From: Christoph Hellwig Date: Wed, 8 Apr 2026 06:06:42 +0000 (+0200) Subject: ecryptfs: keep the lower iattr contained in truncate_upper X-Git-Tag: v7.1-rc1~77^2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e836ec1819b0cc50e0b45a53b0bdce6c596f0207;p=thirdparty%2Flinux.git ecryptfs: keep the lower iattr contained in truncate_upper Currently the two callers of truncate_upper handle passing information very differently. ecryptfs_truncate passes a zeroed lower_ia and expects truncate_upper to fill it in from the upper ia created just for that, while ecryptfs_setattr passes a fully initialized lower_ia copied from the upper one. Both of them then call notify_change on the lower_ia. Switch to only passing the upper ia, and derive the lower ia from it inside truncate_upper, and call notify_change inside the function itself. Because the old name is misleading now, rename the resulting function to __ecryptfs_truncate as it deals with both the lower and upper inodes. Signed-off-by: Christoph Hellwig Signed-off-by: Tyler Hicks --- diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index a06b84033ff3..546c1fe692c0 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -721,36 +721,33 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, } /** - * truncate_upper + * __ecryptfs_truncate * @dentry: The ecryptfs layer dentry * @ia: Address of the ecryptfs inode's attributes - * @lower_ia: Address of the lower inode's attributes * - * Function to handle truncations modifying the size of the file. Note - * that the file sizes are interpolated. When expanding, we are simply - * writing strings of 0's out. When truncating, we truncate the upper - * inode and update the lower_ia according to the page index - * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return, - * the caller must use lower_ia in a call to notify_change() to perform - * the truncation of the lower inode. + * Handle truncations modifying the size of the file. Note that the file sizes + * are interpolated. When expanding, we are simply writing strings of 0's out. + * When truncating, we truncate the upper inode and update the lower_ia + * according to the page index interpolations. * * Returns zero on success; non-zero otherwise */ -static int truncate_upper(struct dentry *dentry, struct iattr *ia, - struct iattr *lower_ia) +static int __ecryptfs_truncate(struct dentry *dentry, const struct iattr *ia) { + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); struct inode *inode = d_inode(dentry); struct ecryptfs_crypt_stat *crypt_stat; loff_t i_size = i_size_read(inode); loff_t lower_size_before_truncate; loff_t lower_size_after_truncate; + struct iattr lower_ia; size_t num_zeros; int rc; - if (unlikely((ia->ia_size == i_size))) { - lower_ia->ia_valid &= ~ATTR_SIZE; + ecryptfs_iattr_to_lower(&lower_ia, ia); + + if (unlikely((ia->ia_size == i_size))) return 0; - } crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; lower_size_before_truncate = @@ -783,15 +780,13 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, * new end of the file. */ rc = ecryptfs_write(inode, zero, ia->ia_size - 1, 1); - lower_ia->ia_valid &= ~ATTR_SIZE; goto out; } if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { truncate_setsize(inode, ia->ia_size); - lower_ia->ia_size = ia->ia_size; - lower_ia->ia_valid |= ATTR_SIZE; - goto out; + lower_ia.ia_size = ia->ia_size; + goto set_size; } /* @@ -821,12 +816,15 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, * We are reducing the size of the ecryptfs file, and need to know if we * need to reduce the size of the lower file. */ - if (lower_size_after_truncate < lower_size_before_truncate) { - lower_ia->ia_size = lower_size_after_truncate; - lower_ia->ia_valid |= ATTR_SIZE; - } else { - lower_ia->ia_valid &= ~ATTR_SIZE; - } + if (lower_size_after_truncate >= lower_size_before_truncate) + goto out; + + lower_ia.ia_size = lower_size_after_truncate; +set_size: + lower_ia.ia_valid |= ATTR_SIZE; + inode_lock(d_inode(lower_dentry)); + rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL); + inode_unlock(d_inode(lower_dentry)); out: ecryptfs_put_lower_file(inode); return rc; @@ -844,20 +842,12 @@ out: */ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) { - struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length }; - struct iattr lower_ia = { .ia_valid = 0 }; - int rc; - - rc = truncate_upper(dentry, &ia, &lower_ia); - if (!rc && lower_ia.ia_valid & ATTR_SIZE) { - struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); + const struct iattr ia = { + .ia_valid = ATTR_SIZE, + .ia_size = new_length, + }; - inode_lock(d_inode(lower_dentry)); - rc = notify_change(&nop_mnt_idmap, lower_dentry, - &lower_ia, NULL); - inode_unlock(d_inode(lower_dentry)); - } - return rc; + return __ecryptfs_truncate(dentry, &ia); } static int @@ -887,7 +877,6 @@ static int ecryptfs_setattr(struct mnt_idmap *idmap, struct inode *inode = d_inode(dentry); struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); struct inode *lower_inode = ecryptfs_inode_to_lower(inode); - struct iattr lower_ia; struct ecryptfs_crypt_stat *crypt_stat; int rc; @@ -935,17 +924,18 @@ static int ecryptfs_setattr(struct mnt_idmap *idmap, if (rc) goto out; - ecryptfs_iattr_to_lower(&lower_ia, ia); if (ia->ia_valid & ATTR_SIZE) { - rc = truncate_upper(dentry, ia, &lower_ia); - if (rc < 0) - goto out; - } + rc = __ecryptfs_truncate(dentry, ia); + } else { + struct iattr lower_ia; + ecryptfs_iattr_to_lower(&lower_ia, ia); - inode_lock(d_inode(lower_dentry)); - rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL); - inode_unlock(d_inode(lower_dentry)); + inode_lock(d_inode(lower_dentry)); + rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, + NULL); + inode_unlock(d_inode(lower_dentry)); + } out: fsstack_copy_attr_all(inode, lower_inode); return rc;