mirror of https://gitee.com/openkylin/linux.git
827 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Marc Dionne
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dc2557308e |
afs: Fix partial writeback of large files on fsync and close
In commit |
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David Howells
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f610a5a29c |
afs: Fix the nlink handling of dir-over-dir rename
Fix rename of one directory over another such that the nlink on the deleted
directory is cleared to 0 rather than being decremented to 1.
This was causing the generic/035 xfstest to fail.
Fixes:
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Gustavo A. R. Silva
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b2db6c35ba |
afs: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple fallthrough pseudo-keywords in places where the code is intended to fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-hardening@vger.kernel.org Link: https://lore.kernel.org/r/51150b54e0b0431a2c401cd54f2c4e7f50e94601.1605896059.git.gustavoars@kernel.org/ # v1 Link: https://lore.kernel.org/r/20210420211615.GA51432@embeddedor/ # v2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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David Howells
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22650f1481 |
afs: Fix speculative status fetches
The generic/464 xfstest causes kAFS to emit occasional warnings of the
form:
kAFS: vnode modified {100055:8a} 30->31 YFS.StoreData64 (c=6015)
This indicates that the data version received back from the server did not
match the expected value (the DV should be incremented monotonically for
each individual modification op committed to a vnode).
What is happening is that a lookup call is doing a bulk status fetch
speculatively on a bunch of vnodes in a directory besides getting the
status of the vnode it's actually interested in. This is racing with a
StoreData operation (though it could also occur with, say, a MakeDir op).
On the client, a modification operation locks the vnode, but the bulk
status fetch only locks the parent directory, so no ordering is imposed
there (thereby avoiding an avenue to deadlock).
On the server, the StoreData op handler doesn't lock the vnode until it's
received all the request data, and downgrades the lock after committing the
data until it has finished sending change notifications to other clients -
which allows the status fetch to occur before it has finished.
This means that:
- a status fetch can access the target vnode either side of the exclusive
section of the modification
- the status fetch could start before the modification, yet finish after,
and vice-versa.
- the status fetch and the modification RPCs can complete in either order.
- the status fetch can return either the before or the after DV from the
modification.
- the status fetch might regress the locally cached DV.
Some of these are handled by the previous fix[1], but that's not sufficient
because it checks the DV it received against the DV it cached at the start
of the op, but the DV might've been updated in the meantime by a locally
generated modification op.
Fix this by the following means:
(1) Keep track of when we're performing a modification operation on a
vnode. This is done by marking vnode parameters with a 'modification'
note that causes the AFS_VNODE_MODIFYING flag to be set on the vnode
for the duration.
(2) Alter the speculation race detection to ignore speculative status
fetches if either the vnode is marked as being modified or the data
version number is not what we expected.
Note that whilst the "vnode modified" warning does get recovered from as it
causes the client to refetch the status at the next opportunity, it will
also invalidate the pagecache, so changes might get lost.
Fixes:
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Linus Torvalds
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fafe1e39ed |
AFS: Use the new netfs lib
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Merge tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"Use the new netfs lib.
Begin the process of overhauling the use of the fscache API by AFS and
the introduction of support for features such as Transparent Huge
Pages (THPs).
- Add some support for THPs, including using core VM helper functions
to find details of pages.
- Use the ITER_XARRAY I/O iterator to mediate access to the pagecache
as this handles THPs and doesn't require allocation of large bvec
arrays.
- Delegate address_space read/pre-write I/O methods for AFS to the
netfs helper library. A method is provided to the library that
allows it to issue a read against the server.
This includes a change in use for PG_fscache (it now indicates a
DIO write in progress from the marked page), so a number of waits
need to be deployed for it.
- Split the core AFS writeback function to make it easier to modify
in future patches to handle writing to the cache. [This might
feasibly make more sense moved out into my fscache-iter branch].
I've tested these with "xfstests -g quick" against an AFS volume
(xfstests needs patching to make it work). With this, AFS without a
cache passes all expected xfstests; with a cache, there's an extra
failure, but that's also there before these patches. Fixing that
probably requires a greater overhaul (as can be found on my
fscache-iter branch, but that's for a later time).
