From f6075c79074378910e131bbebc9d1dab53fd9986 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 9 Dec 2019 11:10:01 +0000 Subject: fs/adfs: dir: improve update failure handling When we update a directory, a number of errors may happen. If we failed to find the entry to update, we can just release the directory buffers as normal. However, if we have some other error, we may have partially updated the buffers, resulting in an invalid directory. In this case, we need to discard the buffers to avoid writing the contents back to the media, and later re-read the directory from the media. Signed-off-by: Russell King Signed-off-by: Al Viro --- fs/adfs/dir.c | 48 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 36 insertions(+), 12 deletions(-) diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c index ff9c921be31c..5e5d344bae7c 100644 --- a/fs/adfs/dir.c +++ b/fs/adfs/dir.c @@ -64,12 +64,8 @@ int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src, return 0; } -void adfs_dir_relse(struct adfs_dir *dir) +static void __adfs_dir_cleanup(struct adfs_dir *dir) { - unsigned int i; - - for (i = 0; i < dir->nr_buffers; i++) - brelse(dir->bhs[i]); dir->nr_buffers = 0; if (dir->bhs != dir->bh) @@ -78,6 +74,26 @@ void adfs_dir_relse(struct adfs_dir *dir) dir->sb = NULL; } +void adfs_dir_relse(struct adfs_dir *dir) +{ + unsigned int i; + + for (i = 0; i < dir->nr_buffers; i++) + brelse(dir->bhs[i]); + + __adfs_dir_cleanup(dir); +} + +static void adfs_dir_forget(struct adfs_dir *dir) +{ + unsigned int i; + + for (i = 0; i < dir->nr_buffers; i++) + bforget(dir->bhs[i]); + + __adfs_dir_cleanup(dir); +} + int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr, unsigned int size, struct adfs_dir *dir) { @@ -288,20 +304,28 @@ adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait) goto unlock; ret = ops->update(&dir, obj); + if (ret) + goto forget; up_write(&adfs_dir_rwsem); - if (ret == 0) - adfs_dir_mark_dirty(&dir); + adfs_dir_mark_dirty(&dir); - if (wait) { - int err = adfs_dir_sync(&dir); - if (!ret) - ret = err; - } + if (wait) + ret = adfs_dir_sync(&dir); adfs_dir_relse(&dir); return ret; + /* + * If the updated failed because the entry wasn't found, we can + * just release the buffers. If it was any other error, forget + * the dirtied buffers so they aren't written back to the media. + */ +forget: + if (ret == -ENOENT) + adfs_dir_relse(&dir); + else + adfs_dir_forget(&dir); unlock: up_write(&adfs_dir_rwsem); #endif -- cgit