An upper dir is marked "impure" to let ovl_iterate() know that this directory may contain non pure upper entries whose d_ino may need to be read from the origin inode. We already mark a non-merge dir "impure" when moving a non-pure child entry inside it, to let ovl_iterate() know not to iterate the non-merge dir directly. Mark also a merge dir "impure" when moving a non-pure child entry inside it and when copying up a child entry inside it. This can be used to optimize ovl_iterate() to perform a "pure merge" of upper and lower directories, merging the content of the directories, without having to read d_ino from origin inodes. Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> --- fs/overlayfs/copy_up.c | 7 +++++++ fs/overlayfs/dir.c | 31 ++++++------------------------- fs/overlayfs/namei.c | 20 -------------------- fs/overlayfs/overlayfs.h | 14 +++++++++++--- fs/overlayfs/super.c | 5 ++++- fs/overlayfs/util.c | 32 ++++++++++++++++++++++++++++++++ 6 files changed, 60 insertions(+), 49 deletions(-) Miklos, w.r.t. the clause in constant d_ino commit message: "There is an overhead of lookup per upper entry in readdir. That overhead is a waste for a merge dir with only pure upper entries (i.e. no copy ups), but that can be optimized later." Please consider this patch for v4.12 on top of the one already in overlayfs-next. Not sure how common the use case of "pure merge" is, but the optimization of not doing the origin lookup in ovl_interate() is trivial, so better have the merge dir marked "impure" now when introducing overlay.origin. Amir. v2: - Check on mount if upper dir is impure - Test the optimization with constant d_ino patch [1] [1] https://github.com/amir73il/linux/commit/e40e7e0fd22cf873e79919bed5145402d2fd46ca#diff-853a764a671403777b1350d492f54b78R415 diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 843ed2a..1ae1790 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -459,6 +459,13 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, ovl_path_upper(parent, &parentpath); upperdir = parentpath.dentry; + /* Mark parent "impure" because it may now contain non-pure upper */ + if (!ovl_dentry_is_impure(parent)) { + err = ovl_set_impure(parent, upperdir); + if (err) + return err; + } + err = vfs_getattr(&parentpath, &pstat, STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT); if (err) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index f2a118b..c9efc54 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -149,22 +149,6 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) return ovl_set_opaque_xerr(dentry, upperdentry, -EIO); } -static int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) -{ - int err; - - /* - * Do not fail when upper doesn't support xattrs. - * Upper inodes won't have origin nor redirect xattr anyway. - */ - err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE, - "y", 1, 0); - if (!err) - ovl_dentry_set_impure(dentry); - - return err; -} - /* Common operations required to be done after creation of file on upper */ static void ovl_instantiate(struct dentry *dentry, struct inode *inode, struct dentry *newdentry, bool hardlink) @@ -976,21 +960,18 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, if (!samedir) { /* * When moving a merge dir or non-dir with copy up origin into - * a non-merge upper dir (a.k.a pure upper dir), we are making - * the target parent dir "impure". ovl_iterate() iterates pure - * upper dirs directly, because there is no need to filter out - * whiteouts and merge dir content with lower dir. But for the - * case of an "impure" upper dir, ovl_iterate() cannot iterate - * the real directory directly, because it looks for the inode - * numbers to fill d_ino in the entries origin inode. + * a new parent, we are marking the new parent dir "impure". + * When ovl_iterate() iterates an "impure" upper dir, it will + * lookup the origin inodes of the entries to fill d_ino. */ - if (ovl_type_origin(old) && !ovl_type_merge(new->d_parent)) { + if (ovl_type_origin(old) && + !ovl_dentry_is_impure(new->d_parent)) { err = ovl_set_impure(new->d_parent, new_upperdir); if (err) goto out_revert_creds; } if (!overwrite && ovl_type_origin(new) && - !ovl_type_merge(old->d_parent)) { + !ovl_dentry_is_impure(old->d_parent)) { err = ovl_set_impure(old->d_parent, old_upperdir); if (err) goto out_revert_creds; diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 0c72a59..f3136c3 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -167,31 +167,11 @@ static struct dentry *ovl_get_origin(struct dentry *dentry, goto out; } -static bool ovl_check_dir_xattr(struct dentry *dentry, const char *name) -{ - int res; - char val; - - if (!d_is_dir(dentry)) - return false; - - res = vfs_getxattr(dentry, name, &val, 1); - if (res == 1 && val == 'y') - return true; - - return false; -} - static bool ovl_is_opaquedir(struct dentry *dentry) { return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE); } -static bool ovl_is_impuredir(struct dentry *dentry) -{ - return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE); -} - static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, const char *name, unsigned int namelen, size_t prelen, const char *post, diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index a9fb958..a2ca3d615 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -221,6 +221,17 @@ 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); +bool ovl_check_dir_xattr(struct dentry *dentry, const char *name); +int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, + const char *name, const void *value, size_t size, + int xerr); +int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); + +static inline bool ovl_is_impuredir(struct dentry *dentry) +{ + return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE); +} + /* namei.c */ int ovl_path_next(int idx, struct dentry *dentry, struct path *path); @@ -281,6 +292,3 @@ int ovl_copy_up(struct dentry *dentry); int ovl_copy_up_flags(struct dentry *dentry, int flags); int ovl_copy_xattr(struct dentry *old, struct dentry *new); int ovl_set_attr(struct dentry *upper, struct kstat *stat); -int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, - const char *name, const void *value, size_t size, - int xerr); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index f164762..4882ffb 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -974,7 +974,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) path_put(&workpath); kfree(lowertmp); - oe->__upperdentry = upperpath.dentry; + if (upperpath.dentry) { + oe->__upperdentry = upperpath.dentry; + oe->impure = ovl_is_impuredir(upperpath.dentry); + } for (i = 0; i < numlower; i++) { oe->lowerstack[i].dentry = stack[i].dentry; oe->lowerstack[i].mnt = ufs->lower_mnt[i]; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index e0dfb07..dcaa7b4 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -311,6 +311,22 @@ void ovl_copy_up_end(struct dentry *dentry) spin_unlock(&ofs->copyup_wq.lock); } +bool ovl_check_dir_xattr(struct dentry *dentry, const char *name) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + int res; + char val; + + if (ofs->noxattr || !d_is_dir(dentry)) + return false; + + res = vfs_getxattr(dentry, name, &val, 1); + if (res == 1 && val == 'y') + return true; + + return false; +} + int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, const char *name, const void *value, size_t size, int xerr) @@ -331,3 +347,19 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, return err; } + +int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) +{ + int err; + + /* + * Do not fail when upper doesn't support xattrs. + * Upper inodes won't have origin nor redirect xattr anyway. + */ + err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE, + "y", 1, 0); + if (!err) + ovl_dentry_set_impure(dentry); + + return err; +} -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
