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authorLinus Torvalds <torvalds@linux-foundation.org>2020-09-03 08:41:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-09-03 08:41:36 -0700
commit26acd8b07a07000d9f61ee64dc6fde0494997b47 (patch)
tree68a72f5cdf717e4764185c419fb025fea404262d
parent0fdf68c767c08004ff3a2fc032a139bdaf7826c5 (diff)
parentd3a84a8d0dde4e26bc084b36ffcbdc5932ac85e2 (diff)
downloadlinux-26acd8b07a07000d9f61ee64dc6fde0494997b47.tar.bz2
Merge tag 'affs-for-5.9-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull affs fix from David Sterba: "One fix to make permissions work the same way as on AmigaOS" * tag 'affs-for-5.9-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: affs: fix basic permission bits to actually work
-rw-r--r--Documentation/filesystems/affs.rst16
-rw-r--r--fs/affs/amigaffs.c27
-rw-r--r--fs/affs/file.c26
3 files changed, 62 insertions, 7 deletions
diff --git a/Documentation/filesystems/affs.rst b/Documentation/filesystems/affs.rst
index 7f1a40dce6d3..5776cbd5fa53 100644
--- a/Documentation/filesystems/affs.rst
+++ b/Documentation/filesystems/affs.rst
@@ -110,13 +110,15 @@ The Amiga protection flags RWEDRWEDHSPARWED are handled as follows:
- R maps to r for user, group and others. On directories, R implies x.
- - If both W and D are allowed, w will be set.
+ - W maps to w.
- E maps to x.
- - H and P are always retained and ignored under Linux.
+ - D is ignored.
- - A is always reset when a file is written to.
+ - H, S and P are always retained and ignored under Linux.
+
+ - A is cleared when a file is written to.
User id and group id will be used unless set[gu]id are given as mount
options. Since most of the Amiga file systems are single user systems
@@ -128,11 +130,13 @@ Linux -> Amiga:
The Linux rwxrwxrwx file mode is handled as follows:
- - r permission will set R for user, group and others.
+ - r permission will allow R for user, group and others.
+
+ - w permission will allow W for user, group and others.
- - w permission will set W and D for user, group and others.
+ - x permission of the user will allow E for plain files.
- - x permission of the user will set E for plain files.
+ - D will be allowed for user, group and others.
- All other flags (suid, sgid, ...) are ignored and will
not be retained.
diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c
index f708c45d5f66..29f11e10a7c7 100644
--- a/fs/affs/amigaffs.c
+++ b/fs/affs/amigaffs.c
@@ -420,24 +420,51 @@ affs_mode_to_prot(struct inode *inode)
u32 prot = AFFS_I(inode)->i_protect;
umode_t mode = inode->i_mode;
+ /*
+ * First, clear all RWED bits for owner, group, other.
+ * Then, recalculate them afresh.
+ *
+ * We'll always clear the delete-inhibit bit for the owner, as that is
+ * the classic single-user mode AmigaOS protection bit and we need to
+ * stay compatible with all scenarios.
+ *
+ * Since multi-user AmigaOS is an extension, we'll only set the
+ * delete-allow bit if any of the other bits in the same user class
+ * (group/other) are used.
+ */
+ prot &= ~(FIBF_NOEXECUTE | FIBF_NOREAD
+ | FIBF_NOWRITE | FIBF_NODELETE
+ | FIBF_GRP_EXECUTE | FIBF_GRP_READ
+ | FIBF_GRP_WRITE | FIBF_GRP_DELETE
+ | FIBF_OTR_EXECUTE | FIBF_OTR_READ
+ | FIBF_OTR_WRITE | FIBF_OTR_DELETE);
+
+ /* Classic single-user AmigaOS flags. These are inverted. */
if (!(mode & 0100))
prot |= FIBF_NOEXECUTE;
if (!(mode & 0400))
prot |= FIBF_NOREAD;
if (!(mode & 0200))
prot |= FIBF_NOWRITE;
+
+ /* Multi-user extended flags. Not inverted. */
if (mode & 0010)
prot |= FIBF_GRP_EXECUTE;
if (mode & 0040)
prot |= FIBF_GRP_READ;
if (mode & 0020)
prot |= FIBF_GRP_WRITE;
+ if (mode & 0070)
+ prot |= FIBF_GRP_DELETE;
+
if (mode & 0001)
prot |= FIBF_OTR_EXECUTE;
if (mode & 0004)
prot |= FIBF_OTR_READ;
if (mode & 0002)
prot |= FIBF_OTR_WRITE;
+ if (mode & 0007)
+ prot |= FIBF_OTR_DELETE;
AFFS_I(inode)->i_protect = prot;
}
diff --git a/fs/affs/file.c b/fs/affs/file.c
index a26a0f96c119..d91b0133d95d 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -429,6 +429,24 @@ static int affs_write_begin(struct file *file, struct address_space *mapping,
return ret;
}
+static int affs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned int len, unsigned int copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ int ret;
+
+ ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+ /* Clear Archived bit on file writes, as AmigaOS would do */
+ if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
+ AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
+ mark_inode_dirty(inode);
+ }
+
+ return ret;
+}
+
static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,affs_get_block);
@@ -438,7 +456,7 @@ const struct address_space_operations affs_aops = {
.readpage = affs_readpage,
.writepage = affs_writepage,
.write_begin = affs_write_begin,
- .write_end = generic_write_end,
+ .write_end = affs_write_end,
.direct_IO = affs_direct_IO,
.bmap = _affs_bmap
};
@@ -795,6 +813,12 @@ done:
if (tmp > inode->i_size)
inode->i_size = AFFS_I(inode)->mmu_private = tmp;
+ /* Clear Archived bit on file writes, as AmigaOS would do */
+ if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
+ AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
+ mark_inode_dirty(inode);
+ }
+
err_first_bh:
unlock_page(page);
put_page(page);