From 52ab956000214aa111254e52e5eac3d91bd7cf4b Mon Sep 17 00:00:00 2001 From: Russ Knize Date: Tue, 24 Sep 2013 15:49:23 -0500 Subject: [PATCH] f2fs: don't GC or take an fs_lock from f2fs_initxattrs() f2fs_initxattrs() is called internally from within F2FS and should not call functions that are used by VFS handlers. This avoids certain deadlocks: - vfs_create() - f2fs_create() <-- takes an fs_lock - f2fs_add_link() - __f2fs_add_link() - init_inode_metadata() - f2fs_init_security() - security_inode_init_security() - f2fs_initxattrs() - f2fs_setxattr() <-- also takes an fs_lock If the caller happens to grab the same fs_lock from the pool in both places, they will deadlock. There are also deadlocks involving multiple threads and mutexes: - f2fs_write_begin() - f2fs_balance_fs() <-- takes gc_mutex - f2fs_gc() - write_checkpoint() - block_operations() - mutex_lock_all() <-- blocks trying to grab all fs_locks - f2fs_mkdir() <-- takes an fs_lock - __f2fs_add_link() - f2fs_init_security() - security_inode_init_security() - f2fs_initxattrs() - f2fs_setxattr() - f2fs_balance_fs() <-- blocks trying to take gc_mutex Signed-off-by: Russ Knize Signed-off-by: Jaegeuk Kim --- fs/f2fs/xattr.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 1ac8a5f6e380..3d900ea34e47 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -154,6 +154,9 @@ static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name, } #ifdef CONFIG_F2FS_FS_SECURITY +static int __f2fs_setxattr(struct inode *inode, int name_index, + const char *name, const void *value, size_t value_len, + struct page *ipage); static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array, void *page) { @@ -161,7 +164,7 @@ static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array, int err = 0; for (xattr = xattr_array; xattr->name != NULL; xattr++) { - err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY, + err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY, xattr->name, xattr->value, xattr->value_len, (struct page *)page); if (err < 0) @@ -469,16 +472,15 @@ cleanup: return error; } -int f2fs_setxattr(struct inode *inode, int name_index, const char *name, - const void *value, size_t value_len, struct page *ipage) +static int __f2fs_setxattr(struct inode *inode, int name_index, + const char *name, const void *value, size_t value_len, + struct page *ipage) { - struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); struct f2fs_inode_info *fi = F2FS_I(inode); struct f2fs_xattr_entry *here, *last; void *base_addr; int found, newsize; size_t name_len; - int ilock; __u32 new_hsize; int error = -ENOMEM; @@ -493,10 +495,6 @@ int f2fs_setxattr(struct inode *inode, int name_index, const char *name, if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode)) return -ERANGE; - f2fs_balance_fs(sbi); - - ilock = mutex_lock_op(sbi); - base_addr = read_all_xattrs(inode, ipage); if (!base_addr) goto exit; @@ -578,7 +576,24 @@ int f2fs_setxattr(struct inode *inode, int name_index, const char *name, else update_inode_page(inode); exit: - mutex_unlock_op(sbi, ilock); kzfree(base_addr); return error; } + +int f2fs_setxattr(struct inode *inode, int name_index, const char *name, + const void *value, size_t value_len, struct page *ipage) +{ + struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); + int ilock; + int err; + + f2fs_balance_fs(sbi); + + ilock = mutex_lock_op(sbi); + + err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage); + + mutex_unlock_op(sbi, ilock); + + return err; +} -- 2.39.5