cstyle: Resolve C style issues

[mirror_zfs.git] / module / zfs / zfs_ctldir.c

diff --git a/module/zfs/zfs_ctldir.c b/module/zfs/zfs_ctldir.c
index 3cf0089ecef0aa2c069a96b35c495c5280a65e9b..96520545a2804d12f187db0e5f9749917de10abb 100644 (file)
--- a/module/zfs/zfs_ctldir.c
+++ b/module/zfs/zfs_ctldir.c
@@ -27,6 +27,7 @@
  * Rewritten for Linux by:
  *   Rohan Puri <rohan.puri15@gmail.com>
  *   Brian Behlendorf <behlendorf1@llnl.gov>
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 /*
@@ -99,7 +100,7 @@ static taskq_t *zfs_expire_taskq;
 static zfs_snapentry_t *
 zfsctl_sep_alloc(void)
 {
-       return kmem_zalloc(sizeof (zfs_snapentry_t), KM_SLEEP);
+       return (kmem_zalloc(sizeof (zfs_snapentry_t), KM_SLEEP));
 }
 
 void
@@ -254,7 +255,6 @@ zfsctl_inode_lookup(zfs_sb_t *zsb, uint64_t id,
 void
 zfsctl_inode_destroy(struct inode *ip)
 {
-       return;
 }
 
 /*
@@ -286,11 +286,11 @@ zfsctl_create(zfs_sb_t *zsb)
        zsb->z_ctldir = zfsctl_inode_alloc(zsb, ZFSCTL_INO_ROOT,
            &zpl_fops_root, &zpl_ops_root);
        if (zsb->z_ctldir == NULL)
-               return (ENOENT);
+               return (SET_ERROR(ENOENT));
 
        return (0);
 #else
-       return (EOPNOTSUPP);
+       return (SET_ERROR(EOPNOTSUPP));
 #endif /* CONFIG_64BIT */
 }
 
@@ -331,7 +331,7 @@ zfsctl_fid(struct inode *ip, fid_t *fidp)
        if (fidp->fid_len < SHORT_FID_LEN) {
                fidp->fid_len = SHORT_FID_LEN;
                ZFS_EXIT(zsb);
-               return (ENOSPC);
+               return (SET_ERROR(ENOSPC));
        }
 
        zfid = (zfid_short_t *)fidp;
@@ -355,11 +355,11 @@ zfsctl_snapshot_zname(struct inode *ip, const char *name, int len, char *zname)
        objset_t *os = ITOZSB(ip)->z_os;
 
        if (snapshot_namecheck(name, NULL, NULL) != 0)
-               return (EILSEQ);
+               return (SET_ERROR(EILSEQ));
 
        dmu_objset_name(os, zname);
        if ((strlen(zname) + 1 + strlen(name)) >= len)
-               return (ENAMETOOLONG);
+               return (SET_ERROR(ENAMETOOLONG));
 
        (void) strcat(zname, "@");
        (void) strcat(zname, name);
@@ -367,6 +367,11 @@ zfsctl_snapshot_zname(struct inode *ip, const char *name, int len, char *zname)
        return (0);
 }
 
+/*
+ * Gets the full dataset name that corresponds to the given snapshot name
+ * Example:
+ *     zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1"
+ */
 static int
 zfsctl_snapshot_zpath(struct path *path, int len, char *zpath)
 {
@@ -383,7 +388,7 @@ zfsctl_snapshot_zpath(struct path *path, int len, char *zpath)
 
        path_len = path_buffer + len - 1 - path_ptr;
        if (path_len > len) {
-               error = EFAULT;
+               error = SET_ERROR(EFAULT);
                goto out;
        }
 
@@ -421,7 +426,7 @@ zfsctl_root_lookup(struct inode *dip, char *name, struct inode **ipp,
        }
 
        if (*ipp == NULL)
-               error = ENOENT;
+               error = SET_ERROR(ENOENT);
 
        ZFS_EXIT(zsb);
 
@@ -457,7 +462,7 @@ zfsctl_snapdir_lookup(struct inode *dip, char *name, struct inode **ipp,
                (*ipp)->i_flags |= S_AUTOMOUNT;
 #endif /* HAVE_AUTOMOUNT */
        } else {
-               error = ENOENT;
+               error = SET_ERROR(ENOENT);
        }
 
