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path: root/fs/cachefiles/namei.c
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Diffstat (limited to 'fs/cachefiles/namei.c')
-rw-r--r--fs/cachefiles/namei.c98
1 files changed, 47 insertions, 51 deletions
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index d1edb2ac3837..e5ec90dccc27 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -93,12 +93,11 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
_enter(",,%s", dirname);
/* search the current directory for the element name */
- inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
retry:
ret = cachefiles_inject_read_error();
if (ret == 0)
- subdir = lookup_one(&nop_mnt_idmap, &QSTR(dirname), dir);
+ subdir = start_creating(&nop_mnt_idmap, dir, &QSTR(dirname));
else
subdir = ERR_PTR(ret);
trace_cachefiles_lookup(NULL, dir, subdir);
@@ -129,10 +128,12 @@ retry:
if (ret < 0)
goto mkdir_error;
ret = cachefiles_inject_write_error();
- if (ret == 0)
- subdir = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
- else
+ if (ret == 0) {
+ subdir = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700, NULL);
+ } else {
+ end_creating(subdir);
subdir = ERR_PTR(ret);
+ }
if (IS_ERR(subdir)) {
trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
cachefiles_trace_mkdir_error);
@@ -141,7 +142,7 @@ retry:
trace_cachefiles_mkdir(dir, subdir);
if (unlikely(d_unhashed(subdir) || d_is_negative(subdir))) {
- dput(subdir);
+ end_creating(subdir);
goto retry;
}
ASSERT(d_backing_inode(subdir));
@@ -154,7 +155,7 @@ retry:
/* Tell rmdir() it's not allowed to delete the subdir */
inode_lock(d_inode(subdir));
- inode_unlock(d_inode(dir));
+ end_creating_keep(subdir);
if (!__cachefiles_mark_inode_in_use(NULL, d_inode(subdir))) {
pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
@@ -196,14 +197,11 @@ mark_error:
return ERR_PTR(-EBUSY);
mkdir_error:
- inode_unlock(d_inode(dir));
- if (!IS_ERR(subdir))
- dput(subdir);
+ end_creating(subdir);
pr_err("mkdir %s failed with error %d\n", dirname, ret);
return ERR_PTR(ret);
lookup_error:
- inode_unlock(d_inode(dir));
ret = PTR_ERR(subdir);
pr_err("Lookup %s failed with error %d\n", dirname, ret);
return ERR_PTR(ret);
@@ -263,6 +261,8 @@ static int cachefiles_unlink(struct cachefiles_cache *cache,
* - File backed objects are unlinked
* - Directory backed objects are stuffed into the graveyard for userspace to
* delete
+ * On entry dir must be locked. It will be unlocked on exit.
+ * On entry there must be at least 2 refs on rep, one will be dropped on exit.
*/
int cachefiles_bury_object(struct cachefiles_cache *cache,
struct cachefiles_object *object,
@@ -278,27 +278,23 @@ int cachefiles_bury_object(struct cachefiles_cache *cache,
_enter(",'%pd','%pd'", dir, rep);
if (rep->d_parent != dir) {
- inode_unlock(d_inode(dir));
+ end_removing(rep);
_leave(" = -ESTALE");
return -ESTALE;
}
/* non-directories can just be unlinked */
if (!d_is_dir(rep)) {
- dget(rep); /* Stop the dentry being negated if it's only pinned
- * by a file struct.
