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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-30 15:17:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-30 15:17:08 -0700
commitd652502ef46895820533aada50ddfd94abe078fe (patch)
tree06b1394b756279419a832f1ea1400147e5cb446c /fs/overlayfs
parentd42f323a7df0b298c07313db00b44b78555ca8e6 (diff)
parent5e717c6fa41ff9b9b0c1e5959ccf5d8ef42f804b (diff)
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Merge tag 'ovl-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs update from Miklos Szeredi: - Fix a regression introduced in 5.2 that resulted in valid overlayfs mounts being rejected with ELOOP (Too many levels of symbolic links) - Fix bugs found by various tools - Miscellaneous improvements and cleanups * tag 'ovl-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: add debug print to ovl_do_getxattr() ovl: invalidate readdir cache on changes to dir with origin ovl: allow upperdir inside lowerdir ovl: show "userxattr" in the mount data ovl: trivial typo fixes in the file inode.c ovl: fix misspellings using codespell tool ovl: do not copy attr several times ovl: remove ovl_map_dev_ino() return value ovl: fix error for ovl_fill_super() ovl: fix missing revert_creds() on error path ovl: fix leaked dentry ovl: restrict lower null uuid for "xino=auto" ovl: check that upperdir path is not on a read-only mount ovl: plumb through flush method
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c3
-rw-r--r--fs/overlayfs/file.c21
-rw-r--r--fs/overlayfs/inode.c18
-rw-r--r--fs/overlayfs/namei.c1
-rw-r--r--fs/overlayfs/overlayfs.h37
-rw-r--r--fs/overlayfs/readdir.c12
-rw-r--r--fs/overlayfs/super.c66
-rw-r--r--fs/overlayfs/util.c33
8 files changed, 124 insertions, 67 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 0b2891c6c71e..2846b943e80c 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -932,7 +932,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
static int ovl_copy_up_flags(struct dentry *dentry, int flags)
{
int err = 0;
- const struct cred *old_cred = ovl_override_creds(dentry->d_sb);
+ const struct cred *old_cred;
bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED);
/*
@@ -943,6 +943,7 @@ static int ovl_copy_up_flags(struct dentry *dentry, int flags)
if (WARN_ON(disconnected && d_is_dir(dentry)))
return -EIO;
+ old_cred = ovl_override_creds(dentry->d_sb);
while (!err) {
struct dentry *next;
struct dentry *parent = NULL;
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index c144183a7e09..4d53d3b7e5fe 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -571,6 +571,26 @@ static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,
remap_flags, op);
}
+static int ovl_flush(struct file *file, fl_owner_t id)
+{
+ struct fd real;
+ const struct cred *old_cred;
+ int err;
+
+ err = ovl_real_fdget(file, &real);
+ if (err)
+ return err;
+
+ if (real.file->f_op->flush) {
+ old_cred = ovl_override_creds(file_inode(file)->i_sb);
+ err = real.file->f_op->flush(real.file, id);
+ revert_creds(old_cred);
+ }
+ fdput(real);
+
+ return err;
+}
+
const struct file_operations ovl_file_operations = {
.open = ovl_open,
.release = ovl_release,
@@ -581,6 +601,7 @@ const struct file_operations ovl_file_operations = {
.mmap = ovl_mmap,
.fallocate = ovl_fallocate,
.fadvise = ovl_fadvise,
+ .flush = ovl_flush,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index c3c96b4b3b33..5e828a1c98a8 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -97,7 +97,7 @@ out:
return err;
}
-static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
+static void 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);
@@ -110,21 +110,21 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
* which is friendly to du -x.
*/
stat->dev = dentry->d_sb->s_dev;
- return 0;
+ return;
} else if (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). The lowest xinobit is reserved for mapping
- * the non-peresistent inode numbers range in case of overflow.
+ * the non-persistent inode numbers range in case of overflow.
* This way all overlay inode numbers are unique and use the
* overlay st_dev.
