overlayfs fixes for 4.19-rc4
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCW5qpOgAKCRDh3BK/laaZ PDCQAQCIKLg0aLeWOkfUO76mBjlp5srKgJfrqpFoyuozD6l2fQEAl/W2x9NOduV+ PK4sCYMT8SpI0hMrbv9P4zZ683kmaA8= =RnZU -----END PGP SIGNATURE----- Merge tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs fixes from Miklos Szeredi: "This fixes a regression in the recent file stacking update, reported and fixed by Amir Goldstein. The fix is fairly trivial, but involves adding a fadvise() f_op and the associated churn in the vfs. As discussed on -fsdevel, there are other possible uses for this method, than allowing proper stacking for overlays. And there's one other fix for a syzkaller detected oops" * tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix oopses in ovl_fill_super() failure paths ovl: add ovl_fadvise() vfs: implement readahead(2) using POSIX_FADV_WILLNEED vfs: add the fadvise() file operation Documentation/filesystems: update documentation of file_operations ovl: fix GPF in swapfile_activate of file from overlayfs over xfs ovl: respect FIEMAP_FLAG_SYNC flag
This commit is contained in:
Linus Torvalds
commit
48751b562b
8 changed files with 134 additions and 80 deletions
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@ -848,7 +848,7 @@ struct file_operations
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----------------------
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This describes how the VFS can manipulate an open file. As of kernel
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4.1, the following members are defined:
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4.18, the following members are defined:
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struct file_operations {
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struct module *owner;
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@ -858,11 +858,11 @@ struct file_operations {
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ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
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ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
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int (*iterate) (struct file *, struct dir_context *);
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int (*iterate_shared) (struct file *, struct dir_context *);
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__poll_t (*poll) (struct file *, struct poll_table_struct *);
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long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
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long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
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int (*mmap) (struct file *, struct vm_area_struct *);
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int (*mremap)(struct file *, struct vm_area_struct *);
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int (*open) (struct inode *, struct file *);
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int (*flush) (struct file *, fl_owner_t id);
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int (*release) (struct inode *, struct file *);
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@ -882,6 +882,10 @@ struct file_operations {
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#ifndef CONFIG_MMU
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unsigned (*mmap_capabilities)(struct file *);
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#endif
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ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int);
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int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
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int (*dedupe_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
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int (*fadvise)(struct file *, loff_t, loff_t, int);
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};
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Again, all methods are called without any locks being held, unless
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@ -899,6 +903,9 @@ otherwise noted.
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iterate: called when the VFS needs to read the directory contents
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iterate_shared: called when the VFS needs to read the directory contents
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when filesystem supports concurrent dir iterators
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poll: called by the VFS when a process wants to check if there is
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activity on this file and (optionally) go to sleep until there
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is activity. Called by the select(2) and poll(2) system calls
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@ -951,6 +958,16 @@ otherwise noted.
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fallocate: called by the VFS to preallocate blocks or punch a hole.
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copy_file_range: called by the copy_file_range(2) system call.
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clone_file_range: called by the ioctl(2) system call for FICLONERANGE and
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FICLONE commands.
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dedupe_file_range: called by the ioctl(2) system call for FIDEDUPERANGE
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command.
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fadvise: possibly called by the fadvise64() system call.
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Note that the file operations are implemented by the specific
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filesystem in which the inode resides. When opening a device node
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(character or block special) most filesystems will call special
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@ -131,9 +131,6 @@ static int ovl_open(struct inode *inode, struct file *file)
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if (IS_ERR(realfile))
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return PTR_ERR(realfile);
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/* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
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file->f_mapping = realfile->f_mapping;
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file->private_data = realfile;
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return 0;
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@ -334,6 +331,25 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
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return ret;
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}
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static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
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{
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struct fd real;
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const struct cred *old_cred;
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int ret;
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ret = ovl_real_fdget(file, &real);
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if (ret)
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return ret;
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old_cred = ovl_override_creds(file_inode(file)->i_sb);
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ret = vfs_fadvise(real.file, offset, len, advice);
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revert_creds(old_cred);
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fdput(real);
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return ret;
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}
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static long ovl_real_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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@ -502,6 +518,7 @@ const struct file_operations ovl_file_operations = {
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.fsync = ovl_fsync,
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.mmap = ovl_mmap,
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.fallocate = ovl_fallocate,
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.fadvise = ovl_fadvise,
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.unlocked_ioctl = ovl_ioctl,
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.compat_ioctl = ovl_compat_ioctl,
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@ -467,6 +467,10 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
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return -EOPNOTSUPP;
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old_cred = ovl_override_creds(inode->i_sb);
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if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
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filemap_write_and_wait(realinode->i_mapping);
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err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
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revert_creds(old_cred);
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@ -500,6 +504,11 @@ static const struct inode_operations ovl_special_inode_operations = {
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.update_time = ovl_update_time,
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};
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const struct address_space_operations ovl_aops = {
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/* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
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.direct_IO = noop_direct_IO,
