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-rw-r--r--fs/overlayfs/copy_up.c14
-rw-r--r--fs/overlayfs/namei.c43
-rw-r--r--fs/overlayfs/overlayfs.h23
-rw-r--r--fs/overlayfs/ovl_entry.h4
-rw-r--r--fs/overlayfs/params.c14
-rw-r--r--fs/overlayfs/readdir.c7
-rw-r--r--fs/overlayfs/super.c67
-rw-r--r--fs/overlayfs/util.c53
8 files changed, 136 insertions, 89 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index b8e25ca51016..8586e2f5d243 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -265,20 +265,18 @@ static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry,
if (IS_ERR(old_file))
return PTR_ERR(old_file);
+ /* Try to use clone_file_range to clone up within the same fs */
+ cloned = vfs_clone_file_range(old_file, 0, new_file, 0, len, 0);
+ if (cloned == len)
+ goto out_fput;
+
+ /* Couldn't clone, so now we try to copy the data */
error = rw_verify_area(READ, old_file, &old_pos, len);
if (!error)
error = rw_verify_area(WRITE, new_file, &new_pos, len);
if (error)
goto out_fput;
- /* Try to use clone_file_range to clone up within the same fs */
- ovl_start_write(dentry);
- cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0);
- ovl_end_write(dentry);
- if (cloned == len)
- goto out_fput;
- /* Couldn't clone, so now we try to copy the data */
-
/* Check if lower fs supports seek operation */
if (old_file->f_mode & FMODE_LSEEK)
skip_hole = true;
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 984ffdaeed6c..5764f91d283e 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -18,10 +18,11 @@
struct ovl_lookup_data {
struct super_block *sb;
- struct vfsmount *mnt;
+ const struct ovl_layer *layer;
struct qstr name;
bool is_dir;
bool opaque;
+ bool xwhiteouts;
bool stop;
bool last;
char *redirect;
@@ -201,17 +202,13 @@ struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
return real;
}
-static bool ovl_is_opaquedir(struct ovl_fs *ofs, const struct path *path)
-{
- return ovl_path_check_dir_xattr(ofs, path, OVL_XATTR_OPAQUE);
-}
-
static struct dentry *ovl_lookup_positive_unlocked(struct ovl_lookup_data *d,
const char *name,
struct dentry *base, int len,
bool drop_negative)
{
- struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->mnt), name, base, len);
+ struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->layer->mnt), name,
+ base, len);
if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
if (drop_negative && ret->d_lockref.count == 1) {
@@ -232,10 +229,13 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
size_t prelen, const char *post,
struct dentry **ret, bool drop_negative)
{
+ struct ovl_fs *ofs = OVL_FS(d->sb);
struct dentry *this;
struct path path;
int err;
bool last_element = !post[0];
+ bool is_upper = d->layer->idx == 0;
+ char val;
this = ovl_lookup_positive_unlocked(d, name, base, namelen, drop_negative);
if (IS_ERR(this)) {
@@ -253,8 +253,8 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
}
path.dentry = this;
- path.mnt = d->mnt;
- if (ovl_path_is_whiteout(OVL_FS(d->sb), &path)) {
+ path.mnt = d->layer->mnt;
+ if (ovl_path_is_whiteout(ofs, &path)) {
d->stop = d->opaque = true;
goto put_and_out;
}
@@ -272,7 +272,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
d->stop = true;
goto put_and_out;
}
- err = ovl_check_metacopy_xattr(OVL_FS(d->sb), &path, NULL);
+ err = ovl_check_metacopy_xattr(ofs, &path, NULL);
if (err < 0)
goto out_err;
@@ -292,7 +292,12 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
if (d->last)
goto out;
- if (ovl_is_opaquedir(OVL_FS(d->sb), &path)) {
+ /* overlay.opaque=x means xwhiteouts directory */
+ val = ovl_get_opaquedir_val(ofs, &path);
+ if (last_element && !is_upper && val == 'x') {
+ d->xwhiteouts = true;
+ ovl_layer_set_xwhiteouts(ofs, d->layer);
+ } else if (val == 'y') {
d->stop = true;
if (last_element)
d->opaque = true;
@@ -863,7 +868,8 @@ fail:
* Returns next layer in stack starting from top.
* Returns -1 if this is the last layer.