Thanks should go to Marc Dionne and Jeff Altman of AuriStor for
exercising the patches in their test farm also"
Link: https://lore.kernel.org/lkml/3785063.1619482429@warthog.procyon.org.uk/
* tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Use the netfs_write_begin() helper
afs: Use new netfs lib read helper API
afs: Use the fs operation ops to handle FetchData completion
afs: Prepare for use of THPs
afs: Extract writeback extension into its own function
afs: Wait on PG_fscache before modifying/releasing a page
afs: Use ITER_XARRAY for writing
afs: Set up the iov_iter before calling afs_extract_data()
afs: Log remote unmarshalling errors
afs: Don't truncate iter during data fetch
afs: Move key to afs_read struct
afs: Print the operation debug_id when logging an unexpected data version
afs: Pass page into dirty region helpers to provide THP size
afs: Disable use of the fscache I/O routines
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Linus Torvalds
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d1466bc583 |
Merge branch 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode type handling updates from Al Viro: "We should never change the type bits of ->i_mode or the method tables (->i_op and ->i_fop) of a live inode. Unfortunately, not all filesystems took care to prevent that" * 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: spufs: fix bogosity in S_ISGID handling 9p: missing chunk of "fs/9p: Don't update file type when updating file attributes" openpromfs: don't do unlock_new_inode() until the new inode is set up hostfs_mknod(): don't bother with init_special_inode() cifs: have cifs_fattr_to_inode() refuse to change type on live inode cifs: have ->mkdir() handle race with another client sanely do_cifs_create(): don't set ->i_mode of something we had not created gfs2: be careful with inode refresh ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap... vboxsf: don't allow to change the inode type afs: Fix updating of i_mode due to 3rd party change ceph: don't allow type or device number to change on non-I_NEW inodes ceph: fix up error handling with snapdirs new helper: inode_wrong_type() |
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David Howells
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3003bbd069 |
afs: Use the netfs_write_begin() helper
Make AFS use the new netfs_write_begin() helper to do the pre-reading required before the write. If successful, the helper returns with the required page filled in and locked. It may read more than just one page, expanding the read to meet cache granularity requirements as necessary. Note: A more advanced version of this could be made that does generic_perform_write() for a whole cache granule. This would make it easier to avoid doing the download/read for the data to be overwritten. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588546422.3465195.1546354372589291098.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161539563244.286939.16537296241609909980.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653819291.2770958.406013201547420544.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789102743.6155.17396591236631761195.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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5cbf03985c |
afs: Use new netfs lib read helper API
Make AFS use the new netfs read helpers to implement the VM read operations: - afs_readpage() now hands off responsibility to netfs_readpage(). - afs_readpages() is gone and replaced with afs_readahead(). - afs_readahead() just hands off responsibility to netfs_readahead(). These make use of the cache if a cookie is supplied, otherwise just call the ->issue_op() method a sufficient number of times to complete the entire request. Changes: v5: - Use proper wait function for PG_fscache in afs_page_mkwrite()[1]. - Use killable wait for PG_writeback in afs_page_mkwrite()[1]. v4: - Folded in error handling fixes to afs_req_issue_op(). - Added flag to netfs_subreq_terminated() to indicate that the caller may have been running async and stuff that might sleep needs punting to a workqueue. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk [1] Link: https://lore.kernel.org/r/160588542733.3465195.7526541422073350302.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118158436.1232039.3884845981224091996.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161053540.2537118.14904446369309535330.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340418739.1303470.5908092911600241280.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539561926.286939.5729036262354802339.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653817977.2770958.17696456811587237197.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789101258.6155.3879271028895121537.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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dc4191841d |
afs: Use the fs operation ops to handle FetchData completion
Use the 'success' and 'aborted' afs_operations_ops methods and add a 'failed' method to handle the completion of an AFS.FetchData, AFS.FetchData64 or YFS.FetchData64 RPC operation rather than directly calling the done func pointed to by the afs_read struct from the call delivery handler. This means the done function will be called back on error also, not just on successful completion. This allows motion towards asynchronous data reception on data fetch calls and allows any error to be handed off to the fscache read helper in the same place as a successful completion. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588541471.3465195.8807019223378490810.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118157260.1232039.6549085372718234792.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161052647.2537118.12922380836599003659.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340417106.1303470.3502017303898569631.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539560673.286939.391310781674212229.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653816367.2770958.5856904574822446404.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789099994.6155.473719823490561190.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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e87b03f583 |
afs: Prepare for use of THPs
As a prelude to supporting transparent huge pages, use thp_size() and similar rather than PAGE_SIZE/SHIFT. Further, try and frame everything in terms of file positions and lengths rather than page indices and numbers of pages. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588540227.3465195.4752143929716269062.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118155821.1232039.540445038028845740.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161051439.2537118.15577827510426326534.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340415869.1303470.6040191748634322355.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539559365.286939.18344613540296085269.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653815142.2770958.454490670311230206.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789098713.6155.16394227991842480300.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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810caa3e67 |
