diff options
Diffstat (limited to 'fs/jffs2/nodemgmt.c')
| -rw-r--r-- | fs/jffs2/nodemgmt.c | 42 |
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); |