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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-05 13:05:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-05 13:05:20 -0800
commit139351f1f98546c312a1942215977ea703b383b8 (patch)
tree1b1d35d469f2461a2bd88950e5a7996a26aa6e9f /fs/dcache.c
parent2deb41b245320f0eefb535a5c8ea19ed66b33c04 (diff)
parent9b6faee074702bbbc207e7027b9416c2d8fea9fe (diff)
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi: "This work from Amir adds NFS export capability to overlayfs. NFS exporting an overlay filesystem is a challange because we want to keep track of any copy-up of a file or directory between encoding the file handle and decoding it. This is achieved by indexing copied up objects by lower layer file handle. The index is already used for hard links, this patchset extends the use to NFS file handle decoding" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (51 commits) ovl: check ERR_PTR() return value from ovl_encode_fh() ovl: fix regression in fsnotify of overlay merge dir ovl: wire up NFS export operations ovl: lookup indexed ancestor of lower dir ovl: lookup connected ancestor of dir in inode cache ovl: hash non-indexed dir by upper inode for NFS export ovl: decode pure lower dir file handles ovl: decode indexed dir file handles ovl: decode lower file handles of unlinked but open files ovl: decode indexed non-dir file handles ovl: decode lower non-dir file handles ovl: encode lower file handles ovl: copy up before encoding non-connectable dir file handle ovl: encode non-indexed upper file handles ovl: decode connected upper dir file handles ovl: decode pure upper file handles ovl: encode pure upper file handles ovl: document NFS export vfs: factor out helpers d_instantiate_anon() and d_alloc_anon() ovl: store 'has_upper' and 'opaque' as bit flags ...
Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c88
1 files changed, 57 insertions, 31 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index cca2b377ff0a..7c38f39958bc 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1698,9 +1698,15 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
}
EXPORT_SYMBOL(d_alloc);
+struct dentry *d_alloc_anon(struct super_block *sb)
+{
+ return __d_alloc(sb, NULL);
+}
+EXPORT_SYMBOL(d_alloc_anon);
+
struct dentry *d_alloc_cursor(struct dentry * parent)
{
- struct dentry *dentry = __d_alloc(parent->d_sb, NULL);
+ struct dentry *dentry = d_alloc_anon(parent->d_sb);
if (dentry) {
dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR;
dentry->d_parent = dget(parent);
@@ -1886,7 +1892,7 @@ struct dentry *d_make_root(struct inode *root_inode)
struct dentry *res = NULL;
if (root_inode) {
- res = __d_alloc(root_inode->i_sb, NULL);
+ res = d_alloc_anon(root_inode->i_sb);
if (res)
d_instantiate(res, root_inode);
else
@@ -1925,33 +1931,19 @@ struct dentry *d_find_any_alias(struct inode *inode)
}
EXPORT_SYMBOL(d_find_any_alias);
-static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
+static struct dentry *__d_instantiate_anon(struct dentry *dentry,
+ struct inode *inode,
+ bool disconnected)
{
- struct dentry *tmp;
struct dentry *res;
unsigned add_flags;
- if (!inode)
- return ERR_PTR(-ESTALE);
- if (IS_ERR(inode))
- return ERR_CAST(inode);
-
- res = d_find_any_alias(inode);
- if (res)
- goto out_iput;
-
- tmp = __d_alloc(inode->i_sb, NULL);
- if (!tmp) {
- res = ERR_PTR(-ENOMEM);
- goto out_iput;
- }
-
- security_d_instantiate(tmp, inode);
+ security_d_instantiate(dentry, inode);
spin_lock(&inode->i_lock);
res = __d_find_any_alias(inode);
if (res) {
spin_unlock(&inode->i_lock);
- dput(tmp);
+ dput(dentry);
goto out_iput;
}
@@ -1961,24 +1953,57 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
if (disconnected)
add_flags |= DCACHE_DISCONNECTED;
- spin_lock(&tmp->d_lock);
- __d_set_inode_and_type(tmp, inode, add_flags);
- hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry);
+ spin_lock(&dentry->d_lock);
+ __d_set_inode_and_type(dentry, inode, add_flags);
+ hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
if (!disconnected) {
- hlist_bl_lock(&tmp->d_sb->s_roots);
- hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_roots);
- hlist_bl_unlock(&tmp->d_sb->s_roots);
+ hlist_bl_lock(&dentry->d_sb->s_roots);
+ hlist_bl_add_head(&dentry->d_hash, &dentry->d_sb->s_roots);
+ hlist_bl_unlock(&dentry->d_sb->s_roots);
}
- spin_unlock(&tmp->d_lock);
+ spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
- return tmp;
+ return dentry;
out_iput:
iput(inode);
return res;
}
+struct dentry *d_instantiate_anon(struct dentry *dentry, struct inode *inode)
+{
+ return __d_instantiate_anon(dentry, inode, true);
+}
+EXPORT_SYMBOL(d_instantiate_anon);
+
+static struct dentry *__d_obtain_alias(struct inode *inode, bool disconnected)
+{
+ struct dentry *tmp;
+ struct dentry *res;
+
+ if (!inode)
+ return ERR_PTR(-ESTALE);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
+ res = d_find_any_alias(inode);
+ if (res)
+ goto out_iput;
+
+ tmp = d_alloc_anon(inode->i_sb);
+ if (!tmp) {
+ res = ERR_PTR(-ENOMEM);
+ goto out_iput;
+ }
+
+ return __d_instantiate_anon(tmp, inode, disconnected);
+
+out_iput:
+ iput(inode);
+ return res;
+}
+
/**
* d_obtain_alias - find or allocate a DISCONNECTED dentry for a given inode
* @inode: inode to allocate the dentry for
@@ -1999,7 +2024,7 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
*/
struct dentry *d_obtain_alias(struct inode *inode)
{
- return __d_obtain_alias(inode, 1);
+ return __d_obtain_alias(inode, true);
}
EXPORT_SYMBOL(d_obtain_alias);
@@ -2020,7 +2045,7 @@ EXPORT_SYMBOL(d_obtain_alias);
*/
struct dentry *d_obtain_root(struct inode *inode)
{
- return __d_obtain_alias(inode, 0);
+ return __d_obtain_alias(inode, false);
}
EXPORT_SYMBOL(d_obtain_root);
@@ -3527,6 +3552,7 @@ bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
return result;
}
+EXPORT_SYMBOL(is_subdir);
static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry)
{