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| author |   Steven J. Magnani <steve.magnani@digidescorp.com> | 2019-08-27 07:13:59 -0500 |
|---|---|---|
| committer |   Jan Kara <jack@suse.cz> | 2019-08-27 15:38:46 +0200 |
| commit | c3367a1b47d590f97109cd4b5189e750fb26c0f1 (patch) | |
| tree | 8f29eb87d3375f3ff048b3384bef9692bde86367 /fs/udf/inode.c | |
| parent | udf: Use dynamic debug infrastructure (diff) | |
| download | linux-dev-c3367a1b47d590f97109cd4b5189e750fb26c0f1.tar.xz linux-dev-c3367a1b47d590f97109cd4b5189e750fb26c0f1.zip | |
udf: augment UDF permissions on new inodes
Windows presents files created within Linux as read-only, even when
permissions in Linux indicate the file should be writable.
UDF defines a slightly different set of basic file permissions than Linux.
Specifically, UDF has "delete" and "change attribute" permissions for each
access class (user/group/other). Linux has no equivalents for these.
When the Linux UDF driver creates a file (or directory), no UDF delete or
change attribute permissions are granted. The lack of delete permission
appears to cause Windows to mark an item read-only when its permissions
otherwise indicate that it should be read-write.
Fix this by having UDF delete permissions track Linux write permissions.
Also grant UDF change attribute permission to the owner when creating a
new inode.
Reported by: Ty Young
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Link: https://lore.kernel.org/r/20190827121359.9954-1-steve@digidescorp.com
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf/inode.c')
| -rw-r--r-- | fs/udf/inode.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 54eee39f2698..ea80036d7897 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -45,6 +45,13 @@ #define EXTENT_MERGE_SIZE 5 +#define FE_MAPPED_PERMS (FE_PERM_U_READ | FE_PERM_U_WRITE | FE_PERM_U_EXEC | \ + FE_PERM_G_READ | FE_PERM_G_WRITE | FE_PERM_G_EXEC | \ + FE_PERM_O_READ | FE_PERM_O_WRITE | FE_PERM_O_EXEC) + +#define FE_DELETE_PERMS (FE_PERM_U_DELETE | FE_PERM_G_DELETE | \ + FE_PERM_O_DELETE) + static umode_t udf_convert_permissions(struct fileEntry *); static int udf_update_inode(struct inode *, int); static int udf_sync_inode(struct inode *inode); @@ -1458,6 +1465,8 @@ reread: else inode->i_mode = udf_convert_permissions(fe); inode->i_mode &= ~sbi->s_umask; + iinfo->i_extraPerms = le32_to_cpu(fe->permissions) & ~FE_MAPPED_PERMS; + read_unlock(&sbi->s_cred_lock); link_count = le16_to_cpu(fe->fileLinkCount); @@ -1631,6 +1640,23 @@ static umode_t udf_convert_permissions(struct fileEntry *fe) return mode; } +void udf_update_extra_perms(struct inode *inode, umode_t mode) +{ + struct udf_inode_info *iinfo = UDF_I(inode); + + /* + * UDF 2.01 sec. 3.3.3.3 Note 2: + * In Unix, delete permission tracks write + */ + iinfo->i_extraPerms &= ~FE_DELETE_PERMS; + if (mode & 0200) + iinfo->i_extraPerms |= FE_PERM_U_DELETE; + if (mode & 0020) + iinfo->i_extraPerms |= FE_PERM_G_DELETE; + if (mode & 0002) + iinfo->i_extraPerms |= FE_PERM_O_DELETE; +} + int udf_write_inode(struct inode *inode, struct writeback_control *wbc) { return udf_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL); @@ -1703,10 +1729,7 @@ static int udf_update_inode(struct inode *inode, int do_sync) ((inode->i_mode & 0070) << 2) | ((inode->i_mode & 0700) << 4); - udfperms |= (le32_to_cpu(fe->permissions) & - (FE_PERM_O_DELETE | FE_PERM_O_CHATTR | - FE_PERM_G_DELETE | FE_PERM_G_CHATTR | - FE_PERM_U_DELETE | FE_PERM_U_CHATTR)); + udfperms |= iinfo->i_extraPerms; fe->permissions = cpu_to_le32(udfperms); if (S_ISDIR(inode->i_mode) && inode->i_nlink > 0) |