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authorHugh Dickins <hugh@veritas.com>2008-07-28 18:46:19 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-28 19:30:20 -0400
commit14fcc23fdc78e9d32372553ccf21758a9bd56fa1 (patch)
tree594fc0e0e85c03205ba2d80a4b4e0a8fc6ffaa8a /mm/shmem.c
parentca5b172bd2b2fe489e7ba11cedd46ddf772d132f (diff)
tmpfs: fix kernel BUG in shmem_delete_inode
SuSE's insserve initscript ordering program hits kernel BUG at mm/shmem.c:814 on 2.6.26. It's using posix_fadvise on directories, and the shmem_readpage method added in 2.6.23 is letting POSIX_FADV_WILLNEED allocate useless pages to a tmpfs directory, incrementing i_blocks count but never decrementing it. Fix this by assigning shmem_aops (pointing to readpage and writepage and set_page_dirty) only when it's needed, on a regular file or a long symlink. Many thanks to Kel for outstanding bugreport and steps to reproduce it. Reported-by: Kel Modderman <kel@otaku42.de> Tested-by: Kel Modderman <kel@otaku42.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 952d361774bb..c1e5a3b4f758 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1513,7 +1513,6 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
1513 inode->i_uid = current->fsuid; 1513 inode->i_uid = current->fsuid;
1514 inode->i_gid = current->fsgid; 1514 inode->i_gid = current->fsgid;
1515 inode->i_blocks = 0; 1515 inode->i_blocks = 0;
1516 inode->i_mapping->a_ops = &shmem_aops;
1517 inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; 1516 inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
1518 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1517 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1519 inode->i_generation = get_seconds(); 1518 inode->i_generation = get_seconds();
@@ -1528,6 +1527,7 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
1528 init_special_inode(inode, mode, dev); 1527 init_special_inode(inode, mode, dev);
1529 break; 1528 break;
1530 case S_IFREG: 1529 case S_IFREG:
1530 inode->i_mapping->a_ops = &shmem_aops;
1531 inode->i_op = &shmem_inode_operations; 1531 inode->i_op = &shmem_inode_operations;
1532 inode->i_fop = &shmem_file_operations; 1532 inode->i_fop = &shmem_file_operations;
1533 mpol_shared_policy_init(&info->policy, 1533 mpol_shared_policy_init(&info->policy,
@@ -1929,6 +1929,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
1929 return error; 1929 return error;
1930 } 1930 }
1931 unlock_page(page); 1931 unlock_page(page);
1932 inode->i_mapping->a_ops = &shmem_aops;
1932 inode->i_op = &shmem_symlink_inode_operations; 1933 inode->i_op = &shmem_symlink_inode_operations;
1933 kaddr = kmap_atomic(page, KM_USER0); 1934 kaddr = kmap_atomic(page, KM_USER0);
1934 memcpy(kaddr, symname, len); 1935 memcpy(kaddr, symname, len);