From 0f831ec85eda1ae27490baba106aba632c1d8e94 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Sat, 16 Nov 2019 18:14:41 +0200 Subject: ovl: simplify ovl_same_sb() helper No code uses the sb returned from this helper, so make it retrun a boolean and rename it to ovl_same_fs(). The xino mode is irrelevant when all layers are on same fs, so instead of describing samefs with mode OVL_XINO_OFF, use a new xino_mode state, which is 0 in the case of samefs, -1 in the case of xino=off and > 0 with xino enabled. Create a new helper ovl_same_dev(), to use instead of the common check for (ovl_same_fs() || xinobits). Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/inode.c | 8 ++++---- fs/overlayfs/overlayfs.h | 17 +++++++++++++---- fs/overlayfs/ovl_entry.h | 9 +++++++-- fs/overlayfs/readdir.c | 4 ++-- fs/overlayfs/super.c | 21 +++++++++++---------- fs/overlayfs/util.c | 12 ------------ 6 files changed, 37 insertions(+), 34 deletions(-) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 13981b0a8235..cf51fa1e45a8 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -78,7 +78,7 @@ out: static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, struct ovl_layer *lower_layer) { - bool samefs = ovl_same_sb(dentry->d_sb); + bool samefs = ovl_same_fs(dentry->d_sb); unsigned int xinobits = ovl_xino_bits(dentry->d_sb); if (samefs) { @@ -146,7 +146,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, struct path realpath; const struct cred *old_cred; bool is_dir = S_ISDIR(dentry->d_inode->i_mode); - bool samefs = ovl_same_sb(dentry->d_sb); + bool samefs = ovl_same_fs(dentry->d_sb); struct ovl_layer *lower_layer = NULL; int err; bool metacopy_blocks = false; @@ -168,7 +168,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, * If lower filesystem supports NFS file handles, this also guaranties * persistent st_ino across mount cycle. */ - if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) { + if (!is_dir || ovl_same_dev(dentry->d_sb)) { if (!OVL_TYPE_UPPER(type)) { lower_layer = ovl_layer_lower(dentry); } else if (OVL_TYPE_ORIGIN(type)) { @@ -586,7 +586,7 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev, * ovl_new_inode(), ino arg is 0, so i_ino will be updated to real * upper inode i_ino on ovl_inode_init() or ovl_inode_update(). */ - if (ovl_same_sb(inode->i_sb) || xinobits) { + if (ovl_same_dev(inode->i_sb)) { inode->i_ino = ino; if (xinobits && fsid && !(ino >> (64 - xinobits))) inode->i_ino |= (unsigned long)fsid << (64 - xinobits); diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index fea79f7680c8..e4ae3a459145 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -224,7 +224,6 @@ int ovl_want_write(struct dentry *dentry); void ovl_drop_write(struct dentry *dentry); struct dentry *ovl_workdir(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); -struct super_block *ovl_same_sb(struct super_block *sb); int ovl_can_decode_fh(struct super_block *sb); struct dentry *ovl_indexdir(struct super_block *sb); bool ovl_index_all(struct super_block *sb); @@ -302,11 +301,21 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE); } -static inline unsigned int ovl_xino_bits(struct super_block *sb) +/* All layers on same fs? */ +static inline bool ovl_same_fs(struct super_block *sb) { - struct ovl_fs *ofs = sb->s_fs_info; + return OVL_FS(sb)->xino_mode == 0; +} - return ofs->xino_bits; +/* All overlay inodes have same st_dev? */ +static inline bool ovl_same_dev(struct super_block *sb) +{ + return OVL_FS(sb)->xino_mode >= 0; +} + +static inline unsigned int ovl_xino_bits(struct super_block *sb) +{ + return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0; } static inline int ovl_inode_lock(struct inode *inode) diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 64baf04cdede..9a785702a2a4 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -71,10 +71,15 @@ struct ovl_fs { struct inode *workbasedir_trap; struct inode *workdir_trap; struct inode *indexdir_trap; - /* Inode numbers in all layers do not use the high xino_bits */ - unsigned int