From 2c27c65ed0696f0b5df2dad2cf6462d72164d547 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:30:04 +0200 Subject: check ATTR_SIZE contraints in inode_change_ok Make sure we check the truncate constraints early on in ->setattr by adding those checks to inode_change_ok. Also clean up and document inode_change_ok to make this obvious. As a fallout we don't have to call inode_newsize_ok from simple_setsize and simplify it down to a truncate_setsize which doesn't return an error. This simplifies a lot of setattr implementations and means we use truncate_setsize almost everywhere. Get rid of fat_setsize now that it's trivial and mark ext2_setsize static to make the calling convention obvious. Keep the inode_newsize_ok in vmtruncate for now as all callers need an audit for its removal anyway. Note: setattr code in ecryptfs doesn't call inode_change_ok at all and needs a deeper audit, but that is left for later. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c index b3dec19..65794b8 100644 --- a/fs/adfs/inode.c +++ b/fs/adfs/inode.c @@ -333,10 +333,7 @@ adfs_notify_change(struct dentry *dentry, struct iattr *attr) /* XXX: this is missing some actual on-disk truncation.. */ if (ia_valid & ATTR_SIZE) - error = simple_setsize(inode, attr->ia_size); - - if (error) - goto out; + truncate_setsize(inode, attr->ia_size); if (ia_valid & ATTR_MTIME) { inode->i_mtime = attr->ia_mtime; diff --git a/fs/attr.c b/fs/attr.c index ed44d8a..7ca4181 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -14,35 +14,53 @@ #include #include -/* Taken over from the old code... */ - -/* POSIX UID/GID verification for setting inode attributes. */ +/** + * inode_change_ok - check if attribute changes to an inode are allowed + * @inode: inode to check + * @attr: attributes to change + * + * Check if we are allowed to change the attributes contained in @attr + * in the given inode. This includes the normal unix access permission + * checks, as well as checks for rlimits and others. + * + * Should be called as the first thing in ->setattr implementations, + * possibly after taking additional locks. + */ int inode_change_ok(const struct inode *inode, struct iattr *attr) { - int retval = -EPERM; unsigned int ia_valid = attr->ia_valid; + /* + * First check size constraints. These can't be overriden using + * ATTR_FORCE. + */ + if (ia_valid & ATTR_SIZE) { + int error = inode_newsize_ok(inode, attr->ia_size); + if (error) + return error; + } + /* If force is set do it anyway. */ if (ia_valid & ATTR_FORCE) - goto fine; + return 0; /* Make sure a caller can chown. */ if ((ia_valid & ATTR_UID) && (current_fsuid() != inode->i_uid || attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN)) - goto error; + return -EPERM; /* Make sure caller can chgrp. */ if ((ia_valid & ATTR_GID) && (current_fsuid() != inode->i_uid || (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) && !capable(CAP_CHOWN)) - goto error; + return -EPERM; /* Make sure a caller can chmod. */ if (ia_valid & ATTR_MODE) { if (!is_owner_or_cap(inode)) - goto error; + return -EPERM; /* Also check the setgid bit! */ if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : inode->i_gid) && !capable(CAP_FSETID)) @@ -52,12 +70,10 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr) /* Check for setting the inode time. */ if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) { if (!is_owner_or_cap(inode)) - goto error; + return -EPERM; } -fine: - retval = 0; -error: - return retval; + + return 0; } EXPORT_SYMBOL(inode_change_ok); @@ -113,7 +129,7 @@ EXPORT_SYMBOL(inode_newsize_ok); * * setattr_copy updates the inode's metadata with that specified * in attr. Noticably missing is inode size update, which is more complex - * as it requires pagecache updates. See simple_setsize. + * as it requires pagecache updates. * * The inode is not marked as dirty after this operation. The rationale is * that for "simple" filesystems, the struct inode is the inode storage. diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 31ef525..82900b0 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -804,10 +804,20 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, size_t num_zeros = (PAGE_CACHE_SIZE - (ia->ia_size & ~PAGE_CACHE_MASK)); + + /* + * XXX(truncate) this should