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authorAl Viro <viro@zeniv.linux.org.uk>2014-12-24 21:41:47 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2015-01-25 23:16:26 -0500
commit5e993e2534e29b62790f9a2908b551b7fb3a63f0 (patch)
tree3278906dba789c91609feb98f636538031e61dd8
parentad52184b705c1048aa01225eccde119ef5c93000 (diff)
ncpfs: get rid of d_validate() nonsense
What we want is to have non-counting references to children in pagecache of parent directory, and avoid picking them after a child has been freed. Fine, so let's just have ->d_prune() clear parent's inode "has directory contents in page cache" flag. That way we don't need ->d_fsdata for storing offsets, so we can use it as a quick and dirty "is it referenced from page cache" flag. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/ncpfs/dir.c98
-rw-r--r--fs/ncpfs/ncp_fs_i.h1
-rw-r--r--fs/ncpfs/ncplib_kernel.h30
3 files changed, 52 insertions, 77 deletions
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 008960101520..e7ca827d7694 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -77,6 +77,7 @@ static int ncp_hash_dentry(const struct dentry *, struct qstr *);
static int ncp_compare_dentry(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
static int ncp_delete_dentry(const struct dentry *);
+static void ncp_d_prune(struct dentry *dentry);
const struct dentry_operations ncp_dentry_operations =
{
@@ -84,6 +85,7 @@ const struct dentry_operations ncp_dentry_operations =
.d_hash = ncp_hash_dentry,
.d_compare = ncp_compare_dentry,
.d_delete = ncp_delete_dentry,
+ .d_prune = ncp_d_prune,
};
#define ncp_namespace(i) (NCP_SERVER(i)->name_space[NCP_FINFO(i)->volNumber])
@@ -384,42 +386,6 @@ finished:
return val;
}
-static struct dentry *
-ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
-{
- struct dentry *dent = dentry;
-
- if (d_validate(dent, parent)) {
- if (dent->d_name.len <= NCP_MAXPATHLEN &&
- (unsigned long)dent->d_fsdata == fpos) {
- if (!dent->d_inode) {
- dput(dent);
- dent = NULL;
- }
- return dent;
- }
- dput(dent);
- }
-
- /* If a pointer is invalid, we search the dentry. */
- spin_lock(&parent->d_lock);
- list_for_each_entry(dent, &parent->d_subdirs, d_child) {
- if ((unsigned long)dent->d_fsdata == fpos) {
- if (dent->d_inode)
- dget(dent);
- else
- dent = NULL;
- spin_unlock(&parent->d_lock);
- goto out;
- }
- }
- spin_unlock(&parent->d_lock);
- return NULL;
-
-out:
- return dent;
-}
-
static time_t ncp_obtain_mtime(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
@@ -435,6 +401,20 @@ static time_t ncp_obtain_mtime(struct dentry *dentry)
return ncp_date_dos2unix(i.modifyTime, i.modifyDate);
}
+static inline void
+ncp_invalidate_dircache_entries(struct dentry *parent)
+{
+ struct ncp_server *server = NCP_SERVER(parent->d_inode);
+ struct dentry *dentry;
+
+ spin_lock(&parent->d_lock);
+ list_for_each_entry(dentry, &parent->d_subdirs, d_child) {
+ dentry->d_fsdata = NULL;
+ ncp_age_dentry(server, dentry);
+ }
+ spin_unlock(&parent->d_lock);
+}
+
static int ncp_readdir(struct file *file, struct dir_context *ctx)
{
struct dentry *dentry = file->f_path.dentry;
@@ -500,10 +480,21 @@ static int ncp_readdir(struct file *file, struct dir_context *ctx)
struct dentry *dent;
bool over;
- dent = ncp_dget_fpos(ctl.cache->dentry[ctl.idx],
- dentry, ctx->pos);
- if (!dent)
+ spin_lock(&dentry->d_lock);
+ if (!(NCP_FINFO(inode)->flags & NCPI_DIR_CACHE)) {
