diff options
Diffstat (limited to 'fs/overlayfs/util.c')
| -rw-r--r-- | fs/overlayfs/util.c | 149 |
1 files changed, 119 insertions, 30 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 117794582f9f..930784a26623 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -17,7 +17,6 @@ #include <linux/namei.h> #include <linux/ratelimit.h> #include "overlayfs.h" -#include "ovl_entry.h" int ovl_want_write(struct dentry *dentry) { @@ -64,6 +63,22 @@ struct dentry *ovl_indexdir(struct super_block *sb) return ofs->indexdir; } +/* Index all files on copy up. For now only enabled for NFS export */ +bool ovl_index_all(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + return ofs->config.nfs_export && ofs->config.index; +} + +/* Verify lower origin on lookup. For now only enabled for NFS export */ +bool ovl_verify_lower(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + return ofs->config.nfs_export && ofs->config.index; +} + struct ovl_entry *ovl_alloc_entry(unsigned int numlower) { size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); @@ -125,7 +140,12 @@ void ovl_path_lower(struct dentry *dentry, struct path *path) { struct ovl_entry *oe = dentry->d_fsdata; - *path = oe->numlower ? oe->lowerstack[0] : (struct path) { }; + if (oe->numlower) { + path->mnt = oe->lowerstack[0].layer->mnt; + path->dentry = oe->lowerstack[0].dentry; + } else { + *path = (struct path) { }; + } } enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) @@ -190,10 +210,24 @@ void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) OVL_I(inode)->cache = cache; } +void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry) +{ + set_bit(flag, &OVL_E(dentry)->flags); +} + +void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry) +{ + clear_bit(flag, &OVL_E(dentry)->flags); +} + +bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry) +{ + return test_bit(flag, &OVL_E(dentry)->flags); +} + bool ovl_dentry_is_opaque(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - return oe->opaque; + return ovl_dentry_test_flag(OVL_E_OPAQUE, dentry); } bool ovl_dentry_is_whiteout(struct dentry *dentry) @@ -203,28 +237,23 @@ bool ovl_dentry_is_whiteout(struct dentry *dentry) void ovl_dentry_set_opaque(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - - oe->opaque = true; + ovl_dentry_set_flag(OVL_E_OPAQUE, dentry); } /* - * For hard links it's possible for ovl_dentry_upper() to return positive, while - * there's no actual upper alias for the inode. Copy up code needs to know - * about the existence of the upper alias, so it can't use ovl_dentry_upper(). + * For hard links and decoded file handles, it's possible for ovl_dentry_upper() + * to return positive, while there's no actual upper alias for the inode. + * Copy up code needs to know about the existence of the upper alias, so it + * can't use ovl_dentry_upper(). */ bool ovl_dentry_has_upper_alias(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - - return oe->has_upper; + return ovl_dentry_test_flag(OVL_E_UPPER_ALIAS, dentry); } void ovl_dentry_set_upper_alias(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - - oe->has_upper = true; + ovl_dentry_set_flag(OVL_E_UPPER_ALIAS, dentry); } bool ovl_redirect_dir(struct super_block *sb) @@ -253,7 +282,7 @@ void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, if (upperdentry) OVL_I(inode)->__upperdentry = upperdentry; if (lowerdentry) - OVL_I(inode)->lower = d_inode(lowerdentry); + OVL_I(inode)->lower = igrab(d_inode(lowerdentry)); ovl_copyattr(d_inode(upperdentry ?: lowerdentry), inode); } @@ -269,7 +298,7 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) */ smp_wmb(); OVL_I(inode)->__upperdentry = upperdentry; - if (!S_ISDIR(upperinode->i_mode) && inode_unhashed(inode)) { + if (inode_unhashed(inode)) { inode->i_private = upperinode; __insert_inode_hash(inode, (unsigned long) upperinode); } @@ -329,6 +358,19 @@ void ovl_copy_up_end(struct dentry *dentry) mutex_unlock(&OVL_I(d_inode(dentry))->lock); } +bool ovl_check_origin_xattr(struct dentry *dentry) +{ + int res; + + res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0); + + /* Zero size value means "copied up but origin unknown" */ + if (res >= 0) + return true; + + return