Fix as Christoph suggested [1] [2], "remove is_inode_fast_symlink and just opencode it in the few places using it" and "Please just set the ops directly instead of obsfucating that in a single caller, single line inline function. And please set it instead of the normal symlink iops in the same place where you also set those." [1] https://lore.kernel.org/r/20190830163910.GB29603@xxxxxxxxxxxxx/ [2] https://lore.kernel.org/r/20190829102426.GE20598@xxxxxxxxxxxxx/ Reported-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx> --- fs/erofs/inode.c | 68 ++++++++++++++++++--------------------------- fs/erofs/internal.h | 10 ------- fs/erofs/super.c | 5 ++-- 3 files changed, 29 insertions(+), 54 deletions(-) diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index a42f5fc14df9..770f3259c862 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -127,50 +127,39 @@ static int read_inode(struct inode *inode, void *data) return -EFSCORRUPTED; } -/* - * try_lock can be required since locking order is: - * file data(fs_inode) - * meta(bd_inode) - * but the majority of the callers is "iget", - * in that case we are pretty sure no deadlock since - * no data operations exist. However I tend to - * try_lock since it takes no much overhead and - * will success immediately. - */ -static int fill_inline_data(struct inode *inode, void *data, - unsigned int m_pofs) +static int erofs_fill_symlink(struct inode *inode, void *data, + unsigned int m_pofs) { struct erofs_inode *vi = EROFS_I(inode); struct erofs_sb_info *sbi = EROFS_I_SB(inode); + char *lnk; - /* should be tail-packing data inline */ - if (vi->datalayout != EROFS_INODE_FLAT_INLINE) + /* if it cannot be handled with fast symlink scheme */ + if (vi->datalayout != EROFS_INODE_FLAT_INLINE || + inode->i_size >= PAGE_SIZE) { + inode->i_op = &erofs_symlink_iops; return 0; + } - /* fast symlink */ - if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) { - char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL); - - if (!lnk) - return -ENOMEM; - - m_pofs += vi->inode_isize + vi->xattr_isize; + lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL); + if (!lnk) + return -ENOMEM; - /* inline symlink data shouldn't cross page boundary as well */ - if (m_pofs + inode->i_size > PAGE_SIZE) { - kfree(lnk); - errln("inline data cross block boundary @ nid %llu", - vi->nid); - DBG_BUGON(1); - return -EFSCORRUPTED; - } + m_pofs += vi->inode_isize + vi->xattr_isize; + /* inline symlink data shouldn't cross page boundary as well */ + if (m_pofs + inode->i_size > PAGE_SIZE) { + kfree(lnk); + errln("inline data cross block boundary @ nid %llu", + vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } - memcpy(lnk, data + m_pofs, inode->i_size); - lnk[inode->i_size] = '\0'; + memcpy(lnk, data + m_pofs, inode->i_size); + lnk[inode->i_size] = '\0'; - inode->i_link = lnk; - set_inode_fast_symlink(inode); - } + inode->i_link = lnk; + inode->i_op = &erofs_fast_symlink_iops; return 0; } @@ -217,8 +206,9 @@ static int fill_inode(struct inode *inode, int isdir) inode->i_fop = &erofs_dir_fops; break; case S_IFLNK: - /* by default, page_get_link is used for symlink */ - inode->i_op = &erofs_symlink_iops; + err = erofs_fill_symlink(inode, data, ofs); + if (err) + goto out_unlock; inode_nohighmem(inode); break; case S_IFCHR: @@ -237,11 +227,7 @@ static int fill_inode(struct inode *inode, int isdir) err = z_erofs_fill_inode(inode); goto out_unlock; } - inode->i_mapping->a_ops = &erofs_raw_access_aops; - - /* fill last page if inline data is available */ - err = fill_inline_data(inode, data, ofs); } out_unlock: diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 10497ee07cae..cc1ea98c5c89 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -479,16 +479,6 @@ extern const struct inode_operations erofs_generic_iops; extern const struct inode_operations erofs_symlink_iops; extern const struct inode_operations erofs_fast_symlink_iops; -static inline void set_inode_fast_symlink(struct inode *inode) -{ - inode->i_op = &erofs_fast_symlink_iops; -} - -static inline bool is_inode_fast_symlink(struct inode *inode) -{ - return inode->i_op == &erofs_fast_symlink_iops; -} - struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); int erofs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags); diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 3986be582dbb..b8b0e35f6621 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -40,10 +40,9 @@ static void free_inode(struct inode *inode) { struct erofs_inode *vi = EROFS_I(inode); - /* be careful RCU symlink path (see ext4_inode_info->i_data)! */ - if (is_inode_fast_symlink(inode)) + /* be careful of RCU symlink path */ + if (inode->i_op == &erofs_fast_symlink_iops) kfree(inode->i_link); - kfree(vi->xattr_shared_xattrs); kmem_cache_free(erofs_inode_cachep, vi); -- 2.17.1
