ext2 reservations

Val's cross-port of the ext3 reservations code into ext2.

[mbligh@mbligh.org: Small type error for printk
[akpm@linux-foundation.org: fix types, sync with ext3]
[mbligh@mbligh.org: Bring ext2 reservations code in line with latest ext3]
[akpm@linux-foundation.org: kill noisy printk]
[akpm@linux-foundation.org: remember to dirty the gdp's block]
[akpm@linux-foundation.org: cross-port the missed 5dea5176e5c32ef9f0d1a41d28427b3bf6881b3a]
[akpm@linux-foundation.org: cross-port e6022603b9aa7d61d20b392e69edcdbbc1789969]
[akpm@linux-foundation.org: Port the omitted 08fb306fe63d98eb86e3b16f4cc21816fa47f18e]
[akpm@linux-foundation.org: Backport the missed 20acaa18d0c002fec180956f87adeb3f11f635a6]
[akpm@linux-foundation.org: fixes]
[cmm@us.ibm.com: fix reservation extension]
[bunk@stusta.de: make ext2_get_blocks() static]
[hugh@veritas.com: fix hang]
[hugh@veritas.com: ext2_new_blocks should reset the reservation window size]
[hugh@veritas.com: ext2 balloc: fix off-by-one against rsv_end]
[hugh@veritas.com: grp_goal 0 is a genuine goal (unlike -1), so ext2_try_to_allocate_with_rsv should treat it as such]
[hugh@veritas.com: rbtree usage cleanup]
[pbadari@us.ibm.com: Fix for ext2 reservation]
[bunk@kernel.org: remove fs/ext2/balloc.c:reserve_blocks()]
[hugh@veritas.com: ext2 balloc: use io_error label]
Cc: "Martin J. Bligh" <mbligh@mbligh.org>
Cc: Valerie Henson <val_henson@linux.intel.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index 3bcd25422ee4..c2324d5fe4ac 100644
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -22,6 +22,7 @@ int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
 {
         struct ext2_inode_info *ei = EXT2_I(inode);
         unsigned int flags;
+        unsigned short rsv_window_size;
 
         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
 
@@ -83,6 +84,50 @@ int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
                 inode->i_ctime = CURRENT_TIME_SEC;
                 mark_inode_dirty(inode);
                 return 0;
+        case EXT2_IOC_GETRSVSZ:
+                if (test_opt(inode->i_sb, RESERVATION)
+                        && S_ISREG(inode->i_mode)
+                        && ei->i_block_alloc_info) {
+                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+                        return put_user(rsv_window_size, (int __user *)arg);
+                }
+                return -ENOTTY;
+        case EXT2_IOC_SETRSVSZ: {
+
+                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+                        return -ENOTTY;
+
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+
+                if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+                        return -EACCES;
+
+                if (get_user(rsv_window_size, (int __user *)arg))
+                        return -EFAULT;
+
+                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
+                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
+
+                /*
+                 * need to allocate reservation structure for this inode
+                 * before set the window size
+                 */
+                /*
+                 * XXX What lock should protect the rsv_goal_size?
+                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
+                 */
+                mutex_lock(&ei->truncate_mutex);
+                if (!ei->i_block_alloc_info)
+                        ext2_init_block_alloc_info(inode);
+
+                if (ei->i_block_alloc_info){
+                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+                        rsv->rsv_goal_size = rsv_window_size;
+                }
+                mutex_unlock(&ei->truncate_mutex);
+                return 0;
+        }
         default:
                 return -ENOTTY;
         }