luck/tmp_suning_uos_patched
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ovl: generalize the lower_layers[] array

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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.

[SzM: replace ofs->numlower with ofs->numlayer, the latter's value is
incremented by one]

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Amir Goldstein 2019-11-15 14:12:40 +02:00 committed by Miklos Szeredi
parent b504c6540d
commit 94375f9d51
4 changed files with 35 additions and 31 deletions
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6
fs/overlayfs/export.c
View File

@ -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);
/*

12
fs/overlayfs/namei.c
View File

@ -322,16 +322,16 @@ 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->numlayer; 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;
@ -354,7 +354,7 @@ 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;
@ -885,7 +885,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (!d.stop && poe->numlower) {
err = -ENOMEM;
stack = kcalloc(ofs->numlower, sizeof(struct ovl_path),
stack = kcalloc(ofs->numlayer - 1, sizeof(struct ovl_path),
GFP_KERNEL);
if (!stack)
goto out_put_upper;

4
fs/overlayfs/ovl_entry.h
View File

@ -45,10 +45,10 @@ struct ovl_path {
/* private information held for overlayfs's superblock */
struct ovl_fs {
struct vfsmount *upper_mnt;
unsigned int numlower;
unsigned int numlayer;
/* 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;

44
fs/overlayfs/super.c
View File

@ -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->numlayer; 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);
@ -1319,16 +1319,16 @@ 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),
@ -1336,6 +1336,12 @@ 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;
ofs->numlayer = 1;
for (i = 0; i < numlower; i++) {
struct vfsmount *mnt;
struct inode *trap;
@ -1369,15 +1375,15 @@ 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->layers[ofs->numlayer].trap = trap;
ofs->layers[ofs->numlayer].mnt = mnt;
ofs->layers[ofs->numlayer].idx = ofs->numlayer;
ofs->layers[ofs->numlayer].fsid = fsid;
if (fsid) {
ofs->lower_layers[ofs->numlower].fs =
ofs->layers[ofs->numlayer].fs =
&ofs->lower_fs[fsid - 1];
}
ofs->numlower++;
ofs->numlayer++;
}
/*
@ -1464,7 +1470,7 @@ 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;
@ -1475,7 +1481,7 @@ 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)
@ -1556,9 +1562,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
return err;
}
for (i = 0; i < ofs->numlower; i++) {
for (i = 1; i < ofs->numlayer; 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;