diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-02-17 09:28:52 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-02-17 09:28:52 +1100 |
commit | b65a0b17d49ec28dc4efbb16549f23709bfd3dbf (patch) | |
tree | b3b063e58909627f7a297deca2cf68eafb1b6e6c | |
parent | 723ff150193636c058174d32116f6bcf2bd63cae (diff) | |
parent | 51f8f3c4e22535933ef9aecc00e9a6069e051b57 (diff) |
Merge remote-tracking branch 'overlayfs/overlayfs-next'
-rw-r--r-- | fs/namei.c | 68 | ||||
-rw-r--r-- | fs/open.c | 14 | ||||
-rw-r--r-- | fs/overlayfs/copy_up.c | 91 | ||||
-rw-r--r-- | fs/overlayfs/overlayfs.h | 11 | ||||
-rw-r--r-- | fs/overlayfs/ovl_entry.h | 3 | ||||
-rw-r--r-- | fs/overlayfs/super.c | 39 | ||||
-rw-r--r-- | fs/overlayfs/util.c | 30 | ||||
-rw-r--r-- | fs/read_write.c | 9 | ||||
-rw-r--r-- | include/linux/fs.h | 29 |
9 files changed, 219 insertions, 75 deletions
diff --git a/fs/namei.c b/fs/namei.c index ad74877e1442..7d87699c3e2e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3353,13 +3353,50 @@ out: return error; } +struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag) +{ + static const struct qstr name = QSTR_INIT("/", 1); + struct dentry *child = NULL; + struct inode *dir = dentry->d_inode; + struct inode *inode; + int error; + + /* we want directory to be writable */ + error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + if (error) + goto out_err; + error = -EOPNOTSUPP; + if (!dir->i_op->tmpfile) + goto out_err; + error = -ENOMEM; + child = d_alloc(dentry, &name); + if (unlikely(!child)) + goto out_err; + error = dir->i_op->tmpfile(dir, child, mode); + if (error) + goto out_err; + error = -ENOENT; + inode = child->d_inode; + if (unlikely(!inode)) + goto out_err; + if (!(open_flag & O_EXCL)) { + spin_lock(&inode->i_lock); + inode->i_state |= I_LINKABLE; + spin_unlock(&inode->i_lock); + } + return child; + +out_err: + dput(child); + return ERR_PTR(error); +} +EXPORT_SYMBOL(vfs_tmpfile); + static int do_tmpfile(struct nameidata *nd, unsigned flags, const struct open_flags *op, struct file *file, int *opened) { - static const struct qstr name = QSTR_INIT("/", 1); struct dentry *child; - struct inode *dir; struct path path; int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path); if (unlikely(error)) @@ -3367,25 +3404,12 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, error = mnt_want_write(path.mnt); if (unlikely(error)) goto out; - dir = path.dentry->d_inode; - /* we want directory to be writable */ - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); - if (error) - goto out2; - if (!dir->i_op->tmpfile) { - error = -EOPNOTSUPP; - goto out2; - } - child = d_alloc(path.dentry, &name); - if (unlikely(!child)) { - error = -ENOMEM; + child = vfs_tmpfile(path.dentry, op->mode, op->open_flag); + error = PTR_ERR(child); + if (unlikely(IS_ERR(child))) goto out2; - } dput(path.dentry); path.dentry = child; - error = dir->i_op->tmpfile(dir, child, op->mode); - if (error) - goto out2; audit_inode(nd->name, child, 0); /* Don't check for other permissions, the inode was just created */ error = may_open(&path, 0, op->open_flag); @@ -3396,14 +3420,8 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, if (error) goto out2; error = open_check_o_direct(file); - if (error) { + if (error) fput(file); - } else if (!(op->open_flag & O_EXCL)) { - struct inode *inode = file_inode(file); - spin_lock(&inode->i_lock); - inode->i_state |= I_LINKABLE; - spin_unlock(&inode->i_lock); - } out2: mnt_drop_write(path.mnt); out: diff --git a/fs/open.c b/fs/open.c index 9921f70bc5ca..949cef29c3bb 100644 --- a/fs/open.c +++ b/fs/open.c @@ -301,12 +301,10 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (S_ISFIFO(inode->i_mode)) return -ESPIPE; - /* - * Let individual file system decide if it supports preallocation - * for directories or not. - */ - if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode) && - !S_ISBLK(inode->i_mode)) + if (S_ISDIR(inode->i_mode)) + return -EISDIR; + + if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) return -ENODEV; /* Check for wrap through zero too */ @@ -316,7 +314,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (!file->f_op->fallocate) return -EOPNOTSUPP; - sb_start_write(inode->i_sb); + file_start_write(file); ret = file->f_op->fallocate(file, mode, offset, len); /* @@ -329,7 +327,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (ret == 0) fsnotify_modify(file); - sb_end_write(inode->i_sb); + file_end_write(file); return ret; } EXPORT_SYMBOL_GPL(vfs_fallocate); diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index f57043dace62..48eb8812ac5b 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -20,6 +20,7 @@ #include <linux/fdtable.h> #include <linux/ratelimit.h> #include "overlayfs.h" +#include "ovl_entry.h" #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) @@ -232,12 +233,14 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, struct dentry *dentry, struct path *lowerpath, - struct kstat *stat, const char *link) + struct kstat *stat, const char *link, + struct kstat *pstat, bool tmpfile) { struct inode *wdir = workdir->d_inode; struct inode *udir = upperdir->d_inode; struct dentry *newdentry = NULL; struct dentry *upper = NULL; + struct dentry *temp = NULL; int err; const struct cred *old_creds = NULL; struct cred *new_creds = NULL; @@ -248,25 +251,30 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, .link = link }; - newdentry = ovl_lookup_temp(workdir, dentry); - err = PTR_ERR(newdentry); - if (IS_ERR(newdentry)) - goto out; - upper = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(upper); if (IS_ERR(upper)) - goto out1; + goto out; err = security_inode_copy_up(dentry, &new_creds); if (err < 0) - goto out2; + goto out1; if (new_creds) old_creds = override_creds(new_creds); - err = ovl_create_real(wdir, newdentry, &cattr, NULL, true); + if (tmpfile) + temp = ovl_do_tmpfile(upperdir, stat->mode); + else + temp = ovl_lookup_temp(workdir, dentry); + err = PTR_ERR(temp); + if (IS_ERR(temp)) + goto out1; + + err = 0; + if (!tmpfile) + err = ovl_create_real(wdir, temp, &cattr, NULL, true); if (new_creds) { revert_creds(old_creds); @@ -281,39 +289,55 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, ovl_path_upper(dentry, &upperpath); BUG_ON(upperpath.dentry != NULL); - upperpath.dentry = newdentry; + upperpath.dentry = temp; + + if (tmpfile) { + inode_unlock(udir); + err = ovl_copy_up_data(lowerpath, &upperpath, + stat->size); + inode_lock_nested(udir, I_MUTEX_PARENT); + } else { + err = ovl_copy_up_data(lowerpath, &upperpath, + stat->size); + } - err = ovl_copy_up_data(lowerpath, &upperpath, stat->size); if (err) goto out_cleanup; } - err = ovl_copy_xattr(lowerpath->dentry, newdentry); + err = ovl_copy_xattr(lowerpath->dentry, temp); if (err) goto out_cleanup; - inode_lock(newdentry->d_inode); - err = ovl_set_attr(newdentry, stat); - inode_unlock(newdentry->d_inode); + inode_lock(temp->d_inode); + err = ovl_set_attr(temp, stat); + inode_unlock(temp->d_inode); if (err) goto out_cleanup; - err = ovl_do_rename(wdir, newdentry, udir, upper, 0); + if (tmpfile) + err = ovl_do_link(temp, udir, upper, true); + else + err = ovl_do_rename(wdir, temp, udir, upper, 0); if (err) goto out_cleanup; + newdentry = dget(tmpfile ? upper : temp); ovl_dentry_update(dentry, newdentry); ovl_inode_update(d_inode(dentry), d_inode(newdentry)); - newdentry = NULL; + + /* Restore timestamps on parent (best effort) */ + ovl_set_timestamps(upperdir, pstat); out2: - dput(upper); + dput(temp); out1: - dput(newdentry); + dput(upper); out: return err; out_cleanup: - ovl_cleanup(wdir, newdentry); + if (!tmpfile) + ovl_cleanup(wdir, temp); goto out2; } @@ -337,6 +361,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, struct dentry *lowerdentry = lowerpath->dentry; struct dentry *upperdir; const char *link = NULL; + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; if (WARN_ON(!workdir)) return -EROFS; @@ -356,6 +381,25 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, return PTR_ERR(link); } + /* Should we copyup