6 files changed, 97 insertions, 13 deletions

diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index 44dca1f041c5..413ef89c2d1b 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -32,6 +32,13 @@ struct jffs2_inodirty;
 struct jffs2_mount_opts {
         bool override_compr;
         unsigned int compr;
+
+        /* The size of the reserved pool. The reserved pool is the JFFS2 flash
+         * space which may only be used by root cannot be used by the other
+         * users. This is implemented simply by means of not allowing the
+         * latter users to write to the file system if the amount if the
+         * available space is less then 'rp_size'. */
+        unsigned int rp_size;
 };
 
 /* A struct for the overall file system control.  Pointers to
diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c
index 6784d1e7a7eb..0c96eb52c797 100644
--- a/fs/jffs2/nodemgmt.c
+++ b/fs/jffs2/nodemgmt.c
@@ -18,6 +18,37 @@
 #include "nodelist.h"
 #include "debug.h"
 
+/*
+ * Check whether the user is allowed to write.
+ */
+static int jffs2_rp_can_write(struct jffs2_sb_info *c)
+{
+        uint32_t avail;
+        struct jffs2_mount_opts *opts = &c->mount_opts;
+
+        avail = c->dirty_size + c->free_size + c->unchecked_size +
+                c->erasing_size - c->resv_blocks_write * c->sector_size
+                - c->nospc_dirty_size;
+
+        if (avail < 2 * opts->rp_size)
+                jffs2_dbg(1, "rpsize %u, dirty_size %u, free_size %u, "
+                          "erasing_size %u, unchecked_size %u, "
+                          "nr_erasing_blocks %u, avail %u, resrv %u\n",
+                          opts->rp_size, c->dirty_size, c->free_size,
+                          c->erasing_size, c->unchecked_size,
+                          c->nr_erasing_blocks, avail, c->nospc_dirty_size);
+
+        if (avail > opts->rp_size)
+                return 1;
+
+        /* Always allow root */
+        if (capable(CAP_SYS_RESOURCE))
+                return 1;
+
+        jffs2_dbg(1, "forbid writing\n");
+        return 0;
+}
+
 /**
  *      jffs2_reserve_space - request physical space to write nodes to flash
  *      @c: superblock info
@@ -55,6 +86,15 @@ int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 
         spin_lock(&c->erase_completion_lock);
 
+        /*
+         * Check if the free space is greater then size of the reserved pool.
+         * If not, only allow root to proceed with writing.
+         */
+        if (prio != ALLOC_DELETION && !jffs2_rp_can_write(c)) {
+                ret = -ENOSPC;
+                goto out;
+        }
+
         /* this needs a little more thought (true <tglx> :)) */
         while(ret == -EAGAIN) {
                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
@@ -158,6 +198,8 @@ int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
                         jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret);
                 }
         }
+
+out:
         spin_unlock(&c->erase_completion_lock);
         if (!ret)
                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index dc0437e84763..1ea349fff68b 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -1266,19 +1266,25 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
                         /* Symlink's inode data is the target path. Read it and
                          * keep in RAM to facilitate quick follow symlink
                          * operation. */
-                        f->target = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
+                        uint32_t csize = je32_to_cpu(latest_node->csize);
+                        if (csize > JFFS2_MAX_NAME_LEN) {
+                                mutex_unlock(&f->sem);
+                                jffs2_do_clear_inode(c, f);
+                                return -ENAMETOOLONG;
+                        }
+                        f->target = kmalloc(csize + 1, GFP_KERNEL);
                         if (!f->target) {
-                                JFFS2_ERROR("can't allocate %d bytes of memory for the symlink target path cache\n", je32_to_cpu(latest_node->csize));
+                                JFFS2_ERROR("can't allocate %u bytes of memory for the symlink target path cache\n", csize);
                                 mutex_unlock(&f->sem);
                                 jffs2_do_clear_inode(c, f);
                                 return -ENOMEM;
                         }
 
                         ret = jffs2_flash_read(c, ref_offset(rii.latest_ref) + sizeof(*latest_node),
-                                                je32_to_cpu(latest_node->csize), &retlen, (char *)f->target);
+                                               csize, &retlen, (char *)f->target);
 
-                        if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
-                                if (retlen != je32_to_cpu(latest_node->csize))
+                        if (ret || retlen != csize) {
+                                if (retlen != csize)
                                         ret = -EIO;
                                 kfree(f->target);
                                 f->target = NULL;
@@ -1287,7 +1293,7 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
                                 return ret;
                         }
 
-                        f->target[je32_to_cpu(latest_node->csize)] = '\0';
+                        f->target[csize] = '\0';
                         dbg_readinode("symlink's target '%s' cached\n", f->target);
                 }
 