- */
ret = cachefiles_unlink(cache, object, dir, rep, why);
- dput(rep);
+ end_removing(rep);
- inode_unlock(d_inode(dir));
_leave(" = %d", ret);
return ret;
}
/* directories have to be moved to the graveyard */
_debug("move stale object to graveyard");
- inode_unlock(d_inode(dir));
+ end_removing(rep);
try_again:
/* first step is to make up a grave dentry in the graveyard */
@@ -425,13 +421,12 @@ int cachefiles_delete_object(struct cachefiles_object *object,
_enter(",OBJ%x{%pD}", object->debug_id, object->file);
- /* Stop the dentry being negated if it's only pinned by a file struct. */
- dget(dentry);
-
- inode_lock_nested(d_backing_inode(fan), I_MUTEX_PARENT);
- ret = cachefiles_unlink(volume->cache, object, fan, dentry, why);
- inode_unlock(d_backing_inode(fan));
- dput(dentry);
+ dentry = start_removing_dentry(fan, dentry);
+ if (IS_ERR(dentry))
+ ret = PTR_ERR(dentry);
+ else
+ ret = cachefiles_unlink(volume->cache, object, fan, dentry, why);
+ end_removing(dentry);
return ret;
}
@@ -644,9 +639,13 @@ bool cachefiles_look_up_object(struct cachefiles_object *object)
if (!d_is_reg(dentry)) {
pr_err("%pd is not a file\n", dentry);
- inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
- ret = cachefiles_bury_object(volume->cache, object, fan, dentry,
- FSCACHE_OBJECT_IS_WEIRD);
+ struct dentry *de = start_removing_dentry(fan, dentry);
+ if (IS_ERR(de))
+ ret = PTR_ERR(de);
+ else
+ ret = cachefiles_bury_object(volume->cache, object,
+ fan, de,
+ FSCACHE_OBJECT_IS_WEIRD);
dput(dentry);
if (ret < 0)
return false;
@@ -679,36 +678,41 @@ bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
_enter(",%pD", object->file);
- inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
ret = cachefiles_inject_read_error();
if (ret == 0)
- dentry = lookup_one(&nop_mnt_idmap, &QSTR(object->d_name), fan);
+ dentry = start_creating(&nop_mnt_idmap, fan, &QSTR(object->d_name));
else
dentry = ERR_PTR(ret);
if (IS_ERR(dentry)) {
trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry),
cachefiles_trace_lookup_error);
_debug("lookup fail %ld", PTR_ERR(dentry));
- goto out_unlock;
+ goto out;
}
- if (!d_is_negative(dentry)) {
+ /*
+ * This loop will only execute more than once if some other thread
+ * races to create the object we are trying to create.
+ */
+ while (!d_is_negative(dentry)) {
ret = cachefiles_unlink(volume->cache, object, fan, dentry,
FSCACHE_OBJECT_IS_STALE);
if (ret < 0)
- goto out_dput;
+ goto out_end;
+
+ end_creating(dentry);
- dput(dentry);
ret = cachefiles_inject_read_error();
if (ret == 0)
- dentry = lookup_one(&nop_mnt_idmap, &QSTR(object->d_name), fan);
+ dentry = start_creating(&nop_mnt_idmap, fan,
+ &QSTR(object->d_name));
else
dentry = ERR_PTR(ret);
if (IS_ERR(dentry)) {
trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry),
cachefiles_trace_lookup_error);
_debug("lookup fail %ld", PTR_ERR(dentry));
- goto out_unlock;
+ goto out;
}
}
@@ -729,10 +733,9 @@ bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
success = true;
}
-out_dput:
- dput(dentry);
-out_unlock:
- inode_unlock(d_inode(fan));
+out_end:
+ end_creating(dentry);
+out:
_leave(" = %u", success);
return success;
}
@@ -748,26 +751,20 @@ static struct dentry *cachefiles_lookup_for_cull(struct cachefiles_cache *cache,
struct dentry *victim;
int ret = -ENOENT;
- inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
+ victim = start_removing(&nop_mnt_idmap, dir, &QSTR(filename));
- victim = lookup_one(&nop_mnt_idmap, &QSTR(filename), dir);
if (IS_ERR(victim))
goto lookup_error;
- if (d_is_negative(victim))
- goto lookup_put;
if (d_inode(victim)->i_flags & S_KERNEL_FILE)
goto lookup_busy;
return victim;
lookup_busy:
ret = -EBUSY;
-lookup_put:
- inode_unlock(d_inode(dir));
- dput(victim);
+ end_removing(victim);
return ERR_PTR(ret);
lookup_error:
- inode_unlock(d_inode(dir));
ret = PTR_ERR(victim);
if (ret == -ENOENT)
return ERR_PTR(-ESTALE); /* Probably got retired by the netfs */
@@ -815,18 +812,17 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
ret = cachefiles_bury_object(cache, NULL, dir, victim,
FSCACHE_OBJECT_WAS_CULLED);
+ dput(victim);
if (ret < 0)
goto error;
fscache_count_culled();
- dput(victim);
_leave(" = 0");
return 0;
error_unlock:
- inode_unlock(d_inode(dir));
+ end_removing(victim);
error:
- dput(victim);
if (ret == -ENOENT)
return -ESTALE; /* Probably got retired by the netfs */
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-03 06:57:15 +0000