afs: Extract writeback extension into its own function
Extract writeback extension into its own function to break up the writeback function a bit. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588538471.3465195.782513375683399583.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118154610.1232039.1765365632920504822.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161050546.2537118.2202554806419189453.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340414102.1303470.9078891484034668985.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539558417.286939.2879469588895925399.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653813972.2770958.12671731209438112378.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789097132.6155.4916609419912731964.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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630f5dda84 |
afs: Wait on PG_fscache before modifying/releasing a page
PG_fscache is going to be used to indicate that a page is being written to the cache, and that the page should not be modified or released until it's finished. Make afs_invalidatepage() and afs_releasepage() wait for it. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/158861253957.340223.7465334678444521655.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465832417.1377938.3571599385208729791.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588536286.3465195.13231895135369807920.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118153708.1232039.3535103645871176749.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161049369.2537118.11591934943429117060.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340412903.1303470.6424701655031380012.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539556890.286939.5873470593519458598.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653812726.2770958.18167145829938766503.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789096241.6155.5907241930823579235.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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bd80d8a80e |
afs: Use ITER_XARRAY for writing
Use a single ITER_XARRAY iterator to describe the portion of a file to be transmitted to the server rather than generating a series of small ITER_BVEC iterators on the fly. This will make it easier to implement AIO in afs. In theory we could maybe use one giant ITER_BVEC, but that means potentially allocating a huge array of bio_vec structs (max 256 per page) when in fact the pagecache already has a structure listing all the relevant pages (radix_tree/xarray) that can be walked over. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/153685395197.14766.16289516750731233933.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/158861251312.340223.17924900795425422532.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465828607.1377938.6903132788463419368.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588535018.3465195.14509994354240338307.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118152415.1232039.6452879415814850025.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161048194.2537118.13763612220937637316.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340411602.1303470.4661108879482218408.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539555629.286939.5241869986617154517.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653811456.2770958.7017388543246759245.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789095005.6155.6789055030327407928.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
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c450846461 |
afs: Set up the iov_iter before calling afs_extract_data()
afs_extract_data() sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.
Instead:
(1) Put an iterator in the afs_call struct.
(2) Set the iterator for each marshalling stage to load data into the
appropriate places. A number of convenience functions are provided to
this end (eg. afs_extract_to_buf()).
This iterator is then passed to afs_extract_data().
(3) Use the new ITER_XARRAY iterator when reading data to load directly
into the inode's pages without needing to create a list of them.
This will allow O_DIRECT calls to be supported in future patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/152898380012.11616.12094591785228251717.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/153685394431.14766.3178466345696987059.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/153999787395.866.11218209749223643998.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/154033911195.12041.3882700371848894587.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/158861250059.340223.1248231474865140653.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465827399.1377938.11181327349704960046.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588533776.3465195.3612752083351956948.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118151238.1232039.17015723405750601161.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161047240.2537118.14721975104810564022.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340410333.1303470.16260122230371140878.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539554187.286939.15305559004905459852.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653810525.2770958.4630666029125411789.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789093719.6155.7877160739235087723.stgit@warthog.procyon.org.uk/ # v6
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David Howells
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05092755aa |
afs: Log remote unmarshalling errors
Log unmarshalling errors reported by the peer (ie. it can't parse what we sent it). Limit the maximum number of messages to 3. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/159465826250.1377938.16372395422217583913.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588532584.3465195.15618385466614028590.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118149739.1232039.208060911149801695.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161046033.2537118.7779717661044373273.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340409118.1303470.17812607349396199116.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539552964.286939.16503232687974398308.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653808989.2770958.11530765353025697860.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789092349.6155.8581594259882708631.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
|
f105da1a79 |
afs: Don't truncate iter during data fetch