*/
if (likely(!(stat->ino >> xinoshift))) {
stat->ino |= ((u64)fsid) << (xinoshift + 1);
stat->dev = dentry->d_sb->s_dev;
- return 0;
+ return;
} 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);
@@ -153,8 +153,6 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
*/
stat->dev = OVL_FS(dentry->d_sb)->fs[fsid].pseudo_dev;
}
-
- return 0;
}
int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
@@ -253,9 +251,7 @@ int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
}
}
- err = ovl_map_dev_ino(dentry, stat, fsid);
- if (err)
- goto out;
+ ovl_map_dev_ino(dentry, stat, fsid);
/*
* It's probably not worth it to count subdirs to get the
@@ -410,7 +406,7 @@ static bool ovl_can_list(struct super_block *sb, const char *s)
if (ovl_is_private_xattr(sb, s))
return false;
- /* List all non-trusted xatts */
+ /* List all non-trusted xattrs */
if (strncmp(s, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0)
return true;
@@ -615,7 +611,7 @@ static const struct address_space_operations ovl_aops = {
* 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
- * inode lock will use the lockdep annotaion ovl_i_mutex_key[depth].
+ * inode lock will use the lockdep annotation ovl_i_mutex_key[depth].
*
* For example, here is a snip from /proc/lockdep_chains after
* dir_iterate of nested overlayfs:
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 1d573972ce22..210cd6f66e28 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -919,6 +919,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
continue;
if ((uppermetacopy || d.metacopy) && !ofs->config.metacopy) {
+ dput(this);
err = -EPERM;
pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", dentry);
goto out_put;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index f38cb5e07eff..6ec73db4bf9e 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -186,7 +186,12 @@ static inline ssize_t ovl_do_getxattr(struct ovl_fs *ofs, struct dentry *dentry,
size_t size)
{
const char *name = ovl_xattr(ofs, ox);
- return vfs_getxattr(&init_user_ns, dentry, name, value, size);
+ int err = vfs_getxattr(&init_user_ns, dentry, name, value, size);
+ int len = (value && err > 0) ? err : 0;
+
+ pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
+ dentry, name, min(len, 48), value, size, err);
+ return err;
}
static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
@@ -319,9 +324,6 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
enum ovl_xattr ox, const void *value, size_t size,
int xerr);
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
-void ovl_set_flag(unsigned long flag, struct inode *inode);
-void ovl_clear_flag(unsigned long flag, struct inode *inode);
-bool ovl_test_flag(unsigned long flag, struct inode *inode);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
bool ovl_is_inuse(struct dentry *dentry);
@@ -335,6 +337,21 @@ char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
int padding);
int ovl_sync_status(struct ovl_fs *ofs);
+static inline void ovl_set_flag(unsigned long flag, struct inode *inode)
+{
+ set_bit(flag, &OVL_I(inode)->flags);
+}
+
+static inline void ovl_clear_flag(unsigned long flag, struct inode *inode)
+{
+ clear_bit(flag, &OVL_I(inode)->flags);
+}
+
+static inline bool ovl_test_flag(unsigned long flag, struct inode *inode)
+{
+ return test_bit(flag, &OVL_I(inode)->flags);
+}
+
static inline bool ovl_is_impuredir(struct super_block *sb,
struct dentry *dentry)
{
@@ -439,6 +456,18 @@ int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
struct dentry *dentry, int level);
int ovl_indexdir_cleanup(struct ovl_fs *ofs);
+/*
+ * Can we iterate real dir directly?
+ *
+ * Non-merge dir may contain whiteouts from a time it was a merge upper, before
+ * lower dir was removed under it and possibly before it was rotated from upper
+ * to lower layer.
+ */
+static inline bool ovl_dir_is_real(struct dentry *dir)
+{
+ return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
+}
+
/* inode.c */
int ovl_set_nlink_upper(struct dentry *dentry);
int ovl_set_nlink_lower(struct dentry *dentry);
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 1ddad0967255..e8ad2c2c77dd 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -319,18 +319,6 @@ static inline int ovl_dir_read(struct path *realpath,
return err;
}
-/*
- * Can we iterate real dir directly?
- *
- * Non-merge dir may contain whiteouts from a time it was a merge upper, before
- * lower dir was removed under it and possibly before it was rotated from upper
- * to lower layer.
- */
-static bool ovl_dir_is_real(struct dentry *dir)
-{
- return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
-}
-
static void ovl_dir_reset(struct file *file)
{
struct ovl_dir_file *od = file->private_data;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index fdd72f1a9c5e..b01d4147520d 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -380,6 +380,8 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
ofs->config.metacopy ? "on" : "off");
if (ofs->config.ovl_volatile)
seq_puts(m, ",volatile");
+ if (ofs->config.userxattr)
+ seq_puts(m, ",userxattr");
return 0;
}
@@ -945,6 +947,16 @@ static int ovl_lower_dir(const char *name, struct path *path,
pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
name);
}
+ /*
+ * Decoding origin file handle is required for persistent st_ino.