@@ -1415,6 +1421,7 @@ int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *i
                 mutex_unlock(&f->sem);
                 jffs2_do_clear_inode(c, f);
         }
+        jffs2_xattr_do_crccheck_inode(c, ic);
         kfree (f);
         return ret;
 }
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index bc586f204228..61ea41389f90 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -90,6 +90,8 @@ static int jffs2_show_options(struct seq_file *s, struct dentry *root)
 
         if (opts->override_compr)
                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
+        if (opts->rp_size)
+                seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
 
         return 0;
 }
@@ -154,15 +156,18 @@ static const struct export_operations jffs2_export_ops = {
  * JFFS2 mount options.
  *
  * Opt_override_compr: override default compressor
+ * Opt_rp_size: size of reserved pool in KiB
  * Opt_err: just end of array marker
  */
 enum {
         Opt_override_compr,
+        Opt_rp_size,
         Opt_err,
 };
 
 static const match_table_t tokens = {
         {Opt_override_compr, "compr=%s"},
+        {Opt_rp_size, "rp_size=%u"},
         {Opt_err, NULL},
 };
 
@@ -170,6 +175,7 @@ static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
 {
         substring_t args[MAX_OPT_ARGS];
         char *p, *name;
+        unsigned int opt;
 
         if (!data)
                 return 0;
@@ -207,6 +213,17 @@ static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
                         kfree(name);
                         c->mount_opts.override_compr = true;
                         break;
+                case Opt_rp_size:
+                        if (match_int(&args[0], &opt))
+                                return -EINVAL;
+                        opt *= 1024;
+                        if (opt > c->mtd->size) {
+                                pr_warn("Too large reserve pool specified, max "
+                                        "is %llu KB\n", c->mtd->size / 1024);
+                                return -EINVAL;
+                        }
+                        c->mount_opts.rp_size = opt;
+                        break;
                 default:
                         pr_err("Error: unrecognized mount option '%s' or missing value\n",
                                p);
diff --git a/fs/jffs2/xattr.c b/fs/jffs2/xattr.c
index b55b803eddcb..3034e970eb9a 100644
--- a/fs/jffs2/xattr.c
+++ b/fs/jffs2/xattr.c
@@ -11,6 +11,8 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#define JFFS2_XATTR_IS_CORRUPTED        1
+
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
@@ -153,7 +155,7 @@ static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_dat
                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
                             offset, je32_to_cpu(rx.hdr_crc), crc);
                 xd->flags |= JFFS2_XFLAGS_INVALID;
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         }
         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
@@ -169,7 +171,7 @@ static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_dat
                             je32_to_cpu(rx.xid), xd->xid,
                             je32_to_cpu(rx.version), xd->version);
                 xd->flags |= JFFS2_XFLAGS_INVALID;
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         }
         xd->xprefix = rx.xprefix;
         xd->name_len = rx.name_len;
@@ -227,12 +229,12 @@ static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum
         data[xd->name_len] = '\0';
         crc = crc32(0, data, length);
         if (crc != xd->data_crc) {
-                JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
+                JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
                               ref_offset(xd->node), xd->data_crc, crc);
                 kfree(data);
                 xd->flags |= JFFS2_XFLAGS_INVALID;
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         }
 
         xd->flags |= JFFS2_XFLAGS_HOT;
@@ -270,7 +272,7 @@ static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *x
         if (xd->xname)
                 return 0;
         if (xd->flags & JFFS2_XFLAGS_INVALID)
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         if (unlikely(is_xattr_datum_unchecked(c, xd)))
                 rc = do_verify_xattr_datum(c, xd);
         if (!rc)
@@ -435,6 +437,8 @@ static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datu
  *   is called to release xattr related objects when unmounting. 
  * check_xattr_ref_inode(c, ic)
  *   is used to confirm inode does not have duplicate xattr name/value pair.
+ * jffs2_xattr_do_crccheck_inode(c, ic)
+ *   is used to force xattr data integrity check during the initial gc scan.
  * -------------------------------------------------- */
 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 {
@@ -462,7 +466,7 @@ static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref
         if (crc != je32_to_cpu(rr.node_crc)) {
                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
                             offset, je32_to_cpu(rr.node_crc), crc);
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         }
         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
@@ -472,7 +476,7 @@ static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref
                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
-                return -EIO;
+                return JFFS2_XATTR_IS_CORRUPTED;
         }
         ref->ino = je32_to_cpu(rr.ino);
         ref->xid = je32_to_cpu(rr.xid);
@@ -682,6 +686,11 @@ static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cac
         return rc;
 }
 
+void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
+{
+        check_xattr_ref_inode(c, ic);
+}
+
 /* -------- xattr subsystem functions ---------------
  * jffs2_init_xattr_subsystem(c)
  *   is used to initialize semaphore and list_head, and some variables.
diff --git a/fs/jffs2/xattr.h b/fs/jffs2/xattr.h
index 7be4beb306f3..467ff376ee26 100644
--- a/fs/jffs2/xattr.h
+++ b/fs/jffs2/xattr.h
@@ -77,6 +77,7 @@ extern void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c);
 extern struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
                                                          uint32_t xid, uint32_t version);
 
+extern void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
 extern void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
 extern void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
 
@@ -108,6 +109,7 @@ extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t);
 #define jffs2_build_xattr_subsystem(c)
 #define jffs2_clear_xattr_subsystem(c)
 
+#define jffs2_xattr_do_crccheck_inode(c, ic)
 #define jffs2_xattr_delete_inode(c, ic)
 #define jffs2_xattr_free_inode(c, ic)
 #define jffs2_verify_xattr(c)                   (1)