diff options
| -rw-r--r-- | Documentation/filesystems/Locking | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 2 | ||||
| -rw-r--r-- | fs/inode.c | 21 | ||||
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/namespace.c | 64 | ||||
| -rw-r--r-- | fs/open.c | 8 | ||||
| -rw-r--r-- | fs/overlayfs/dir.c | 11 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 14 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 8 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 383 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 11 | ||||
| -rw-r--r-- | fs/overlayfs/util.c | 24 | ||||
| -rw-r--r-- | fs/xattr.c | 9 | ||||
| -rw-r--r-- | include/linux/dcache.h | 14 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
15 files changed, 496 insertions, 79 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index fe25787ff6d4..75d2d57e2c44 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -22,7 +22,7 @@ prototypes: struct vfsmount *(*d_automount)(struct path *path); int (*d_manage)(const struct path *, bool); struct dentry *(*d_real)(struct dentry *, const struct inode *, - unsigned int); + unsigned int, unsigned int); locking rules: rename_lock ->d_lock may block rcu-walk diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 405a3df759b3..5fd325df59e2 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -988,7 +988,7 @@ struct dentry_operations { struct vfsmount *(*d_automount)(struct path *); int (*d_manage)(const struct path *, bool); struct dentry *(*d_real)(struct dentry *, const struct inode *, - unsigned int); + unsigned int, unsigned int); }; d_revalidate: called when the VFS needs to revalidate a dentry. This diff --git a/fs/inode.c b/fs/inode.c index 210054157a49..d1e35b53bb23 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1570,11 +1570,24 @@ EXPORT_SYMBOL(bmap); static void update_ovl_inode_times(struct dentry *dentry, struct inode *inode, bool rcu) { - if (!rcu) { - struct inode *realinode = d_real_inode(dentry); + struct dentry *upperdentry; - if (unlikely(inode != realinode) && - (!timespec_equal(&inode->i_mtime, &realinode->i_mtime) || + /* + * Nothing to do if in rcu or if non-overlayfs + */ + if (rcu || likely(!(dentry->d_flags & DCACHE_OP_REAL))) + return; + + upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER); + + /* + * If file is on lower then we can't update atime, so no worries about + * stale mtime/ctime. + */ + if (upperdentry) { + struct inode *realinode = d_inode(upperdentry); + + if ((!timespec_equal(&inode->i_mtime, &realinode->i_mtime) || !timespec_equal(&inode->i_ctime, &realinode->i_ctime))) { inode->i_mtime = realinode->i_mtime; inode->i_ctime = realinode->i_ctime; diff --git a/fs/internal.h b/fs/internal.h index fedfe94d84ba..48cee21b4f14 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -71,8 +71,10 @@ extern void __init mnt_init(void); extern int __mnt_want_write(struct vfsmount *); extern int __mnt_want_write_file(struct file *); +extern int mnt_want_write_file_path(struct file *); extern void __mnt_drop_write(struct vfsmount *); extern void __mnt_drop_write_file(struct file *); +extern void mnt_drop_write_file_path(struct file *); /* * fs_struct.c diff --git a/fs/namespace.c b/fs/namespace.c index f8893dc6a989..df0f7521979a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -431,13 +431,18 @@ int __mnt_want_write_file(struct file *file) } /** - * mnt_want_write_file - get write access to a file's mount + * mnt_want_write_file_path - get write access to a file's mount * @file: the file who's mount on which to take a write * * This is like mnt_want_write, but it takes a file and can * do some optimisations if the file is open for write already + * + * Called by the vfs for cases when we have an open file at hand, but will do an + * inode operation on it (important distinction for files opened on overlayfs, + * since the file operations will come from the real underlying file, while + * inode operations come from the overlay). */ -int mnt_want_write_file(struct file *file) +int mnt_want_write_file_path(struct file *file) { int ret; @@ -447,6 +452,53 @@ int mnt_want_write_file(struct file *file) sb_end_write(file->f_path.mnt->mnt_sb); return ret; } + +static inline int may_write_real(struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + struct dentry *upperdentry; + + /* Writable file? */ + if (file->f_mode & FMODE_WRITER) + return 0; + + /* Not overlayfs? */ + if (likely(!