Don't truncate the iterator to correspond to the actual data size when fetching the data from the server - rather, pass the length we want to read to rxrpc. This will allow the clear-after-read code in future to simply clear the remaining iterator capacity rather than having to reinitialise the iterator. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/158861249201.340223.13035445866976590375.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465825061.1377938.14403904452300909320.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588531418.3465195.10712005940763063144.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118148567.1232039.13380313332292947956.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161044610.2537118.17908520793806837792.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340407907.1303470.6501394859511712746.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539551721.286939.14655713136572200716.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653807790.2770958.14034599989374173734.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789090823.6155.15673999934535049102.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
|
c69bf479ba |
afs: Move key to afs_read struct
Stash the key used to authenticate read operations in the afs_read struct. This will be necessary to reissue the operation against the server if a read from the cache fails in upcoming cache changes. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/158861248336.340223.1851189950710196001.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465823899.1377938.11925978022348532049.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588529557.3465195.7303323479305254243.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118147693.1232039.13780672951838643842.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161043340.2537118.511899217704140722.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340406678.1303470.12676824086429446370.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539550819.286939.1268332875889175195.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653806683.2770958.11300984379283401542.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789089556.6155.14603302893431820997.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
|
f015cf1d6b |
afs: Print the operation debug_id when logging an unexpected data version
Print the afs_operation debug_id when logging an unexpected change in the data version. This allows the logged message to be matched against tracelines. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588528377.3465195.2206051235095182302.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118146111.1232039.11398082422487058312.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161042180.2537118.2471333561661033316.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340405772.1303470.3877167548944248214.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539549628.286939.15234870409714613954.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653805530.2770958.15120507632529970934.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789088290.6155.3494369629853673866.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
|
67d78a6f6e |
afs: Pass page into dirty region helpers to provide THP size
Pass a pointer to the page being accessed into the dirty region helpers so that the size of the page can be determined in case it's a transparent huge page. This also required the page to be passed into the afs_page_dirty trace point - so there's no need to specifically pass in the index or private data as these can be retrieved directly from the page struct. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588527183.3465195.16107942526481976308.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118144921.1232039.11377711180492625929.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161040747.2537118.11435394902674511430.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340404553.1303470.11414163641767769882.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539548385.286939.8864598314493255313.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653804285.2770958.3497360004849598038.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789087043.6155.16922142208140170528.stgit@warthog.procyon.org.uk/ # v6 |
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David Howells
|
03ffae9092 |
afs: Disable use of the fscache I/O routines
Disable use of the fscache I/O routined by the AFS filesystem. It's about to transition to passing iov_iters down and fscache is about to have its I/O path to use iov_iter, so all that needs to change. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/158861209824.340223.1864211542341758994.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465768717.1376105.2229314852486665807.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588457929.3465195.1730097418904945578.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118143744.1232039.2727898205333669064.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161039077.2537118.7986870854927176905.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340403323.1303470.8159439948319423431.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539547167.286939.3536238932531122332.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653802797.2770958.547311814861545911.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789085806.6155.2596146255056027428.stgit@warthog.procyon.org.uk/ # v6 |
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Matthew Wilcox (Oracle)
|
75b6979961 |
afs: Use wait_on_page_writeback_killable
Open-coding this function meant it missed out on the recent bugfix
for waiters being woken by a delayed wake event from a previous
instantiation of the page[1].
[DH: Changed the patch to use vmf->page rather than variable page which
doesn't exist yet upstream]
Fixes:
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David Howells
|
a7889c6320 |
afs: Stop listxattr() from listing "afs.*" attributes
afs_listxattr() lists all the available special afs xattrs (i.e. those in
the "afs.*" space), no matter what type of server we're dealing with. But
OpenAFS servers, for example, cannot deal with some of the extra-capable
attributes that AuriStor (YFS) servers provide. Unfortunately, the
presence of the afs.yfs.* attributes causes errors[1] for anything that
tries to read them if the server is of the wrong type.
Fix the problem by removing afs_listxattr() so that none of the special
xattrs are listed (AFS doesn't support xattrs). It does mean, however,
that getfattr won't list them, though they can still be accessed with
getxattr() and setxattr().
This can be tested with something like:
getfattr -d -m ".*" /afs/example.com/path/to/file
With this change, none of the afs.* attributes should be visible.
Changes:
ver #2:
- Hide all of the afs.* xattrs, not just the ACL ones.
Fixes:
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David Howells
|
64fcbb6158 |
afs: Fix accessing YFS xattrs on a non-YFS server
If someone attempts to access YFS-related xattrs (e.g. afs.yfs.acl) on a
file on a non-YFS AFS server (such as OpenAFS), then the kernel will jump
to a NULL function pointer because the afs_fetch_acl_operation descriptor
doesn't point to a function for issuing an operation on a non-YFS
server[1].