with O_TMPFILE or with workdir? */ + if (S_ISREG(stat->mode) && ofs->tmpfile) { + err = ovl_copy_up_start(dentry); + /* err < 0: interrupted, err > 0: raced with another copy-up */ + if (unlikely(err)) { + pr_debug("ovl_copy_up_start(%pd2) = %i\n", dentry, err); + if (err > 0) + err = 0; + goto out_done; + } + + inode_lock_nested(upperdir->d_inode, I_MUTEX_PARENT); + err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath, + stat, link, &pstat, true); + inode_unlock(upperdir->d_inode); + ovl_copy_up_end(dentry); + goto out_done; + } + err = -EIO; if (lock_rename(workdir, upperdir) != NULL) { pr_err("overlayfs: failed to lock workdir+upperdir\n"); @@ -368,13 +412,10 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, } err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath, - stat, link); - if (!err) { - /* Restore timestamps on parent (best effort) */ - ovl_set_timestamps(upperdir, &pstat); - } + stat, link, &pstat, false); out_unlock: unlock_rename(workdir, upperdir); +out_done: do_delayed_call(&done); return err; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 8af450b0e57a..741dc0b6931f 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -127,6 +127,15 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) return err; } +static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode) +{ + struct dentry *ret = vfs_tmpfile(dentry, mode, 0); + int err = IS_ERR(ret) ? PTR_ERR(ret) : 0; + + pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); + return ret; +} + static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) { unsigned long x = (unsigned long) READ_ONCE(inode->i_private); @@ -169,6 +178,8 @@ void ovl_dentry_version_inc(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); +int ovl_copy_up_start(struct dentry *dentry); +void ovl_copy_up_end(struct dentry *dentry); /* namei.c */ int ovl_path_next(int idx, struct dentry *dentry, struct path *path); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index d14bca1850d9..59614faa14c3 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -27,6 +27,8 @@ struct ovl_fs { struct ovl_config config; /* creds of process who forced instantiation of super block */ const struct cred *creator_cred; + bool tmpfile; + wait_queue_head_t copyup_wq; }; /* private information held for every overlayfs dentry */ @@ -38,6 +40,7 @@ struct ovl_entry { u64 version; const char *redirect; bool opaque; + bool copying; }; struct rcu_head rcu; }; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 20f48abbb82f..7b2188181367 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -160,6 +160,25 @@ static void ovl_put_super(struct super_block *sb) kfree(ufs); } +static int ovl_sync_fs(struct super_block *sb, int wait) +{ + struct ovl_fs *ufs = sb->s_fs_info; + struct super_block *upper_sb; + int ret; + + if (!ufs->upper_mnt) + return 0; + upper_sb = ufs->upper_mnt->mnt_sb; + if (!upper_sb->s_op->sync_fs) + return 0; + + /* real inodes have already been synced by sync_filesystem(ovl_sb) */ + down_read(&upper_sb->s_umount); + ret = upper_sb->s_op->sync_fs(upper_sb, wait); + up_read(&upper_sb->s_umount); + return ret; +} + /** * ovl_statfs * @sb: The overlayfs super block @@ -222,6 +241,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data) static const struct super_operations ovl_super_operations = { .put_super = ovl_put_super, + .sync_fs = ovl_sync_fs, .statfs = ovl_statfs, .show_options = ovl_show_options, .remount_fs = ovl_remount, @@ -701,6 +721,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) unsigned int stacklen = 0; unsigned int i; bool remote = false; + struct cred *cred; int err; err = -ENOMEM; @@ -708,6 +729,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (!ufs) goto out; + init_waitqueue_head(&ufs->copyup_wq); ufs->config.redirect_dir = ovl_redirect_dir_def; err = ovl_parse_opt((char *) data, &ufs->config); if (err) @@ -825,6 +847,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) * creation of workdir in previous step. */ if (ufs->workdir) { + struct dentry *temp; + err = ovl_check_d_type_supported(&workpath); if (err < 0) goto out_put_workdir; @@ -836,6 +860,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) */ if (!err) pr_warn("overlayfs: upper fs needs to support d_type.