#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
+#include <linux/sched/mm.h>
#include <linux/fsnotify.h>
#include <linux/personality.h>
#include <linux/security.h>
.procname = "protected_symlinks",
.data = &sysctl_protected_symlinks,
.maxlen = sizeof(int),
- .mode = 0600,
+ .mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
.procname = "protected_hardlinks",
.data = &sysctl_protected_hardlinks,
.maxlen = sizeof(int),
- .mode = 0600,
+ .mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
.procname = "protected_fifos",
.data = &sysctl_protected_fifos,
.maxlen = sizeof(int),
- .mode = 0600,
+ .mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
.procname = "protected_regular",
.data = &sysctl_protected_regular,
.maxlen = sizeof(int),
- .mode = 0600,
+ .mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
EXPORT_SYMBOL(lookup_one);
/**
- * lookup_one_len_unlocked - filesystem helper to lookup single pathname component
+ * lookup_one_unlocked - filesystem helper to lookup single pathname component
+ * @mnt_userns: idmapping of the mount the lookup is performed from
* @name: pathname component to lookup
* @base: base directory to lookup from
* @len: maximum length @len should be interpreted to
* Unlike lookup_one_len, it should be called without the parent
* i_mutex held, and will take the i_mutex itself if necessary.
*/
- struct dentry *lookup_one_len_unlocked(const char *name,
- struct dentry *base, int len)
+ struct dentry *lookup_one_unlocked(struct user_namespace *mnt_userns,
+ const char *name, struct dentry *base,
+ int len)
{
struct qstr this;
int err;
struct dentry *ret;
- err = lookup_one_common(&init_user_ns, name, base, len, &this);
+ err = lookup_one_common(mnt_userns, name, base, len, &this);
if (err)
return ERR_PTR(err);
ret = lookup_slow(&this, base, 0);
return ret;
}
+ EXPORT_SYMBOL(lookup_one_unlocked);
+
+ /**
+ * lookup_one_positive_unlocked - filesystem helper to lookup single
+ * pathname component
+ * @mnt_userns: idmapping of the mount the lookup is performed from
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ * @len: maximum length @len should be interpreted to
+ *
+ * This helper will yield ERR_PTR(-ENOENT) on negatives. The helper returns
+ * known positive or ERR_PTR(). This is what most of the users want.
+ *
+ * Note that pinned negative with unlocked parent _can_ become positive at any
+ * time, so callers of lookup_one_unlocked() need to be very careful; pinned
+ * positives have >d_inode stable, so this one avoids such problems.
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * The helper should be called without i_mutex held.
+ */
+ struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns,
+ const char *name,
+ struct dentry *base, int len)
+ {
+ struct dentry *ret = lookup_one_unlocked(mnt_userns, name, base, len);
+
+ if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
+ dput(ret);
+ ret = ERR_PTR(-ENOENT);
+ }
+ return ret;
+ }
+ EXPORT_SYMBOL(lookup_one_positive_unlocked);
+
+ /**
+ * lookup_one_len_unlocked - filesystem helper to lookup single pathname component
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ * @len: maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * Unlike lookup_one_len, it should be called without the parent
+ * i_mutex held, and will take the i_mutex itself if necessary.
+ */
+ struct dentry *lookup_one_len_unlocked(const char *name,
+ struct dentry *base, int len)
+ {
+ return lookup_one_unlocked(&init_user_ns, name, base, len);
+ }
EXPORT_SYMBOL(lookup_one_len_unlocked);
/*
struct dentry *lookup_positive_unlocked(const char *name,
struct dentry *base, int len)
{
- struct dentry *ret = lookup_one_len_unlocked(name, base, len);
- if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
- dput(ret);
- ret = ERR_PTR(-ENOENT);
- }
- return ret;
+ return lookup_one_positive_unlocked(&init_user_ns, name, base, len);
}
EXPORT_SYMBOL(lookup_positive_unlocked);
{
struct dentry *dentry = ERR_PTR(-EEXIST);
struct qstr last;
+ bool want_dir = lookup_flags & LOOKUP_DIRECTORY;
+ unsigned int reval_flag = lookup_flags & LOOKUP_REVAL;
+ unsigned int create_flags = LOOKUP_CREATE | LOOKUP_EXCL;
int type;
int err2;
int error;
- bool is_dir = (lookup_flags & LOOKUP_DIRECTORY);
- /*
- * Note that only LOOKUP_REVAL and LOOKUP_DIRECTORY matter here. Any
- * other flags passed in are ignored!
