ceph: quota: support for ceph.quota.max_files

This patch adds support for the max_files quota.  It hooks into all the
ceph functions that add new filesystem objects that need to be checked
against the quota limits.  When these limits are hit, -EDQUOT is returned.

Note that we're not checking quotas on ceph_link().  ceph_link doesn't
really create a new inode,  and since the MDS doesn't update the directory
statistics when a new (hard) link is created (only with symlinks), they
are not accounted as a new file.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Luis Henriques 2018-01-05 10:47:19 +00:00 committed by Ilya Dryomov
parent fb18a57568
commit b7a2921765
4 changed files with 95 additions and 1 deletions

View File

@ -828,6 +828,9 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
if (ceph_quota_is_max_files_exceeded(dir))
return -EDQUOT;
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
return err;
@ -881,6 +884,9 @@ static int ceph_symlink(struct inode *dir, struct dentry *dentry,
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
if (ceph_quota_is_max_files_exceeded(dir))
return -EDQUOT;
dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
if (IS_ERR(req)) {
@ -930,6 +936,11 @@ static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
goto out;
}
if (ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
}
mode |= S_IFDIR;
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)

View File

@ -402,7 +402,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
struct ceph_mds_request *req;
struct dentry *dn;
struct ceph_acls_info acls = {};
int mask;
int mask;
int err;
dout("atomic_open %p dentry %p '%pd' %s flags %d mode 0%o\n",
@ -413,6 +413,8 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
return -ENAMETOOLONG;
if (flags & O_CREAT) {
if (ceph_quota_is_max_files_exceeded(dir))
return -EDQUOT;
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
return err;

View File

@ -63,3 +63,83 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
iput(inode);
}
enum quota_check_op {
QUOTA_CHECK_MAX_FILES_OP /* check quota max_files limit */
};
/*
* check_quota_exceeded() will walk up the snaprealm hierarchy and, for each
* realm, it will execute quota check operation defined by the 'op' parameter.
* The snaprealm walk is interrupted if the quota check detects that the quota
* is exceeded or if the root inode is reached.
*/
static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
loff_t delta)
{
struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
struct ceph_inode_info *ci;
struct ceph_snap_realm *realm, *next;
struct ceph_vino vino;
struct inode *in;
u64 max, rvalue;
bool is_root;
bool exceeded = false;
down_read(&mdsc->snap_rwsem);
realm = ceph_inode(inode)->i_snap_realm;
ceph_get_snap_realm(mdsc, realm);
while (realm) {
vino.ino = realm->ino;
vino.snap = CEPH_NOSNAP;
in = ceph_find_inode(inode->i_sb, vino);
if (!in) {
pr_warn("Failed to find inode for %llu\n", vino.ino);
break;
}
ci = ceph_inode(in);
spin_lock(&ci->i_ceph_lock);
if (op == QUOTA_CHECK_MAX_FILES_OP) {
max = ci->i_max_files;
rvalue = ci->i_rfiles + ci->i_rsubdirs;
}
is_root = (ci->i_vino.ino == CEPH_INO_ROOT);
spin_unlock(&ci->i_ceph_lock);
switch (op) {
case QUOTA_CHECK_MAX_FILES_OP:
exceeded = (max && (rvalue >= max));
break;
default:
/* Shouldn't happen */
pr_warn("Invalid quota check op (%d)\n", op);
exceeded = true; /* Just break the loop */
}
iput(in);
if (is_root || exceeded)
break;
next = realm->parent;
ceph_get_snap_realm(mdsc, next);
ceph_put_snap_realm(mdsc, realm);
realm = next;
}
ceph_put_snap_realm(mdsc, realm);
up_read(&mdsc->snap_rwsem);
return exceeded;
}
/*
* ceph_quota_is_max_files_exceeded - check if we can create a new file
* @inode: directory where a new file is being created
*
* This functions returns true is max_files quota allows a new file to be
* created. It is necessary to walk through the snaprealm hierarchy (until the
* FS root) to check all realms with quotas set.
*/
bool ceph_quota_is_max_files_exceeded(struct inode *inode)
{
WARN_ON(!S_ISDIR(inode->i_mode));
return check_quota_exceeded(inode, QUOTA_CHECK_MAX_FILES_OP, 0);
}

View File

@ -1077,5 +1077,6 @@ extern void ceph_fs_debugfs_cleanup(struct ceph_fs_client *client);
extern void ceph_handle_quota(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session,
struct ceph_msg *msg);
extern bool ceph_quota_is_max_files_exceeded(struct inode *inode);
#endif /* _FS_CEPH_SUPER_H */