really happen at the begginning + * of ->setattr. But the code is too messy to that as part + * of a larger patch. ecryptfs is also totally missing out + * on the inode_change_ok check at the beginning of + * ->setattr while would include this. + */ + rc = inode_newsize_ok(inode, ia->ia_size); + if (rc) + goto out; + if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { - rc = simple_setsize(inode, ia->ia_size); - if (rc) - goto out; + truncate_setsize(inode, ia->ia_size); lower_ia->ia_size = ia->ia_size; lower_ia->ia_valid |= ATTR_SIZE; goto out; @@ -830,7 +840,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, goto out; } } - simple_setsize(inode, ia->ia_size); + truncate_setsize(inode, ia->ia_size); rc = ecryptfs_write_inode_size_to_metadata(inode); if (rc) { printk(KERN_ERR "Problem with " diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 7dee7b3..069620b 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1156,15 +1156,10 @@ static void ext2_truncate_blocks(struct inode *inode, loff_t offset) __ext2_truncate_blocks(inode, offset); } -int ext2_setsize(struct inode *inode, loff_t newsize) +static int ext2_setsize(struct inode *inode, loff_t newsize) { - loff_t oldsize; int error; - error = inode_newsize_ok(inode, newsize); - if (error) - return error; - if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) return -EINVAL; @@ -1184,10 +1179,7 @@ int ext2_setsize(struct inode *inode, loff_t newsize) if (error) return error; - oldsize = inode->i_size; - i_size_write(inode, newsize); - truncate_pagecache(inode, oldsize, newsize); - + truncate_setsize(inode, newsize); __ext2_truncate_blocks(inode, newsize); inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 27ac257..d75a77f 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -306,7 +306,6 @@ extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, extern const struct file_operations fat_file_operations; extern const struct inode_operations fat_file_inode_operations; extern int fat_setattr(struct dentry * dentry, struct iattr * attr); -extern int fat_setsize(struct inode *inode, loff_t offset); extern void fat_truncate_blocks(struct inode *inode, loff_t offset); extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); diff --git a/fs/fat/file.c b/fs/fat/file.c index b2eedce..7257752 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -364,18 +364,6 @@ static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode) return 0; } -int fat_setsize(struct inode *inode, loff_t offset) -{ - int error; - - error = simple_setsize(inode, offset); - if (error) - return error; - fat_truncate_blocks(inode, offset); - - return error; -} - #define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET) /* valid file mode bits */ #define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO) @@ -441,9 +429,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) } if (attr->ia_valid & ATTR_SIZE) { - error = fat_setsize(inode, attr->ia_size); - if (error) - goto out; + truncate_setsize(inode, attr->ia_size); + fat_truncate_blocks(inode, attr->ia_size); } setattr_copy(inode, attr); diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 43a9b37..3978a42 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1280,12 +1280,8 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc) return 0; - if (attr->ia_valid & ATTR_SIZE) { - err = inode_newsize_ok(inode, attr->ia_size); - if (err) - return err; + if (attr->ia_valid & ATTR_SIZE) is_truncate = true; - } req = fuse_get_req(fc); if (IS_ERR(req)) diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 703000d..54fe087 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -702,12 +702,12 @@ out: page_cache_release(page); /* - * XXX(hch): the call below should probably be replaced with + * XXX(truncate): the call below should probably be replaced with * a call to the gfs2-specific truncate blocks helper to actually * release disk blocks.. */ if (pos + len > ip->i_inode.i_size) - simple_setsize(&ip->i_inode, ip->i_inode.i_size); + truncate_setsize(&ip->i_inode, ip->i_inode.i_size); out_endtrans: gfs2_trans_end(sdp); out_trans_fail: diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c index d7d410a..1009be2 100644 --- a/fs/gfs2/ops_inode.c +++ b/fs/gfs2/ops_inode.c @@ -1072,7 +1072,7 @@ int