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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/coda/dir.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/coda/dir.c')
-rw-r--r-- | fs/coda/dir.c | 704 |
1 files changed, 704 insertions, 0 deletions
diff --git a/fs/coda/dir.c b/fs/coda/dir.c new file mode 100644 index 0000000..2391766 --- /dev/null +++ b/fs/coda/dir.c @@ -0,0 +1,704 @@ + +/* + * Directory operations for Coda filesystem + * Original version: (C) 1996 P. Braam and M. Callahan + * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University + * + * Carnegie Mellon encourages users to contribute improvements to + * the Coda project. Contact Peter Braam (coda@cs.cmu.edu). + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/stat.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/smp_lock.h> + +#include <asm/uaccess.h> + +#include <linux/coda.h> +#include <linux/coda_linux.h> +#include <linux/coda_psdev.h> +#include <linux/coda_fs_i.h> +#include <linux/coda_cache.h> +#include <linux/coda_proc.h> + +/* dir inode-ops */ +static int coda_create(struct inode *dir, struct dentry *new, int mode, struct nameidata *nd); +static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, struct nameidata *nd); +static int coda_link(struct dentry *old_dentry, struct inode *dir_inode, + struct dentry *entry); +static int coda_unlink(struct inode *dir_inode, struct dentry *entry); +static int coda_symlink(struct inode *dir_inode, struct dentry *entry, + const char *symname); +static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, int mode); +static int coda_rmdir(struct inode *dir_inode, struct dentry *entry); +static int coda_rename(struct inode *old_inode, struct dentry *old_dentry, + struct inode *new_inode, struct dentry *new_dentry); + +/* dir file-ops */ +static int coda_readdir(struct file *file, void *dirent, filldir_t filldir); + +/* dentry ops */ +static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd); +static int coda_dentry_delete(struct dentry *); + +/* support routines */ +static int coda_venus_readdir(struct file *filp, filldir_t filldir, + void *dirent, struct dentry *dir); +int coda_fsync(struct file *, struct dentry *dentry, int datasync); + +/* same as fs/bad_inode.c */ +static int coda_return_EIO(void) +{ + return -EIO; +} +#define CODA_EIO_ERROR ((void *) (coda_return_EIO)) + +static struct dentry_operations coda_dentry_operations = +{ + .d_revalidate = coda_dentry_revalidate, + .d_delete = coda_dentry_delete, +}; + +struct inode_operations coda_dir_inode_operations = +{ + .create = coda_create, + .lookup = coda_lookup, + .link = coda_link, + .unlink = coda_unlink, + .symlink = coda_symlink, + .mkdir = coda_mkdir, + .rmdir = coda_rmdir, + .mknod = CODA_EIO_ERROR, + .rename = coda_rename, + .permission = coda_permission, + .getattr = coda_getattr, + .setattr = coda_setattr, +}; + +struct file_operations coda_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .readdir = coda_readdir, + .open = coda_open, + .flush = coda_flush, + .release = coda_release, + .fsync = coda_fsync, +}; + + +/* inode operations for directories */ +/* access routines: lookup, readlink, permission */ +static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd) +{ + struct inode *res_inode = NULL; + struct CodaFid resfid = { { 0, } }; + int dropme = 0; /* to indicate entry should not be cached */ + int type = 0; + int error = 0; + const char *name = entry->d_name.name; + size_t length = entry->d_name.len; + + if ( length > CODA_MAXNAMLEN ) { + printk("name too long: lookup, %s (%*s)\n", + coda_i2s(dir), (int)length, name); + return ERR_PTR(-ENAMETOOLONG); + } + + lock_kernel(); + /* control object, create inode on the fly */ + if (coda_isroot(dir) && coda_iscontrol(name, length)) { + error = coda_cnode_makectl(&res_inode, dir->i_sb); + dropme = 1; + goto exit; + } + + error = venus_lookup(dir->i_sb, coda_i2f(dir), + (const char *)name, length, &type, &resfid); + + res_inode = NULL; + if (!error) { + if (type & CODA_NOCACHE) { + type &= (~CODA_NOCACHE); + dropme = 1; + } + + error = coda_cnode_make(&res_inode, &resfid, dir->i_sb); + if (error) { + unlock_kernel(); + return ERR_PTR(error); + } + } else if (error != -ENOENT) { + unlock_kernel(); + return ERR_PTR(error); + } + +exit: + entry->d_time = 0; + entry->d_op = &coda_dentry_operations; + d_add(entry, res_inode); + if ( dropme ) { + d_drop(entry); + coda_flag_inode(res_inode, C_VATTR); + } + unlock_kernel(); + return NULL; +} + + +int coda_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + int error = 0; + + if (!mask) + return 0; + + lock_kernel(); + + coda_vfs_stat.permission++; + + if (coda_cache_check(inode, mask)) + goto out; + + error = venus_access(inode->i_sb, coda_i2f(inode), mask); + + if (!error) + coda_cache_enter(inode, mask); + + out: + unlock_kernel(); + + return error; +} + + +static inline void coda_dir_changed(struct inode *dir, int link) +{ +#ifdef REQUERY_VENUS_FOR_MTIME + /* invalidate the directory cnode's attributes so we refetch the + * attributes from venus next time the inode is referenced */ + coda_flag_inode(dir, C_VATTR); +#else + /* optimistically we can also act as if our nose bleeds. The + * granularity of the mtime is coarse anyways so we might actually be + * right most of the time. Note: we only do this for directories. */ + dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; +#endif + if (link) + dir->i_nlink += link; +} + +/* creation routines: create, mknod, mkdir, link, symlink */ +static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd) +{ + int error=0; + const char *name=de->d_name.name; + int length=de->d_name.len; + struct inode *inode; + struct CodaFid newfid; + struct coda_vattr attrs; + + lock_kernel(); + coda_vfs_stat.create++; + + if (coda_isroot(dir) && coda_iscontrol(name, length)) { + unlock_kernel(); + return -EPERM; + } + + error = venus_create(dir->i_sb, coda_i2f(dir), name, length, + 0, mode, &newfid, &attrs); + + if ( error ) { + unlock_kernel(); + d_drop(de); + return error; + } + + inode = coda_iget(dir->i_sb, &newfid, &attrs); + if ( IS_ERR(inode) ) { + unlock_kernel(); + d_drop(de); + return PTR_ERR(inode); + } + + /* invalidate the directory cnode's attributes */ + coda_dir_changed(dir, 0); + unlock_kernel(); + d_instantiate(de, inode); + return 0; +} + +static int coda_mkdir(struct inode *dir, struct dentry *de, int mode) +{ + struct inode *inode; + struct coda_vattr attrs; + const char *name = de->d_name.name; + int len = de->d_name.len; + int error; + struct CodaFid newfid; + + lock_kernel(); + coda_vfs_stat.mkdir++; + + if (coda_isroot(dir) && coda_iscontrol(name, len)) { + unlock_kernel(); + return -EPERM; + } + + attrs.va_mode = mode; + error = venus_mkdir(dir->i_sb, coda_i2f(dir), + name, len, &newfid, &attrs); + + if ( error ) { + unlock_kernel(); + d_drop(de); + return error; + } + + inode = coda_iget(dir->i_sb, &newfid, &attrs); + if ( IS_ERR(inode) ) { + unlock_kernel(); + d_drop(de); + return PTR_ERR(inode); + } + + /* invalidate the directory cnode's attributes */ + coda_dir_changed(dir, 1); + unlock_kernel(); + d_instantiate(de, inode); + return 0; +} + +/* try to make de an entry in dir_inodde linked to source_de */ +static int coda_link(struct dentry *source_de, struct inode *dir_inode, + struct dentry *de) +{ + struct inode *inode = source_de->d_inode; + const char * name = de->d_name.name; + int len = de->d_name.len; + int error; + + lock_kernel(); + coda_vfs_stat.link++; + + if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) { + unlock_kernel(); + return -EPERM; + } + + error = venus_link(dir_inode->i_sb, coda_i2f(inode), + coda_i2f(dir_inode), (const char *)name, len); + + if (error) { + d_drop(de); + goto out; + } + + coda_dir_changed(dir_inode, 0); + atomic_inc(&inode->i_count); + d_instantiate(de, inode); + inode->i_nlink++; + +out: + unlock_kernel(); + return(error); +} + + +static int coda_symlink(struct inode *dir_inode, struct dentry *de, + const char *symname) +{ + const char *name = de->d_name.name; + int len = de->d_name.len; + int symlen; + int error=0; + + lock_kernel(); + coda_vfs_stat.symlink++; + + if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) { + unlock_kernel(); + return -EPERM; + } + + symlen = strlen(symname); + if ( symlen > CODA_MAXPATHLEN ) { + unlock_kernel(); + return -ENAMETOOLONG; + } + + /* + * This entry is now negative. Since we do not create + * an inode for the entry we have to drop it. + */ + d_drop(de); + error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len, + symname, symlen); + + /* mtime is no good anymore */ + if ( !error ) + coda_dir_changed(dir_inode, 0); + + unlock_kernel(); + return error; +} + +/* destruction routines: unlink, rmdir */ +int coda_unlink(struct inode *dir, struct dentry *de) +{ + int error; + const char *name = de->d_name.name; + int len = de->d_name.len; + + lock_kernel(); + coda_vfs_stat.unlink++; + + error = venus_remove(dir->i_sb, coda_i2f(dir), name, len); + if ( error ) { + unlock_kernel(); + return error; + } + + coda_dir_changed(dir, 0); + de->d_inode->i_nlink--; + unlock_kernel(); + + return 0; +} + +int coda_rmdir(struct inode *dir, struct dentry *de) +{ + const char *name = de->d_name.name; + int len = de->d_name.len; + int error; + + lock_kernel(); + coda_vfs_stat.rmdir++; + + if (!d_unhashed(de)) { + unlock_kernel(); + return -EBUSY; + } + error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len); + + if ( error ) { + unlock_kernel(); + return error; + } + + coda_dir_changed(dir, -1); + de->d_inode->i_nlink--; + d_delete(de); + unlock_kernel(); + + return 0; +} + +/* rename */ +static int coda_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + const char *old_name = old_dentry->d_name.name; + const char *new_name = new_dentry->d_name.name; + int old_length = old_dentry->d_name.len; + int new_length = new_dentry->d_name.len; + int link_adjust = 0; + int error; + + lock_kernel(); + coda_vfs_stat.rename++; + + error = venus_rename(old_dir->i_sb, coda_i2f(old_dir), + coda_i2f(new_dir), old_length, new_length, + (const char *) old_name, (const char *)new_name); + + if ( !error ) { + if ( new_dentry->d_inode ) { + if ( S_ISDIR(new_dentry->d_inode->i_mode) ) + link_adjust = 1; + + coda_dir_changed(old_dir, -link_adjust); + coda_dir_changed(new_dir, link_adjust); + coda_flag_inode(new_dentry->d_inode, C_VATTR); + } else { + coda_flag_inode(old_dir, C_VATTR); + coda_flag_inode(new_dir, C_VATTR); + } + } + unlock_kernel(); + + return error; +} + + +/* file operations for directories */ +int coda_readdir(struct file *coda_file, void *dirent, filldir_t filldir) +{ + struct dentry *coda_dentry = coda_file->f_dentry; + struct coda_file_info *cfi; + struct file *host_file; + struct inode *host_inode; + int ret; + + cfi = CODA_FTOC(coda_file); + BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); + host_file = cfi->cfi_container; + + coda_vfs_stat.readdir++; + + host_inode = host_file->f_dentry->d_inode; + down(&host_inode->i_sem); + host_file->f_pos = coda_file->f_pos; + + if (!host_file->f_op->readdir) { + /* Venus: we must read Venus dirents from the file */ + ret = coda_venus_readdir(host_file, filldir, dirent, coda_dentry); + } else { + /* potemkin case: we were handed a directory inode. */ + /* Yuk, we can't call vfs_readdir because we are already + * holding the inode semaphore. */ + ret = -ENOTDIR; + if (!host_file->f_op || !host_file->f_op->readdir) + goto out; + + ret = -ENOENT; + if (!IS_DEADDIR(host_inode)) { + ret = host_file->f_op->readdir(host_file, filldir, dirent); + file_accessed(host_file); + } + } +out: + coda_file->f_pos = host_file->f_pos; + up(&host_inode->i_sem); + + return ret; +} + +static inline unsigned int CDT2DT(unsigned char cdt) +{ + unsigned int dt; + + switch(cdt) { + case CDT_UNKNOWN: dt = DT_UNKNOWN; break; + case CDT_FIFO: dt = DT_FIFO; break; + case CDT_CHR: dt = DT_CHR; break; + case CDT_DIR: dt = DT_DIR; break; + case CDT_BLK: dt = DT_BLK; break; + case CDT_REG: dt = DT_REG; break; + case CDT_LNK: dt = DT_LNK; break; + case CDT_SOCK: dt = DT_SOCK; break; + case CDT_WHT: dt = DT_WHT; break; + default: dt = DT_UNKNOWN; break; + } + return dt; +} + +/* support routines */ +static int coda_venus_readdir(struct file *filp, filldir_t filldir, + void *dirent, struct dentry *dir) +{ + int result = 0; /* # of entries returned */ + struct venus_dirent *vdir; + unsigned long vdir_size = + (unsigned long)(&((struct venus_dirent *)0)->d_name); + unsigned int type; + struct qstr name; + ino_t ino; + int ret, i; + + vdir = (struct venus_dirent *)kmalloc(sizeof(*vdir), GFP_KERNEL); + if (!vdir) return -ENOMEM; + + i = filp->f_pos; + switch(i) { + case 0: + ret = filldir(dirent, ".", 1, 0, dir->d_inode->i_ino, DT_DIR); + if (ret < 0) break; + result++; + filp->f_pos++; + /* fallthrough */ + case 1: + ret = filldir(dirent, "..", 2, 1, dir->d_parent->d_inode->i_ino, DT_DIR); + if (ret < 0) break; + result++; + filp->f_pos++; + /* fallthrough */ + default: + while (1) { + /* read entries from the directory file */ + ret = kernel_read(filp, filp->f_pos - 2, (char *)vdir, + sizeof(*vdir)); + if (ret < 0) { + printk("coda_venus_readdir: read dir failed %d\n", ret); + break; + } + if (ret == 0) break; /* end of directory file reached */ + + /* catch truncated reads */ + if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) { + printk("coda_venus_readdir: short read: %ld\n", + filp->f_dentry->d_inode->i_ino); + ret = -EBADF; + break; + } + /* validate whether the directory file actually makes sense */ + if (vdir->d_reclen < vdir_size + vdir->d_namlen) { + printk("coda_venus_readdir: Invalid dir: %ld\n", + filp->f_dentry->d_inode->i_ino); + ret = -EBADF; + break; + } + + name.len = vdir->d_namlen; + name.name = vdir->d_name; + + /* Make sure we skip '.' and '..', we already got those */ + if (name.name[0] == '.' && (name.len == 1 || + (vdir->d_name[1] == '.' && name.len == 2))) + vdir->d_fileno = name.len = 0; + + /* skip null entries */ + if (vdir->d_fileno && name.len) { + /* try to look up this entry in the dcache, that way + * userspace doesn't have to worry about breaking + * getcwd by having mismatched inode numbers for + * internal volume mountpoints. */ + ino = find_inode_number(dir, &name); + if (!ino) ino = vdir->d_fileno; + + type = CDT2DT(vdir->d_type); + ret = filldir(dirent, name.name, name.len, filp->f_pos, + ino, type); + /* failure means no space for filling in this round */ + if (ret < 0) break; + result++; + } + /* we'll always have progress because d_reclen is unsigned and + * we've already established it is non-zero. */ + filp->f_pos += vdir->d_reclen; + } + } + kfree(vdir); + return result ? result : ret; +} + +/* called when a cache lookup succeeds */ +static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd) +{ + struct inode *inode = de->d_inode; + struct coda_inode_info *cii; + + if (!inode) + return 1; + lock_kernel(); + if (coda_isroot(inode)) + goto out; + if (is_bad_inode(inode)) + goto bad; + + cii = ITOC(de->d_inode); + if (!(cii->c_flags & (C_PURGE | C_FLUSH))) + goto out; + + shrink_dcache_parent(de); + + /* propagate for a flush */ + if (cii->c_flags & C_FLUSH) + coda_flag_inode_children(inode, C_FLUSH); + + if (atomic_read(&de->d_count) > 1) + /* pretend it's valid, but don't change the flags */ + goto out; + + /* clear the flags. */ + cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH); + +bad: + unlock_kernel(); + return 0; +out: + unlock_kernel(); + return 1; +} + +/* + * This is the callback from dput() when d_count is going to 0. + * We use this to unhash dentries with bad inodes. + */ +static int coda_dentry_delete(struct dentry * dentry) +{ + int flags; + + if (!dentry->d_inode) + return 0; + + flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE; + if (is_bad_inode(dentry->d_inode) || flags) { + return 1; + } + return 0; +} + + + +/* + * This is called when we want to check if the inode has + * changed on the server. Coda makes this easy since the + * cache manager Venus issues a downcall to the kernel when this + * happens + */ +int coda_revalidate_inode(struct dentry *dentry) +{ + struct coda_vattr attr; + int error = 0; + int old_mode; + ino_t old_ino; + struct inode *inode = dentry->d_inode; + struct coda_inode_info *cii = ITOC(inode); + + lock_kernel(); + if ( !cii->c_flags ) + goto ok; + + if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) { + error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr); + if ( error ) + goto return_bad; + + /* this inode may be lost if: + - it's ino changed + - type changes must be permitted for repair and + missing mount points. + */ + old_mode = inode->i_mode; + old_ino = inode->i_ino; + coda_vattr_to_iattr(inode, &attr); + + if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) { + printk("Coda: inode %ld, fid %s changed type!\n", + inode->i_ino, coda_f2s(&(cii->c_fid))); + } + + /* the following can happen when a local fid is replaced + with a global one, here we lose and declare the inode bad */ + if (inode->i_ino != old_ino) + goto return_bad; + + coda_flag_inode_children(inode, C_FLUSH); + cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH); + } + +ok: + unlock_kernel(); + return 0; + +return_bad: + unlock_kernel(); + return -EIO; +} |