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};
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/*
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* It is possible to stack overlayfs instance on top of another
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* overlayfs instance as lower layer. We need to annonate the
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@ -571,6 +580,7 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
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case S_IFREG:
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inode->i_op = &ovl_file_inode_operations;
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inode->i_fop = &ovl_file_operations;
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inode->i_mapping->a_ops = &ovl_aops;
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break;
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case S_IFDIR:
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@ -982,16 +982,6 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
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if (err)
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goto out;
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err = -EBUSY;
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if (ovl_inuse_trylock(upperpath->dentry)) {
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ofs->upperdir_locked = true;
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} else if (ofs->config.index) {
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pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
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goto out;
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} else {
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pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
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}
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upper_mnt = clone_private_mount(upperpath);
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err = PTR_ERR(upper_mnt);
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if (IS_ERR(upper_mnt)) {
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@ -1002,6 +992,17 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
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/* Don't inherit atime flags */
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upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
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ofs->upper_mnt = upper_mnt;
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err = -EBUSY;
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if (ovl_inuse_trylock(ofs->upper_mnt->mnt_root)) {
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ofs->upperdir_locked = true;
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} else if (ofs->config.index) {
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pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
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goto out;
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} else {
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pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
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}
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err = 0;
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out:
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return err;
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@ -1101,8 +1102,10 @@ static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
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goto out;
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}
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ofs->workbasedir = dget(workpath.dentry);
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err = -EBUSY;
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if (ovl_inuse_trylock(workpath.dentry)) {
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if (ovl_inuse_trylock(ofs->workbasedir)) {
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ofs->workdir_locked = true;
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} else if (ofs->config.index) {
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pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
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@ -1111,7 +1114,6 @@ static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
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pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
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}
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ofs->workbasedir = dget(workpath.dentry);
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err = ovl_make_workdir(ofs, &workpath);
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if (err)
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goto out;
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@ -1763,6 +1763,7 @@ struct file_operations {
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u64);
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int (*dedupe_file_range)(struct file *, loff_t, struct file *, loff_t,
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u64);
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int (*fadvise)(struct file *, loff_t, loff_t, int);
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} __randomize_layout;
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struct inode_operations {
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@ -3459,4 +3460,8 @@ static inline bool dir_relax_shared(struct inode *inode)
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extern bool path_noexec(const struct path *path);
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extern void inode_nohighmem(struct inode *inode);
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/* mm/fadvise.c */
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extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
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int advice);
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#endif /* _LINUX_FS_H */
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@ -32,7 +32,7 @@ ifdef CONFIG_CROSS_MEMORY_ATTACH
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mmu-$(CONFIG_MMU) += process_vm_access.o
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endif
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obj-y := filemap.o mempool.o oom_kill.o \
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obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
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maccess.o page_alloc.o page-writeback.o \
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readahead.o swap.o truncate.o vmscan.o shmem.o \
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util.o mmzone.o vmstat.o backing-dev.o \
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@ -49,7 +49,6 @@ else
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obj-y += bootmem.o
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endif
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obj-$(CONFIG_ADVISE_SYSCALLS) += fadvise.o
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ifdef CONFIG_MMU
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obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o
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endif
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81
mm/fadvise.c
81
mm/fadvise.c
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@ -27,9 +27,9 @@
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* deactivate the pages and clear PG_Referenced.
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*/
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int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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static int generic_fadvise(struct file *file, loff_t offset, loff_t len,
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int advice)
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{
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struct fd f = fdget(fd);
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struct inode *inode;
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struct address_space *mapping;
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struct backing_dev_info *bdi;
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@ -37,22 +37,14 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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pgoff_t start_index;
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pgoff_t end_index;
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unsigned long nrpages;
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int ret = 0;
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if (!f.file)
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return -EBADF;
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inode = file_inode(file);
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if (S_ISFIFO(inode->i_mode))
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return -ESPIPE;
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inode = file_inode(f.file);
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if (S_ISFIFO(inode->i_mode)) {
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ret = -ESPIPE;
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goto out;
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}
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mapping = f.file->f_mapping;
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if (!mapping || len < 0) {
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ret = -EINVAL;
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goto out;
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}
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mapping = file->f_mapping;
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if (!mapping || len < 0)
