linux.git/fs/erofs, branch v6.16

erofs: fix large fragment handling

2025-07-11T20:02:44+00:00

Fragments aren't limited by Z_EROFS_PCLUSTER_MAX_DSIZE. However, if
a fragment's logical length is larger than Z_EROFS_PCLUSTER_MAX_DSIZE
but the fragment is not the whole inode, it currently returns
-EOPNOTSUPP because m_flags has the wrong EROFS_MAP_ENCODED flag set.
It is not intended by design but should be rare, as it can only be
reproduced by mkfs with `-Eall-fragments` in a specific case.

Let's normalize fragment m_flags using the new EROFS_MAP_FRAGMENT.

Reported-by: Axel Fontaine 
Closes: https://github.com/erofs/erofs-utils/issues/23
Fixes: 7c3ca1838a78 ("erofs: restrict pcluster size limitations")
Signed-off-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250711195826.3601157-1-hsiangkao@linux.alibaba.com

erofs: allow readdir() to be interrupted

2025-07-10T09:08:27+00:00

In a quick slow device, readdir() may loop for long time in large
directory, let's give a chance to allow it to be interrupted by
userspace.

Signed-off-by: Chao Yu 
Reviewed-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250710073619.4083422-1-chao@kernel.org
[ Gao Xiang: move cond_resched() to the end of the while loop. ]
Signed-off-by: Gao Xiang

erofs: address D-cache aliasing

2025-07-10T09:08:27+00:00

Flush the D-cache before unlocking folios for compressed inodes, as
they are dirtied during decompression.

Avoid calling flush_dcache_folio() on every CPU write, since it's more
like playing whack-a-mole without real benefit.

It has no impact on x86 and arm64/risc-v: on x86, flush_dcache_folio()
is a no-op, and on arm64/risc-v, PG_dcache_clean (PG_arch_1) is clear
for new page cache folios.  However, certain ARM boards are affected,
as reported.

Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
Closes: https://lore.kernel.org/r/c1e51e16-6cc6-49d0-a63e-4e9ff6c4dd53@pengutronix.de
Closes: https://lore.kernel.org/r/38d43fae-1182-4155-9c5b-ffc7382d9917@siemens.com
Tested-by: Jan Kiszka 
Tested-by: Stefan Kerkmann 
Signed-off-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250709034614.2780117-2-hsiangkao@linux.alibaba.com

erofs: use memcpy_to_folio() to replace copy_to_iter()

2025-07-10T09:08:26+00:00

Using copy_to_iter() here is overkill and even messy.

Signed-off-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250709034614.2780117-1-hsiangkao@linux.alibaba.com

erofs: fix to add missing tracepoint in erofs_read_folio()

2025-07-10T09:08:26+00:00

Commit 771c994ea51f ("erofs: convert all uncompressed cases to iomap")
converts to use iomap interface, it removed trace_erofs_readpage()
tracepoint in the meantime, let's add it back.

Fixes: 771c994ea51f ("erofs: convert all uncompressed cases to iomap")
Signed-off-by: Chao Yu 
Reviewed-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250708111942.3120926-1-chao@kernel.org
Signed-off-by: Gao Xiang

erofs: fix to add missing tracepoint in erofs_readahead()

2025-07-10T09:08:25+00:00

Commit 771c994ea51f ("erofs: convert all uncompressed cases to iomap")
converts to use iomap interface, it removed trace_erofs_readahead()
tracepoint in the meantime, let's add it back.

Fixes: 771c994ea51f ("erofs: convert all uncompressed cases to iomap")
Signed-off-by: Chao Yu 
Reviewed-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250707084832.2725677-1-chao@kernel.org
Signed-off-by: Gao Xiang

erofs: remove a superfluous check for encoded extents

2025-06-20T15:41:12+00:00

It is possible when an inode is split into segments for multi-threaded
compression, and the tail extent of a segment could also be small.

