,7 +1515,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
char *lowertmp, *lower;
struct path *stack = NULL;
unsigned int stacklen, numlower = 0, i;
- bool remote = false;
struct ovl_entry *oe;
err = -ENOMEM;
@@ -1472,7 +1546,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
lower = lowertmp;
for (numlower = 0; numlower < stacklen; numlower++) {
err = ovl_lower_dir(lower, &stack[numlower], ofs,
- &sb->s_stack_depth, &remote);
+ &sb->s_stack_depth);
if (err)
goto out_err;
@@ -1500,11 +1574,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
oe->lowerstack[i].layer = &ofs->layers[i+1];
}
- if (remote)
- sb->s_d_op = &ovl_reval_dentry_operations;
- else
- sb->s_d_op = &ovl_dentry_operations;
-
out:
for (i = 0; i < numlower; i++)
path_put(&stack[i]);
@@ -1589,6 +1658,44 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
return 0;
}
+static struct dentry *ovl_get_root(struct super_block *sb,
+ struct dentry *upperdentry,
+ struct ovl_entry *oe)
+{
+ struct dentry *root;
+ struct ovl_path *lowerpath = &oe->lowerstack[0];
+ unsigned long ino = d_inode(lowerpath->dentry)->i_ino;
+ int fsid = lowerpath->layer->fsid;
+ struct ovl_inode_params oip = {
+ .upperdentry = upperdentry,
+ .lowerpath = lowerpath,
+ };
+
+ root = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
+ if (!root)
+ return NULL;
+
+ root->d_fsdata = oe;
+
+ if (upperdentry) {
+ /* Root inode uses upper st_ino/i_ino */
+ ino = d_inode(upperdentry)->i_ino;
+ fsid = 0;
+ ovl_dentry_set_upper_alias(root);
+ if (ovl_is_impuredir(upperdentry))
+ ovl_set_flag(OVL_IMPURE, d_inode(root));
+ }
+
+ /* Root is always merge -> can have whiteouts */
+ ovl_set_flag(OVL_WHITEOUTS, d_inode(root));
+ ovl_dentry_set_flag(OVL_E_CONNECTED, root);
+ ovl_set_upperdata(d_inode(root));
+ ovl_inode_init(d_inode(root), &oip, ino, fsid);
+ ovl_dentry_update_reval(root, upperdentry, DCACHE_OP_WEAK_REVALIDATE);
+
+ return root;
+}
+
static int ovl_fill_super(struct super_block *sb, void *data, int silent)
{
struct path upperpath = { };
@@ -1598,6 +1705,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
struct cred *cred;
int err;
+ sb->s_d_op = &ovl_dentry_operations;
+
err = -ENOMEM;
ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL);
if (!ofs)
@@ -1624,6 +1733,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_stack_depth = 0;
sb->s_maxbytes = MAX_LFS_FILESIZE;
+ atomic_long_set(&ofs->last_ino, 1);
/* Assume underlaying fs uses 32bit inodes unless proven otherwise */
if (ofs->config.xino != OVL_XINO_OFF) {
ofs->xino_mode = BITS_PER_LONG - 32;
@@ -1710,25 +1820,11 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags |= SB_POSIXACL;
err = -ENOMEM;
- root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
+ root_dentry = ovl_get_root(sb, upperpath.dentry, oe);
if (!root_dentry)
goto out_free_oe;
- root_dentry->d_fsdata = oe;
-
mntput(upperpath.mnt);
- if (upperpath.dentry) {
- ovl_dentry_set_upper_alias(root_dentry);
- if (ovl_is_impuredir(upperpath.dentry))
- ovl_set_flag(OVL_IMPURE, d_inode(root_dentry));
- }
-
- /* Root is always merge -> can have whiteouts */
- ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry));
- ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry);
- ovl_set_upperdata(d_inode(root_dentry));
- ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
- ovl_dentry_lower(root_dentry), NULL);
sb->s_root = root_dentry;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 042f7eb4f7f4..36b60788ee47 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -93,8 +93,24 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
bool ovl_dentry_remote(struct dentry *dentry)
{
return dentry->d_flags &
- (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE |
- DCACHE_OP_REAL);
+ (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+}
+
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask)
+{
+ struct ovl_entry *oe = OVL_E(dentry);
+ unsigned int i, flags = 0;
+
+ if (upperdentry)
+ flags |= upperdentry->d_flags;
+ for (i = 0; i < oe->numlower; i++)
+ flags |= oe->lowerstack[i].dentry->d_flags;
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~mask;
+ dentry->d_flags |= flags & mask;
+ spin_unlock(&dentry->d_lock);
}
bool ovl_dentry_weird(struct dentry *dentry)
@@ -386,24 +402,6 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect)
oi->redirect = redirect;
}
-void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
- struct dentry *lowerdentry, struct dentry *lowerdata)
-{
- struct inode *realinode = d_inode(upperdentry ?: lowerdentry);
-
- if (upperdentry)
- OVL_I(inode)->__upperdentry = upperdentry;
- if (lowerdentry)
- OVL_I(inode)->lower = igrab(d_inode(lowerdentry));
- if (lowerdata)
- OVL_I(inode)->lowerdata = igrab(d_inode(lowerdata));
-
- ovl_copyattr(realinode, inode);
- ovl_copyflags(realinode, inode);
- if (!inode->i_ino)
- inode->i_ino = realinode->i_ino;
-}
-
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
{
struct inode *upperinode = d_inode(upperdentry);
@@ -416,8 +414,6 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
smp_wmb();
OVL_I(inode)->__upperdentry = upperdentry;
if (inode_unhashed(inode)) {
- if (!inode->i_ino)
- inode->i_ino = upperinode->i_ino;
inode->i_private = upperinode;
__insert_inode_hash(inode, (unsigned long) upperinode);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 18:28:06 +0000