From a7a67e8a089e25ef48ab01dd34ce82678ef70f11 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 27 Apr 2015 17:51:30 -0400 Subject: ext4: split inode_operations for encrypted symlinks off the rest Signed-off-by: Al Viro --- fs/ext4/ext4.h | 1 + fs/ext4/inode.c | 6 ++++-- fs/ext4/namei.c | 9 +++++---- fs/ext4/symlink.c | 30 ++++++++++-------------------- 4 files changed, 20 insertions(+), 26 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 009a0590b20f..ad358f2def66 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2847,6 +2847,7 @@ extern int ext4_mpage_readpages(struct address_space *mapping, unsigned nr_pages); /* symlink.c */ +extern const struct inode_operations ext4_encrypted_symlink_inode_operations; extern const struct inode_operations ext4_symlink_inode_operations; extern const struct inode_operations ext4_fast_symlink_inode_operations; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 55b187c3bac1..9f3baa25ec54 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4213,8 +4213,10 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) inode->i_op = &ext4_dir_inode_operations; inode->i_fop = &ext4_dir_operations; } else if (S_ISLNK(inode->i_mode)) { - if (ext4_inode_is_fast_symlink(inode) && - !ext4_encrypted_inode(inode)) { + if (ext4_encrypted_inode(inode)) { + inode->i_op = &ext4_encrypted_symlink_inode_operations; + ext4_set_aops(inode); + } else if (ext4_inode_is_fast_symlink(inode)) { inode->i_op = &ext4_fast_symlink_inode_operations; nd_terminate_link(ei->i_data, inode->i_size, sizeof(ei->i_data) - 1); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 814f3beb4369..39f8e6502639 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3206,10 +3206,12 @@ static int ext4_symlink(struct inode *dir, goto err_drop_inode; sd->len = cpu_to_le16(ostr.len); disk_link.name = (char *) sd; + inode->i_op = &ext4_encrypted_symlink_inode_operations; } if ((disk_link.len > EXT4_N_BLOCKS * 4)) { - inode->i_op = &ext4_symlink_inode_operations; + if (!encryption_required) + inode->i_op = &ext4_symlink_inode_operations; ext4_set_aops(inode); /* * We cannot call page_symlink() with transaction started @@ -3249,9 +3251,8 @@ static int ext4_symlink(struct inode *dir, } else { /* clear the extent format for fast symlink */ ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); - inode->i_op = encryption_required ? - &ext4_symlink_inode_operations : - &ext4_fast_symlink_inode_operations; + if (!encryption_required) + inode->i_op = &ext4_fast_symlink_inode_operations; memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, disk_link.len); inode->i_size = disk_link.len - 1; diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 187b78920314..49575ff7a7bb 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -35,9 +35,6 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) int res; u32 plen, max_size = inode->i_sb->s_blocksize; - if (!ext4_encrypted_inode(inode)) - return page_follow_link_light(dentry, nd); - ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize); if (IS_ERR(ctx)) return ctx; @@ -97,18 +94,16 @@ errout: return ERR_PTR(res); } -static void ext4_put_link(struct dentry *dentry, struct nameidata *nd, - void *cookie) -{ - struct page *page = cookie; - - if (!page) { - kfree(nd_get_link(nd)); - } else { - kunmap(page); - page_cache_release(page); - } -} +const struct inode_operations ext4_encrypted_symlink_inode_operations = { + .readlink = generic_readlink, + .follow_link = ext4_follow_link, + .put_link = kfree_put_link, + .setattr = ext4_setattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, + .listxattr = ext4_listxattr, + .removexattr = generic_removexattr, +}; #endif static void *ext4_follow_fast_link(struct dentry *dentry, struct nameidata *nd) @@ -120,13 +115,8 @@ static void *ext4_follow_fast_link(struct dentry *dentry, struct nameidata *nd) const struct inode_operations ext4_symlink_inode_operations = { .readlink = generic_readlink, -#ifdef CONFIG_EXT4_FS_ENCRYPTION - .follow_link = ext4_follow_link, - .put_link = ext4_put_link, -#else .follow_link = page_follow_link_light, .put_link = page_put_link, -#endif .setattr = ext4_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr, -- cgit v1.2.3 From 75e7566bea0c9b2a257441b66294be94863ef929 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 May 2015 10:13:58 -0400 Subject: ext4: switch to simple_follow_link() for fast symlinks only, of course... Reviewed-by: Jan Kara Signed-off-by: Al Viro --- fs/ext4/inode.c | 1 + fs/ext4/namei.c | 4 +++- fs/ext4/symlink.c | 9 +-------- 3 files changed, 5 insertions(+), 9 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9f3baa25ec54..066fdd7a1e2c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4217,6 +4217,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) inode->i_op = &ext4_encrypted_symlink_inode_operations; ext4_set_aops(inode); } else if (ext4_inode_is_fast_symlink(inode)) { + inode->i_link = (char *)ei->i_data; inode->i_op = &ext4_fast_symlink_inode_operations; nd_terminate_link(ei->i_data, inode->i_size, sizeof(ei->i_data) - 1); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 39f8e6502639..5fdb9f6aa869 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3251,8 +3251,10 @@ static int ext4_symlink(struct inode *dir, } else { /* clear the extent format for fast symlink */ ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); - if (!encryption_required) + if (!encryption_required) { inode->i_op = &ext4_fast_symlink_inode_operations; + inode->i_link = (char *)&EXT4_I(inode)->i_data; + } memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, disk_link.len); inode->i_size = disk_link.len - 1; diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 49575ff7a7bb..4264fb1e341a 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -106,13 +106,6 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = { }; #endif -static void *ext4_follow_fast_link(struct dentry *dentry, struct nameidata *nd) -{ - struct ext4_inode_info *ei = EXT4_I(d_inode(dentry)); - nd_set_link(nd, (char *) ei->i_data); - return NULL; -} - const struct inode_operations ext4_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = page_follow_link_light, @@ -126,7 +119,7 @@ const struct inode_operations ext4_symlink_inode_operations = { const struct inode_operations ext4_fast_symlink_inode_operations = { .readlink = generic_readlink, - .follow_link = ext4_follow_fast_link, + .follow_link = simple_follow_link, .setattr = ext4_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr, -- cgit v1.2.3 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 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 --- fs/ext4/symlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ext4') diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index afec475aaf5c..ba5bd18a9825 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -23,7 +23,7 @@ #include "xattr.h" #ifdef CONFIG_EXT4_FS_ENCRYPTION -static const char *ext4_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd) +static const char *ext4_follow_link(struct dentry *dentry, void **cookie) { struct page *cpage = NULL; char *caddr, *paddr = NULL; -- cgit v1.2.3