From 1a39ba99b5d533647c5dac45cd6a3e0baa7cb66a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 13 May 2016 03:59:17 +0200 Subject: [PATCH] gfs2: Switch to generic xattr handlers Switch to the generic xattr handlers and take the necessary glocks at the layer below. The following are the new xattr "entry points"; they are called with the glock held already in the following cases: gfs2_xattr_get: From SELinux, during lookups. gfs2_xattr_set: The glock is never held. gfs2_get_acl: From gfs2_create_inode -> posix_acl_create and gfs2_setattr -> posix_acl_chmod. gfs2_set_acl: From gfs2_setattr -> posix_acl_chmod. Signed-off-by: Andreas Gruenbacher Signed-off-by: Al Viro --- fs/gfs2/acl.c | 58 +++++++++++++++++++++++++++------- fs/gfs2/acl.h | 1 + fs/gfs2/inode.c | 82 +++++++------------------------------------------ fs/gfs2/xattr.c | 46 +++++++++++++++++++++++---- 4 files changed, 99 insertions(+), 88 deletions(-) diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c index 791932617d1a..363ba9e9d8d0 100644 --- a/fs/gfs2/acl.c +++ b/fs/gfs2/acl.c @@ -24,6 +24,7 @@ #include "glock.h" #include "inode.h" #include "meta_io.h" +#include "rgrp.h" #include "trans.h" #include "util.h" @@ -38,7 +39,7 @@ static const char *gfs2_acl_name(int type) return NULL; } -struct posix_acl *gfs2_get_acl(struct inode *inode, int type) +static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type) { struct gfs2_inode *ip = GFS2_I(inode); struct posix_acl *acl; @@ -50,29 +51,41 @@ struct posix_acl *gfs2_get_acl(struct inode *inode, int type) return NULL; name = gfs2_acl_name(type); - if (name == NULL) - return ERR_PTR(-EINVAL); - len = gfs2_xattr_acl_get(ip, name, &data); - if (len < 0) + if (len <= 0) return ERR_PTR(len); - if (len == 0) - return NULL; - acl = posix_acl_from_xattr(&init_user_ns, data, len); kfree(data); return acl; } -int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) +struct posix_acl *gfs2_get_acl(struct inode *inode, int type) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + bool need_unlock = false; + struct posix_acl *acl; + + if (!gfs2_glock_is_locked_by_me(ip->i_gl)) { + int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, + LM_FLAG_ANY, &gh); + if (ret) + return ERR_PTR(ret); + need_unlock = true; + } + acl = __gfs2_get_acl(inode, type); + if (need_unlock) + gfs2_glock_dq_uninit(&gh); + return acl; +} + +int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) { int error; int len; char *data; const char *name = gfs2_acl_name(type); - BUG_ON(name == NULL); - if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode))) return -E2BIG; @@ -115,3 +128,26 @@ out: kfree(data); return error; } + +int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + bool need_unlock = false; + int ret; + + ret = gfs2_rsqa_alloc(ip); + if (ret) + return ret; + + if (!gfs2_glock_is_locked_by_me(ip->i_gl)) { + ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + if (ret) + return ret; + need_unlock = true; + } + ret = __gfs2_set_acl(inode, acl, type); + if (need_unlock) + gfs2_glock_dq_uninit(&gh); + return ret; +} diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h index 3af4f407a483..f674fdd22337 100644 --- a/fs/gfs2/acl.h +++ b/fs/gfs2/acl.h @@ -15,6 +15,7 @@ #define GFS2_ACL_MAX_ENTRIES(sdp) ((300 << (sdp)->sd_sb.sb_bsize_shift) >> 12) extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type); +extern int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type); extern int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type); #endif /* __ACL_DOT_H__ */ diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 45f516cada78..72e9c64ae371 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -692,12 +692,12 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry, considered free. Any failures need to undo the gfs2 structures. */ if (default_acl) { - error = gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT); + error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT); posix_acl_release(default_acl); } if (acl) { if (!error) - error = gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS); + error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS); posix_acl_release(acl); } @@ -1948,66 +1948,6 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry, return 0; } -static int gfs2_setxattr(struct dentry *dentry, const char *name, - const void *data, size_t size, int flags) -{ - struct inode *inode = d_inode(dentry); - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_holder gh; - int ret; - - gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); - ret = gfs2_glock_nq(&gh); - if (ret == 0) { - ret = gfs2_rsqa_alloc(ip); - if (ret == 0) - ret = generic_setxattr(dentry, name, data, size, flags); - gfs2_glock_dq(&gh); - } - gfs2_holder_uninit(&gh); - return ret; -} - -static ssize_t gfs2_getxattr(struct dentry *dentry, struct inode *inode, - const char *name, void *data, size_t size) -{ - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_holder gh; - int ret; - - /* For selinux during lookup */ - if (gfs2_glock_is_locked_by_me(ip->i_gl)) - return generic_getxattr(dentry, inode, name, data, size); - - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh); - ret = gfs2_glock_nq(&gh); - if (ret == 0) { - ret = generic_getxattr(dentry, inode, name, data, size); - gfs2_glock_dq(&gh); - } - gfs2_holder_uninit(&gh); - return ret; -} - -static int gfs2_removexattr(struct dentry *dentry, const char *name) -{ - struct inode *inode = d_inode(dentry); - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_holder gh; - int ret; - - gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); - ret = gfs2_glock_nq(&gh); - if (ret == 0) { - ret = gfs2_rsqa_alloc(ip); - if (ret == 0) - ret = generic_removexattr(dentry, name); - gfs2_glock_dq(&gh); - } - gfs2_holder_uninit(&gh); - return ret; -} - static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { @@ -2054,10 +1994,10 @@ const struct inode_operations gfs2_file_iops = { .permission = gfs2_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, - .setxattr = gfs2_setxattr, - .getxattr = gfs2_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = gfs2_listxattr, - .removexattr = gfs2_removexattr, + .removexattr = generic_removexattr, .fiemap = gfs2_fiemap, .get_acl = gfs2_get_acl, .set_acl = gfs2_set_acl, @@ -2076,10 +2016,10 @@ const struct inode_operations gfs2_dir_iops = { .permission = gfs2_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, - .setxattr = gfs2_setxattr, - .getxattr = gfs2_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = gfs2_listxattr, - .removexattr = gfs2_removexattr, + .removexattr = generic_removexattr, .fiemap = gfs2_fiemap, .get_acl = gfs2_get_acl, .set_acl = gfs2_set_acl, @@ -2092,10 +2032,10 @@ const struct inode_operations gfs2_symlink_iops = { .permission = gfs2_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, - .setxattr = gfs2_setxattr, - .getxattr = gfs2_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = gfs2_listxattr, - .removexattr = gfs2_removexattr, + .removexattr = generic_removexattr, .fiemap = gfs2_fiemap, }; diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c index 619886ba6e78..f42ab53bd30d 100644 --- a/fs/gfs2/xattr.c +++ b/fs/gfs2/xattr.c @@ -583,13 +583,11 @@ out: * * Returns: actual size of data on success, -errno on error */ -static int gfs2_xattr_get(const struct xattr_handler *handler, - struct dentry *unused, struct inode *inode, - const char *name, void *buffer, size_t size) +static int __gfs2_xattr_get(struct inode *inode, const char *name, + void *buffer, size_t size, int type) { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_ea_location el; - int type = handler->flags; int error; if (!ip->i_eattr) @@ -611,6 +609,29 @@ static int gfs2_xattr_get(const struct xattr_handler *handler, return error; } +static int gfs2_xattr_get(const struct xattr_handler *handler, + struct dentry *unused, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + bool need_unlock = false; + int ret; + + /* During lookup, SELinux calls this function with the glock locked. */ + + if (!gfs2_glock_is_locked_by_me(ip->i_gl)) { + ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh); + if (ret) + return ret; + need_unlock = true; + } + ret = __gfs2_xattr_get(inode, name, buffer, size, handler->flags); + if (need_unlock) + gfs2_glock_dq_uninit(&gh); + return ret; +} + /** * ea_alloc_blk - allocates a new block for extended attributes. * @ip: A pointer to the inode that's getting extended attributes @@ -1233,8 +1254,21 @@ static int gfs2_xattr_set(const struct xattr_handler *handler, struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { - return __gfs2_xattr_set(d_inode(dentry), name, value, - size, flags, handler->flags); + struct inode *inode = d_inode(dentry); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + int ret; + + ret = gfs2_rsqa_alloc(ip); + if (ret) + return ret; + + ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + if (ret) + return ret; + ret = __gfs2_xattr_set(inode, name, value, size, flags, handler->flags); + gfs2_glock_dq_uninit(&gh); + return ret; } static int ea_dealloc_indirect(struct gfs2_inode *ip)