- 20 Jul, 2017 3 commits
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Amir Goldstein authored
Index should always be of the same file type as origin, except for the case of a whiteout index. A whiteout index should only exist if all lower aliases have been unlinked, which means that finding a lower origin on lookup whose index is a whiteout should be treated as a lookup error. Signed-off-by:
Amir Goldstein <amir73il@gmail.com> Signed-off-by:
Miklos Szeredi <mszeredi@redhat.com>
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Amir Goldstein authored
Directory index entries are going to be used for looking up redirected upper dirs by lower dir fh when decoding an overlay file handle of a merge dir. Whiteout index entries are going to be used as an indication that an exported overlay file handle should be treated as stale (i.e. after unlink of the overlay inode). We don't know the verification rules for directory and whiteout index entries, because they have not been implemented yet, so fail to mount overlay rw if those entries are found to avoid corrupting an index that was created by a newer kernel. Signed-off-by:
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Miklos Szeredi authored
inode_doinit_with_dentry() in SELinux wants to read the upper inode's xattr to get security label, and ovl_xattr_get() calls ovl_dentry_real(), which depends on dentry->d_inode, but d_inode is null and not initialized yet at this point resulting in an Oops. Fix by getting the upperdentry info from the inode directly in this case. Reported-by:
Eryu Guan <eguan@redhat.com> Fixes: 09d8b586 ("ovl: move __upperdentry to ovl_inode") Signed-off-by:
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- 13 Jul, 2017 4 commits
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Amir Goldstein authored
ovl_workdir_create() returns a valid index dentry or NULL. Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Amir Goldstein authored
Commit 54fb347e ("ovl: verify index dir matches upper dir") introduced a new ovl_fh flag OVL_FH_FLAG_PATH_UPPER to indicate an upper file handle, but forgot to add the flag to the mask of valid flags, so index dir origin verification always discards existing origin and stores a new one. Signed-off-by:
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Amir Goldstein authored
When linking a file with copy up origin into a new parent, mark the new parent dir "impure". Fixes: ee1d6d37 ("ovl: mark upper dir with type origin entries "impure"") Cc: <stable@vger.kernel.org> # v4.12 Signed-off-by:
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Amir Goldstein authored
On failure to prepare_creds(), mount fails with a random return value, as err was last set to an integer cast of a valid lower mnt pointer or set to 0 if inodes index feature is enabled. Reported-by:
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- 04 Jul, 2017 33 commits
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Amir Goldstein authored
Signed-off-by: -
Amir Goldstein authored
The inodes index feature introduces a behavior change - on mount, upper root origin file handle is verified to match the lower root dir. This implies that copied layers cannot be mounted with the inodes index feature enabled, without explicitly removing the upper dir origin xattr and the index dir. The inodes index feature is required to support: - Prevent breaking hardlinks on copy up - NFS export support (upcoming) - Overlayfs snapshots (POC) Signed-off-by:
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Amir Goldstein authored
index entry should live only as long as there are upper or lower hardlinks. Cleanup orphan index entries on mount and when dropping the last overlay inode nlink. When about to cleanup or link up to orphan index and the index inode nlink > 1, admit that something went wrong and adjust overlay nlink to index inode nlink - 1 to prevent it from dropping below zero. This could happen when adding lower hardlinks underneath a mounted overlay and then trying to unlink them. Signed-off-by:
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Amir Goldstein authored
With inodes index enabled, an overlay inode nlink counts the union of upper and non-covered lower hardlinks. During the lifetime of a non-pure upper inode, the following nlink modifying operations can happen: 1. Lower hardlink copy up 2. Upper hardlink created, unlinked or renamed over 3. Lower hardlink whiteout or renamed over For the first, copy up case, the union nlink does not change, whether the operation succeeds or fails, but the upper inode nlink may change. Therefore, before copy up, we store the union nlink value relative to the lower inode nlink in the index inode xattr trusted.overlay.nlink. For the second, upper hardlink case, the union nlink should be incremented or decremented IFF the operation succeeds, aligned with nlink change of the upper inode. Therefore, before link/unlink/rename, we store the union nlink value relative to the upper inode nlink in the index inode. For the last, lower cover up case, we simplify things by preceding the whiteout or cover up with copy up. This makes sure that there is an index upper inode where the nlink xattr can be stored before the copied up upper entry is unlink. Return the overlay inode nlinks for indexed upper inodes on stat(2). Signed-off-by:
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Amir Goldstein authored
Implement a copy up method for non-dir objects using index dir to prevent breaking lower hardlinks on copy up. This method requires that the inodes index dir feature was enabled and that all underlying fs support file handle encoding/decoding. On the first lower hardlink copy up, upper file is created in index dir, named after the hex representation of the lower origin inode file handle. On the second lower hardlink copy up, upper file is found in index dir, by the same lower handle key. On either case, the upper indexed inode is then linked to the copy up upper path. The index entry remains linked for future lower hardlink copy up and for lower to upper inode map, that is needed for exporting overlayfs to NFS. Signed-off-by:
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Miklos Szeredi authored
Move ovl_copy_up_start()/ovl_copy_up_end() out so that it's used for both tempfile and workdir copy ups. Signed-off-by: -
Miklos Szeredi authored
Split up and rearrange copy up functions to make them better readable. Signed-off-by: -
Miklos Szeredi authored
For rename, we need to ensure that an upper alias exists for hard links before attempting the operation. Introduce a flag in ovl_entry to track the state of the upper alias. Signed-off-by: -
Miklos Szeredi authored
This cleans up functions with too many arguments. Signed-off-by: -
Miklos Szeredi authored
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Amir Goldstein authored
