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Diffstat (limited to 'fs/jffs2/nodemgmt.c')
-rw-r--r--fs/jffs2/nodemgmt.c42
1 files changed, 42 insertions, 0 deletions
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);