(dentry->d_flags & DCACHE_OP_REAL))) + return 0; + + /* File refers to upper, writable layer? */ + upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER); + if (upperdentry && file_inode(file) == d_inode(upperdentry)) + return 0; + + /* Lower layer: can't write to real file, sorry... */ + return -EPERM; +} + +/** + * mnt_want_write_file - get write access to a file's mount + * @file: the file who's mount on which to take a write + * + * This is like mnt_want_write, but it takes a file and can + * do some optimisations if the file is open for write already + * + * Mostly called by filesystems from their ioctl operation before performing + * modification. On overlayfs this needs to check if the file is on a read-only + * lower layer and deny access in that case. + */ +int mnt_want_write_file(struct file *file) +{ + int ret; + + ret = may_write_real(file); + if (!ret) { + sb_start_write(file_inode(file)->i_sb); + ret = __mnt_want_write_file(file); + if (ret) + sb_end_write(file_inode(file)->i_sb); + } + return ret; +} EXPORT_SYMBOL_GPL(mnt_want_write_file); /** @@ -484,10 +536,16 @@ void __mnt_drop_write_file(struct file *file) __mnt_drop_write(file->f_path.mnt); } -void mnt_drop_write_file(struct file *file) +void mnt_drop_write_file_path(struct file *file) { mnt_drop_write(file->f_path.mnt); } + +void mnt_drop_write_file(struct file *file) +{ + __mnt_drop_write(file->f_path.mnt); + sb_end_write(file_inode(file)->i_sb); +} EXPORT_SYMBOL(mnt_drop_write_file); static int mnt_make_readonly(struct mount *mnt) diff --git a/fs/open.c b/fs/open.c index 35bb784763a4..7ea118471dce 100644 --- a/fs/open.c +++ b/fs/open.c @@ -96,7 +96,7 @@ long vfs_truncate(const struct path *path, loff_t length) * write access on the upper inode, not on the overlay inode. For * non-overlay filesystems d_real() is an identity function. */ - upperdentry = d_real(path->dentry, NULL, O_WRONLY); + upperdentry = d_real(path->dentry, NULL, O_WRONLY, 0); error = PTR_ERR(upperdentry); if (IS_ERR(upperdentry)) goto mnt_drop_write_and_out; @@ -670,12 +670,12 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) if (!f.file) goto out; - error = mnt_want_write_file(f.file); + error = mnt_want_write_file_path(f.file); if (error) goto out_fput; audit_file(f.file); error = chown_common(&f.file->f_path, user, group); - mnt_drop_write_file(f.file); + mnt_drop_write_file_path(f.file); out_fput: fdput(f); out: @@ -857,7 +857,7 @@ EXPORT_SYMBOL(file_path); int vfs_open(const struct path *path, struct file *file, const struct cred *cred) { - struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags); + struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags, 0); if (IS_ERR(dentry)) return PTR_ERR(dentry); diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 48b70e6490f3..9cb0c80e5967 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -155,7 +155,7 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) static void ovl_instantiate(struct dentry *dentry, struct inode *inode, struct dentry *newdentry, bool hardlink) { - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, false); ovl_dentry_set_upper_alias(dentry); if (!hardlink) { ovl_inode_update(inode, newdentry); @@ -692,7 +692,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) if (flags) ovl_cleanup(wdir, upper); - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, true); out_d_drop: d_drop(dentry); dput(whiteout); @@ -742,7 +742,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) err = vfs_rmdir(dir, upper); else err = vfs_unlink(dir, upper, NULL); - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, ovl_type_origin(dentry)); /* * Keeping this dentry hashed would mean having to release @@ -1089,8 +1089,9 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, drop_nlink(d_inode(new)); } - ovl_dentry_version_inc(old->d_parent); - ovl_dentry_version_inc(new->d_parent); + ovl_dentry_version_inc(old->d_parent, + !overwrite && ovl_type_origin(new)); + ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old)); out_dput: dput(newdentry); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 5bc71642b226..a619addecafc 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -498,6 +498,9 @@ static int ovl_set_nlink_common(struct dentry *dentry, len = snprintf(buf, sizeof(buf), format, (int) (inode->i_nlink - realinode->i_nlink)); + if (WARN_ON(len >= sizeof(buf))) + return -EIO; + return ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_NLINK, buf, len, 0); } @@ -576,10 +579,13 @@ static int ovl_inode_set(struct inode *inode, void *data) static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry, struct dentry *upperdentry) { - struct inode *lowerinode = lowerdentry ? d_inode(lowerdentry) : NULL; - - /* Lower (origin) inode must match, even if NULL */ - if (ovl_inode_lower(inode) != lowerinode) + /* + * Allow non-NULL lower inode in ovl_inode even if lowerdentry is NULL. + * This happens when finding a copied up overlay inode for a renamed + * or hardlinked overlay dentry and lower dentry cannot be followed + * by origin because lower fs does not support file handles. + */ + if (lowerdentry && ovl_inode_lower(inode) != d_inode(lowerdentry)) return false; /* diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index e927a62c97ae..d4e8c1a08fb0 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -204,8 +204,8 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode); struct inode *ovl_inode_upper(struct inode *inode); struct inode *ovl_inode_lower(struct inode *inode); struct inode *ovl_inode_real(struct inode *inode); -struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); -void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); +struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); +void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); bool ovl_dentry_is_opaque(struct dentry *dentry); bool ovl_dentry_is_whiteout(struct dentry *dentry); void ovl_dentry_set_opaque(struct dentry *dentry); @@ -217,7 +217,7 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, struct dentry *lowerdentry); void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); -void ovl_dentry_version_inc(struct dentry *dentry); +void ovl_dentry_version_inc(struct dentry *dentry, bool impurity); 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); @@ -229,6 +229,7 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, int xerr); int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); void ovl_set_flag(unsigned long flag, struct inode *inode); +void ovl_clear_flag(unsigned long flag, struct inode *inode); bool ovl_test_flag(unsigned long flag, struct inode *inode); bool ovl_inuse_trylock(struct dentry *dentry); void ovl_inuse_unlock(struct dentry *dentry); @@ -256,6 +257,7 @@ extern const struct file_operations ovl_dir_operations; int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); void ovl_cache_free(struct list_head *list); +void ovl_dir_cache_free(struct inode *inode); int ovl_check_d_type_supported(struct path *realpath); void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index f0fd3adb1693..62e9b22a2077 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -15,11 +15,13 @@ #include <linux/rbtree.h> #include <linux/security.h> #include <linux/cred.h> +#include <linux/ratelimit.h> #include "overlayfs.h" struct ovl_cache_entry { unsigned int len; unsigned int type; + u64 real_ino; u64 ino; struct list_head l_node; struct