gfs2_permission(struct inode *inode, int mask) } /* - * XXX: should be changed to have proper ordering by opencoding simple_setsize + * XXX(truncate): the truncate_setsize calls should be moved to the end. */ static int setattr_size(struct inode *inode, struct iattr *attr) { @@ -1084,10 +1084,8 @@ static int setattr_size(struct inode *inode, struct iattr *attr) error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks); if (error) return error; - error = simple_setsize(inode, attr->ia_size); + truncate_setsize(inode, attr->ia_size); gfs2_trans_end(sdp); - if (error) - return error; } error = gfs2_truncatei(ip, attr->ia_size); diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 459d39d..1b24266 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -169,13 +169,13 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr) mutex_unlock(&f->sem); jffs2_complete_reservation(c); - /* We have to do the simple_setsize() without f->sem held, since + /* We have to do the truncate_setsize() without f->sem held, since some pages may be locked and waiting for it in readpage(). We are protected from a simultaneous write() extending i_size back past iattr->ia_size, because do_truncate() holds the generic inode semaphore. */ if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) { - simple_setsize(inode, iattr->ia_size); + truncate_setsize(inode, iattr->ia_size); inode->i_blocks = (inode->i_size + 511) >> 9; } diff --git a/fs/libfs.c b/fs/libfs.c index 4056222..0a9da95 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -327,49 +327,6 @@ int simple_rename(struct inode *old_dir, struct dentry *old_dentry, } /** - * simple_setsize - handle core mm and vfs requirements for file size change - * @inode: inode - * @newsize: new file size - * - * Returns 0 on success, -error on failure. - * - * simple_setsize must be called with inode_mutex held. - * - * simple_setsize will check that the requested new size is OK (see - * inode_newsize_ok), and then will perform the necessary i_size update - * and pagecache truncation (if necessary). It will be typically be called - * from the filesystem's setattr function when ATTR_SIZE is passed in. - * - * The inode itself must have correct permissions and attributes to allow - * i_size to be changed, this function then just checks that the new size - * requested is valid. - * - * In the case of simple in-memory filesystems with inodes stored solely - * in the inode cache, and file data in the pagecache, nothing more needs - * to be done to satisfy a truncate request. Filesystems with on-disk - * blocks for example will need to free them in the case of truncate, in - * that case it may be easier not to use simple_setsize (but each of its - * components will likely be required at some point to update pagecache - * and inode etc). - */ -int simple_setsize(struct inode *inode, loff_t newsize) -{ - loff_t oldsize; - int error; - - error = inode_newsize_ok(inode, newsize); - if (error) - return error; - - oldsize = inode->i_size; - i_size_write(inode, newsize); - truncate_pagecache(inode, oldsize, newsize); - - return error; -} -EXPORT_SYMBOL(simple_setsize); - -/** * simple_setattr - setattr for simple filesystem * @dentry: dentry * @iattr: iattr structure @@ -394,12 +351,8 @@ int simple_setattr(struct dentry *dentry, struct iattr *iattr) if (error) return error; - if (iattr->ia_valid & ATTR_SIZE) { - error = simple_setsize(inode, iattr->ia_size); - if (error) - return error; - } - + if (iattr->ia_valid & ATTR_SIZE) + truncate_setsize(inode, iattr->ia_size); setattr_copy(inode, iattr); mark_inode_dirty(inode); return 0; diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 584cf8a..81296b4 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1233,7 +1233,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) } /* - * This will intentionally not wind up calling simple_setsize(), + * This will intentionally not wind up calling truncate_setsize(), * since all the work for a size change has been done above. * Otherwise, we could get into problems with truncate as * ip_alloc_sem is used there to protect against i_size @@ -2308,12 +2308,12 @@ relock: * blocks outside i_size. Trim these off again. * Don't need i_size_read because we hold i_mutex. * - * XXX(hch): this looks buggy because