+ * Without persistent st_ino, xino=auto falls back to xino=off.
+ */
+ if (ofs->config.xino == OVL_XINO_AUTO &&
+ ofs->config.upperdir && !fh_type) {
+ ofs->config.xino = OVL_XINO_OFF;
+ pr_warn("fs on '%s' does not support file handles, falling back to xino=off.\n",
+ name);
+ }
/* Check if lower fs has 32bit inode numbers */
if (fh_type != FILEID_INO32_GEN)
@@ -1042,9 +1054,6 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
}
err = ovl_xattr_set(dentry, inode, handler->name, value, size, flags);
- if (!err)
- ovl_copyattr(ovl_inode_real(inode), inode);
-
return err;
out_acl_release:
@@ -1185,8 +1194,8 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
if (err)
goto out;
- /* Upper fs should not be r/o */
- if (sb_rdonly(upperpath->mnt->mnt_sb)) {
+ /* Upperdir path should not be r/o */
+ if (__mnt_is_readonly(upperpath->mnt)) {
pr_err("upper fs is r/o, try multi-lower layers mount\n");
err = -EINVAL;
goto out;
@@ -1401,9 +1410,19 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
err = ovl_do_setxattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE, "0", 1);
if (err) {
ofs->noxattr = true;
- ofs->config.index = false;
- ofs->config.metacopy = false;
- pr_warn("upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
+ if (ofs->config.index || ofs->config.metacopy) {
+ ofs->config.index = false;
+ ofs->config.metacopy = false;
+ pr_warn("upper fs does not support xattr, falling back to index=off,metacopy=off.\n");
+ }
+ /*
+ * xattr support is required for persistent st_ino.
+ * Without persistent st_ino, xino=auto falls back to xino=off.
+ */
+ if (ofs->config.xino == OVL_XINO_AUTO) {
+ ofs->config.xino = OVL_XINO_OFF;
+ pr_warn("upper fs does not support xattr, falling back to xino=off.\n");
+ }
err = 0;
} else {
ovl_do_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE);
@@ -1580,7 +1599,8 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
* user opted-in to one of the new features that require following the
* lower inode of non-dir upper.
*/
- if (!ofs->config.index && !ofs->config.metacopy && !ofs->config.xino &&
+ if (!ofs->config.index && !ofs->config.metacopy &&
+ ofs->config.xino != OVL_XINO_ON &&
uuid_is_null(uuid))
return false;
@@ -1609,6 +1629,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
dev_t dev;
int err;
bool bad_uuid = false;
+ bool warn = false;
for (i = 0; i < ofs->numfs; i++) {
if (ofs->fs[i].sb == sb)
@@ -1617,13 +1638,20 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
if (!ovl_lower_uuid_ok(ofs, &sb->s_uuid)) {
bad_uuid = true;
+ if (ofs->config.xino == OVL_XINO_AUTO) {
+ ofs->config.xino = OVL_XINO_OFF;
+ warn = true;
+ }
if (ofs->config.index || ofs->config.nfs_export) {
ofs->config.index = false;
ofs->config.nfs_export = false;
- pr_warn("%s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
+ warn = true;
+ }
+ if (warn) {
+ pr_warn("%s uuid detected in lower fs '%pd2', falling back to xino=%s,index=off,nfs_export=off.\n",
uuid_is_null(&sb->s_uuid) ? "null" :
"conflicting",
- path->dentry);
+ path->dentry, ovl_xino_str[ofs->config.xino]);
}
}
@@ -1826,7 +1854,8 @@ out_err:
* - upper/work dir of any overlayfs instance
*/
static int ovl_check_layer(struct super_block *sb, struct ovl_fs *ofs,
- struct dentry *dentry, const char *name)
+ struct dentry *dentry, const char *name,
+ bool is_lower)
{
struct dentry *next = dentry, *parent;
int err = 0;
@@ -1838,7 +1867,7 @@ static int ovl_check_layer(struct super_block *sb, struct ovl_fs *ofs,
/* Walk back ancestors to root (inclusive) looking for traps */
while (!err && parent != next) {
- if (ovl_lookup_trap_inode(sb, parent)) {
+ if (is_lower && ovl_lookup_trap_inode(sb, parent)) {
err = -ELOOP;
pr_err("overlapping %s path\n", name);
} else if (ovl_is_inuse(parent)) {
@@ -1864,7 +1893,7 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
if (ovl_upper_mnt(ofs)) {
err = ovl_check_layer(sb, ofs, ovl_upper_mnt(ofs)->mnt_root,
- "upperdir");
+ "upperdir", false);
if (err)
return err;
@@ -1875,7 +1904,8 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
* workbasedir. In that case, we already have their traps in
* inode cache and we will catch that case on lookup.
