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author | Boaz Harrosh <bharrosh@panasas.com> | 2008-10-28 13:38:12 (GMT) |
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committer | Boaz Harrosh <bharrosh@panasas.com> | 2009-03-31 16:44:31 (GMT) |
commit | e6af00f1d1697ca41ab6a55307066ef3466833a9 (patch) | |
tree | 7aa0b64f14a994f30e6bdc8e8c0b7f811038e794 /fs/exofs/namei.c | |
parent | beaec07ba6af35d387643b76a2920a7a6e22207b (diff) | |
download | linux-e6af00f1d1697ca41ab6a55307066ef3466833a9.tar.xz |
exofs: dir_inode and directory operations
implementation of directory and inode operations.
* A directory is treated as a file, and essentially contains a list
of <file name, inode #> pairs for files that are found in that
directory. The object IDs correspond to the files' inode numbers
and are allocated using a 64bit incrementing global counter.
* Each file's control block (AKA on-disk inode) is stored in its
object's attributes. This applies to both regular files and other
types (directories, device files, symlinks, etc.).
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Diffstat (limited to 'fs/exofs/namei.c')
-rw-r--r-- | fs/exofs/namei.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/fs/exofs/namei.c b/fs/exofs/namei.c new file mode 100644 index 0000000..77fdd76 --- /dev/null +++ b/fs/exofs/namei.c @@ -0,0 +1,342 @@ +/* + * Copyright (C) 2005, 2006 + * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com) + * Copyright (C) 2005, 2006 + * International Business Machines + * Copyright (C) 2008, 2009 + * Boaz Harrosh <bharrosh@panasas.com> + * + * Copyrights for code taken from ext2: + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * from + * linux/fs/minix/inode.c + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This file is part of exofs. + * + * exofs is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation. Since it is based on ext2, and the only + * valid version of GPL for the Linux kernel is version 2, the only valid + * version of GPL for exofs is version 2. + * + * exofs is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with exofs; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "exofs.h" + +static inline int exofs_add_nondir(struct dentry *dentry, struct inode *inode) +{ + int err = exofs_add_link(dentry, inode); + if (!err) { + d_instantiate(dentry, inode); + return 0; + } + inode_dec_link_count(inode); + iput(inode); + return err; +} + +static struct dentry *exofs_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + struct inode *inode; + ino_t ino; + + if (dentry->d_name.len > EXOFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + ino = exofs_inode_by_name(dir, dentry); + inode = NULL; + if (ino) { + inode = exofs_iget(dir->i_sb, ino); + if (IS_ERR(inode)) + return ERR_CAST(inode); + } + return d_splice_alias(inode, dentry); +} + +static int exofs_create(struct inode *dir, struct dentry *dentry, int mode, + struct nameidata *nd) +{ + struct inode *inode = exofs_new_inode(dir, mode); + int err = PTR_ERR(inode); + if (!IS_ERR(inode)) { + inode->i_op = &exofs_file_inode_operations; + inode->i_fop = &exofs_file_operations; + inode->i_mapping->a_ops = &exofs_aops; + mark_inode_dirty(inode); + err = exofs_add_nondir(dentry, inode); + } + return err; +} + +static int exofs_mknod(struct inode *dir, struct dentry *dentry, int mode, + dev_t rdev) +{ + struct inode *inode; + int err; + + if (!new_valid_dev(rdev)) + return -EINVAL; + + inode = exofs_new_inode(dir, mode); + err = PTR_ERR(inode); + if (!IS_ERR(inode)) { + init_special_inode(inode, inode->i_mode, rdev); + mark_inode_dirty(inode); + err = exofs_add_nondir(dentry, inode); + } + return err; +} + +static int exofs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct super_block *sb = dir->i_sb; + int err = -ENAMETOOLONG; + unsigned l = strlen(symname)+1; + struct inode *inode; + struct exofs_i_info *oi; + + if (l > sb->s_blocksize) + goto out; + + inode = exofs_new_inode(dir, S_IFLNK | S_IRWXUGO); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out; + + oi = exofs_i(inode); + if (l > sizeof(oi->i_data)) { + /* slow symlink */ + inode->i_op = &exofs_symlink_inode_operations; + inode->i_mapping->a_ops = &exofs_aops; + memset(oi->i_data, 0, sizeof(oi->i_data)); + + err = page_symlink(inode, symname, l); + if (err) + goto