xino_bits; + /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */ + int xino_mode; }; +static inline struct ovl_fs *OVL_FS(struct super_block *sb) +{ + return (struct ovl_fs *)sb->s_fs_info; +} + /* private information held for every overlayfs dentry */ struct ovl_entry { union { diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index a9816f25a1bb..c8e478fa96a5 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -469,7 +469,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) int xinobits = ovl_xino_bits(dir->d_sb); int err = 0; - if (!ovl_same_sb(dir->d_sb) && !xinobits) + if (!ovl_same_dev(dir->d_sb)) goto out; if (p->name[0] == '.') { @@ -744,7 +744,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) * entries. */ if (ovl_xino_bits(dentry->d_sb) || - (ovl_same_sb(dentry->d_sb) && + (ovl_same_fs(dentry->d_sb) && (ovl_is_impure_dir(file) || OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) { return ovl_iterate_real(file, ctx); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 374a07633dca..8f08313eb897 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -358,7 +358,7 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) if (ofs->config.nfs_export != ovl_nfs_export_def) seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ? "on" : "off"); - if (ofs->config.xino != ovl_xino_def()) + if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(sb)) seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]); if (ofs->config.metacopy != ovl_metacopy_def) seq_printf(m, ",metacopy=%s", @@ -811,7 +811,7 @@ static int ovl_lower_dir(const char *name, struct path *path, /* Check if lower fs has 32bit inode numbers */ if (fh_type != FILEID_INO32_GEN) - ofs->xino_bits = 0; + ofs->xino_mode = -1; return 0; @@ -1142,7 +1142,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, /* Check if upper fs has 32bit inode numbers */ if (fh_type != FILEID_INO32_GEN) - ofs->xino_bits = 0; + ofs->xino_mode = -1; /* NFS export of r/w mount depends on index */ if (ofs->config.nfs_export && !ofs->config.index) { @@ -1395,21 +1395,22 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs, * inode number. */ if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) { - ofs->xino_bits = 0; - ofs->config.xino = OVL_XINO_OFF; - } else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) { + if (ofs->config.xino == OVL_XINO_ON) + pr_info("\"xino=on\" is useless with all layers on same fs, ignore.\n"); + ofs->xino_mode = 0; + } else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) { /* * This is a roundup of number of bits needed for numlowerfs+1 * (i.e. ilog2(numlowerfs+1 - 1) + 1). fsid 0 is reserved for * upper fs even with non upper overlay. */ BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31); - ofs->xino_bits = ilog2(ofs->numlowerfs) + 1; + ofs->xino_mode = ilog2(ofs->numlowerfs) + 1; } - if (ofs->xino_bits) { + if (ofs->xino_mode > 0) { pr_info("\"xino\" feature enabled using %d upper inode bits.\n", - ofs->xino_bits); + ofs->xino_mode); } err = 0; @@ -1610,7 +1611,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) sb->s_maxbytes = MAX_LFS_FILESIZE; /* Assume underlaying fs uses 32bit inodes unless proven otherwise */ if (ofs->config.xino != OVL_XINO_OFF) - ofs->xino_bits = BITS_PER_LONG - 32; + ofs->xino_mode = BITS_PER_LONG - 32; /* alloc/destroy_inode needed for setting up traps in inode cache */ sb->s_op = &ovl_super_operations; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index cb4a5eaf0ba5..df503a8c6bcf 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -40,18 +40,6 @@ const struct cred *ovl_override_creds(struct super_block *sb) return override_creds(ofs->creator_cred); } -struct super_block *ovl_same_sb(struct super_block *sb) -{ - struct ovl_fs *ofs = sb->s_fs_info; - - if (!ofs->numlowerfs) - return ofs->upper_mnt->mnt_sb; - else if (ofs->numlowerfs == 1 && !ofs->upper_mnt) - return ofs->lower_fs[0].sb; - else - return NULL; -} - /* * Check if underlying fs supports file handles and try to determine encoding * type, in order to deduce maximum inode number used by fs. -- cgit v1.2.3