        ZFS_EXIT(zsb);
@@ -529,7 +534,7 @@ zfsctl_snapdir_rename(struct inode *sdip, char *snm,
         * Cannot move snapshots out of the snapdir.
         */
        if (sdip != tdip) {
-               error = EINVAL;
+               error = SET_ERROR(EINVAL);
                goto out;
        }
 
@@ -626,7 +631,7 @@ zfsctl_snapdir_mkdir(struct inode *dip, char *dirname, vattr_t *vap,
        dsname = kmem_alloc(MAXNAMELEN, KM_SLEEP);
 
        if (snapshot_namecheck(dirname, NULL, NULL) != 0) {
-               error = EILSEQ;
+               error = SET_ERROR(EILSEQ);
                goto out;
        }
 
@@ -686,7 +691,7 @@ zfsctl_snapdir_inactive(struct inode *ip)
  * best effort.  In the case where it does fail, perhaps because
  * it's in use, the unmount will fail harmlessly.
  */
-#define SET_UNMOUNT_CMD \
+#define        SET_UNMOUNT_CMD \
        "exec 0</dev/null " \
        "     1>/dev/null " \
        "     2>/dev/null; " \
@@ -710,7 +715,7 @@ __zfsctl_unmount_snapshot(zfs_snapentry_t *sep, int flags)
         * converted to the more sensible EBUSY.
         */
        if (error)
-               error = EBUSY;
+               error = SET_ERROR(EBUSY);
 
        /*
         * This was the result of a manual unmount, cancel the delayed work
@@ -746,7 +751,7 @@ zfsctl_unmount_snapshot(zfs_sb_t *zsb, char *name, int flags)
                else
                        zfsctl_sep_free(sep);
        } else {
-               error = ENOENT;
+               error = SET_ERROR(ENOENT);
        }
 
        mutex_exit(&zsb->z_ctldir_lock);
@@ -795,7 +800,9 @@ zfsctl_unmount_snapshots(zfs_sb_t *zsb, int flags, int *count)
        return ((*count > 0) ? EEXIST : 0);
 }
 
-#define SET_MOUNT_CMD \
+#define        MOUNT_BUSY 0x80         /* Mount failed due to EBUSY (from mntent.h) */
+
+#define        SET_MOUNT_CMD \
        "exec 0</dev/null " \
        "     1>/dev/null " \
        "     2>/dev/null; " \
@@ -833,17 +840,23 @@ zfsctl_mount_snapshot(struct path *path, int flags)
         * function is marked GPL-only and cannot be used.  On error we
         * careful to log the real error to the console and return EISDIR
         * to safely abort the automount.  This should be very rare.
+        *
+        * If the user mode helper happens to return EBUSY, a concurrent
+        * mount is already in progress in which case the error is ignored.
+        * Take note that if the program was executed successfully the return
+        * value from call_usermodehelper() will be (exitcode << 8 + signal).
         */
        argv[2] = kmem_asprintf(SET_MOUNT_CMD, full_name, full_path);
        error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
        strfree(argv[2]);
-       if (error) {
+       if (error && !(error & MOUNT_BUSY << 8)) {
                printk("ZFS: Unable to automount %s at %s: %d\n",
                    full_name, full_path, error);
-               error = EISDIR;
+               error = SET_ERROR(EISDIR);
                goto error;
        }
 
+       error = 0;
        mutex_enter(&zsb->z_ctldir_lock);
 
        /*
@@ -948,7 +961,7 @@ zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid, zfs_sb_t **zsbp)
                        deactivate_super(sbp);
                }
        } else {
-               error = EINVAL;
+               error = SET_ERROR(EINVAL);
        }
 out:
        mutex_exit(&zsb->z_ctldir_lock);
@@ -971,7 +984,7 @@ zfsctl_shares_lookup(struct inode *dip, char *name, struct inode **ipp,
 
        if (zsb->z_shares_dir == 0) {
                ZFS_EXIT(zsb);
-               return (ENOTSUP);
+               return (SET_ERROR(ENOTSUP));
        }
 
        error = zfs_zget(zsb, zsb->z_shares_dir, &dzp);