- */
- lookup_flags &= LOOKUP_REVAL;
-
- error = filename_parentat(dfd, name, lookup_flags, path, &last, &type);
+ error = filename_parentat(dfd, name, reval_flag, path, &last, &type);
if (error)
return ERR_PTR(error);
/* don't fail immediately if it's r/o, at least try to report other errors */
err2 = mnt_want_write(path->mnt);
/*
- * Do the final lookup.
+ * Do the final lookup. Suppress 'create' if there is a trailing
+ * '/', and a directory wasn't requested.
*/
- lookup_flags |= LOOKUP_CREATE | LOOKUP_EXCL;
+ if (last.name[last.len] && !want_dir)
+ create_flags = 0;
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
- dentry = __lookup_hash(&last, path->dentry, lookup_flags);
+ dentry = __lookup_hash(&last, path->dentry, reval_flag | create_flags);
if (IS_ERR(dentry))
goto unlock;
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
- if (unlikely(!is_dir && last.name[last.len])) {
+ if (unlikely(!create_flags)) {
error = -ENOENT;
goto fail;
}
}
EXPORT_SYMBOL(page_readlink);
-/*
- * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS
- */
-int __page_symlink(struct inode *inode, const char *symname, int len, int nofs)
+int page_symlink(struct inode *inode, const char *symname, int len)
{
struct address_space *mapping = inode->i_mapping;
+ const struct address_space_operations *aops = mapping->a_ops;
+ bool nofs = !mapping_gfp_constraint(mapping, __GFP_FS);
struct page *page;
void *fsdata;
int err;
- unsigned int flags = 0;
- if (nofs)
- flags |= AOP_FLAG_NOFS;
+ unsigned int flags;
retry:
- err = pagecache_write_begin(NULL, mapping, 0, len-1,
- flags, &page, &fsdata);
+ if (nofs)
+ flags = memalloc_nofs_save();
+ err = aops->write_begin(NULL, mapping, 0, len-1, &page, &fsdata);
+ if (nofs)
+ memalloc_nofs_restore(flags);
if (err)
goto fail;
memcpy(page_address(page), symname, len-1);
- err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
+ err = aops->write_end(NULL, mapping, 0, len-1, len-1,
page, fsdata);
if (err < 0)
goto fail;
fail:
return err;
}
-EXPORT_SYMBOL(__page_symlink);
-
-int page_symlink(struct inode *inode, const char *symname, int len)
-{
- return __page_symlink(inode, symname, len,
- !mapping_gfp_constraint(inode->i_mapping, __GFP_FS));
-}
EXPORT_SYMBOL(page_symlink);
const struct inode_operations page_symlink_inode_operations = {
#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
static struct file *ovl_open_realfile(const struct file *file,
- struct inode *realinode)
+ struct path *realpath)
{
+ struct inode *realinode = d_inode(realpath->dentry);
struct inode *inode = file_inode(file);
+ struct user_namespace *real_mnt_userns;
struct file *realfile;
const struct cred *old_cred;
int flags = file->f_flags | OVL_OPEN_FLAGS;
acc_mode |= MAY_APPEND;
old_cred = ovl_override_creds(inode->i_sb);
- err = inode_permission(&init_user_ns, realinode, MAY_OPEN | acc_mode);
+ real_mnt_userns = mnt_user_ns(realpath->mnt);
+ err = inode_permission(real_mnt_userns, realinode, MAY_OPEN | acc_mode);
if (err) {
realfile = ERR_PTR(err);
} else {
- if (!inode_owner_or_capable(&init_user_ns, realinode))
+ if (!inode_owner_or_capable(real_mnt_userns, realinode))
flags &= ~O_NOATIME;
realfile = open_with_fake_path(&file->f_path, flags, realinode,
if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
return -EPERM;
- if (flags & O_DIRECT) {
