From: Valerie Aurora Subject: [PATCH 13/35] fallthru: ext2 fallthru support Date: Thu, 15 Apr 2010 16:04:20 -0700 Message-ID: <1271372682-21225-14-git-send-email-vaurora@redhat.com> References: <1271372682-21225-1-git-send-email-vaurora@redhat.com> <1271372682-21225-2-git-send-email-vaurora@redhat.com> <1271372682-21225-3-git-send-email-vaurora@redhat.com> <1271372682-21225-4-git-send-email-vaurora@redhat.com> <1271372682-21225-5-git-send-email-vaurora@redhat.com> <1271372682-21225-6-git-send-email-vaurora@redhat.com> <1271372682-21225-7-git-send-email-vaurora@redhat.com> <1271372682-21225-8-git-send-email-vaurora@redhat.com> <1271372682-21225-9-git-send-email-vaurora@redhat.com> <1271372682-21225-10-git-send-email-vaurora@redhat.com> <1271372682-21225-11-git-send-email-vaurora@redhat.com> <1271372682-21225-12-git-send-email-vaurora@redhat.com> <1271372682-21225-13-git-send-email-vaurora@redhat.com> Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Valerie Aurora , Theodore Tso , linux-ext4@vger.kernel.org, Jan Blunck To: Alexander Viro Return-path: In-Reply-To: <1271372682-21225-13-git-send-email-vaurora@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Add support for fallthru directory entries to ext2. XXX - Makes up inode number for fallthru entry XXX - Might be better implemented as special symlinks Cc: Theodore Tso Cc: linux-ext4@vger.kernel.org Signed-off-by: Valerie Aurora Signed-off-by: Jan Blunck --- fs/ext2/dir.c | 92 ++++++++++++++++++++++++++++++++++++++++++++-- fs/ext2/ext2.h | 1 + fs/ext2/namei.c | 22 +++++++++++ include/linux/ext2_fs.h | 1 + 4 files changed, 112 insertions(+), 4 deletions(-) diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c index 030bd46..f3b4aff 100644 --- a/fs/ext2/dir.c +++ b/fs/ext2/dir.c @@ -219,7 +219,8 @@ static inline int ext2_match (int len, const char * const name, { if (len != de->name_len) return 0; - if (!de->inode && (de->file_type != EXT2_FT_WHT)) + if (!de->inode && ((de->file_type != EXT2_FT_WHT) && + (de->file_type != EXT2_FT_FALLTHRU))) return 0; return !memcmp(name, de->name, len); } @@ -256,6 +257,7 @@ static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { [EXT2_FT_SOCK] = DT_SOCK, [EXT2_FT_SYMLINK] = DT_LNK, [EXT2_FT_WHT] = DT_WHT, + [EXT2_FT_FALLTHRU] = DT_UNKNOWN, }; #define S_SHIFT 12 @@ -342,6 +344,24 @@ ext2_readdir (struct file * filp, void * dirent, filldir_t filldir) ext2_put_page(page); return 0; } + } else if (de->file_type == EXT2_FT_FALLTHRU) { + int over; + unsigned char d_type = DT_UNKNOWN; + + offset = (char *)de - kaddr; + /* XXX We don't know the inode number + * of the directory entry in the + * underlying file system. Should + * look it up, either on fallthru + * creation at first readdir or now at + * filldir time. */ + over = filldir(dirent, de->name, de->name_len, + (n<f_pos += ext2_rec_len_from_disk(de->rec_len); } @@ -463,6 +483,10 @@ ino_t ext2_inode_by_dentry(struct inode *dir, struct dentry *dentry) spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_WHITEOUT; spin_unlock(&dentry->d_lock); + } else if(!res && de->file_type == EXT2_FT_FALLTHRU) { + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_FALLTHRU; + spin_unlock(&dentry->d_lock); } ext2_put_page(page); } @@ -532,6 +556,7 @@ static ext2_dirent * ext2_append_entry(struct dentry * dentry, de->name_len = 0; de->rec_len = ext2_rec_len_to_disk(chunk_size); de->inode = 0; + de->file_type = 0; goto got_it; } if (de->rec_len == 0) { @@ -545,6 +570,7 @@ static ext2_dirent * ext2_append_entry(struct dentry * dentry, name_len = EXT2_DIR_REC_LEN(de->name_len); rec_len = ext2_rec_len_from_disk(de->rec_len); if (!de->inode && (de->file_type != EXT2_FT_WHT) && + (de->file_type != EXT2_FT_FALLTHRU) && (rec_len >= reclen)) goto got_it; if (rec_len >= name_len + reclen) @@ -587,7 +613,8 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode) err = -EEXIST; if (ext2_match (namelen, name, de)) { - if (de->file_type == EXT2_FT_WHT) + if ((de->file_type == EXT2_FT_WHT) || + (de->file_type == EXT2_FT_FALLTHRU)) goto got_it; goto out_unlock; } @@ -602,7 +629,8 @@ got_it: &page, NULL); if (err) goto out_unlock; - if (de->inode || ((de->file_type == EXT2_FT_WHT) && + if (de->inode || (((de->file_type == EXT2_FT_WHT) || + (de->file_type == EXT2_FT_FALLTHRU)) && !ext2_match (namelen, name, de))) { ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); @@ -627,6 +655,60 @@ out_unlock: } /* + * Create a fallthru entry. + */ +int ext2_fallthru_entry (struct inode *dir, struct dentry *dentry) +{ + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + unsigned short rec_len, name_len; + ext2_dirent * de; + struct page *page; + loff_t pos; + int err; + + de = ext2_append_entry(dentry, &page); + if (IS_ERR(de)) + return PTR_ERR(de); + + err = -EEXIST; + if (ext2_match (namelen, name, de)) + goto out_unlock; + + name_len = EXT2_DIR_REC_LEN(de->name_len); + rec_len = ext2_rec_len_from_disk(de->rec_len); + + pos = page_offset(page) + + (char*)de - (char*)page_address(page); + err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0, + &page, NULL); + if (err) + goto out_unlock; + if (de->inode || (de->file_type == EXT2_FT_WHT) || + (de->file_type == EXT2_FT_FALLTHRU)) { + ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); + de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); + de->rec_len = ext2_rec_len_to_disk(name_len); + de = de1; + } + de->name_len = namelen; + memcpy(de->name, name, namelen); + de->inode = 0; + de->file_type = EXT2_FT_FALLTHRU; + err = ext2_commit_chunk(page, pos, rec_len); + dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; + EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; + mark_inode_dirty(dir); + /* OFFSET_CACHE */ +out_put: + ext2_put_page(page); + return err; +out_unlock: + unlock_page(page); + goto out_put; +} + +/* * ext2_delete_entry deletes a directory entry by merging it with the * previous entry. Page is up-to-date. Releases the page. */ @@ -711,7 +793,9 @@ int ext2_whiteout_entry (struct inode * dir, struct dentry * dentry, */ if (ext2_match (namelen, name, de)) de->inode = 0; - if (de->inode || (de->file_type == EXT2_FT_WHT)) { + if (de->inode || (((de->file_type == EXT2_FT_WHT) || + (de->file_type == EXT2_FT_FALLTHRU)) && + !ext2_match (namelen, name, de))) { ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); de->rec_len = ext2_rec_len_to_disk(name_len); diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 44d190c..2fa32b3 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -108,6 +108,7 @@ extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct qstr *, extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *); extern int ext2_whiteout_entry (struct inode *, struct dentry *, struct ext2_dir_entry_2 *, struct page *); +extern int ext2_fallthru_entry (struct inode *, struct dentry *); extern int ext2_empty_dir (struct inode *); extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **); extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int); diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 12195a5..f28154c 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -349,6 +349,7 @@ static int ext2_whiteout(struct inode *dir, struct dentry *dentry, goto out; spin_lock(&new_dentry->d_lock); + new_dentry->d_flags &= ~DCACHE_FALLTHRU; new_dentry->d_flags |= DCACHE_WHITEOUT; spin_unlock(&new_dentry->d_lock); d_add(new_dentry, NULL); @@ -367,6 +368,26 @@ out: return err; } +/* + * Create a fallthru entry. + */ +static int ext2_fallthru (struct inode *dir, struct dentry *dentry) +{ + int err; + + dquot_initialize(dir); + + err = ext2_fallthru_entry(dir, dentry); + if (err) + return err; + + d_instantiate(dentry, NULL); + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_FALLTHRU; + spin_unlock(&dentry->d_lock); + return 0; +} + static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, struct inode * new_dir, struct dentry * new_dentry ) { @@ -470,6 +491,7 @@ const struct inode_operations ext2_dir_inode_operations = { .rmdir = ext2_rmdir, .mknod = ext2_mknod, .whiteout = ext2_whiteout, + .fallthru = ext2_fallthru, .rename = ext2_rename, #ifdef CONFIG_EXT2_FS_XATTR .setxattr = generic_setxattr, diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h index 20468bd..cb3d400 100644 --- a/include/linux/ext2_fs.h +++ b/include/linux/ext2_fs.h @@ -577,6 +577,7 @@ enum { EXT2_FT_SOCK = 6, EXT2_FT_SYMLINK = 7, EXT2_FT_WHT = 8, + EXT2_FT_FALLTHRU = 9, EXT2_FT_MAX }; -- 1.6.3.3