From 5214b729e1c2dc3af8f55e6c4c548844c3bea0f5 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Fri, 28 Mar 2008 14:15:55 -0700 Subject: afs: prevent double cell registration kafs doesn't check if the cell already exists - so if you do an echo "add newcell.org 1.2.3.4" >/proc/fs/afs/cells it will try to create this cell again. kobject will also complain about a double registration. To prevent such problems, return -EEXIST in that case. Signed-off-by: Sven Schnelle Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/afs/cell.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'fs/afs/cell.c') diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 970d38f3056..788865df1bc 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -127,14 +127,20 @@ struct afs_cell *afs_cell_create(const char *name, char *vllist) _enter("%s,%s", name, vllist); + down_write(&afs_cells_sem); + read_lock(&afs_cells_lock); + list_for_each_entry(cell, &afs_cells, link) { + if (strcasecmp(cell->name, name) == 0) + goto duplicate_name; + } + read_unlock(&afs_cells_lock); + cell = afs_cell_alloc(name, vllist); if (IS_ERR(cell)) { _leave(" = %ld", PTR_ERR(cell)); return cell; } - down_write(&afs_cells_sem); - /* add a proc directory for this cell */ ret = afs_proc_cell_setup(cell); if (ret < 0) @@ -167,6 +173,11 @@ error: kfree(cell); _leave(" = %d", ret); return ERR_PTR(ret); + +duplicate_name: + read_unlock(&afs_cells_lock); + up_write(&afs_cells_sem); + return ERR_PTR(-EEXIST); } /* -- cgit v1.2.3 From a5f37c3252b174efdcdd808797a7c529064c95c0 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Wed, 2 Apr 2008 13:17:18 +0100 Subject: afs: add missing up_write() on return If afs_cell_alloc() fails, afs_cells_sem doesn't get unlocked, which leads to a deadlock. Unlock it before returning. Signed-off-by: Sven Schnelle Signed-off-by: David Howells Signed-off-by: Linus Torvalds --- fs/afs/cell.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/afs/cell.c') diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 788865df1bc..584bb0f9c36 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -138,6 +138,7 @@ struct afs_cell *afs_cell_create(const char *name, char *vllist) cell = afs_cell_alloc(name, vllist); if (IS_ERR(cell)) { _leave(" = %ld", PTR_ERR(cell)); + up_write(&afs_cells_sem); return cell; } -- cgit v1.2.3