*/
- err = ovl_check_layer(sb, ofs, ofs->workbasedir, "workdir");
+ err = ovl_check_layer(sb, ofs, ofs->workbasedir, "workdir",
+ false);
if (err)
return err;
}
@@ -1883,7 +1913,7 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
for (i = 1; i < ofs->numlayer; i++) {
err = ovl_check_layer(sb, ofs,
ofs->layers[i].mnt->mnt_root,
- "lowerdir");
+ "lowerdir", true);
if (err)
return err;
}
@@ -1952,6 +1982,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!ofs)
goto out;
+ err = -ENOMEM;
ofs->creator_cred = cred = prepare_creds();
if (!cred)
goto out_err;
@@ -1980,6 +2011,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!splitlower)
goto out_err;
+ err = -EINVAL;
numlower = ovl_split_lowerdirs(splitlower);
if (numlower > OVL_MAX_STACK) {
pr_err("too many lower directories, limit is %d\n",
@@ -1987,6 +2019,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
goto out_err;
}
+ err = -ENOMEM;
layers = kcalloc(numlower + 1, sizeof(struct ovl_layer), GFP_KERNEL);
if (!layers)
goto out_err;
@@ -2013,6 +2046,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (ofs->config.upperdir) {
struct super_block *upper_sb;
+ err = -EINVAL;
if (!ofs->config.workdir) {
pr_err("missing 'workdir'\n");
goto out_err;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 7f5a01a11f97..b9d03627f364 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -214,7 +214,7 @@ const struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
/*
* ovl_dentry_lower() could return either a data dentry or metacopy dentry
- * dependig on what is stored in lowerstack[0]. At times we need to find
+ * depending on what is stored in lowerstack[0]. At times we need to find
* lower dentry which has data (and not metacopy dentry). This helper
* returns the lower data dentry.
*/
@@ -422,18 +422,20 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
}
}
-static void ovl_dentry_version_inc(struct dentry *dentry, bool impurity)
+static void ovl_dir_version_inc(struct dentry *dentry, bool impurity)
{
struct inode *inode = d_inode(dentry);
WARN_ON(!inode_is_locked(inode));
+ WARN_ON(!d_is_dir(dentry));
/*
- * Version is used by readdir code to keep cache consistent. For merge
- * dirs all changes need to be noted. For non-merge dirs, cache only
- * contains impure (ones which have been copied up and have origins)
- * entries, so only need to note changes to impure entries.
+ * Version is used by readdir code to keep cache consistent.
+ * For merge dirs (or dirs with origin) all changes need to be noted.
+ * For non-merge dirs, cache contains only impure entries (i.e. ones
+ * which have been copied up and have origins), so only need to note
+ * changes to impure entries.
*/
- if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity)
+ if (!ovl_dir_is_real(dentry) || impurity)
OVL_I(inode)->version++;
}
@@ -442,7 +444,7 @@ void ovl_dir_modified(struct dentry *dentry, bool impurity)
/* Copy mtime/ctime */
ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
- ovl_dentry_version_inc(dentry, impurity);
+ ovl_dir_version_inc(dentry, impurity);
}
u64 ovl_dentry_version_get(struct dentry *dentry)
@@ -638,21 +640,6 @@ int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)
return err;
}
-void ovl_set_flag(unsigned long flag, struct inode *inode)
-{
- set_bit(flag, &OVL_I(inode)->flags);
-}
-
-void ovl_clear_flag(unsigned long flag, struct inode *inode)
-{
- clear_bit(flag, &OVL_I(inode)->flags);
-}
-
-bool ovl_test_flag(unsigned long flag, struct inode *inode)
-{
- return test_bit(flag, &OVL_I(inode)->flags);
-}
-
/**
* Caller must hold a reference to inode to prevent it from being freed while
* it is marked inuse.