Fix this by making afs_wait_for_operation() check that the issue_afs_rpc
method is set before jumping to it and setting -ENOTSUPP if not. This fix
also covers other potential operations that also only exist on YFS servers.
afs_xattr_get/set_yfs() then need to translate -ENOTSUPP to -ENODATA as the
former error is internal to the kernel.
The bug shows up as an oops like the following:
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[...]
Call Trace:
afs_wait_for_operation+0x83/0x1b0 [kafs]
afs_xattr_get_yfs+0xe6/0x270 [kafs]
__vfs_getxattr+0x59/0x80
vfs_getxattr+0x11c/0x140
getxattr+0x181/0x250
? __check_object_size+0x13f/0x150
? __fput+0x16d/0x250
__x64_sys_fgetxattr+0x64/0xb0
do_syscall_64+0x49/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fb120a9defe
This was triggered with "cp -a" which attempts to copy xattrs, including
afs ones, but is easier to reproduce with getfattr, e.g.:
getfattr -d -m ".*" /afs/openafs.org/
Fixes:
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David Howells
|
6e1eb04a87 |
afs: Fix updating of i_mode due to 3rd party change
Fix afs_apply_status() to mask off the irrelevant bits from status->mode
when OR'ing them into i_mode. This can happen when a 3rd party chmod
occurs.
Also fix afs_inode_init_from_status() to mask off the mode bits when
initialising i_mode.
Fixes:
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Linus Torvalds
|
7d6beb71da |
idmapped-mounts-v5.12
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
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David Howells
|
5399d52233 |
rxrpc: Fix deadlock around release of dst cached on udp tunnel
AF_RXRPC sockets use UDP ports in encap mode. This causes socket and dst
from an incoming packet to get stolen and attached to the UDP socket from
whence it is leaked when that socket is closed.
When a network namespace is removed, the wait for dst records to be cleaned
up happens before the cleanup of the rxrpc and UDP socket, meaning that the
wait never finishes.
Fix this by moving the rxrpc (and, by dependence, the afs) private
per-network namespace registrations to the device group rather than subsys
group. This allows cached rxrpc local endpoints to be cleared and their
UDP sockets closed before we try waiting for the dst records.
The symptom is that lines looking like the following:
unregister_netdevice: waiting for lo to become free
get emitted at regular intervals after running something like the
referenced syzbot test.
Thanks to Vadim for tracking this down and work out the fix.
Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com
Reported-by: Vadim Fedorenko <vfedorenko@novek.ru>
Fixes:
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Christian Brauner
|
549c729771
|
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> |
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Christian Brauner
|
0d56a4518d
|
stat: handle idmapped mounts
The generic_fillattr() helper fills in the basic attributes associated with an inode. Enable it to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace before we store the uid and gid. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> |
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Christian Brauner
|
e65ce2a50c
|
acl: handle idmapped mounts
The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> |
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David Howells
|
366911cd76 |
afs: Fix directory entry size calculation
The number of dirent records used by an AFS directory entry should be
calculated using the assumption that there is a 16-byte name field in the
first block, rather than a 20-byte name field (which is actually the case).
This miscalculation is historic and effectively standard, so we have to use
it.
The calculation we need to use is:
1 + (((strlen(name) + 1) + 15) >> 5)
where we are adding one to the strlen() result to account for the NUL
termination.
Fix this by the following means:
(1) Create an inline function to do the calculation for a given name
length.
(2) Use the function to calculate the number of records used for a dirent
in afs_dir_iterate_block().
Use this to move the over-end check out of the loop since it only
needs to be done once.
Further use this to only go through the loop for the 2nd+ records
composing an entry. The only test there now is for if the record is
allocated - and we already checked the first block at the top of the
outer loop.
(3) Add a max name length check in afs_dir_iterate_block().
(4) Make afs_edit_dir_add() and afs_edit_dir_remove() use the function
from (1) to calculate the number of blocks rather than doing it
incorrectly themselves.
Fixes:
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David Howells
|
26982a89ca |
afs: Work around strnlen() oops with CONFIG_FORTIFIED_SOURCE=y
AFS has a structured layout in its directory contents (AFS dirs are downloaded as files and parsed locally by the client for lookup/readdir). The slots in the directory are defined by union afs_xdr_dirent. This, however, only directly allows a name of a length that will fit into that union. To support a longer name, the next 1-8 contiguous entries are annexed to the first one and the name flows across these. afs_dir_iterate_block() uses strnlen(), limited to the space to the end of the page, to find out how long the name is. This worked fine until |
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David Howells
|
4cb6829647 |
afs: Fix memory leak when mounting with multiple source parameters
There's a memory leak in afs_parse_source() whereby multiple source=
parameters overwrite fc->source in the fs_context struct without freeing
the previously recorded source.