rb_node node; @@ -32,18 +34,20 @@ struct ovl_dir_cache { long refcount; u64 version; struct list_head entries; + struct rb_root root; }; struct ovl_readdir_data { struct dir_context ctx; struct dentry *dentry; bool is_lowest; - struct rb_root root; + struct rb_root *root; struct list_head *list; struct list_head middle; struct ovl_cache_entry *first_maybe_whiteout; int count; int err; + bool is_upper; bool d_type_supported; }; @@ -58,7 +62,33 @@ struct ovl_dir_file { static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n) { - return container_of(n, struct ovl_cache_entry, node); + return rb_entry(n, struct ovl_cache_entry, node); +} + +static bool ovl_cache_entry_find_link(const char *name, int len, + struct rb_node ***link, + struct rb_node **parent) +{ + bool found = false; + struct rb_node **newp = *link; + + while (!found && *newp) { + int cmp; + struct ovl_cache_entry *tmp; + + *parent = *newp; + tmp = ovl_cache_entry_from_node(*newp); + cmp = strncmp(name, tmp->name, len); + if (cmp > 0) + newp = &tmp->node.rb_right; + else if (cmp < 0 || len < tmp->len) + newp = &tmp->node.rb_left; + else + found = true; + } + *link = newp; + + return found; } static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, @@ -82,6 +112,32 @@ static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, return NULL; } +static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, + struct ovl_cache_entry *p) +{ + /* Don't care if not doing ovl_iter() */ + if (!rdd->dentry) + return false; + + /* Always recalc d_ino for parent */ + if (strcmp(p->name, "..") == 0) + return true; + + /* If this is lower, then native d_ino will do */ + if (!rdd->is_upper) + return false; + + /* + * Recalc d_ino for '.' and for all entries if dir is impure (contains + * copied up entries) + */ + if ((p->name[0] == '.' && p->len == 1) || + ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry))) + return true; + + return false; +} + static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, const char *name, int len, u64 ino, unsigned int d_type) @@ -97,7 +153,11 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, p->name[len] = '\0'; p->len = len; p->type = d_type; + p->real_ino = ino; p->ino = ino; + /* Defer setting d_ino for upper entry to ovl_iterate() */ + if (ovl_calc_d_ino(rdd, p)) + p->ino = 0; p->is_whiteout = false; if (d_type == DT_CHR) { @@ -111,32 +171,22 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd, const char *name, int len, u64 ino, unsigned int d_type) { - struct rb_node **newp = &rdd->root.rb_node; + struct rb_node **newp = &rdd->root->rb_node; struct rb_node *parent = NULL; struct ovl_cache_entry *p; - while (*newp) { - int cmp; - struct ovl_cache_entry *tmp; - - parent = *newp; - tmp = ovl_cache_entry_from_node(*newp); - cmp = strncmp(name, tmp->name, len); - if (cmp > 0) - newp = &tmp->node.rb_right; - else if (cmp < 0 || len < tmp->len) - newp = &tmp->node.rb_left; - else - return 0; - } + if (ovl_cache_entry_find_link(name, len, &newp, &parent)) + return 0; p = ovl_cache_entry_new(rdd, name, len, ino, d_type); - if (p == NULL) + if (p == NULL) { + rdd->err = -ENOMEM; return -ENOMEM; + } list_add_tail(&p->l_node, rdd->list); rb_link_node(&p->node, parent, newp); - rb_insert_color(&p->node, &rdd->root); + rb_insert_color(&p->node, rdd->root); return 0; } @@ -147,7 +197,7 @@ static int ovl_fill_lowest(struct ovl_readdir_data *rdd, { struct ovl_cache_entry *p; - p = ovl_cache_entry_find(&rdd->root, name, namelen); + p = ovl_cache_entry_find(rdd->root, name, namelen); if (p) { list_move_tail(&p->l_node, &rdd->middle); } else { @@ -172,6 +222,16 @@ void ovl_cache_free(struct list_head *list) INIT_LIST_HEAD(list); } +void ovl_dir_cache_free(struct inode *inode) +{ + struct ovl_dir_cache *cache = ovl_dir_cache(inode); + + if (cache) { + ovl_cache_free(&cache->entries); + kfree(cache); + } +} + static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) { struct