+ spin_unlock(&dentry->d_lock);
+ goto invalid_cache;
+ }
+ dent = ctl.cache->dentry[ctl.idx];
+ if (unlikely(!lockref_get_not_dead(&dent->d_lockref))) {
+ spin_unlock(&dentry->d_lock);
+ goto invalid_cache;
+ }
+ spin_unlock(&dentry->d_lock);
+ if (!dent->d_inode) {
+ dput(dent);
goto invalid_cache;
+ }
over = !dir_emit(ctx, dent->d_name.name,
dent->d_name.len,
dent->d_inode->i_ino, DT_UNKNOWN);
@@ -548,6 +539,9 @@ init_cache:
ctl.filled = 0;
ctl.valid = 1;
read_really:
+ spin_lock(&dentry->d_lock);
+ NCP_FINFO(inode)->flags |= NCPI_DIR_CACHE;
+ spin_unlock(&dentry->d_lock);
if (ncp_is_server_root(inode)) {
ncp_read_volume_list(file, ctx, &ctl);
} else {
@@ -573,6 +567,13 @@ out:
return result;
}
+static void ncp_d_prune(struct dentry *dentry)
+{
+ if (!dentry->d_fsdata) /* not referenced from page cache */
+ return;
+ NCP_FINFO(dentry->d_parent->d_inode)->flags &= ~NCPI_DIR_CACHE;
+}
+
static int
ncp_fill_cache(struct file *file, struct dir_context *ctx,
struct ncp_cache_control *ctrl, struct ncp_entry_info *entry,
@@ -630,6 +631,10 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx,
d_instantiate(newdent, inode);
if (!hashed)
d_rehash(newdent);
+ } else {
+ spin_lock(&dentry->d_lock);
+ NCP_FINFO(inode)->flags &= ~NCPI_DIR_CACHE;
+ spin_unlock(&dentry->d_lock);
}
} else {
struct inode *inode = newdent->d_inode;
@@ -639,12 +644,6 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx,
mutex_unlock(&inode->i_mutex);
}
- if (newdent->d_inode) {
- ino = newdent->d_inode->i_ino;
- newdent->d_fsdata = (void *) ctl.fpos;
- ncp_new_dentry(newdent);
- }
-
if (ctl.idx >= NCP_DIRCACHE_SIZE) {
if (ctl.page) {
kunmap(ctl.page);
@@ -660,8 +659,13 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx,
ctl.cache = kmap(ctl.page);
}
if (ctl.cache) {
- ctl.cache->dentry[ctl.idx] = newdent;
- valid = 1;
+ if (newdent->d_inode) {
+ newdent->d_fsdata = newdent;
+ ctl.cache->dentry[ctl.idx] = newdent;
+ ino = newdent->d_inode->i_ino;
+ ncp_new_dentry(newdent);
+ }
+ valid = 1;
}
dput(newdent);
end_advance:
diff --git a/fs/ncpfs/ncp_fs_i.h b/fs/ncpfs/ncp_fs_i.h
index 4b0bec477846..c4794504f843 100644
--- a/fs/ncpfs/ncp_fs_i.h
+++ b/fs/ncpfs/ncp_fs_i.h
@@ -22,6 +22,7 @@ struct ncp_inode_info {
int access;
int flags;
#define NCPI_KLUDGE_SYMLINK 0x0001
+#define NCPI_DIR_CACHE 0x0002
__u8 file_handle[6];
struct inode vfs_inode;
};
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index b785f74bfe3c..250e443a07f3 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -184,36 +184,6 @@ ncp_new_dentry(struct dentry* dentry)
dentry->d_time = jiffies;
}
-static inline void
-ncp_renew_dentries(struct dentry *parent)
-{
- struct ncp_server *server = NCP_SERVER(parent->d_inode);
- struct dentry *dentry;
-
- spin_lock(&parent->d_lock);
- list_for_each_entry(dentry, &parent->d_subdirs, d_child) {
- if (dentry->d_fsdata == NULL)
- ncp_age_dentry(server, dentry);
- else
- ncp_new_dentry(dentry);
- }
- spin_unlock(&parent->d_lock);
-}
-
-static inline void
-ncp_invalidate_dircache_entries(struct dentry *parent)
-{
- struct ncp_server *server = NCP_SERVER(parent->d_inode);
- struct dentry *dentry;
-
- spin_lock(&parent->d_lock);
- list_for_each_entry(dentry, &parent->d_subdirs, d_child) {
- dentry->d_fsdata = NULL;
- ncp_age_dentry(server, dentry);
- }
- spin_unlock(&parent->d_lock);
-}
-
struct ncp_cache_head {
time_t mtime;
unsigned long time; /* cache age */