Fix this by only permitting a single source parameter and rejecting with
an error all subsequent ones.
This was caught by syzbot with the kernel memory leak detector, showing
something like the following trace:
unreferenced object 0xffff888114375440 (size 32):
comm "repro", pid 5168, jiffies 4294923723 (age 569.948s)
backtrace:
slab_post_alloc_hook+0x42/0x79
__kmalloc_track_caller+0x125/0x16a
kmemdup_nul+0x24/0x3c
vfs_parse_fs_string+0x5a/0xa1
generic_parse_monolithic+0x9d/0xc5
do_new_mount+0x10d/0x15a
do_mount+0x5f/0x8e
__do_sys_mount+0xff/0x127
do_syscall_64+0x2d/0x3a
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes:
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David Howells
|
a9e5c87ca7 |
afs: Fix speculative status fetch going out of order wrt to modifications
When doing a lookup in a directory, the afs filesystem uses a bulk
status fetch to speculatively retrieve the statuses of up to 48 other
vnodes found in the same directory and it will then either update extant
inodes or create new ones - effectively doing 'lookup ahead'.
To avoid the possibility of deadlocking itself, however, the filesystem
doesn't lock all of those inodes; rather just the directory inode is
locked (by the VFS).
When the operation completes, afs_inode_init_from_status() or
afs_apply_status() is called, depending on whether the inode already
exists, to commit the new status.
A case exists, however, where the speculative status fetch operation may
straddle a modification operation on one of those vnodes. What can then
happen is that the speculative bulk status RPC retrieves the old status,
and whilst that is happening, the modification happens - which returns
an updated status, then the modification status is committed, then we
attempt to commit the speculative status.
This results in something like the following being seen in dmesg:
kAFS: vnode modified {100058:861} 8->9 YFS.InlineBulkStatus
showing that for vnode 861 on volume 100058, we saw YFS.InlineBulkStatus
say that the vnode had data version 8 when we'd already recorded version
9 due to a local modification. This was causing the cache to be
invalidated for that vnode when it shouldn't have been. If it happens
on a data file, this might lead to local changes being lost.
Fix this by ignoring speculative status updates if the data version
doesn't match the expected value.
Note that it is possible to get a DV regression if a volume gets
restored from a backup - but we should get a callback break in such a
case that should trigger a recheck anyway. It might be worth checking
the volume creation time in the volsync info and, if a change is
observed in that (as would happen on a restore), invalidate all caches
associated with the volume.
Fixes:
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David Howells
|
3ad216ee73 |
afs: Fix afs_write_end() when called with copied == 0 [ver #3]
When afs_write_end() is called with copied == 0, it tries to set the
dirty region, but there's no way to actually encode a 0-length region in
the encoding in page->private.
"0,0", for example, indicates a 1-byte region at offset 0. The maths
miscalculates this and sets it incorrectly.
Fix it to just do nothing but unlock and put the page in this case. We
don't actually need to mark the page dirty as nothing presumably
changed.
Fixes:
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David Howells
|
f4c79144ed |
afs: Fix incorrect freeing of the ACL passed to the YFS ACL store op
The cleanup for the yfs_store_opaque_acl2_operation calls the wrong
function to destroy the ACL content buffer. It's an afs_acl struct, not
a yfs_acl struct - and the free function for latter may pass invalid
pointers to kfree().
Fix this by using the afs_acl_put() function. The yfs_acl_put()
function is then no longer used and can be removed.
general protection fault, probably for non-canonical address 0x7ebde00000000: 0000 [#1] SMP PTI
...
RIP: 0010:compound_head+0x0/0x11
...
Call Trace:
virt_to_cache+0x8/0x51
kfree+0x5d/0x79
yfs_free_opaque_acl+0x16/0x29
afs_put_operation+0x60/0x114
__vfs_setxattr+0x67/0x72
__vfs_setxattr_noperm+0x66/0xe9
vfs_setxattr+0x67/0xce
setxattr+0x14e/0x184
__do_sys_fsetxattr+0x66/0x8f
do_syscall_64+0x2d/0x3a
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes:
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David Howells
|
c80afa1d9c |
afs: Fix warning due to unadvanced marshalling pointer
When using the afs.yfs.acl xattr to change an AuriStor ACL, a warning
can be generated when the request is marshalled because the buffer
pointer isn't increased after adding the last element, thereby
triggering the check at the end if the ACL wasn't empty. This just
causes something like the following warning, but doesn't stop the call
from happening successfully:
kAFS: YFS.StoreOpaqueACL2: Request buffer underflow (36<108)
Fix this simply by increasing the count prior to the check.