ocfs2 did not + * XXX(truncate): this looks buggy because ocfs2 did not * actually implement ->truncate. Take a look at * the new truncate sequence and update this accordingly */ if (*ppos + count > inode->i_size) - simple_setsize(inode, inode->i_size); + truncate_setsize(inode, inode->i_size); ret = written; goto out_dio; } diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 8d44f03..9eead2c 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -146,9 +146,8 @@ static int ramfs_nommu_resize(struct inode *inode, loff_t newsize, loff_t size) return ret; } - ret = simple_setsize(inode, newsize); - - return ret; + truncate_setsize(inode, newsize); + return 0; } /*****************************************************************************/ diff --git a/fs/smbfs/inode.c b/fs/smbfs/inode.c index 9551cb6..e338f0a 100644 --- a/fs/smbfs/inode.c +++ b/fs/smbfs/inode.c @@ -714,9 +714,7 @@ smb_notify_change(struct dentry *dentry, struct iattr *attr) error = server->ops->truncate(inode, attr->ia_size); if (error) goto out; - error = simple_setsize(inode, attr->ia_size); - if (error) - goto out; + truncate_setsize(inode, attr->ia_size); refresh = 1; } diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 12f445c..03ae894 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -967,14 +967,15 @@ static int do_writepage(struct page *page, int len) * the page locked, and it locks @ui_mutex. However, write-back does take inode * @i_mutex, which means other VFS operations may be run on this inode at the * same time. And the problematic one is truncation to smaller size, from where - * we have to call 'simple_setsize()', which first changes @inode->i_size, then + * we have to call 'truncate_setsize()', which first changes @inode->i_size, then * drops the truncated pages. And while dropping the pages, it takes the page - * lock. This means that 'do_truncation()' cannot call 'simple_setsize()' with + * lock. This means that 'do_truncation()' cannot call 'truncate_setsize()' with * @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. This * means that @inode->i_size is changed while @ui_mutex is unlocked. * - * XXX: with the new truncate the above is not true anymore, the simple_setsize - * calls can be replaced with the individual components. + * XXX(truncate): with the new truncate sequence this is not true anymore, + * and the calls to truncate_setsize can be move around freely. They should + * be moved to the very end of the truncate sequence. * * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond * inode size. How do we do this if @inode->i_size may became smaller while we @@ -1128,9 +1129,7 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode, budgeted = 0; } - err = simple_setsize(inode, new_size); - if (err) - goto out_budg; + truncate_setsize(inode, new_size); if (offset) { pgoff_t index = new_size >> PAGE_CACHE_SHIFT; @@ -1217,16 +1216,14 @@ static int do_setattr(struct ubifs_info *c, struct inode *inode, if (attr->ia_valid & ATTR_SIZE) { dbg_gen("size %lld -> %lld", inode->i_size, new_size); - err = simple_setsize(inode, new_size); - if (err) - goto out; + truncate_setsize(inode, new_size); } mutex_lock(&ui->ui_mutex); if (attr->ia_valid & ATTR_SIZE) { /* Truncation changes inode [mc]time */ inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); - /* 'simple_setsize()' changed @i_size, update @ui_size */ + /* 'truncate_setsize()' changed @i_size, update @ui_size */ ui->ui_size = inode->i_size; } @@ -1248,10 +1245,6 @@ static int do_setattr(struct ubifs_info *c, struct inode *inode, if (IS_SYNC(inode)) err = inode->i_sb->s_op->write_inode(inode, NULL); return err; - -out: - ubifs_release_budget(c, &req); - return err; } int ubifs_setattr(struct dentry *dentry, struct iattr *attr) diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 0431087..0c9876b 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -379,7 +379,7 @@ struct ubifs_gced_idx_leb { * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot * make sure @inode->i_size is always changed under @ui_mutex, because it - * cannot call 'simple_setsize()' with @ui_mutex locked, because it would deadlock + * cannot call 'truncate_setsize()' with @ui_mutex locked, because it would deadlock * with 'ubifs_writepage()' (see file.c). All