ovl_dir_cache *cache = od->cache; @@ -179,8 +239,8 @@ static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) WARN_ON(cache->refcount <= 0); cache->refcount--; if (!cache->refcount) { - if (ovl_dir_cache(dentry) == cache) - ovl_set_dir_cache(dentry, NULL); + if (ovl_dir_cache(d_inode(dentry)) == cache) + ovl_set_dir_cache(d_inode(dentry), NULL); ovl_cache_free(&cache->entries); kfree(cache); @@ -273,7 +333,8 @@ static void ovl_dir_reset(struct file *file) od->is_real = false; } -static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) +static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list, + struct rb_root *root) { int err; struct path realpath; @@ -281,13 +342,14 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) .ctx.actor = ovl_fill_merge, .dentry = dentry, .list = list, - .root = RB_ROOT, + .root = root, .is_lowest = false, }; int idx, next; for (idx = 0; idx != -1; idx = next) { next = ovl_path_next(idx, dentry, &realpath); + rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry; if (next != -1) { err = ovl_dir_read(&realpath, &rdd); @@ -326,12 +388,13 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) int res; struct ovl_dir_cache *cache; - cache = ovl_dir_cache(dentry); + cache = ovl_dir_cache(d_inode(dentry)); if (cache && ovl_dentry_version_get(dentry) == cache->version) { + WARN_ON(!cache->refcount); cache->refcount++; return cache; } - ovl_set_dir_cache(dentry, NULL); + ovl_set_dir_cache(d_inode(dentry), NULL); cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); if (!cache) @@ -339,8 +402,9 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) cache->refcount = 1; INIT_LIST_HEAD(&cache->entries); + cache->root = RB_ROOT; - res = ovl_dir_read_merged(dentry, &cache->entries); + res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root); if (res) { ovl_cache_free(&cache->entries); kfree(cache); @@ -348,22 +412,266 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) } cache->version = ovl_dentry_version_get(dentry); - ovl_set_dir_cache(dentry, cache); + ovl_set_dir_cache(d_inode(dentry), cache); return cache; } +/* + * Set d_ino for upper entries. Non-upper entries should always report + * the uppermost real inode ino and should not call this function. + * + * When not all layer are on same fs, report real ino also for upper. + * + * When all layers are on the same fs, and upper has a reference to + * copy up origin, call vfs_getattr() on the overlay entry to make + * sure that d_ino will be consistent with st_ino from stat(2). + */ +static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) + +{ + struct dentry *dir = path->dentry; + struct dentry *this = NULL; + enum ovl_path_type type; + u64 ino = p->real_ino; + int err = 0; + + if (!ovl_same_sb(dir->d_sb)) + goto out; + + if (p->name[0] == '.') { + if (p->len == 1) { + this = dget(dir); + goto get; + } + if (p->len == 2 && p->name[1] == '.') { + /* we shall not be moved */ + this = dget(dir->d_parent); + goto get; + } + } + this = lookup_one_len(p->name, dir, p->len); + if (IS_ERR_OR_NULL(this) || !this->d_inode) { + if (IS_ERR(this)) { + err = PTR_ERR(this); + this = NULL; + goto fail; + } + goto out; + } + +get: + type = ovl_path_type(this); + if (OVL_TYPE_ORIGIN(type)) { + struct kstat stat; + struct path statpath = *path; + + statpath.dentry = this; + err = vfs_getattr(&statpath, &stat, STATX_INO, 0); + if (err) + goto fail; + + WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); + ino = stat.ino; + } + +out: + p->ino = ino; + dput(this); + return err; + +fail: + pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n", + p->name, err); + goto out; +} + +static int ovl_fill_plain(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_cache_entry *p; + struct ovl_readdir_data *rdd = + container_of(ctx, struct ovl_readdir_data, ctx); + + rdd->count++; + p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type); + if (p == NULL) { + rdd->err = -ENOMEM; + return -ENOMEM; + } + list_add_tail(&p->l_node, rdd->list); + + return 0; +} + +static int ovl_dir_read_impure(struct path *path, struct list_head *list, + struct rb_root *root) +{ + int err; + struct path realpath; + struct ovl_cache_entry *p, *n; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_fill_plain, + .list = list, + .root = root, + }; + + INIT_LIST_HEAD(list); + *root = RB_ROOT; + ovl_path_upper(path->dentry, &realpath); + + err = ovl_dir_read(&realpath, &rdd); + if (err) + return err; + + list_for_each_entry_safe(p, n, list, l_node) { + if (strcmp(p->name, ".") != 0 && + strcmp(p->name, "..") != 0) { + err = ovl_cache_update_ino(path, p); + if (err) + return err; + } + if (p->ino == p->real_ino) { + list_del(&p->l_node); + kfree(p); + } else { + struct rb_node **newp = &root->rb_node; + struct rb_node *parent = NULL; + + if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len, + &newp, &parent))) + return -EIO; + + rb_link_node(&p->node, parent, newp); + rb_insert_color(&p->node, root); + } + } + return 0; +} + +static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path) +{ + int res; + struct dentry *dentry = path->dentry; + struct ovl_dir_cache *cache; + + cache = ovl_dir_cache(d_inode(dentry)); + if (cache && ovl_dentry_version_get(dentry) == cache->version) + return cache; + + /* Impure cache is not refcounted, free it here */ + ovl_dir_cache_free(d_inode(dentry)); + ovl_set_dir_cache(d_inode(dentry), NULL); + + cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); + if (!cache) + return ERR_PTR(-ENOMEM); + + res = ovl_dir_read_impure(path, &cache->entries, &cache->root); + if (res) { + ovl_cache_free(&cache->entries); + kfree(cache); + return ERR_PTR(res); + } + if (list_empty(&cache->entries)) { + /* Good oportunity to get rid of an unnecessary "impure" flag */ + ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE); + ovl_clear_flag(OVL_IMPURE, d_inode(dentry)); + kfree(cache); + return NULL; + } + + cache->version = ovl_dentry_version_get(dentry); + ovl_set_dir_cache(d_inode(dentry), cache); + + return cache; +} + +struct ovl_readdir_translate { + struct dir_context *orig_ctx; + struct ovl_dir_cache *cache; + struct dir_context ctx; + u64 parent_ino; +}; + +static int ovl_fill_real(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_readdir_translate *rdt = + container_of(ctx, struct ovl_readdir_translate, ctx); + struct dir_context *orig_ctx = rdt->orig_ctx; + + if (rdt->parent_ino && strcmp(name, "..") == 0) + ino = rdt->parent_ino; + else if (rdt->cache) { + struct ovl_cache_entry *p; + + p = ovl_cache_entry_find(&rdt->cache->root, name, namelen); + if (p) + ino = p->ino; + } + + return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type); +} + +static int ovl_iterate_real(struct file *file, struct dir_context *ctx) +{ + int err; + struct ovl_dir_file *od = file->private_data; + struct dentry *dir = file->f_path.dentry; + struct ovl_readdir_translate rdt = { + .ctx.actor = ovl_fill_real, + .orig_ctx = ctx, + }; + + if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) { + struct kstat stat; + struct path statpath = file->f_path; + + statpath.dentry = dir->d_parent; + err = vfs_getattr(&statpath, &stat, STATX_INO, 0); + if (err) + return err; + + WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); + rdt.parent_ino = stat.ino; + } + + if (ovl_test_flag(OVL_IMPURE, d_inode(dir))) { + rdt.cache = ovl_cache_get_impure(&file->f_path); + if (IS_ERR(rdt.cache)) + return PTR_ERR(rdt.cache); + } + + return iterate_dir(od->realfile, &rdt.ctx); +} + + static int ovl_iterate(struct file *file, struct dir_context *ctx) { struct ovl_dir_file *od = file->private_data; struct dentry *dentry = file->f_path.dentry; struct ovl_cache_entry *p; + int err; if (!ctx->pos) ovl_dir_reset(file); - if (od->is_real) + if (od->is_real) { + /* + * If parent is merge, then need to adjust d_ino for '..', if + * dir is impure then need to