*/
-int ovl_path_next(int idx, struct dentry *dentry, struct path *path)
+int ovl_path_next(int idx, struct dentry *dentry, struct path *path,
+ const struct ovl_layer **layer)
{
struct ovl_entry *oe = OVL_E(dentry);
struct ovl_path *lowerstack = ovl_lowerstack(oe);
@@ -871,13 +877,16 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path)
BUG_ON(idx < 0);
if (idx == 0) {
ovl_path_upper(dentry, path);
- if (path->dentry)
+ if (path->dentry) {
+ *layer = &OVL_FS(dentry->d_sb)->layers[0];
return ovl_numlower(oe) ? 1 : -1;
+ }
idx++;
}
BUG_ON(idx > ovl_numlower(oe));
path->dentry = lowerstack[idx - 1].dentry;
- path->mnt = lowerstack[idx - 1].layer->mnt;
+ *layer = lowerstack[idx - 1].layer;
+ path->mnt = (*layer)->mnt;
return (idx < ovl_numlower(oe)) ? idx + 1 : -1;
}
@@ -1055,7 +1064,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
old_cred = ovl_override_creds(dentry->d_sb);
upperdir = ovl_dentry_upper(dentry->d_parent);
if (upperdir) {
- d.mnt = ovl_upper_mnt(ofs);
+ d.layer = &ofs->layers[0];
err = ovl_lookup_layer(upperdir, &d, &upperdentry, true);
if (err)
goto out;
@@ -1111,7 +1120,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
else if (d.is_dir || !ofs->numdatalayer)
d.last = lower.layer->idx == ovl_numlower(roe);
- d.mnt = lower.layer->mnt;
+ d.layer = lower.layer;
err = ovl_lookup_layer(lower.dentry, &d, &this, false);
if (err)
goto out_put;
@@ -1278,6 +1287,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (upperopaque)
ovl_dentry_set_opaque(dentry);
+ if (d.xwhiteouts)
+ ovl_dentry_set_xwhiteouts(dentry);
if (upperdentry)
ovl_dentry_set_upper_alias(dentry);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 5ba11eb43767..ee949f3e7c77 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -50,7 +50,6 @@ enum ovl_xattr {
OVL_XATTR_METACOPY,
OVL_XATTR_PROTATTR,
OVL_XATTR_XWHITEOUT,
- OVL_XATTR_XWHITEOUTS,
};
enum ovl_inode_flag {
@@ -70,6 +69,8 @@ enum ovl_entry_flag {
OVL_E_UPPER_ALIAS,
OVL_E_OPAQUE,
OVL_E_CONNECTED,
+ /* Lower stack may contain xwhiteout entries */
+ OVL_E_XWHITEOUTS,
};
enum {
@@ -477,6 +478,10 @@ bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
bool ovl_dentry_is_opaque(struct dentry *dentry);
bool ovl_dentry_is_whiteout(struct dentry *dentry);
void ovl_dentry_set_opaque(struct dentry *dentry);
+bool ovl_dentry_has_xwhiteouts(struct dentry *dentry);
+void ovl_dentry_set_xwhiteouts(struct dentry *dentry);
+void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs,
+ const struct ovl_layer *layer);
bool ovl_dentry_has_upper_alias(struct dentry *dentry);
void ovl_dentry_set_upper_alias(struct dentry *dentry);
bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
@@ -494,11 +499,10 @@ struct file *ovl_path_open(const struct path *path, int flags);
int ovl_copy_up_start(struct dentry *dentry, int flags);
void ovl_copy_up_end(struct dentry *dentry);
bool ovl_already_copied_up(struct dentry *dentry, int flags);
-bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path,
- enum ovl_xattr ox);
+char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path,
+ enum ovl_xattr ox);
bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path);
bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path);
-bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path);
bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs,
const struct path *upperpath);
@@ -573,7 +577,13 @@ static inline bool ovl_is_impuredir(struct super_block *sb,
.mnt = ovl_upper_mnt(ofs),
};
- return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE);
+ return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y';
+}
+
+static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs,
+ const struct path *path)
+{
+ return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE);
}
static inline bool ovl_redirect_follow(struct ovl_fs *ofs)
@@ -680,7 +690,8 @@ int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
struct dentry *origin, bool verify);
-int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
+int ovl_path_next(int idx, struct dentry *dentry, struct path *path,
+ const struct ovl_layer **layer);
int ovl_verify_lowerdata(struct dentry *dentry);
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 5fa9c58af65f..cb449ab310a7 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -40,6 +40,8 @@ struct ovl_layer {
int idx;
/* One fsid per unique underlying sb (upper fsid == 0) */
int fsid;
+ /* xwhiteouts were found on this layer */
+ bool has_xwhiteouts;
};
struct ovl_path {
@@ -59,7 +61,7 @@ struct ovl_fs {
unsigned int numfs;
/* Number of data-only lower layers */
unsigned int numdatalayer;
- const struct ovl_layer *layers;
+ struct ovl_layer *layers;
struct ovl_sb *fs;
/* workbasedir is the path at workdir= mount option */
struct dentry *workbasedir;
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index 112b4b12f825..36dcc530ac28 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -280,12 +280,20 @@ static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path,
{
struct ovl_fs_context *ctx = fc->fs_private;
- if (ovl_dentry_weird(path->dentry))
- return invalfc(fc, "filesystem on %s not supported", name);
-
if (!d_is_dir(path->dentry))
return invalfc(fc, "%s is not a directory", name);
+ /*
+ * Root dentries of case-insensitive capable filesystems might
+ * not have the dentry operations set, but still be incompatible
+ * with overlayfs. Check explicitly to prevent post-mount
+ * failures.
