From 6a3124a3946c16159c3faf83e62ffdb5d1134b3a Mon Sep 17 00:00:00 2001 From: Latchesar Ionkov Date: Thu, 2 Mar 2006 02:54:30 -0800 Subject: [PATCH] v9fs: fix atomic create open In order to assure atomic create+open v9fs stores the open fid produced by v9fs_vfs_create in the dentry, from where v9fs_file_open retrieves it and associates it with the open file. This patch modifies v9fs to use nameidata.intent.open values to do the atomic create+open. Signed-off-by: Latchesar Ionkov Signed-off-by: Eric Van Hensbergen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/9p/vfs_inode.c | 478 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 312 insertions(+), 166 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 63e5b03..dce729d 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -125,6 +125,38 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode) return res; } +int v9fs_uflags2omode(int uflags) +{ + int ret; + + ret = 0; + switch (uflags&3) { + default: + case O_RDONLY: + ret = V9FS_OREAD; + break; + + case O_WRONLY: + ret = V9FS_OWRITE; + break; + + case O_RDWR: + ret = V9FS_ORDWR; + break; + } + + if (uflags & O_EXCL) + ret |= V9FS_OEXCL; + + if (uflags & O_TRUNC) + ret |= V9FS_OTRUNC; + + if (uflags & O_APPEND) + ret |= V9FS_OAPPEND; + + return ret; +} + /** * v9fs_blank_wstat - helper function to setup a 9P stat structure * @v9ses: 9P session info (for determining extended mode) @@ -163,7 +195,7 @@ v9fs_blank_wstat(struct v9fs_wstat *wstat) struct inode *v9fs_get_inode(struct super_block *sb, int mode) { - struct inode *inode = NULL; + struct inode *inode; struct v9fs_session_info *v9ses = sb->s_fs_info; dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode); @@ -222,171 +254,135 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode) return inode; } -/** - * v9fs_create - helper function to create files and directories - * @dir: directory inode file is being created in - * @file_dentry: dentry file is being created in - * @perm: permissions file is being created with - * @open_mode: resulting open mode for file - * - */ - static int -v9fs_create(struct inode *dir, - struct dentry *file_dentry, - unsigned int perm, unsigned int open_mode) +v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, + u32 perm, u8 mode, u32 *fidp, struct v9fs_qid *qid, u32 *iounit) { - struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); - struct super_block *sb = dir->i_sb; - struct v9fs_fid *dirfid = - v9fs_fid_lookup(file_dentry->d_parent); - struct v9fs_fid *fid = NULL; - struct inode *file_inode = NULL; - struct v9fs_fcall *fcall = NULL; - struct v9fs_qid qid; - int dirfidnum = -1; - long newfid = -1; - int result = 0; - unsigned int iounit = 0; - int wfidno = -1; + u32 fid; int err; + struct v9fs_fcall *fcall; - perm = unixmode2p9mode(v9ses, perm); - - dprintk(DEBUG_VFS, "dir: %p dentry: %p perm: %o mode: %o\n", dir, - file_dentry, perm, open_mode); - - if (!dirfid) - return -EBADF; - - dirfidnum = dirfid->fid; - if (dirfidnum < 0) { - dprintk(DEBUG_ERROR, "No fid for the directory #%lu\n", - dir->i_ino); - return -EBADF; - } - - if (file_dentry->d_inode) { - dprintk(DEBUG_ERROR, - "Odd. There is an inode for dir %lu, name :%s:\n", - dir->i_ino, file_dentry->d_name.name); - return -EEXIST; - } - - newfid = v9fs_get_idpool(&v9ses->fidpool); - if (newfid < 0) { + fid = v9fs_get_idpool(&v9ses->fidpool); + if (fid < 0) { eprintk(KERN_WARNING, "no free fids available\n"); - return -ENOSPC; + err = -ENOSPC; + goto