adjust d_ino for copied up + * entries. + */ + if (ovl_same_sb(dentry->d_sb) && + (ovl_test_flag(OVL_IMPURE, d_inode(dentry)) || + OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) { + return ovl_iterate_real(file, ctx); + } return iterate_dir(od->realfile, ctx); + } if (!od->cache) { struct ovl_dir_cache *cache; @@ -378,9 +686,15 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) while (od->cursor != &od->cache->entries) { p = list_entry(od->cursor, struct ovl_cache_entry, l_node); - if (!p->is_whiteout) + if (!p->is_whiteout) { + if (!p->ino) { + err = ovl_cache_update_ino(&file->f_path, p); + if (err) + return err; + } if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) break; + } od->cursor = p->l_node.next; ctx->pos++; } @@ -522,8 +836,9 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) { int err; struct ovl_cache_entry *p; + struct rb_root root = RB_ROOT; - err = ovl_dir_read_merged(dentry, list); + err = ovl_dir_read_merged(dentry, list, &root); if (err) return err; @@ -612,12 +927,13 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level) int err; struct inode *dir = path->dentry->d_inode; LIST_HEAD(list); + struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { .ctx.actor = ovl_fill_merge, .dentry = NULL, .list = &list, - .root = RB_ROOT, + .root = &root, .is_lowest = false, }; @@ -675,12 +991,13 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, struct inode *dir = dentry->d_inode; struct path path = { .mnt = mnt, .dentry = dentry }; LIST_HEAD(list); + struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { .ctx.actor = ovl_fill_merge, .dentry = NULL, .list = &list, - .root = RB_ROOT, + .root = &root, .is_lowest = false, }; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index d86e89f97201..cd49c0298ddf 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -70,20 +70,20 @@ static int ovl_check_append_only(struct inode *inode, int flag) static struct dentry *ovl_d_real(struct dentry *dentry, const struct inode *inode, - unsigned int open_flags) + unsigned int open_flags, unsigned int flags) { struct dentry *real; int err; + if (flags & D_REAL_UPPER) + return ovl_dentry_upper(dentry); + if (!d_is_reg(dentry)) { if (!inode || inode == d_inode(dentry)) return dentry; goto bug; } - if (d_is_negative(dentry)) - return dentry; - if (open_flags) { err = ovl_open_maybe_copy_up(dentry, open_flags); if (err) @@ -105,7 +105,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, goto bug; /* Handle recursion */ - real = d_real(real, inode, open_flags); + real = d_real(real, inode, open_flags, 0); if (!inode || inode == d_inode(real)) return real; @@ -198,6 +198,7 @@ static void ovl_destroy_inode(struct inode *inode) dput(oi->__upperdentry); kfree(oi->redirect); + ovl_dir_cache_free(inode); mutex_destroy(&oi->lock); call_rcu(&inode->i_rcu, ovl_i_callback); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f46ad75dc96a..117794582f9f 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -180,14 +180,14 @@ struct inode *ovl_inode_real(struct inode *inode) } -struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) +struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) { - return OVL_I(d_inode(dentry))->cache; + return OVL_I(inode)->cache; } -void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) +void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) { - OVL_I(d_inode(dentry))->cache = cache; + OVL_I(inode)->cache = cache; } bool ovl_dentry_is_opaque(struct dentry *dentry) @@ -275,12 +275,19 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) } } -void ovl_dentry_version_inc(struct dentry *dentry) +void ovl_dentry_version_inc(struct dentry *dentry, bool impurity) { struct inode *inode = d_inode(dentry); WARN_ON(!inode_is_locked(inode)); - OVL_I(inode)->version++; + /* + * Version is used by readdir code to keep cache consistent. For merge + * dirs all changes need to be noted. For non-merge dirs, cache only + * contains