+ */
+ if (sb_has_encoding(path->mnt->mnt_sb))
+ return invalfc(fc, "case-insensitive capable filesystem on %s not supported", name);
+
+ if (ovl_dentry_weird(path->dentry))
+ return invalfc(fc, "filesystem on %s not supported", name);
/*
* Check whether upper path is read-only here to report failures
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index e71156baa7bc..0ca8af060b0c 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -305,8 +305,6 @@ static inline int ovl_dir_read(const struct path *realpath,
if (IS_ERR(realfile))
return PTR_ERR(realfile);
- rdd->in_xwhiteouts_dir = rdd->dentry &&
- ovl_path_check_xwhiteouts_xattr(OVL_FS(rdd->dentry->d_sb), realpath);
rdd->first_maybe_whiteout = NULL;
rdd->ctx.pos = 0;
do {
@@ -359,10 +357,13 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
.is_lowest = false,
};
int idx, next;
+ const struct ovl_layer *layer;
for (idx = 0; idx != -1; idx = next) {
- next = ovl_path_next(idx, dentry, &realpath);
+ next = ovl_path_next(idx, dentry, &realpath, &layer);
rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry;
+ rdd.in_xwhiteouts_dir = layer->has_xwhiteouts &&
+ ovl_dentry_has_xwhiteouts(dentry);
if (next != -1) {
err = ovl_dir_read(&realpath, &rdd);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 4ab66e3d4cff..36d4b8b1f784 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -28,41 +28,38 @@ MODULE_LICENSE("GPL");
struct ovl_dir_cache;
-static struct dentry *ovl_d_real(struct dentry *dentry,
- const struct inode *inode)
+static struct dentry *ovl_d_real(struct dentry *dentry, enum d_real_type type)
{
- struct dentry *real = NULL, *lower;
+ struct dentry *upper, *lower;
int err;
- /*
- * vfs is only expected to call d_real() with NULL from d_real_inode()
- * and with overlay inode from file_dentry() on an overlay file.
- *
- * TODO: remove @inode argument from d_real() API, remove code in this
- * function that deals with non-NULL @inode and remove d_real() call
- * from file_dentry().
- */
- if (inode && d_inode(dentry) == inode)
- return dentry;
- else if (inode)
+ switch (type) {
+ case D_REAL_DATA:
+ case D_REAL_METADATA:
+ break;
+ default:
goto bug;
+ }
if (!d_is_reg(dentry)) {
/* d_real_inode() is only relevant for regular files */
return dentry;
}
- real = ovl_dentry_upper(dentry);
- if (real && (inode == d_inode(real)))
- return real;
+ upper = ovl_dentry_upper(dentry);
+ if (upper && (type == D_REAL_METADATA ||
+ ovl_has_upperdata(d_inode(dentry))))
+ return upper;
- if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
- return real;
+ if (type == D_REAL_METADATA) {
+ lower = ovl_dentry_lower(dentry);
+ goto real_lower;
+ }
/*
- * Best effort lazy lookup of lowerdata for !inode case to return
+ * Best effort lazy lookup of lowerdata for D_REAL_DATA case to return
* the real lowerdata dentry. The only current caller of d_real() with
- * NULL inode is d_real_inode() from trace_uprobe and this caller is
+ * D_REAL_DATA is d_real_inode() from trace_uprobe and this caller is
* likely going to be followed reading from the file, before placing
* uprobes on offset within the file, so lowerdata should be available
* when setting the uprobe.
@@ -73,18 +70,13 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
lower = ovl_dentry_lowerdata(dentry);
if (!lower)
goto bug;
- real = lower;
- /* Handle recursion */
- real = d_real(real, inode);
+real_lower:
+ /* Handle recursion into stacked lower fs */
+ return d_real(lower, type);
- if (!inode || inode == d_inode(real))
- return real;
bug:
- WARN(1, "%s(%pd4, %s:%lu): real dentry (%p/%lu) not found\n",
- __func__, dentry, inode ? inode->i_sb->s_id : "NULL",
- inode ? inode->i_ino : 0, real,
- real && d_inode(real) ? d_inode(real)->i_ino : 0);
+ WARN(1, "%s(%pd4, %d): real dentry not found\n", __func__, dentry, type);
return dentry;
}
@@ -1249,6 +1241,7 @@ static struct dentry *ovl_get_root(struct super_block *sb,
struct ovl_entry *oe)
{
struct dentry *root;
+ struct ovl_fs *ofs = OVL_FS(sb);
struct ovl_path *lowerpath = ovl_lowerstack(oe);
unsigned long ino = d_inode(lowerpath->dentry)->i_ino;
int fsid = lowerpath->layer->fsid;
@@ -1270,6 +1263,20 @@ static struct dentry *ovl_get_root(struct super_block *sb,
ovl_set_flag(OVL_IMPURE, d_inode(root));
}
+ /* Look for xwhiteouts marker except in the lowermost layer */
+ for (int i = 0; i < ovl_numlower(oe) - 1; i++, lowerpath++) {
+ struct path path = {
+ .mnt = lowerpath->layer->mnt,
+ .dentry = lowerpath->dentry,
+ };
+
+ /* overlay.opaque=x means xwhiteouts directory */
+ if (ovl_get_opaquedir_val(ofs, &path) == 'x') {
+ ovl_layer_set_xwhiteouts(ofs, lowerpath->layer);
+ ovl_dentry_set_xwhiteouts(root);
+ }
+ }
+
/* Root is always merge -> can have whiteouts */
ovl_set_flag(OVL_WHITEOUTS, d_inode(root));
ovl_dentry_set_flag(OVL_E_CONNECTED, root);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index ed71480d8adb..d285d1d7baad 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -461,6 +461,33 @@ void ovl_dentry_set_opaque(struct dentry *dentry)
ovl_dentry_set_flag(OVL_E_OPAQUE, dentry);
}
+bool ovl_dentry_has_xwhiteouts(struct dentry *dentry)
+{
+ return ovl_dentry_test_flag(OVL_E_XWHITEOUTS, dentry);
+}
+
+void ovl_dentry_set_xwhiteouts(struct dentry *dentry)
+{
+ ovl_dentry_set_flag(OVL_E_XWHITEOUTS, dentry);
+}
+
+/*
+ * ovl_layer_set_xwhiteouts() is called before adding the overlay dir
+ * dentry to dcache, while readdir of that same directory happens after
+ * the overlay dir dentry is in dcache, so if some cpu observes that
+ * ovl_dentry_is_xwhiteouts(), it will also observe layer->has_xwhiteouts
+ * for the layers where xwhiteouts marker was found in that merge dir.
+ */
+void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs,
+ const struct ovl_layer *layer)
+{
+ if (layer->has_xwhiteouts)
+ return;
+
+ /* Write once to read-mostly layer properties */
+ ofs->layers[layer->idx].has_xwhiteouts = true;
+}
+
/*
* For hard links and decoded file handles, it's possible for ovl_dentry_upper()
* to return positive, while there's no actual upper alias for the inode.
@@ -739,19 +766,6 @@ bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path)
return res >= 0;
}
-bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path)
-{
- struct dentry *dentry = path->dentry;
- int res;
-
- /* xattr.whiteouts must be a directory */
- if (!d_is_dir(dentry))
- return false;
-
- res = ovl_path_getxattr(ofs, path, OVL_XATTR_XWHITEOUTS, NULL, 0);
- return res >= 0;
-}
-
/*
* Load persistent uuid from xattr into s_uuid if found, or store a new
* random generated value in s_uuid and in xattr.
@@ -815,20 +829,17 @@ fail:
return false;
}
-bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path,
- enum ovl_xattr ox)
+char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path,
+ enum ovl_xattr ox)
{
int res;
char val;
if (!d_is_dir(path->dentry))
- return false;
+ return 0;
res = ovl_path_getxattr(ofs, path, ox, &val, 1);
- if (res == 1 && val == 'y')
- return true;
-
- return false;
+ return res == 1 ? val : 0;
}
#define OVL_XATTR_OPAQUE_POSTFIX "opaque"
@@ -841,7 +852,6 @@ bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path,
#define OVL_XATTR_METACOPY_POSTFIX "metacopy"
#define OVL_XATTR_PROTATTR_POSTFIX "protattr"
#define OVL_XATTR_XWHITEOUT_POSTFIX "whiteout"
-#define OVL_XATTR_XWHITEOUTS_POSTFIX "whiteouts"
#define OVL_XATTR_TAB_ENTRY(x) \
[x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \
@@ -858,7 +868,6 @@ const char *const ovl_xattr_table[][2] = {
OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY),
OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR),
OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUT),
- OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUTS),
};
int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-17 12:31:29 +0000