From 60380f193ee5a667842a4da4a3e936689bb0e5e6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 May 2015 10:24:43 -0400 Subject: shmem: switch to simple_follow_link() Reviewed-by: Jan Kara Signed-off-by: Al Viro --- mm/shmem.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index de981370fbc5..7f6e2f889122 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2451,6 +2451,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return -ENOMEM; } inode->i_op = &shmem_short_symlink_operations; + inode->i_link = info->symlink; } else { error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL); if (error) { @@ -2474,12 +2475,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return 0; } -static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd) -{ - nd_set_link(nd, SHMEM_I(d_inode(dentry))->symlink); - return NULL; -} - static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) { struct page *page = NULL; @@ -2642,7 +2637,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) static const struct inode_operations shmem_short_symlink_operations = { .readlink = generic_readlink, - .follow_link = shmem_follow_short_symlink, + .follow_link = simple_follow_link, #ifdef CONFIG_TMPFS_XATTR .setxattr = shmem_setxattr, .getxattr = shmem_getxattr, -- cgit 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 --- mm/shmem.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index 7f6e2f889122..d1693dcb4285 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2475,24 +2475,23 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return 0; } -static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) +static const char *shmem_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd) { struct page *page = NULL; int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL); - nd_set_link(nd, error ? ERR_PTR(error) : kmap(page)); - if (page) - unlock_page(page); - return page; + if (error) + return ERR_PTR(error); + unlock_page(page); + *cookie = page; + return kmap(page); } -static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) +static void shmem_put_link(struct dentry *dentry, void *cookie) { - if (!IS_ERR(nd_get_link(nd))) { - struct page *page = cookie; - kunmap(page); - mark_page_accessed(page); - page_cache_release(page); - } + struct page *page = cookie; + kunmap(page); + mark_page_accessed(page); + page_cache_release(page); } #ifdef CONFIG_TMPFS_XATTR -- cgit From 6e77137b363b8d866ac29c5a0c95e953614fb2d8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 May 2015 13:37:52 -0400 Subject: don't pass nameidata to ->follow_link() its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index d1693dcb4285..e02682267046 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2475,7 +2475,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return 0; } -static const char *shmem_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd) +static const char *shmem_follow_link(struct dentry *dentry, void **cookie) { struct page *page = NULL; int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL); -- cgit From 5f2c4179e129bdc47870a81a65d0aff85aa18293 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 7 May 2015 11:14:26 -0400 Subject: switch ->put_link() from dentry to inode only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index e02682267046..a59087edf728 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2486,7 +2486,7 @@ static const char *shmem_follow_link(struct dentry *dentry, void **cookie) return kmap(page); } -static void shmem_put_link(struct dentry *dentry, void *cookie) +static void shmem_put_link(struct inode *unused, void *cookie) { struct page *page = cookie; kunmap(page); -- cgit