Fixes: 1d191b4ca51d ("erofs: implement encoded extent metadata")
Signed-off-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250620153108.1368029-1-hsiangkao@linux.alibaba.com

erofs: refuse crafted out-of-file-range encoded extents

2025-06-19T05:01:38+00:00

Crafted encoded extents could record out-of-range `lstart`, which should
not happen in normal cases.

It caused an iomap_iter_done() complaint [1] reported by syzbot.

[1] https://lore.kernel.org/r/684cb499.a00a0220.c6bd7.0010.GAE@google.com

Fixes: 1d191b4ca51d ("erofs: implement encoded extent metadata")
Reported-and-tested-by: syzbot+d8f000c609f05f52d9b5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d8f000c609f05f52d9b5
Signed-off-by: Gao Xiang 
Link: https://lore.kernel.org/r/20250619032839.2642193-1-hsiangkao@linux.alibaba.com

erofs: impersonate the opener's credentials when accessing backing file

2025-06-18T05:40:48+00:00

Previously, file operations on a file-backed mount used the current
process' credentials to access the backing FD. Attempting to do so on
Android lead to SELinux denials, as ACL rules on the backing file (e.g.
/system/apex/foo.apex) is restricted to a small set of process.
Arguably, this error is redundant and leaking implementation details, as
access to files on a mount is already ACL'ed by path.

Instead, override to use the opener's cred when accessing the backing
file. This makes the behavior similar to a loop-backed mount, which
uses kworker cred when accessing the backing file and does not cause
SELinux denials.

Signed-off-by: Tatsuyuki Ishi 
Reviewed-by: Gao Xiang 
Reviewed-by: Hongbo Li 
Link: https://lore.kernel.org/r/20250612-b4-erofs-impersonate-v1-1-8ea7d6f65171@google.com
Signed-off-by: Gao Xiang

Merge tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-06-02T22:04:06+00:00

Pull netfs updates from Christian Brauner:

 - The main API document has been extensively updated/rewritten

 - Fix an oops in write-retry due to mis-resetting the I/O iterator

 - Fix the recording of transferred bytes for short DIO reads

 - Fix a request's work item to not require a reference, thereby
   avoiding the need to get rid of it in BH/IRQ context

 - Fix waiting and waking to be consistent about the waitqueue used

 - Remove NETFS_SREQ_SEEK_DATA_READ, NETFS_INVALID_WRITE,
   NETFS_ICTX_WRITETHROUGH, NETFS_READ_HOLE_CLEAR,
   NETFS_RREQ_DONT_UNLOCK_FOLIOS, and NETFS_RREQ_BLOCKED

 - Reorder structs to eliminate holes

 - Remove netfs_io_request::ractl

 - Only provide proc_link field if CONFIG_PROC_FS=y

 - Remove folio_queue::marks3

 - Fix undifferentiation of DIO reads from unbuffered reads

* tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  netfs: Fix undifferentiation of DIO reads from unbuffered reads
  netfs: Fix wait/wake to be consistent about the waitqueue used
  netfs: Fix the request's work item to not require a ref
  netfs: Fix setting of transferred bytes with short DIO reads
  netfs: Fix oops in write-retry from mis-resetting the subreq iterator
  fs/netfs: remove unused flag NETFS_RREQ_BLOCKED
  fs/netfs: remove unused flag NETFS_RREQ_DONT_UNLOCK_FOLIOS
  folio_queue: remove unused field `marks3`
  fs/netfs: declare field `proc_link` only if CONFIG_PROC_FS=y
  fs/netfs: remove `netfs_io_request.ractl`
  fs/netfs: reorder struct fields to eliminate holes
  fs/netfs: remove unused enum choice NETFS_READ_HOLE_CLEAR
  fs/netfs: remove unused flag NETFS_ICTX_WRITETHROUGH
  fs/netfs: remove unused source NETFS_INVALID_WRITE
  fs/netfs: remove unused flag NETFS_SREQ_SEEK_DATA_READ