Fixes:
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David Howells
|
2d9900f26a |
afs: Fix dirty-region encoding on ppc32 with 64K pages
The dirty region bounds stored in page->private on an afs page are 15 bits
on a 32-bit box and can, at most, represent a range of up to 32K within a
32K page with a resolution of 1 byte. This is a problem for powerpc32 with
64K pages enabled.
Further, transparent huge pages may get up to 2M, which will be a problem
for the afs filesystem on all 32-bit arches in the future.
Fix this by decreasing the resolution. For the moment, a 64K page will
have a resolution determined from PAGE_SIZE. In the future, the page will
need to be passed in to the helper functions so that the page size can be
assessed and the resolution determined dynamically.
Note that this might not be the ideal way to handle this, since it may
allow some leakage of undirtied zero bytes to the server's copy in the case
of a 3rd-party conflict. Fixing that would require a separately allocated
record and is a more complicated fix.
Fixes:
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David Howells
|
f86726a69d |
afs: Fix afs_invalidatepage to adjust the dirty region
Fix afs_invalidatepage() to adjust the dirty region recorded in
page->private when truncating a page. If the dirty region is entirely
removed, then the private data is cleared and the page dirty state is
cleared.
Without this, if the page is truncated and then expanded again by truncate,
zeros from the expanded, but no-longer dirty region may get written back to
the server if the page gets laundered due to a conflicting 3rd-party write.
It mustn't, however, shorten the dirty region of the page if that page is
still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is
stored in page->private to record this.
Fixes:
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David Howells
|
65dd2d6072 |
afs: Alter dirty range encoding in page->private
Currently, page->private on an afs page is used to store the range of
dirtied data within the page, where the range includes the lower bound, but
excludes the upper bound (e.g. 0-1 is a range covering a single byte).
This, however, requires a superfluous bit for the last-byte bound so that
on a 4KiB page, it can say 0-4096 to indicate the whole page, the idea
being that having both numbers the same would indicate an empty range.
This is unnecessary as the PG_private bit is clear if it's an empty range
(as is PG_dirty).
Alter the way the dirty range is encoded in page->private such that the
upper bound is reduced by 1 (e.g. 0-0 is then specified the same single
byte range mentioned above).
Applying this to both bounds frees up two bits, one of which can be used in
a future commit.
This allows the afs filesystem to be compiled on ppc32 with 64K pages;
without this, the following warnings are seen:
../fs/afs/internal.h: In function 'afs_page_dirty_to':
../fs/afs/internal.h:881:15: warning: right shift count >= width of type [-Wshift-count-overflow]
881 | return (priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK;
| ^~
../fs/afs/internal.h: In function 'afs_page_dirty':
../fs/afs/internal.h:886:28: warning: left shift count >= width of type [-Wshift-count-overflow]
886 | return ((unsigned long)to << __AFS_PAGE_PRIV_SHIFT) | from;
| ^~
Fixes:
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|
|
David Howells
|
185f0c7073 |
afs: Wrap page->private manipulations in inline functions
The afs filesystem uses page->private to store the dirty range within a
page such that in the event of a conflicting 3rd-party write to the server,
we write back just the bits that got changed locally.
However, there are a couple of problems with this:
(1) I need a bit to note if the page might be mapped so that partial
invalidation doesn't shrink the range.
(2) There aren't necessarily sufficient bits to store the entire range of
data altered (say it's a 32-bit system with 64KiB pages or transparent
huge pages are in use).
So wrap the accesses in inline functions so that future commits can change
how this works.
Also move them out of the tracing header into the in-directory header.
There's not really any need for them to be in the tracing header.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
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David Howells
|
f792e3ac82 |
afs: Fix where page->private is set during write
In afs, page->private is set to indicate the dirty region of a page. This
is done in afs_write_begin(), but that can't take account of whether the
copy into the page actually worked.
Fix this by moving the change of page->private into afs_write_end().
Fixes:
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|
|
David Howells
|
21db2cdc66 |
afs: Fix page leak on afs_write_begin() failure
Fix the leak of the target page in afs_write_begin() when it fails.