\n"); + + /* Check if upper/work fs supports O_TMPFILE */ + temp = ovl_do_tmpfile(ufs->workdir, S_IFREG | 0); + ufs->tmpfile = !IS_ERR(temp); + if (ufs->tmpfile) + dput(temp); + else + pr_warn("overlayfs: upper fs does not support tmpfile.\n"); } } @@ -870,10 +902,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) else sb->s_d_op = &ovl_dentry_operations; - ufs->creator_cred = prepare_creds(); - if (!ufs->creator_cred) + ufs->creator_cred = cred = prepare_creds(); + if (!cred) goto out_put_lower_mnt; + /* Never override disk quota limits or use reserved space */ + cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); + err = -ENOMEM; oe = ovl_alloc_entry(numlower); if (!oe) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 952286f4826c..01157d6e8cfe 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -263,3 +263,33 @@ struct file *ovl_path_open(struct path *path, int flags) { return dentry_open(path, flags | O_NOATIME, current_cred()); } + +int ovl_copy_up_start(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + int err; + + spin_lock(&ofs->copyup_wq.lock); + err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying); + if (!err) { + if (oe->__upperdentry) + err = 1; /* Already copied up */ + else + oe->copying = true; + } + spin_unlock(&ofs->copyup_wq.lock); + + return err; +} + +void ovl_copy_up_end(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + + spin_lock(&ofs->copyup_wq.lock); + oe->copying = false; + wake_up_locked(&ofs->copyup_wq); + spin_unlock(&ofs->copyup_wq.lock); +} diff --git a/fs/read_write.c b/fs/read_write.c index 5816d4c4cab0..820a3f06c46a 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1518,6 +1518,11 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (flags != 0) return -EINVAL; + if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) + return -EISDIR; + if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) + return -EINVAL; + ret = rw_verify_area(READ, file_in, &pos_in, len); if (unlikely(ret)) return ret; @@ -1538,7 +1543,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (len == 0) return 0; - sb_start_write(inode_out->i_sb); + file_start_write(file_out); /* * Try cloning first, this is supported by more file systems, and @@ -1574,7 +1579,7 @@ done: inc_syscr(current); inc_syscw(current); - sb_end_write(inode_out->i_sb); + file_end_write(file_out); return ret; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 2ba074328894..78c81e6f5d76 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1561,6 +1561,9 @@ extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int); extern int vfs_whiteout(struct inode *, struct dentry *); +extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, + int open_flag); + /* * VFS file helper functions. */ @@ -1738,19 +1741,6 @@ extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, extern int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same); -static inline int do_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - u64 len) -{ - int ret; - - sb_start_write(file_inode(file_out)->i_sb); - ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len); - sb_end_write(file_inode(file_out)->i_sb); - - return ret; -} - struct super_operations { struct inode *(*alloc_inode)(struct super_block *sb); void (*destroy_inode)(struct inode *); @@ -2561,6 +2551,19 @@ static inline void file_end_write(struct file *file) __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE); } +static inline int do_clone_file_range(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + u64 len) +{ + int ret; + + file_start_write(file_out); + ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len); + file_end_write(file_out); + + return ret; +} + /* * get_write_access() gets write permission for a file. * put_write_access() releases this write permission. |