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return -EINVAL;
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bdi = inode_to_bdi(mapping->host);
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@ -67,9 +59,9 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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/* no bad return value, but ignore advice */
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break;
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default:
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ret = -EINVAL;
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return -EINVAL;
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}
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goto out;
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return 0;
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}
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/*
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@ -85,21 +77,21 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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switch (advice) {
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case POSIX_FADV_NORMAL:
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f.file->f_ra.ra_pages = bdi->ra_pages;
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spin_lock(&f.file->f_lock);
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f.file->f_mode &= ~FMODE_RANDOM;
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spin_unlock(&f.file->f_lock);
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file->f_ra.ra_pages = bdi->ra_pages;
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spin_lock(&file->f_lock);
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file->f_mode &= ~FMODE_RANDOM;
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spin_unlock(&file->f_lock);
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break;
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case POSIX_FADV_RANDOM:
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spin_lock(&f.file->f_lock);
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f.file->f_mode |= FMODE_RANDOM;
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spin_unlock(&f.file->f_lock);
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spin_lock(&file->f_lock);
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file->f_mode |= FMODE_RANDOM;
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spin_unlock(&file->f_lock);
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break;
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case POSIX_FADV_SEQUENTIAL:
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f.file->f_ra.ra_pages = bdi->ra_pages * 2;
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spin_lock(&f.file->f_lock);
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f.file->f_mode &= ~FMODE_RANDOM;
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spin_unlock(&f.file->f_lock);
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file->f_ra.ra_pages = bdi->ra_pages * 2;
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spin_lock(&file->f_lock);
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file->f_mode &= ~FMODE_RANDOM;
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spin_unlock(&file->f_lock);
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break;
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case POSIX_FADV_WILLNEED:
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/* First and last PARTIAL page! */
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@ -115,8 +107,7 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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* Ignore return value because fadvise() shall return
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* success even if filesystem can't retrieve a hint,
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*/
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force_page_cache_readahead(mapping, f.file, start_index,
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nrpages);
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force_page_cache_readahead(mapping, file, start_index, nrpages);
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break;
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case POSIX_FADV_NOREUSE:
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break;
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@ -183,9 +174,32 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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}
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break;
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default:
|
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ret = -EINVAL;
|
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return -EINVAL;
|
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}
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out:
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return 0;
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}
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int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
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{
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if (file->f_op->fadvise)
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return file->f_op->fadvise(file, offset, len, advice);
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return generic_fadvise(file, offset, len, advice);
|
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}
|
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EXPORT_SYMBOL(vfs_fadvise);
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|
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#ifdef CONFIG_ADVISE_SYSCALLS
|
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|
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int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
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{
|
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struct fd f = fdget(fd);
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int ret;
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|
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if (!f.file)
|
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return -EBADF;
|
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|
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ret = vfs_fadvise(f.file, offset, len, advice);
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fdput(f);
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return ret;
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}
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|
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@ -203,3 +217,4 @@ SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
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}
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#endif
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#endif
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|
|
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@ -20,6 +20,7 @@
|
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#include <linux/file.h>
|
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#include <linux/mm_inline.h>
|
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#include <linux/blk-cgroup.h>
|
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#include <linux/fadvise.h>
|
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|
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#include "internal.h"
|
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|
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|
|
@ -575,24 +576,6 @@ page_cache_async_readahead(struct address_space *mapping,
|
|||
}
|
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EXPORT_SYMBOL_GPL(page_cache_async_readahead);
|
||||
|
||||
static ssize_t
|
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do_readahead(struct address_space *mapping, struct file *filp,
|
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pgoff_t index, unsigned long nr)
|
||||
{
|
||||
if (!mapping || !mapping->a_ops)
|
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return -EINVAL;
|
||||
|
||||
/*
|
||||
* Readahead doesn't make sense for DAX inodes, but we don't want it
|
||||
* to report a failure either. Instead, we just return success and
|
||||
* don't do any work.
|
||||
*/
|
||||
if (dax_mapping(mapping))
|
||||
return 0;
|
||||
|
||||
return force_page_cache_readahead(mapping, filp, index, nr);
|
||||
}
|
||||
|
||||
ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
|
||||
{
|
||||
ssize_t ret;
|
||||
|
|
@ -600,16 +583,22 @@ ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
|
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|
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ret = -EBADF;
|
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f = fdget(fd);
|
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if (f.file) {
|
||||
if (f.file->f_mode & FMODE_READ) {
|
||||
struct address_space *mapping = f.file->f_mapping;
|
||||
pgoff_t start = offset >> PAGE_SHIFT;
|
||||
pgoff_t end = (offset + count - 1) >> PAGE_SHIFT;
|
||||
unsigned long len = end - start + 1;
|
||||
ret = do_readahead(mapping, f.file, start, len);
|
||||
}
|
||||
fdput(f);
|
||||
}
|
||||
if (!f.file || !(f.file->f_mode & FMODE_READ))
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* The readahead() syscall is intended to run only on files
|
||||
* that can execute readahead. If readahead is not possible
|
||||
* on this file, then we must return -EINVAL.
|
||||
*/
|
||||
ret = -EINVAL;
|
||||
if (!f.file->f_mapping || !f.file->f_mapping->a_ops ||
|
||||
!S_ISREG(file_inode(f.file)->i_mode))
|
||||
goto out;
|
||||
|
||||
ret = vfs_fadvise(f.file, offset, count, POSIX_FADV_WILLNEED);
|
||||
out:
|
||||
fdput(f);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue