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authorRonnie Sahlberg <lsahlber@redhat.com>2022-05-10 02:42:07 +0300
committerSteve French <stfrench@microsoft.com>2022-05-24 22:33:11 +0300
commitd87c48ce4d8951f46d21f17ea86bba8853049862 (patch)
tree9d5b70fa32e36691fecab1cf6e45657c78eb92e4 /fs/cifs
parent5752bf645f9dd7db600651f726eb04a97c9f597f (diff)
downloadlinux-d87c48ce4d8951f46d21f17ea86bba8853049862.tar.xz
cifs: cache the dirents for entries in a cached directory
This adds caching of the directory entries for a cached directory while we keep a lease on the directory. Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifsglob.h22
-rw-r--r--fs/cifs/misc.c2
-rw-r--r--fs/cifs/readdir.c181
-rw-r--r--fs/cifs/smb2ops.c16
4 files changed, 213 insertions, 8 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 8880a26f234f..b6c2a787be06 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1052,6 +1052,27 @@ struct cifs_fattr {
u32 cf_cifstag;
};
+struct cached_dirent {
+ struct list_head entry;
+ char *name;
+ int namelen;
+ loff_t pos;
+
+ struct cifs_fattr fattr;
+};
+
+struct cached_dirents {
+ bool is_valid:1;
+ bool is_failed:1;
+ struct dir_context *ctx; /*
+ * Only used to make sure we only take entries
+ * from a single context. Never dereferenced.
+ */
+ struct mutex de_mutex;
+ int pos; /* Expected ctx->pos */
+ struct list_head entries;
+};
+
struct cached_fid {
bool is_valid:1; /* Do we have a useable root fid */
bool file_all_info_is_valid:1;
@@ -1064,6 +1085,7 @@ struct cached_fid {
struct dentry *dentry;
struct work_struct lease_break;
struct smb2_file_all_info file_all_info;
+ struct cached_dirents dirents;
};
/*
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index e869c2a51034..af5e68a77811 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -114,6 +114,8 @@ tconInfoAlloc(void)
kfree(ret_buf);
return NULL;
}
+ INIT_LIST_HEAD(&ret_buf->crfid.dirents.entries);
+ mutex_init(&ret_buf->crfid.dirents.de_mutex);
atomic_inc(&tconInfoAllocCount);
ret_buf->status = TID_NEW;
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 1929e80c09ee..ccf34481d801 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -840,9 +840,109 @@ find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
return rc;
}
+static bool emit_cached_dirents(struct cached_dirents *cde,
+ struct dir_context *ctx)
+{
+ struct cached_dirent *dirent;
+ int rc;
+
+ list_for_each_entry(dirent, &cde->entries, entry) {
+ if (ctx->pos >= dirent->pos)
+ continue;
+ ctx->pos = dirent->pos;
+ rc = dir_emit(ctx, dirent->name, dirent->namelen,
+ dirent->fattr.cf_uniqueid,
+ dirent->fattr.cf_dtype);
+ if (!rc)
+ return rc;
+ }
+ return true;
+}
+
+static void update_cached_dirents_count(struct cached_dirents *cde,
+ struct dir_context *ctx)
+{
+ if (cde->ctx != ctx)
+ return;
+ if (cde->is_valid || cde->is_failed)
+ return;
+
+ cde->pos++;
+}
+
+static void finished_cached_dirents_count(struct cached_dirents *cde,
+ struct dir_context *ctx)
+{
+ if (cde->ctx != ctx)
+ return;
+ if (cde->is_valid || cde->is_failed)
+ return;
+ if (ctx->pos != cde->pos)
+ return;
+
+ cde->is_valid = 1;
+}
+
+static void add_cached_dirent(struct cached_dirents *cde,
+ struct dir_context *ctx,
+ const char *name, int namelen,
+ struct cifs_fattr *fattr)
+{
+ struct cached_dirent *de;
+
+ if (cde->ctx != ctx)
+ return;
+ if (cde->is_valid || cde->is_failed)
+ return;
+ if (ctx->pos != cde->pos) {
+ cde->is_failed = 1;
+ return;
+ }
+ de = kzalloc(sizeof(*de), GFP_ATOMIC);
+ if (de == NULL) {
+ cde->is_failed = 1;
+ return;
+ }
+ de->namelen = namelen;
+ de->name = kstrndup(name, namelen, GFP_ATOMIC);
+ if (de->name == NULL) {
+ kfree(de);
+ cde->is_failed = 1;
+ return;
+ }
+ de->pos = ctx->pos;
+
+ memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr));
+
+ list_add_tail(&de->entry, &cde->entries);
+}
+
+static bool cifs_dir_emit(struct dir_context *ctx,
+ const char *name, int namelen,
+ struct cifs_fattr *fattr,
+ struct cached_fid *cfid)
+{
+ bool rc;
+ ino_t ino = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);
+
+ rc = dir_emit(ctx, name, namelen, ino, fattr->cf_dtype);
+ if (!rc)
+ return rc;
+
+ if (cfid) {
+ mutex_lock(&cfid->dirents.de_mutex);
+ add_cached_dirent(&cfid->dirents, ctx, name, namelen,
+ fattr);
+ mutex_unlock(&cfid->dirents.de_mutex);
+ }
+
+ return rc;
+}
+
static int cifs_filldir(char *find_entry, struct file *file,
- struct dir_context *ctx,
- char *scratch_buf, unsigned int max_len)
+ struct dir_context *ctx,
+ char *scratch_buf, unsigned int max_len,
+ struct cached_fid *cfid)
{
struct cifsFileInfo *file_info = file->private_data;
struct super_block *sb = file_inode(file)->i_sb;
@@ -851,7 +951,6 @@ static int cifs_filldir(char *find_entry, struct file *file,
struct cifs_fattr fattr;
struct qstr name;
int rc = 0;
- ino_t ino;
rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
file_info->srch_inf.unicode);
@@ -931,8 +1030,8 @@ static int cifs_filldir(char *find_entry, struct file *file,
cifs_prime_dcache(file_dentry(file), &name, &fattr);
- ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
- return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
+ return !cifs_dir_emit(ctx, name.name, name.len,
+ &fattr, cfid);
}
@@ -941,8 +1040,9 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
int rc = 0;
unsigned int xid;
int i;
+ struct tcon_link *tlink = NULL;
struct cifs_tcon *tcon;
- struct cifsFileInfo *cifsFile = NULL;
+ struct cifsFileInfo *cifsFile;
char *current_entry;
int num_to_fill = 0;
char *tmp_buf = NULL;
@@ -950,6 +1050,8 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
unsigned int max_len;
const char *full_path;
void *page = alloc_dentry_path();
+ struct cached_fid *cfid = NULL;
+ struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
xid = get_xid();
@@ -959,6 +1061,56 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
goto rddir2_exit;
}
+ if (file->private_data == NULL) {
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink))
+ goto cache_not_found;
+ tcon = tlink_tcon(tlink);
+ } else {
+ cifsFile = file->private_data;
+ tcon = tlink_tcon(cifsFile->tlink);
+ }
+
+ rc = open_cached_dir(xid, tcon, full_path, cifs_sb, &cfid);
+ cifs_put_tlink(tlink);
+ if (rc)
+ goto cache_not_found;
+
+ mutex_lock(&cfid->dirents.de_mutex);
+ /*
+ * If this was reading from the start of the directory
+ * we need to initialize scanning and storing the
+ * directory content.
+ */
+ if (ctx->pos == 0 && cfid->dirents.ctx == NULL) {
+ cfid->dirents.ctx = ctx;
+ cfid->dirents.pos = 2;
+ }
+ /*
+ * If we already have the entire directory cached then
+ * we can just serve the cache.