- if (!file->f_mapping->a_ops ||
- !file->f_mapping->a_ops->direct_IO)
- return -EINVAL;
- }
+ if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT))
+ return -EINVAL;
if (file->f_op->check_flags) {
err = file->f_op->check_flags(flags);
static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
bool allow_meta)
{
- struct inode *inode = file_inode(file);
- struct inode *realinode;
+ struct dentry *dentry = file_dentry(file);
+ struct path realpath;
real->flags = 0;
real->file = file->private_data;
if (allow_meta)
- realinode = ovl_inode_real(inode);
+ ovl_path_real(dentry, &realpath);
else
- realinode = ovl_inode_realdata(inode);
+ ovl_path_realdata(dentry, &realpath);
/* Has it been copied up since we'd opened it? */
- if (unlikely(file_inode(real->file) != realinode)) {
+ if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) {
real->flags = FDPUT_FPUT;
- real->file = ovl_open_realfile(file, realinode);
+ real->file = ovl_open_realfile(file, &realpath);
return PTR_ERR_OR_ZERO(real->file);
}
static int ovl_open(struct inode *inode, struct file *file)
{
+ struct dentry *dentry = file_dentry(file);
struct file *realfile;
+ struct path realpath;
int err;
- err = ovl_maybe_copy_up(file_dentry(file), file->f_flags);
+ err = ovl_maybe_copy_up(dentry, file->f_flags);
if (err)
return err;
/* No longer need these flags, so don't pass them on to underlying fs */
file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
- realfile = ovl_open_realfile(file, ovl_inode_realdata(inode));
+ ovl_path_realdata(dentry, &realpath);
+ realfile = ovl_open_realfile(file, &realpath);
if (IS_ERR(realfile))
return PTR_ERR(realfile);
__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
SB_FREEZE_WRITE);
file_end_write(iocb->ki_filp);
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
}
orig_iocb->ki_pos = iocb->ki_pos;
ret = -EINVAL;
if (iocb->ki_flags & IOCB_DIRECT &&
- (!real.file->f_mapping->a_ops ||
- !real.file->f_mapping->a_ops->direct_IO))
+ !(real.file->f_mode & FMODE_CAN_ODIRECT))
goto out_fdput;
old_cred = ovl_override_creds(file_inode(file)->i_sb);
inode_lock(inode);
/* Update mode */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
ret = file_remove_privs(file);
if (ret)
goto out_unlock;
ret = -EINVAL;
if (iocb->ki_flags & IOCB_DIRECT &&
- (!real.file->f_mapping->a_ops ||
- !real.file->f_mapping->a_ops->direct_IO))
+ !(real.file->f_mode & FMODE_CAN_ODIRECT))
goto out_fdput;
if (!ovl_should_sync(OVL_FS(inode->i_sb)))
ovl_iocb_to_rwf(ifl));
file_end_write(real.file);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
} else {
struct ovl_aio_req *aio_req;
struct fd real;
const struct cred *old_cred;
struct inode *inode = file_inode(out);
- struct inode *realinode = ovl_inode_real(inode);
ssize_t ret;
inode_lock(inode);
/* Update mode */
- ovl_copyattr(realinode, inode);
+ ovl_copyattr(inode);
ret = file_remove_privs(out);
if (ret)
goto out_unlock;
file_end_write(real.file);
/* Update size */
- ovl_copyattr(realinode, inode);
+ ovl_copyattr(inode);
revert_creds(old_cred);
fdput(real);
revert_creds(old_cred);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
fdput(real);
revert_creds(old_cred);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode_out), inode_out);
+ ovl_copyattr(inode_out);
fdput(real_in);
fdput(real_out);
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