Factor out helper for copying lower inode data and metadata to temp upper inode, that is common to copy up using O_TMPFILE and workdir. Signed-off-by:
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Miklos Szeredi authored
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Amir Goldstein authored
On copy up of regular file using an O_TMPFILE, lock upper dir only before linking the tempfile in place. Signed-off-by:
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Miklos Szeredi authored
Signed-off-by: -
Amir Goldstein authored
Bad index entries are entries whose name does not match the origin file handle stored in trusted.overlay.origin xattr. Bad index entries could be a result of a system power off in the middle of copy up. Stale index entries are entries whose origin file handle is stale. Stale index entries could be a result of copying layers or removing lower entries while the overlay is not mounted. The case of copying layers should be detected earlier by the verification of upper root dir origin and index dir origin. Both bad and stale index entries are detected and removed on mount. Signed-off-by:
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Amir Goldstein authored
When inodes index feature is enabled, lookup in indexdir for the index entry of lower real inode or copy up origin inode. The index entry name is the hex representation of the lower inode file handle. If the index dentry in negative, then either no lower aliases have been copied up yet, or aliases have been copied up in older kernels and are not indexed. If the index dentry for a copy up origin inode is positive, but points to an inode different than the upper inode, then either the upper inode has been copied up and not indexed or it was indexed, but since then index dir was cleared. Either way, that index cannot be used to indentify the overlay inode. If a positive dentry that matches the upper inode was found, then it is safe to use the copy up origin st_ino for upper hardlinks, because all indexed upper hardlinks are represented by the same overlay inode as the copy up origin. Set the INDEX type flag on an indexed upper dentry. A non-upper dentry may also have a positive index from copy up of another lower hardlink. This situation will be handled by following patches. Index lookup is going to be used to prevent breaking hardlinks on copy up. Signed-off-by:
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Amir Goldstein authored
An index dir contains persistent hardlinks to files in upper dir. Therefore, we must never mount an existing index dir with a differnt upper dir. Store the upper root dir file handle in index dir inode when index dir is created and verify the file handle before using an existing index dir on mount. Add an 'is_upper' flag to the overlay file handle encoding and set it when encoding the upper root file handle. This is not critical for index dir verification, but it is good practice towards a standard overlayfs file handle format for NFS export. Signed-off-by:
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Amir Goldstein authored
When inodes index feature is enabled, verify that the file handle stored in upper root dir matches the lower root dir or fail to mount. If upper root dir has no stored file handle, encode and store the lower root dir file handle in overlay.origin xattr. Signed-off-by:
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Amir Goldstein authored
Create the index dir on mount. The index dir will contain hardlinks to upper inodes, named after the hex representation of their origin lower inodes. The index dir is going to be used to prevent breaking lower hardlinks on copy up and to implement overlayfs NFS export. Because the feature is not fully backward compat, enabling the feature is opt-in by config/module/mount option. Signed-off-by:
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Amir Goldstein authored
Pass in the subdir name to create and specify if subdir is persistent or if it should be cleaned up on every mount. Move fallback to readonly mount on failure to create dir and print of error message into the helper. This function is going to be used for creating the persistent 'index' dir under workbasedir. Signed-off-by:
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Amir Goldstein authored
For the case of all layers not on the same fs, try to decode the copy up origin file handle on any of the lower layers. Signed-off-by:
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Amir Goldstein authored
Bad things can happen if several concurrent overlay mounts try to use the same upperdir/workdir path. Try to get the 'inuse' advisory lock on upperdir and workdir. Fail mount if another overlay mount instance or another user holds the 'inuse' lock on these directories. Note that this provides no protection for concurrent overlay mount that use overlapping (i.e. descendant) upper/work dirs. Signed-off-by:
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Amir Goldstein authored
Added an i_state flag I_INUSE and helpers to set/clear/test the bit. The 'inuse' lock is an 'advisory' inode lock, that can be used to extend exclusive create protection beyond parent->i_mutex lock among cooperating users. This is going to be used by overlayfs to get exclusive ownership on upper and work dirs among overlayfs mounts. Signed-off-by:
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Miklos Szeredi authored
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Amir Goldstein authored
Use the new ovl_inode mutex to synchonize concurrent copy up instead of the super block copy up workqueue. Moving the synchronization object from the overlay dentry to the overlay inode is needed for synchonizing concurrent copy up of lower hardlinks to the same upper inode. Signed-off-by:
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Miklos Szeredi authored
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Miklos Szeredi authored
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Miklos Szeredi authored
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Miklos Szeredi authored
When checking for consistency in directory operations (unlink, rename, etc.) match inodes not dentries. Signed-off-by: -
Miklos Szeredi authored
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Miklos Szeredi authored
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Amir Goldstein authored
We need some more space to store overlay inode data in memory, so allocate overlay inodes from a slab of struct ovl_inode. Signed-off-by:
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Amir Goldstein authored
This patch fixes an overlay inode nlink leak in the case where ovl_rename() renames over a non-dir. This is not so critical, because overlay inode doesn't rely on nlink dropping to zero for inode deletion. Signed-off-by:
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