error; } - result = v9fs_t_walk(v9ses, dirfidnum, newfid, NULL, &fcall); - if (result < 0) { + err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall); + if (err < 0) { PRINT_FCALL_ERROR("clone error", fcall); - v9fs_put_idpool(newfid, &v9ses->fidpool); - newfid = -1; - goto CleanUpFid; + goto error; } - kfree(fcall); - fcall = NULL; - result = v9fs_t_create(v9ses, newfid, (char *)file_dentry->d_name.name, - perm, open_mode, &fcall); - if (result < 0) { + err = v9fs_t_create(v9ses, fid, name, perm, mode, &fcall); + if (err < 0) { PRINT_FCALL_ERROR("create fails", fcall); - goto CleanUpFid; + goto error; } - iounit = fcall->params.rcreate.iounit; - qid = fcall->params.rcreate.qid; + if (iounit) + *iounit = fcall->params.rcreate.iounit; + + if (qid) + *qid = fcall->params.rcreate.qid; + + if (fidp) + *fidp = fid; + kfree(fcall); - fcall = NULL; + return 0; - if (!(perm&V9FS_DMDIR)) { - fid = v9fs_fid_create(file_dentry, v9ses, newfid, 1); - dprintk(DEBUG_VFS, "fid %p %d\n", fid, fid->fidcreate); - if (!fid) { - result = -ENOMEM; - goto CleanUpFid; - } +error: + if (fid >= 0) + v9fs_put_idpool(fid, &v9ses->fidpool); - fid->qid = qid; - fid->iounit = iounit; - } else { - err = v9fs_t_clunk(v9ses, newfid); - newfid = -1; - if (err < 0) - dprintk(DEBUG_ERROR, "clunk for mkdir failed: %d\n", err); - } + kfree(fcall); + return err; +} + +static struct v9fs_fid* +v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry) +{ + int err; + u32 nfid; + struct v9fs_fid *ret; + struct v9fs_fcall *fcall; - /* walk to the newly created file and put the fid in the dentry */ - wfidno = v9fs_get_idpool(&v9ses->fidpool); - if (wfidno < 0) { + nfid = v9fs_get_idpool(&v9ses->fidpool); + if (nfid < 0) { eprintk(KERN_WARNING, "no free fids available\n"); - return -ENOSPC; + err = -ENOSPC; + goto error; } - result = v9fs_t_walk(v9ses, dirfidnum, wfidno, - (char *) file_dentry->d_name.name, &fcall); - if (result < 0) { - PRINT_FCALL_ERROR("clone error", fcall); - v9fs_put_idpool(wfidno, &v9ses->fidpool); - wfidno = -1; - goto CleanUpFid; + err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name, + &fcall); + + if (err < 0) { + PRINT_FCALL_ERROR("walk error", fcall); + v9fs_put_idpool(nfid, &v9ses->fidpool); + goto error; } + kfree(fcall); fcall = NULL; + ret = v9fs_fid_create(v9ses, nfid); + if (!ret) { + err = -ENOMEM; + goto clunk_fid; + } - if (!v9fs_fid_create(file_dentry, v9ses, wfidno, 0)) { - v9fs_put_idpool(wfidno, &v9ses->fidpool); - - goto CleanUpFid; + err = v9fs_fid_insert(ret, dentry); + if (err < 0) { + v9fs_fid_destroy(ret); + goto clunk_fid; } - if ((perm & V9FS_DMSYMLINK) || (perm & V9FS_DMLINK) || - (perm & V9FS_DMNAMEDPIPE) || (perm & V9FS_DMSOCKET) || - (perm & V9FS_DMDEVICE)) - return 0; + return ret; - result = v9fs_t_stat(v9ses, wfidno, &fcall); - if (result < 0) { - PRINT_FCALL_ERROR("stat error", fcall); - goto CleanUpFid; - } +clunk_fid: + v9fs_t_clunk(v9ses, nfid); + +error: + kfree(fcall); + return ERR_PTR(err); +} +struct inode * +v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid, + struct super_block *sb) +{ + int err, umode; + struct inode *ret; + struct v9fs_fcall *fcall; - file_inode = v9fs_get_inode(sb, - p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode)); + ret = NULL; + err = v9fs_t_stat(v9ses, fid, &fcall); + if (err) { + PRINT_FCALL_ERROR("stat error", fcall); + goto error; + } - if ((!file_inode) || IS_ERR(file_inode)) { - dprintk(DEBUG_ERROR, "create inode failed\n"); - result = -EBADF; - goto CleanUpFid; + umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode); + ret = v9fs_get_inode(sb, umode); + if (IS_ERR(ret)) { + err = PTR_ERR(ret); + ret = NULL; + goto error; } - v9fs_stat2inode(&fcall->params.rstat.stat, file_inode, sb); + v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb); kfree(fcall); - fcall = NULL; - file_dentry->d_op = &v9fs_dentry_operations; - d_instantiate(file_dentry, file_inode); - - return 0; + return ret; - CleanUpFid: +error: kfree(fcall); - fcall = NULL; + if (ret) + iput(ret); - if (newfid >= 0) { - err = v9fs_t_clunk(v9ses, newfid); - if (err < 0) - dprintk(DEBUG_ERROR, "clunk failed: %d\n", err); - } - if (wfidno >= 0) { - err = v9fs_t_clunk(v9ses, wfidno); - if (err < 0) - dprintk(DEBUG_ERROR, "clunk failed: %d\n", err); - } - return result; + return ERR_PTR(err); } /** @@ -440,20 +436,97 @@ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir) return result; } +static int +v9fs_open_created(struct inode *inode, struct file *file) +{ + return 0; +} + /** * v9fs_vfs_create - VFS hook to create files * @inode: directory inode that is being deleted * @dentry: dentry that is being deleted - * @perm: create permissions + * @mode: create permissions * @nd: path information * */ static int -v9fs_vfs_create(struct inode *inode, struct dentry *dentry, int perm, +v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { - return v9fs_create(inode, dentry, perm, O_RDWR); + int err; + u32 fid, perm, iounit; + int flags; + struct v9fs_session_info *v9ses; + struct v9fs_fid *dfid, *vfid, *ffid; + struct inode *inode; + struct v9fs_qid qid; + struct file *filp; + + inode = NULL; + vfid = NULL; + v9ses = v9fs_inode2v9ses(dir); + dfid = v9fs_fid_lookup(dentry->d_parent); + perm = unixmode2p9mode(v9ses, mode); + + if (nd && nd->flags & LOOKUP_OPEN) + flags = nd->intent.open.flags - 1; + else + flags = O_RDWR; + + err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name, + perm, v9fs_uflags2omode(flags), &fid, &qid, &iounit); + + if (err) + goto error; + + vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry); + if (IS_ERR(vfid)) { + err = PTR_ERR(vfid); + vfid = NULL; + goto error; + } + + inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto error; + } + + dentry->d_op = &v9fs_dentry_operations; + d_instantiate(dentry, inode); + + if (nd && nd->flags & LOOKUP_OPEN) { + ffid = v9fs_fid_create(v9ses, fid); + if (!ffid) + return -ENOMEM; + + filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created); + if (IS_ERR(filp)) { + v9fs_fid_destroy(ffid); + return PTR_ERR(filp); + } + + ffid->rdir_pos = 0; + ffid->rdir_fcall = NULL; + ffid->fidopen = 1; + ffid->iounit = iounit; + ffid->filp = filp; + filp->private_data = ffid; + } + + return 0; + +error: + if (vfid) + v9fs_fid_destroy(vfid); + + if (inode) + iput(inode); + + return err; } /** @@ -464,9 +537,57 @@ v9fs_vfs_create(struct inode *inode, struct dentry *dentry, int perm, * */ -static int v9fs_vfs_mkdir(struct inode *inode, struct dentry *dentry, int mode) +static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { - return v9fs_create(inode, dentry, mode | S_IFDIR, O_RDONLY); + int err; + u32 fid, perm; + struct v9fs_session_info *v9ses; + struct v9fs_fid *dfid, *vfid; + struct inode *inode; + + inode = NULL; + vfid = NULL; + v9ses = v9fs_inode2v9ses(dir); + dfid = v9fs_fid_lookup(dentry->d_parent); + perm = unixmode2p9mode(v9ses, mode | S_IFDIR); + + err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name, + perm, V9FS_OREAD, &fid, NULL, NULL); + + if (err) { + dprintk(DEBUG_ERROR, "create error %d\n", err); + goto error; + } + + err = v9fs_t_clunk(v9ses, fid); + if (err) { + dprintk(DEBUG_ERROR, "clunk error %d\n", err); + goto error; + } + + vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry); + if (IS_ERR(vfid)) { + err = PTR_ERR(vfid); + vfid = NULL; + goto error; + } + + inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto error; + } + + dentry->d_op = &v9fs_dentry_operations; + d_instantiate(dentry, inode); + return 0; + +error: + if (vfid) + v9fs_fid_destroy(vfid); + + return err; } /** @@ -516,9 +637,8 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, return ERR_PTR(-ENOSPC); } - result = - v9fs_t_walk(v9ses, dirfidnum, newfid, (char *)dentry->d_name.name, - NULL); + result = v9fs_t_walk(v9ses, dirfidnum, newfid, + (char *)dentry->d_name.name, NULL); if (result < 0) { v9fs_put_idpool(newfid, &v9ses->fidpool); if (result == -ENOENT) { @@ -551,13 +671,17 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid); - fid = v9fs_fid_create(dentry, v9ses, newfid, 0); + fid = v9fs_fid_create(v9ses, newfid); if (fid == NULL) { dprintk(DEBUG_ERROR, "couldn't insert\n"); result = -ENOMEM; goto FreeFcall; } + result = v9fs_fid_insert(fid, dentry); + if (result < 0) + goto FreeFcall; + fid->qid = fcall->params.rstat.stat.qid; dentry->d_op = &v9fs_dentry_operations; @@ -886,8 +1010,8 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) } /* copy extension buffer into buffer */ - if (fcall->params.rstat.stat.extension.len+1 < buflen) - buflen = fcall->params.rstat.stat.extension.len + 1; + if (fcall->params.rstat.stat.extension.len < buflen) + buflen = fcall->params.rstat.stat.extension.len; memcpy(buffer, fcall->params.rstat.stat.extension.str, buflen - 1); buffer[buflen-1] = 0; @@ -951,7 +1075,7 @@ static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd) if (!link) link = ERR_PTR(-ENOMEM); else { - len = v9fs_readlink(dentry, link, PATH_MAX); + len = v9fs_readlink(dentry, link, strlen(link)); if (len < 0) { __putname(link); @@ -983,53 +1107,75 @@ static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, int mode, const char *extension) { - int err, retval; + int err; + u32 fid, perm; struct v9fs_session_info *v9ses; + struct v9fs_fid *dfid, *vfid; + struct inode *inode; struct v9fs_fcall *fcall; - struct v9fs_fid *fid; struct v9fs_wstat wstat; - v9ses = v9fs_inode2v9ses(dir); - retval = -EPERM; fcall = NULL; + inode = NULL; + vfid = NULL; + v9ses = v9fs_inode2v9ses(dir); + dfid = v9fs_fid_lookup(dentry->d_parent); + perm = unixmode2p9mode(v9ses, mode); if (!v9ses->extended) { dprintk(DEBUG_ERROR, "not extended\n"); - goto free_mem; + return -EPERM; } - /* issue a create */ - retval = v9fs_create(dir, dentry, mode, 0); - if (retval != 0) - goto free_mem; + err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name, + perm, V9FS_OREAD, &fid, NULL, NULL); - fid = v9fs_fid_get_created(dentry); - if (!fid) { - dprintk(DEBUG_ERROR, "couldn't resolve fid from dentry\n"); - goto free_mem; + if (err) + goto error; + + err = v9fs_t_clunk(v9ses, fid); + if (err) + goto error; + + vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry); + if (IS_ERR(vfid)) { + err = PTR_ERR(vfid); + vfid = NULL; + goto error; + } + + inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto error; } /* issue a Twstat */ v9fs_blank_wstat(&wstat); wstat.muid = v9ses->name; wstat.extension = (char *) extension; - retval = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall); - if (retval < 0) { - PRINT_FCALL_ERROR("wstat error", fcall); - goto free_mem; - } - - err = v9fs_t_clunk(v9ses, fid->fid); + err = v9fs_t_wstat(v9ses, vfid->fid, &wstat, &fcall); if (err < 0) { - dprintk(DEBUG_ERROR, "clunk failed: %d\n", err); - goto free_mem; + PRINT_FCALL_ERROR("wstat error", fcall); + goto error; } - d_drop(dentry); /* FID - will this also clunk? */ + kfree(fcall); + dentry->d_op = &v9fs_dentry_operations; + d_instantiate(dentry, inode); + return 0; -free_mem: +error: kfree(fcall); - return retval; + if (vfid) + v9fs_fid_destroy(vfid); + + if (inode) + iput(inode); + + return err; + } /** -- cgit v1.1 From 731805b49489055c1548f7ccfbd44c9b84013264 Mon Sep 17 00:00:00 2001 From: Latchesar Ionkov Date: Tue, 7 Mar 2006 21:55:42 -0800 Subject: [PATCH] v9fs: fix for access to unitialized variables or freed memory Miscellaneous fixes related to accessing uninitialized variables or memory that was already freed. Signed-off-by: Latchesar Ionkov Cc: Eric Van Hensbergen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/9p/vfs_inode.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index dce729d..3ad8455 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -265,8 +265,7 @@ v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, fid = v9fs_get_idpool(&v9ses->fidpool); if (fid < 0) { eprintk(KERN_WARNING, "no free fids available\n"); - err = -ENOSPC; - goto error; + return -ENOSPC; } err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall); @@ -313,8 +312,7 @@ v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry) nfid = v9fs_get_idpool(&v9ses->fidpool); if (nfid < 0) { eprintk(KERN_WARNING, "no free fids available\n"); - err = -ENOSPC; - goto error; + return ERR_PTR(-ENOSPC); } err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name, @@ -612,7 +610,7 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, int result = 0; dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n", - dir, dentry->d_iname, dentry, nameidata); + dir, dentry->d_name.name, dentry, nameidata); sb = dir->i_sb; v9ses = v9fs_inode2v9ses(dir); -- cgit v1.1 From 5e7a99ac452d7a4ce43b8bacb3495475e1f9fd71 Mon Sep 17 00:00:00 2001 From: Latchesar Ionkov Date: Wed, 22 Mar 2006 00:07:37 -0800 Subject: [PATCH] v9fs: assign dentry ops to negative dentries If a file is not found in v9fs_vfs_lookup, the function creates negative dentry, but doesn't assign any dentry ops. This leaves the negative entry in the cache (there is no d_delete to mark it for removal). If the file is created outside of the mounted v9fs filesystem, the file shows up in the directory with weird permissions. This patch assigns the default v9fs dentry ops to the negative dentry. Signed-off-by: Latchesar Ionkov Signed-off-by: Eric Van Hensbergen Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/9p/vfs_inode.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 3ad8455..651a9e1 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -614,6 +614,7 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, sb = dir->i_sb; v9ses = v9fs_inode2v9ses(dir); + dentry->d_op = &v9fs_dentry_operations; dirfid = v9fs_fid_lookup(dentry->d_parent); if (!dirfid) { @@ -681,8 +682,6 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, goto FreeFcall; fid->qid = fcall->params.rstat.stat.qid; - - dentry->d_op = &v9fs_dentry_operations; v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb); d_add(dentry, inode); -- cgit v1.1