ecryptfs_initialize_file() takes an empty file in the lower mount and turns it into an eCryptfs file by writing out the eCryptfs metadata. If ecryptfs_initialize_file() fails, ecryptfs_create() will also fail, but the empty file will remain around. We should be doing better cleanup to get rid of the empty file upon failure.
To reproduce:
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gentoo-virt mnt # mount -it ecryptfs /mnt/.ecryptfs-ext3 /mnt/ecryptfs-ext3/ -o \
ecryptfs_sig=7fa06f4b66fcde02,ecryptfs_cipher=camellia,ecryptfs_key_bytes=16,rw,noauto
gentoo-virt ecryptfs-ext3 # echo "camellia cipher test" > /mnt/ecryptfs-ext3/test
-bash: /mnt/ecryptfs-ext3/test: Invalid argument
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Relevant log entries:
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Mar 6 10:15:57 gentoo-virt kernel: write_tag_3_packet: Unable to generate code for cipher [camellia]
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_generate_key_packet_set: Error writing tag 3 packet
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_write_headers_virt: Error generating key packet set; rc = [-22]
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_write_metadata: Error whilst writing headers; rc = [-22]
Mar 6 10:15:57 gentoo-virt kernel: Error writing headers; rc = [-22]
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Note that the steps to reproduce are taking advantage of another bug that allows invalid ciphers to be specified at mount time. I should probably open another bug for proper cipher support in eCryptfs at mount.
Oops, forgot to show that the empty file was still there after the echo failed:
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gentoo-virt mnt # du -h /mnt/ecryptfs-
0 /mnt/ecryptfs-
0 /mnt/.ecryptfs-
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Here's the expected output after a successful create in an eCryptfs mount:
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gentoo-virt mnt # du -h /mnt/ecryptfs-
0 /mnt/ecryptfs-
12K /mnt/.ecryptfs-
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