From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Amir Goldstein Subject: [PATCH 2/6] ovl: generalize the lower_layers[] array Date: Sun, 17 Nov 2019 17:43:45 +0200 Message-Id: <20191117154349.28695-3-amir73il@gmail.com> In-Reply-To: <20191117154349.28695-1-amir73il@gmail.com> References: <20191117154349.28695-1-amir73il@gmail.com> To: Miklos Szeredi Cc: Colin Ian King , linux-unionfs@vger.kernel.org List-ID: Rename lower_layers[] array to layers[], extend its size by one and initialize layers[0] with upper layer values. Lower layers are now addressed with index 1..numlower. layers[0] is reserved even with lower only overlay. This gets rid of special casing upper layer in ovl_iterate_real(). Signed-off-by: Amir Goldstein --- fs/overlayfs/export.c | 6 ++---- fs/overlayfs/inode.c | 4 ++-- fs/overlayfs/namei.c | 10 +++++----- fs/overlayfs/overlayfs.h | 2 +- fs/overlayfs/ovl_entry.h | 2 +- fs/overlayfs/readdir.c | 7 +++---- fs/overlayfs/super.c | 43 ++++++++++++++++++++++------------------ fs/overlayfs/util.c | 6 ++++-- 8 files changed, 42 insertions(+), 38 deletions(-) diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c index 70e55588aedc..9128cbb3b198 100644 --- a/fs/overlayfs/export.c +++ b/fs/overlayfs/export.c @@ -424,7 +424,6 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb, struct ovl_layer *layer) { struct ovl_fs *ofs = sb->s_fs_info; - struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt }; struct dentry *index = NULL; struct dentry *this = NULL; struct inode *inode; @@ -466,7 +465,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb, * recursive call walks back from indexed upper to the topmost * connected/hashed upper parent (or up to root). */ - this = ovl_lookup_real(sb, upper, &upper_layer); + this = ovl_lookup_real(sb, upper, &ofs->layers[0]); dput(upper); } @@ -646,8 +645,7 @@ static struct dentry *ovl_get_dentry(struct super_block *sb, struct dentry *index) { struct ovl_fs *ofs = sb->s_fs_info; - struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt }; - struct ovl_layer *layer = upper ? &upper_layer : lowerpath->layer; + struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer; struct dentry *real = upper ?: (index ?: lowerpath->dentry); /* diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index b045cf1826fc..dab39933bbd4 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -170,7 +170,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, */ if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) { if (!OVL_TYPE_UPPER(type)) { - lower_layer = ovl_layer_lower(dentry); + lower_layer = ovl_dentry_layer(dentry); } else if (OVL_TYPE_ORIGIN(type)) { struct kstat lowerstat; u32 lowermask = STATX_INO | STATX_BLOCKS | @@ -200,7 +200,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) || (!ovl_verify_lower(dentry->d_sb) && (is_dir || lowerstat.nlink == 1))) { - lower_layer = ovl_layer_lower(dentry); + lower_layer = ovl_dentry_layer(dentry); /* * Cannot use origin st_dev;st_ino because * origin inode content may differ from overlay diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 80fbca5219d4..f16bf608eed7 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -324,16 +324,16 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, struct dentry *origin = NULL; int i; - for (i = 0; i < ofs->numlower; i++) { + for (i = 1; i <= ofs->numlower; i++) { /* * If lower fs uuid is not unique among lower fs we cannot match * fh->uuid to layer. */ - if (ofs->lower_layers[i].fsid && - ofs->lower_layers[i].fs->bad_uuid) + if (ofs->layers[i].fsid && + ofs->layers[i].fs->bad_uuid) continue; - origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt, + origin = ovl_decode_real_fh(fh, ofs->layers[i].mnt, connected); if (origin) break; @@ -356,7 +356,7 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, } **stackp = (struct ovl_path){ .dentry = origin, - .layer = &ofs->lower_layers[i] + .layer = &ofs->layers[i] }; return 0; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index f283b1d69a9e..50d41a314308 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -237,7 +237,7 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); -struct ovl_layer *ovl_layer_lower(struct dentry *dentry); +struct ovl_layer *ovl_dentry_layer(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); struct dentry *ovl_i_dentry_upper(struct inode *inode); struct inode *ovl_inode_upper(struct inode *inode); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 28348c44ea5b..ffaf7376f4ab 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -48,7 +48,7 @@ struct ovl_fs { unsigned int numlower; /* Number of unique lower sb that differ from upper sb */ unsigned int numlowerfs; - struct ovl_layer *lower_layers; + struct ovl_layer *layers; struct ovl_sb *lower_fs; /* workbasedir is the path at workdir= mount option */ struct dentry *workbasedir; diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 47a91c9733a5..32a7f8a38091 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -508,7 +508,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) ino = stat.ino; } else if (xinobits && !OVL_TYPE_UPPER(type)) { ino = ovl_remap_lower_ino(ino, xinobits, - ovl_layer_lower(this)->fsid, + ovl_dentry_layer(this)->fsid, p->name, p->len); } @@ -685,15 +685,14 @@ 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_layer *lower_layer = ovl_layer_lower(dir); struct ovl_readdir_translate rdt = { .ctx.actor = ovl_fill_real, .orig_ctx = ctx, .xinobits = ovl_xino_bits(dir->d_sb), }; - if (rdt.xinobits && lower_layer) - rdt.fsid = lower_layer->fsid; + if (rdt.xinobits) + rdt.fsid = ovl_dentry_layer(dir)->fsid; if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) { struct kstat stat; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index cfb236e37fd9..4ff6eede5f90 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -224,13 +224,13 @@ static void ovl_free_fs(struct ovl_fs *ofs) if (ofs->upperdir_locked) ovl_inuse_unlock(ofs->upper_mnt->mnt_root); mntput(ofs->upper_mnt); - for (i = 0; i < ofs->numlower; i++) { - iput(ofs->lower_layers[i].trap); - mntput(ofs->lower_layers[i].mnt); + for (i = 1; i <= ofs->numlower; i++) { + iput(ofs->layers[i].trap); + mntput(ofs->layers[i].mnt); } for (i = 0; i < ofs->numlowerfs; i++) free_anon_bdev(ofs->lower_fs[i].pseudo_dev); - kfree(ofs->lower_layers); + kfree(ofs->layers); kfree(ofs->lower_fs); kfree(ofs->config.lowerdir); @@ -1318,16 +1318,16 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path) return ofs->numlowerfs; } -static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, - struct path *stack, unsigned int numlower) +static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs, + struct path *stack, unsigned int numlower) { int err; unsigned int i; err = -ENOMEM; - ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer), - GFP_KERNEL); - if (ofs->lower_layers == NULL) + ofs->layers = kcalloc(numlower + 1, sizeof(struct ovl_layer), + GFP_KERNEL); + if (ofs->layers == NULL) goto out; ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb), @@ -1335,6 +1335,11 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, if (ofs->lower_fs == NULL) goto out; + /* idx 0 is reserved for upper fs even with lower only overlay */ + ofs->layers[0].mnt = ofs->upper_mnt; + ofs->layers[0].idx = 0; + ofs->layers[0].fsid = 0; + for (i = 0; i < numlower; i++) { struct vfsmount *mnt; struct inode *trap; @@ -1368,15 +1373,15 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, */ mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; - ofs->lower_layers[ofs->numlower].trap = trap; - ofs->lower_layers[ofs->numlower].mnt = mnt; - ofs->lower_layers[ofs->numlower].idx = i + 1; - ofs->lower_layers[ofs->numlower].fsid = fsid; + ofs->numlower++; + ofs->layers[ofs->numlower].trap = trap; + ofs->layers[ofs->numlower].mnt = mnt; + ofs->layers[ofs->numlower].idx = ofs->numlower; + ofs->layers[ofs->numlower].fsid = fsid; if (fsid) { - ofs->lower_layers[ofs->numlower].fs = + ofs->layers[ofs->numlower].fs = &ofs->lower_fs[fsid - 1]; } - ofs->numlower++; } /* @@ -1463,7 +1468,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, goto out_err; } - err = ovl_get_lower_layers(sb, ofs, stack, numlower); + err = ovl_get_layers(sb, ofs, stack, numlower); if (err) goto out_err; @@ -1474,7 +1479,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, for (i = 0; i < numlower; i++) { oe->lowerstack[i].dentry = dget(stack[i].dentry); - oe->lowerstack[i].layer = &ofs->lower_layers[i]; + oe->lowerstack[i].layer = &ofs->layers[i+1]; } if (remote) @@ -1555,9 +1560,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb, return err; } - for (i = 0; i < ofs->numlower; i++) { + for (i = 1; i <= ofs->numlower; i++) { err = ovl_check_layer(sb, ofs, - ofs->lower_layers[i].mnt->mnt_root, + ofs->layers[i].mnt->mnt_root, "lowerdir"); if (err) return err; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f5678a3f8350..3fa1ca8ddd48 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -198,11 +198,13 @@ struct dentry *ovl_dentry_lower(struct dentry *dentry) return oe->numlower ? oe->lowerstack[0].dentry : NULL; } -struct ovl_layer *ovl_layer_lower(struct dentry *dentry) +/* Either top most lower layer or upper layer for pure upper */ +struct ovl_layer *ovl_dentry_layer(struct dentry *dentry) { + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; struct ovl_entry *oe = dentry->d_fsdata; - return oe->numlower ? oe->lowerstack[0].layer : NULL; + return oe->numlower ? oe->lowerstack[0].layer : &ofs->layers[0]; } /* -- 2.17.1