From 23f0ab13eaa69b4a351184cbec448be2aad3a3a9 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 4 Jul 2017 22:03:18 +0200 Subject: [PATCH] ovl: use struct copy_up_ctx as function argument This cleans up functions with too many arguments. Signed-off-by: Miklos Szeredi --- fs/overlayfs/copy_up.c | 160 ++++++++++++++++++++--------------------- 1 file changed, 78 insertions(+), 82 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 1264f2434047..8f9e26e91386 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -316,38 +316,45 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower, return err; } -static int ovl_install_temp(struct dentry *workdir, struct dentry *upperdir, - struct dentry *dentry, - struct dentry *temp, struct kstat *pstat, - bool tmpfile, struct dentry **newdentry) +struct ovl_copy_up_ctx { + struct dentry *dentry; + struct path lowerpath; + struct kstat stat; + struct kstat pstat; + const char *link; + struct dentry *upperdir; + struct dentry *workdir; + bool tmpfile; +}; + +static int ovl_install_temp(struct ovl_copy_up_ctx *c, struct dentry *temp, + struct dentry **newdentry) { int err; struct dentry *upper; - struct inode *udir = d_inode(upperdir); + struct inode *udir = d_inode(c->upperdir); - upper = lookup_one_len(dentry->d_name.name, upperdir, - dentry->d_name.len); + upper = lookup_one_len(c->dentry->d_name.name, c->upperdir, + c->dentry->d_name.len); if (IS_ERR(upper)) return PTR_ERR(upper); - if (tmpfile) + if (c->tmpfile) err = ovl_do_link(temp, udir, upper, true); else - err = ovl_do_rename(d_inode(workdir), temp, udir, upper, 0); + err = ovl_do_rename(d_inode(c->workdir), temp, udir, upper, 0); /* Restore timestamps on parent (best effort) */ if (!err) { - ovl_set_timestamps(upperdir, pstat); - *newdentry = dget(tmpfile ? upper : temp); + ovl_set_timestamps(c->upperdir, &c->pstat); + *newdentry = dget(c->tmpfile ? upper : temp); } dput(upper); return err; } -static int ovl_get_tmpfile(struct dentry *workdir, struct dentry *dentry, - struct kstat *stat, const char *link, bool tmpfile, - struct dentry **tempp) +static int ovl_get_tmpfile(struct ovl_copy_up_ctx *c, struct dentry **tempp) { int err; struct dentry *temp; @@ -355,28 +362,28 @@ static int ovl_get_tmpfile(struct dentry *workdir, struct dentry *dentry, struct cred *new_creds = NULL; struct cattr cattr = { /* Can't properly set mode on creation because of the umask */ - .mode = stat->mode & S_IFMT, - .rdev = stat->rdev, - .link = link + .mode = c->stat.mode & S_IFMT, + .rdev = c->stat.rdev, + .link = c->link }; - err = security_inode_copy_up(dentry, &new_creds); + err = security_inode_copy_up(c->dentry, &new_creds); if (err < 0) goto out; if (new_creds) old_creds = override_creds(new_creds); - if (tmpfile) { - temp = ovl_do_tmpfile(workdir, stat->mode); + if (c->tmpfile) { + temp = ovl_do_tmpfile(c->workdir, c->stat.mode); if (IS_ERR(temp)) goto temp_err; } else { - temp = ovl_lookup_temp(workdir); + temp = ovl_lookup_temp(c->workdir); if (IS_ERR(temp)) goto temp_err; - err = ovl_create_real(d_inode(workdir), temp, &cattr, + err = ovl_create_real(d_inode(c->workdir), temp, &cattr, NULL, true); if (err) { dput(temp); @@ -398,29 +405,28 @@ temp_err: goto out; } -static int ovl_copy_up_inode(struct dentry *dentry, struct dentry *temp, - struct path *lowerpath, struct kstat *stat) +static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) { int err; - if (S_ISREG(stat->mode)) { + if (S_ISREG(c->stat.mode)) { struct path upperpath; - ovl_path_upper(dentry, &upperpath); + ovl_path_upper(c->dentry, &upperpath); BUG_ON(upperpath.dentry != NULL); upperpath.dentry = temp; - err = ovl_copy_up_data(lowerpath, &upperpath, stat->size); + err = ovl_copy_up_data(&c->lowerpath, &upperpath, c->stat.size); if (err) return err; } - err = ovl_copy_xattr(lowerpath->dentry, temp); + err = ovl_copy_xattr(c->lowerpath.dentry, temp); if (err) return err; inode_lock(temp->d_inode); - err = ovl_set_attr(temp, stat); + err = ovl_set_attr(temp, &c->stat); inode_unlock(temp->d_inode); if (err) return err; @@ -432,8 +438,8 @@ static int ovl_copy_up_inode(struct dentry *dentry, struct dentry *temp, * Don't set origin when we are breaking the association with a lower * hard link. */ - if (S_ISDIR(stat->mode) || stat->nlink == 1) { - err = ovl_set_origin(dentry, lowerpath->dentry, temp); + if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1) { + err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); if (err) return err; } @@ -441,45 +447,39 @@ static int ovl_copy_up_inode(struct dentry *dentry, struct dentry *temp, return 0; } -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 *pstat, bool tmpfile) +static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c) { - struct inode *wdir = workdir->d_inode; - struct inode *udir = upperdir->d_inode; + struct inode *udir = c->upperdir->d_inode; struct dentry *newdentry = NULL; struct dentry *temp = NULL; int err; - err = ovl_get_tmpfile(workdir, dentry, stat, link, tmpfile, &temp); + err = ovl_get_tmpfile(c, &temp); if (err) goto out; - err = ovl_copy_up_inode(dentry, temp, lowerpath, stat); + err = ovl_copy_up_inode(c, temp); if (err) goto out_cleanup; - if (tmpfile) { + if (c->tmpfile) { inode_lock_nested(udir, I_MUTEX_PARENT); - err = ovl_install_temp(workdir, upperdir, dentry, temp, pstat, - tmpfile, &newdentry); + err = ovl_install_temp(c, temp, &newdentry); inode_unlock(udir); } else { - err = ovl_install_temp(workdir, upperdir, dentry, temp, pstat, - tmpfile, &newdentry); + err = ovl_install_temp(c, temp, &newdentry); } if (err) goto out_cleanup; - ovl_inode_update(d_inode(dentry), newdentry); + ovl_inode_update(d_inode(c->dentry), newdentry); out: dput(temp); return err; out_cleanup: - if (!tmpfile) - ovl_cleanup(wdir, temp); + if (!c->tmpfile) + ovl_cleanup(d_inode(c->workdir), temp); goto out; } @@ -492,75 +492,70 @@ out_cleanup: * is possible that the copy up will lock the old parent. At that point * the file will have already been copied up anyway. */ -static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, - struct path *lowerpath, struct kstat *stat) +static int ovl_copy_up_one(struct dentry *parent, struct ovl_copy_up_ctx *c) { DEFINE_DELAYED_CALL(done); - struct dentry *workdir = ovl_workdir(dentry); int err; - struct kstat pstat; struct path parentpath; - struct dentry *lowerdentry = lowerpath->dentry; - struct dentry *upperdir; - const char *link = NULL; - struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct dentry *lowerdentry = c->lowerpath.dentry; + struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; - if (WARN_ON(!workdir)) + c->workdir = ovl_workdir(c->dentry); + if (WARN_ON(!c->workdir)) return -EROFS; ovl_do_check_copy_up(lowerdentry); ovl_path_upper(parent, &parentpath); - upperdir = parentpath.dentry; + c->upperdir = parentpath.dentry; /* Mark parent "impure" because it may now contain non-pure upper */ - err = ovl_set_impure(parent, upperdir); + err = ovl_set_impure(parent, c->upperdir); if (err) return err; - err = vfs_getattr(&parentpath, &pstat, + err = vfs_getattr(&parentpath, &c->pstat, STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT); if (err) return err; - if (S_ISLNK(stat->mode)) { - link = vfs_get_link(lowerdentry, &done); - if (IS_ERR(link)) - return PTR_ERR(link); + if (S_ISLNK(c->stat.mode)) { + c->link = vfs_get_link(lowerdentry, &done); + if (IS_ERR(c->link)) + return PTR_ERR(c->link); } /* Should we copyup with O_TMPFILE or with workdir? */ - if (S_ISREG(stat->mode) && ofs->tmpfile) { - err = ovl_copy_up_start(dentry); + if (S_ISREG(c->stat.mode) && ofs->tmpfile) { + err = ovl_copy_up_start(c->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); + pr_debug("ovl_copy_up_start(%pd2) = %i\n", c->dentry, + err); if (err > 0) err = 0; goto out_done; } - - err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath, - stat, link, &pstat, true); - ovl_copy_up_end(dentry); + c->tmpfile = true; + err = ovl_copy_up_locked(c); + ovl_copy_up_end(c->dentry); goto out_done; } err = -EIO; - if (lock_rename(workdir, upperdir) != NULL) { + if (lock_rename(c->workdir, c->upperdir) != NULL) { pr_err("overlayfs: failed to lock workdir+upperdir\n"); goto out_unlock; } - if (ovl_dentry_upper(dentry)) { + if (ovl_dentry_upper(c->dentry)) { /* Raced with another copy-up? Nothing to do, then... */ err = 0; goto out_unlock; } - err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath, - stat, link, &pstat, false); + err = ovl_copy_up_locked(c); out_unlock: - unlock_rename(workdir, upperdir); + unlock_rename(c->workdir, c->upperdir); out_done: do_delayed_call(&done); @@ -575,8 +570,7 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags) while (!err) { struct dentry *next; struct dentry *parent; - struct path lowerpath; - struct kstat stat; + struct ovl_copy_up_ctx ctx = { }; enum ovl_path_type type = ovl_path_type(dentry); if (OVL_TYPE_UPPER(type)) @@ -595,14 +589,16 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags) next = parent; } - ovl_path_lower(next, &lowerpath); - err = vfs_getattr(&lowerpath, &stat, + ovl_path_lower(next, &ctx.lowerpath); + err = vfs_getattr(&ctx.lowerpath, &ctx.stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); /* maybe truncate regular file. this has no effect on dirs */ if (flags & O_TRUNC) - stat.size = 0; - if (!err) - err = ovl_copy_up_one(parent, next, &lowerpath, &stat); + ctx.stat.size = 0; + if (!err) { + ctx.dentry = next; + err = ovl_copy_up_one(parent, &ctx); + } dput(parent); dput(next);