+ */
+ if (cfid->dirents.is_valid) {
+ if (!dir_emit_dots(file, ctx)) {
+ mutex_unlock(&cfid->dirents.de_mutex);
+ goto rddir2_exit;
+ }
+ emit_cached_dirents(&cfid->dirents, ctx);
+ mutex_unlock(&cfid->dirents.de_mutex);
+ goto rddir2_exit;
+ }
+ mutex_unlock(&cfid->dirents.de_mutex);
+
+ /* Drop the cache while calling initiate_cifs_search and
+ * find_cifs_entry in case there will be reconnects during
+ * query_directory.
+ */
+ if (cfid) {
+ close_cached_dir(cfid);
+ cfid = NULL;
+ }
+
+ cache_not_found:
/*
* Ensure FindFirst doesn't fail before doing filldir() for '.' and
* '..'. Otherwise we won't be able to notify VFS in case of failure.
@@ -977,7 +1129,6 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
is in current search buffer?
if it before then restart search
if after then keep searching till find it */
-
cifsFile = file->private_data;
if (cifsFile->srch_inf.endOfSearch) {
if (cifsFile->srch_inf.emptyDir) {
@@ -993,12 +1144,18 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
tcon = tlink_tcon(cifsFile->tlink);
rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
&current_entry, &num_to_fill);
+ open_cached_dir(xid, tcon, full_path, cifs_sb, &cfid);
if (rc) {
cifs_dbg(FYI, "fce error %d\n", rc);
goto rddir2_exit;
} else if (current_entry != NULL) {
cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
} else {
+ if (cfid) {
+ mutex_lock(&cfid->dirents.de_mutex);
+ finished_cached_dirents_count(&cfid->dirents, ctx);
+ mutex_unlock(&cfid->dirents.de_mutex);
+ }
cifs_dbg(FYI, "Could not find entry\n");
goto rddir2_exit;
}
@@ -1028,7 +1185,7 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
*/
*tmp_buf = 0;
rc = cifs_filldir(current_entry, file, ctx,
- tmp_buf, max_len);
+ tmp_buf, max_len, cfid);
if (rc) {
if (rc > 0)
rc = 0;
@@ -1036,6 +1193,12 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
}
ctx->pos++;
+ if (cfid) {
+ mutex_lock(&cfid->dirents.de_mutex);
+ update_cached_dirents_count(&cfid->dirents, ctx);
+ mutex_unlock(&cfid->dirents.de_mutex);
+ }
+
if (ctx->pos ==
cifsFile->srch_inf.index_of_last_entry) {
cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
@@ -1050,6 +1213,8 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
kfree(tmp_buf);
rddir2_exit:
+ if (cfid)
+ close_cached_dir(cfid);
free_dentry_path(page);
free_xid(xid);
return rc;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index ed2f8a69658d..7e2c86e0cede 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -699,6 +699,7 @@ smb2_close_cached_fid(struct kref *ref)
{
struct cached_fid *cfid = container_of(ref, struct cached_fid,
refcount);
+ struct cached_dirent *dirent, *q;
if (cfid->is_valid) {
cifs_dbg(FYI, "clear cached root file handle\n");
@@ -718,6 +719,21 @@ smb2_close_cached_fid(struct kref *ref)
dput(cfid->dentry);
cfid->dentry = NULL;
}
+ /*
+ * Delete all cached dirent names
+ */
+ mutex_lock(&cfid->dirents.de_mutex);
+ list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
+ list_del(&dirent->entry);
+ kfree(dirent->name);
+ kfree(dirent);
+ }
+ cfid->dirents.is_valid = 0;
+ cfid->dirents.is_failed = 0;
+ cfid->dirents.ctx = NULL;
+ cfid->dirents.pos = 0;
+ mutex_unlock(&cfid->dirents.de_mutex);
+
}
void close_cached_dir(struct cached_fid *cfid)