Fixes:
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|
|
David Howells
|
fa04a40b16 |
afs: Fix to take ref on page when PG_private is set
Fix afs to take a ref on a page when it sets PG_private on it and to drop
the ref when removing the flag.
Note that in afs_write_begin(), a lot of the time, PG_private is already
set on a page to which we're going to add some data. In such a case, we
leave the bit set and mustn't increment the page count.
As suggested by Matthew Wilcox, use attach/detach_page_private() where
possible.
Fixes:
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|
|
David Howells
|
d383e346f9 |
afs: Fix afs_launder_page to not clear PG_writeback
Fix afs_launder_page() to not clear PG_writeback on the page it is
laundering as the flag isn't set in this case.
Fixes:
|
|
|
Dan Carpenter
|
248c944e21 |
afs: Fix a use after free in afs_xattr_get_acl()
The "op" pointer is freed earlier when we call afs_put_operation().
Fixes:
|
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David Howells
|
acc080d15d |
afs: Fix tracing deref-before-check
The patch dca54a7bbb8c: "afs: Add tracing for cell refcount and active user
count" from Oct 13, 2020, leads to the following Smatch complaint:
fs/afs/cell.c:596 afs_unuse_cell()
warn: variable dereferenced before check 'cell' (see line 592)
Fix this by moving the retrieval of the cell debug ID to after the check of
the validity of the cell pointer.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes:
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David Howells
|
06a17bbe1d |
afs: Fix copy_file_range()
The prevention of splice-write without explicit ops made the
copy_file_write() syscall to an afs file (as done by the generic/112
xfstest) fail with EINVAL.
Fix by using iter_file_splice_write() for afs.
Fixes:
|
|
|
Linus Torvalds
|
fad70111d5 |
afs fixes
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Merge tag 'afs-fixes-20201016' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull afs updates from David Howells:
"A collection of fixes to fix afs_cell struct refcounting, thereby
fixing a slew of related syzbot bugs:
- Fix the cell tree in the netns to use an rwsem rather than RCU.
There seem to be some problems deriving from the use of RCU and a
seqlock to walk the rbtree, but it's not entirely clear what since
there are several different failures being seen.
Changing things to use an rwsem instead makes it more robust. The
extra performance derived from using RCU isn't necessary in this
case since the only time we're looking up a cell is during mount or
when cells are being manually added.
- Fix the refcounting by splitting the usage counter into a memory
refcount and an active users counter. The usage counter was doing
double duty, keeping track of whether a cell is still in use and
keeping track of when it needs to be destroyed - but this makes the
clean up tricky. Separating these out simplifies the logic.
- Fix purging a cell that has an alias. A cell alias pins the cell
it's an alias of, but the alias is always later in the list. Trying
to purge in a single pass causes rmmod to hang in such a case.
- Fix cell removal. If a cell's manager is requeued whilst it's
removing itself, the manager will run again and re-remove itself,
causing problems in various places. Follow Hillf Danton's
suggestion to insert a more terminal state that causes the manager
to do nothing post-removal.
In additional to the above, two other changes:
- Add a tracepoint for the cell refcount and active users count. This
helped with debugging the above and may be useful again in future.
- Downgrade an assertion to a print when a still-active server is
seen during purging. This was happening as a consequence of
incomplete cell removal before the servers were cleaned up"
* tag 'afs-fixes-20201016' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Don't assert on unpurgeable server records
afs: Add tracing for cell refcount and active user count
afs: Fix cell removal
afs: Fix cell purging with aliases
afs: Fix cell refcounting by splitting the usage counter
afs: Fix rapid cell addition/removal by not using RCU on cells tree
|
|
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David Howells
|
7530d3eb3d |
afs: Don't assert on unpurgeable server records
Don't give an assertion failure on unpurgeable afs_server records - which kills the thread - but rather emit a trace line when we are purging a record (which only happens during network namespace removal or rmmod) and print a notice of the problem. Signed-off-by: David Howells <dhowells@redhat.com> |
|
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David Howells
|
dca54a7bbb |
afs: Add tracing for cell refcount and active user count
Add a tracepoint to log the cell refcount and active user count and pass in a reason code through various functions that manipulate these counters. Additionally, a helper function, afs_see_cell(), is provided to log interesting places that deal with a cell without actually doing any accounting directly. Signed-off-by: David Howells <dhowells@redhat.com> |