impure (ones which have been copied up and have origins) + * entries, so only need to note changes to impure entries. + */ + if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity) + OVL_I(inode)->version++; } u64 ovl_dentry_version_get(struct dentry *dentry) @@ -382,6 +389,11 @@ void ovl_set_flag(unsigned long flag, struct inode *inode) set_bit(flag, &OVL_I(inode)->flags); } +void ovl_clear_flag(unsigned long flag, struct inode *inode) +{ + clear_bit(flag, &OVL_I(inode)->flags); +} + bool ovl_test_flag(unsigned long flag, struct inode *inode) { return test_bit(flag, &OVL_I(inode)->flags); diff --git a/fs/xattr.c b/fs/xattr.c index 7b03df6b8be2..4424f7fecf14 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -23,6 +23,7 @@ #include <linux/posix_acl_xattr.h> #include <linux/uaccess.h> +#include "internal.h" static const char * strcmp_prefix(const char *a, const char *a_prefix) @@ -502,10 +503,10 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, if (!f.file) return error; audit_file(f.file); - error = mnt_want_write_file(f.file); + error = mnt_want_write_file_path(f.file); if (!error) { error = setxattr(f.file->f_path.dentry, name, value, size, flags); - mnt_drop_write_file(f.file); + mnt_drop_write_file_path(f.file); } fdput(f); return error; @@ -734,10 +735,10 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) if (!f.file) return error; audit_file(f.file); - error = mnt_want_write_file(f.file); + error = mnt_want_write_file_path(f.file); if (!error) { error = removexattr(f.file->f_path.dentry, name); - mnt_drop_write_file(f.file); + mnt_drop_write_file_path(f.file); } fdput(f); return error; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index aae1cdb76851..ed1a7cf6923a 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -147,7 +147,7 @@ struct dentry_operations { struct vfsmount *(*d_automount)(struct path *); int (*d_manage)(const struct path *, bool); struct dentry *(*d_real)(struct dentry *, const struct inode *, - unsigned int); + unsigned int, unsigned int); } ____cacheline_aligned; /* @@ -562,11 +562,15 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper) return upper; } +/* d_real() flags */ +#define D_REAL_UPPER 0x2 /* return upper dentry or NULL if non-upper */ + /** * d_real - Return the real dentry * @dentry: the dentry to query * @inode: inode to select the dentry from multiple layers (can be NULL) - * @flags: open flags to control copy-up behavior + * @open_flags: open flags to control copy-up behavior + * @flags: flags to control what is returned by this function * * If dentry is on a union/overlay, then return the underlying, real dentry. * Otherwise return the dentry itself. @@ -575,10 +579,10 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper) */ static inline struct dentry *d_real(struct dentry *dentry, const struct inode *inode, - unsigned int flags) + unsigned int open_flags, unsigned int flags) { if (unlikely(dentry->d_flags & DCACHE_OP_REAL)) - return dentry->d_op->d_real(dentry, inode, flags); + return dentry->d_op->d_real(dentry, inode, open_flags, flags); else return dentry; } @@ -593,7 +597,7 @@ static inline struct dentry *d_real(struct dentry *dentry, static inline struct inode *d_real_inode(const struct dentry *dentry) { /* This usage of d_real() results in const dentry */ - return d_backing_inode(d_real((struct dentry *) dentry, NULL, 0)); + return d_backing_inode(d_real((struct dentry *) dentry, NULL, 0, 0)); } struct name_snapshot { diff --git a/include/linux/fs.h b/include/linux/fs.h index 2d0e6748e46e..33d8e45cd874 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1235,7 +1235,7 @@ static inline struct inode *file_inode(const struct file *f) static inline struct dentry *file_dentry(const struct file *file) { - return d_real(file->f_path.dentry, file_inode(file), 0); + return d_real(file->f_path.dentry, file_inode(file), 0, 0); } static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl) |