From: Amir Goldstein <amir73il@gmail.com>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: Colin Ian King <colin.king@canonical.com>, linux-unionfs@vger.kernel.org
Subject: [PATCH 2/6] ovl: generalize the lower_layers[] array
Date: Sun, 17 Nov 2019 17:43:45 +0200 [thread overview]
Message-ID: <20191117154349.28695-3-amir73il@gmail.com> (raw)
In-Reply-To: <20191117154349.28695-1-amir73il@gmail.com>
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 <amir73il@gmail.com>
---
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
next prev parent reply other threads:[~2019-11-17 15:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-17 15:43 [PATCH 0/6] Sort out overlay layers and fs arrays Amir Goldstein
2019-11-17 15:43 ` [PATCH 1/6] ovl: fix corner case of non-unique st_dev;st_ino Amir Goldstein
2019-11-17 15:43 ` Amir Goldstein [this message]
2019-11-17 15:43 ` [PATCH 3/6] ovl: simplify ovl_same_sb() helper Amir Goldstein
2019-11-17 15:43 ` [PATCH 4/6] ovl: generalize the lower_fs[] array Amir Goldstein
2019-11-18 17:01 ` Amir Goldstein
2019-11-17 15:43 ` [PATCH 5/6] ovl: fix corner case of conflicting lower layer uuid Amir Goldstein
2019-11-17 15:43 ` [PATCH 6/6] ovl: fix corner case of non-constant st_dev;st_ino Amir Goldstein
2019-11-18 6:03 ` [PATCH 0/6] Sort out overlay layers and fs arrays Amir Goldstein
2019-11-18 7:57 ` Amir Goldstein
2019-11-22 9:31 ` Amir Goldstein
2019-11-25 14:45 ` Amir Goldstein
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191117154349.28695-3-amir73il@gmail.com \
--to=amir73il@gmail.com \
--cc=colin.king@canonical.com \
--cc=linux-unionfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.