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ecryptfs: keep the lower iattr contained in truncate_upper

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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 <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>
This commit is contained in:
Christoph Hellwig
2026-04-08 18:54:03 -05:00
committed by Tyler Hicks
parent 5d1f0e8cd9
commit e836ec1819
1 changed files with 37 additions and 47 deletions
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fs/ecryptfs/inode.c
+37 -47
View File
@@ -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;
const struct iattr ia = {
.ia_valid = ATTR_SIZE,
.ia_size = new_length,
};
rc = truncate_upper(dentry, &ia, &lower_ia);
if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
struct dentry *lower_dentry = ecryptfs_dentry_to_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));
}
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;