the other inode fields are * changed under @ui_mutex, so they do not need "shadow" fields. Note, one * could consider to rework locking and base it on "shadow" fields. diff --git a/fs/ufs/truncate.c b/fs/ufs/truncate.c index 085e116..34d5cb1 100644 --- a/fs/ufs/truncate.c +++ b/fs/ufs/truncate.c @@ -500,11 +500,6 @@ out: return err; } -/* - * TODO: - * - truncate case should use proper ordering instead of using - * simple_setsize - */ int ufs_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; @@ -518,9 +513,9 @@ int ufs_setattr(struct dentry *dentry, struct iattr *attr) if (ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) { loff_t old_i_size = inode->i_size; - error = simple_setsize(inode, attr->ia_size); - if (error) - return error; + /* XXX(truncate): truncate_setsize should be called last */ + truncate_setsize(inode, attr->ia_size); + error = ufs_truncate(inode, old_i_size); if (error) return error; diff --git a/include/linux/fs.h b/include/linux/fs.h index 6ecb83c..5547b1b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2355,7 +2355,6 @@ extern int simple_link(struct dentry *, struct inode *, struct dentry *); extern int simple_unlink(struct inode *, struct dentry *); extern int simple_rmdir(struct inode *, struct dentry *); extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); -extern int simple_setsize(struct inode *, loff_t); extern int noop_fsync(struct file *, int); extern int simple_empty(struct dentry *); extern int simple_readpage(struct file *file, struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index a2b4804..980164e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -815,6 +815,7 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping, } extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new); +extern void truncate_setsize(struct inode *inode, loff_t newsize); extern int vmtruncate(struct inode *inode, loff_t offset); extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end); diff --git a/mm/shmem.c b/mm/shmem.c index 0a43505..33222ba 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -805,11 +805,10 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) } } - error = simple_setsize(inode, newsize); + /* XXX(truncate): truncate_setsize should be called last */ + truncate_setsize(inode, newsize); if (page) page_cache_release(page); - if (error) - return error; shmem_truncate_range(inode, newsize, (loff_t)-1); } diff --git a/mm/truncate.c b/mm/truncate.c index 937571b..ba887bf 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -541,28 +541,48 @@ void truncate_pagecache(struct inode *inode, loff_t old, loff_t new) EXPORT_SYMBOL(truncate_pagecache); /** + * truncate_setsize - update inode and pagecache for a new file size + * @inode: inode + * @newsize: new file size + * + * truncate_setsize updastes i_size update and performs pagecache + * truncation (if necessary) for a file size updates. It will be + * typically be called from the filesystem's setattr function when + * ATTR_SIZE is passed in. + * + * Must be called with inode_mutex held and after all filesystem + * specific block truncation has been performed. + */ +void truncate_setsize(struct inode *inode, loff_t newsize) +{ + loff_t oldsize; + + oldsize = inode->i_size; + i_size_write(inode, newsize); + + truncate_pagecache(inode, oldsize, newsize); +} +EXPORT_SYMBOL(truncate_setsize); + +/** * vmtruncate - unmap mappings "freed" by truncate() syscall * @inode: inode of the file used * @offset: file offset to start truncating * - * NOTE! We have to be ready to update the memory sharing - * between the file and the memory map for a potential last - * incomplete page. Ugly, but necessary. - * - * This function is deprecated and simple_setsize or truncate_pagecache - * should be used instead. + * This function is deprecated and truncate_setsize or truncate_pagecache + * should be used instead, together with filesystem specific block truncation. */ int vmtruncate(struct inode *inode, loff_t offset) { int error; - error = simple_setsize(inode, offset); + error = inode_newsize_ok(inode, offset); if (error) return error; + truncate_setsize(inode, offset); if (inode->i_op->truncate) inode->i_op->truncate(inode); - - return error; + return 0; } EXPORT_SYMBOL(vmtruncate); -- cgit v0.10.2