out_fail; + } else { + /* fast symlink */ + inode->i_op = &exofs_fast_symlink_inode_operations; + memcpy(oi->i_data, symname, l); + inode->i_size = l-1; + } + mark_inode_dirty(inode); + + err = exofs_add_nondir(dentry, inode); +out: + return err; + +out_fail: + inode_dec_link_count(inode); + iput(inode); + goto out; +} + +static int exofs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct inode *inode = old_dentry->d_inode; + + if (inode->i_nlink >= EXOFS_LINK_MAX) + return -EMLINK; + + inode->i_ctime = CURRENT_TIME; + inode_inc_link_count(inode); + atomic_inc(&inode->i_count); + + return exofs_add_nondir(dentry, inode); +} + +static int exofs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + struct inode *inode; + int err = -EMLINK; + + if (dir->i_nlink >= EXOFS_LINK_MAX) + goto out; + + inode_inc_link_count(dir); + + inode = exofs_new_inode(dir, S_IFDIR | mode); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_dir; + + inode->i_op = &exofs_dir_inode_operations; + inode->i_fop = &exofs_dir_operations; + inode->i_mapping->a_ops = &exofs_aops; + + inode_inc_link_count(inode); + + err = exofs_make_empty(inode, dir); + if (err) + goto out_fail; + + err = exofs_add_link(dentry, inode); + if (err) + goto out_fail; + + d_instantiate(dentry, inode); +out: + return err; + +out_fail: + inode_dec_link_count(inode); + inode_dec_link_count(inode); + iput(inode); +out_dir: + inode_dec_link_count(dir); + goto out; +} + +static int exofs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + struct exofs_dir_entry *de; + struct page *page; + int err = -ENOENT; + + de = exofs_find_entry(dir, dentry, &page); + if (!de) + goto out; + + err = exofs_delete_entry(de, page); + if (err) + goto out; + + inode->i_ctime = dir->i_ctime; + inode_dec_link_count(inode); + err = 0; +out: + return err; +} + +static int exofs_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + int err = -ENOTEMPTY; + + if (exofs_empty_dir(inode)) { + err = exofs_unlink(dir, dentry); + if (!err) { + inode->i_size = 0; + inode_dec_link_count(inode); + inode_dec_link_count(dir); + } + } + return err; +} + +static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct inode *old_inode = old_dentry->d_inode; + struct inode *new_inode = new_dentry->d_inode; + struct page *dir_page = NULL; + struct exofs_dir_entry *dir_de = NULL; + struct page *old_page; + struct exofs_dir_entry *old_de; + int err = -ENOENT; + + old_de = exofs_find_entry(old_dir, old_dentry, &old_page); + if (!old_de) + goto out; + + if (S_ISDIR(old_inode->i_mode)) { + err = -EIO; + dir_de = exofs_dotdot(old_inode, &dir_page); + if (!dir_de) + goto out_old; + } + + if (new_inode) { + struct page *new_page; + struct exofs_dir_entry *new_de; + + err = -ENOTEMPTY; + if (dir_de && !exofs_empty_dir(new_inode)) + goto out_dir; + + err = -ENOENT; + new_de = exofs_find_entry(new_dir, new_dentry, &new_page); + if (!new_de) + goto out_dir; + inode_inc_link_count(old_inode); + err = exofs_set_link(new_dir, new_de, new_page, old_inode); + new_inode->i_ctime = CURRENT_TIME; + if (dir_de) + drop_nlink(new_inode); + inode_dec_link_count(new_inode); + if (err) + goto out_dir; + } else { + if (dir_de) { + err = -EMLINK; + if (new_dir->i_nlink >= EXOFS_LINK_MAX) + goto out_dir; + } + inode_inc_link_count(old_inode); + err = exofs_add_link(new_dentry, old_inode); + if (err) { + inode_dec_link_count(old_inode); + goto out_dir; + } + if (dir_de) + inode_inc_link_count(new_dir); + } + + old_inode->i_ctime = CURRENT_TIME; + + exofs_delete_entry(old_de, old_page); + inode_dec_link_count(old_inode); + + if (dir_de) { + err = exofs_set_link(old_inode, dir_de, dir_page, new_dir); + inode_dec_link_count(old_dir); + if (err) + goto out_dir; + } + return 0; + + +out_dir: + if (dir_de) { + kunmap(dir_page); + page_cache_release(dir_page); + } +out_old: + kunmap(old_page); + page_cache_release(old_page); +out: + return err; +} + +const struct inode_operations exofs_dir_inode_operations = { + .create = exofs_create, + .lookup = exofs_lookup, + .link = exofs_link, + .unlink = exofs_unlink, + .symlink = exofs_symlink, + .mkdir = exofs_mkdir, + .rmdir = exofs_rmdir, + .mknod = exofs_mknod, + .rename = exofs_rename, + .setattr = exofs_setattr, +}; + +const struct inode_operations exofs_special_inode_operations = { + .setattr = exofs_setattr, +}; |