From 680baacbca69d18a6d7315374ad83d05ac9c0977 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 May 2015 13:32:22 -0400 Subject: new ->follow_link() and ->put_link() calling conventions a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro --- fs/ext4/symlink.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 4264fb1e341a..afec475aaf5c 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -23,7 +23,7 @@ #include "xattr.h" #ifdef CONFIG_EXT4_FS_ENCRYPTION -static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) +static const char *ext4_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd) { struct page *cpage = NULL; char *caddr, *paddr = NULL; @@ -37,7 +37,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize); if (IS_ERR(ctx)) - return ctx; + return ERR_CAST(ctx); if (ext4_inode_is_fast_symlink(inode)) { caddr = (char *) EXT4_I(inode)->i_data; @@ -46,7 +46,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) cpage = read_mapping_page(inode->i_mapping, 0, NULL); if (IS_ERR(cpage)) { ext4_put_fname_crypto_ctx(&ctx); - return cpage; + return ERR_CAST(cpage); } caddr = kmap(cpage); caddr[size] = 0; @@ -77,13 +77,12 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) /* Null-terminate the name */ if (res <= plen) paddr[res] = '\0'; - nd_set_link(nd, paddr); ext4_put_fname_crypto_ctx(&ctx); if (cpage) { kunmap(cpage); page_cache_release(cpage); } - return NULL; + return *cookie = paddr; errout: ext4_put_fname_crypto_ctx(&ctx); if (cpage) { -- cgit v1.2.3