false; +} + bool ovl_check_dir_xattr(struct dentry *dentry, const char *name) { int res; @@ -430,10 +472,32 @@ void ovl_inuse_unlock(struct dentry *dentry) } } -/* Called must hold OVL_I(inode)->oi_lock */ +/* + * Does this overlay dentry need to be indexed on copy up? + */ +bool ovl_need_index(struct dentry *dentry) +{ + struct dentry *lower = ovl_dentry_lower(dentry); + + if (!lower || !ovl_indexdir(dentry->d_sb)) + return false; + + /* Index all files for NFS export and consistency verification */ + if (ovl_index_all(dentry->d_sb)) + return true; + + /* Index only lower hardlinks on copy up */ + if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1) + return true; + + return false; +} + +/* Caller must hold OVL_I(inode)->lock */ static void ovl_cleanup_index(struct dentry *dentry) { - struct inode *dir = ovl_indexdir(dentry->d_sb)->d_inode; + struct dentry *indexdir = ovl_indexdir(dentry->d_sb); + struct inode *dir = indexdir->d_inode; struct dentry *lowerdentry = ovl_dentry_lower(dentry); struct dentry *upperdentry = ovl_dentry_upper(dentry); struct dentry *index = NULL; @@ -446,7 +510,7 @@ static void ovl_cleanup_index(struct dentry *dentry) goto fail; inode = d_inode(upperdentry); - if (inode->i_nlink != 1) { + if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) { pr_warn_ratelimited("overlayfs: cleanup linked index (%pd2, ino=%lu, nlink=%u)\n", upperdentry, inode->i_ino, inode->i_nlink); /* @@ -464,11 +528,18 @@ static void ovl_cleanup_index(struct dentry *dentry) } inode_lock_nested(dir, I_MUTEX_PARENT); - /* TODO: whiteout instead of cleanup to block future open by handle */ - index = lookup_one_len(name.name, ovl_indexdir(dentry->d_sb), name.len); + index = lookup_one_len(name.name, indexdir, name.len); err = PTR_ERR(index); - if (!IS_ERR(index)) + if (IS_ERR(index)) { + index = NULL; + } else if (ovl_index_all(dentry->d_sb)) { + /* Whiteout orphan index to block future open by handle */ + err = ovl_cleanup_and_whiteout(indexdir, dir, index); + } else { + /* Cleanup orphan index entries */ err = ovl_cleanup(dir, index); + } + inode_unlock(dir); if (err) goto fail; @@ -492,16 +563,16 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked) const struct cred *old_cred; int err; - if (!d_inode(dentry) || d_is_dir(dentry)) + if (!d_inode(dentry)) return 0; /* * With inodes index is enabled, we store the union overlay nlink - * in an xattr on the index inode. When whiting out lower hardlinks + * in an xattr on the index inode. When whiting out an indexed lower, * we need to decrement the overlay persistent nlink, but before the * first copy up, we have no upper index inode to store the xattr. * - * As a workaround, before whiteout/rename over of a lower hardlink, + * As a workaround, before whiteout/rename over an indexed lower, * copy up to create the upper index. Creating the upper index will * initialize the overlay nlink, so it could be dropped if unlink * or rename succeeds. @@ -509,8 +580,7 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked) * TODO: implement metadata only index copy up when called with * ovl_copy_up_flags(dentry, O_PATH). */ - if (ovl_indexdir(dentry->d_sb) && !ovl_dentry_has_upper_alias(dentry) && - d_inode(ovl_dentry_lower(dentry))->i_nlink > 1) { + if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) { err = ovl_copy_up(dentry); if (err) return err; @@ -520,7 +590,7 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked) if (err) return err; - if (!ovl_test_flag(OVL_INDEX, d_inode(dentry))) + if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, d_inode(dentry))) goto out; old_cred = ovl_override_creds(dentry->d_sb); @@ -557,3 +627,22 @@ void ovl_nlink_end(struct dentry *dentry, bool locked) mutex_unlock(&OVL_I(d_inode(dentry))->lock); } } + +int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir) +{ + /* Workdir should not be the same as upperdir */ + if (workdir == upperdir) + goto err; + + /* Workdir should not be subdir of upperdir and vice versa */ + if (lock_rename(workdir, upperdir) != NULL) + goto err_unlock; + + return 0; + +err_unlock: + unlock_rename(workdir, upperdir); +err: + pr_err("overlayfs: failed to lock workdir+upperdir\n"); + return -EIO; +} |